The URL can be used to link to this page

Home My WebLink AboutReso 115-11 Fallon Crossings GHAD RESOLUTION NO. 115 -11 A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF DUBLIN SETTING A PUBLIC HEARING ON THE FORMATION OF THE FALCON CROSSINGS GEOLOGIC HAZARD ABATEMENT DISTRICT WHEREAS, this Resolution is adopted pursuant to the provisions of Division 17 (Sections 26500-26654) of the Public Resources Code, entitled "Geologic Hazard Abatement Districts"; and WHEREAS, on July 19, 2011 the City Council of the City of Dublin was presented with a petition for the formation of the Fallon Crossings Geologic Hazard Abatement District ("GHAD Petition"), including a plan of control ("Plan of Control"); and WHEREAS, the GHAD Petition, attached hereto as Exhibit A, is substantially in the form described in Sections 26551 and 26552 of the Public Resources Code; and WHEREAS, the City Council reviewed the Plan of Control presented with the GHAD Petition and has determined that the health, safety and welfare require the formation of the Fallon Village Geologic Hazard Abatement District ("District"); and WHEREAS, the City Council intends to schedule a public hearing ("Hearing") on the proposed formation of the District pursuant to the requirements of Section 26557 of the Public Resources Code. NOW, THEREFORE, BE IT RESOLVED THAT: Section 1. Findings and Determinations The City Council hereby finds and determines that the above recitals are true and correct and have served as the basis, in part, for the findings and actions set forth below. Section 2. Public Hearing Scheduled The .City Council will conduct a Hearing on the proposed formation of the District on August 16, 2011, at 7:00 p.m. or as soon thereafter as the matter can be heard, in the City Council Chambers, 100 Civic Plaza, Dublin, California, 94568. At the Hearing, any objections to the proposed District shall be presented. Section 3. Notice of Hearing A notice of the Hearing ("Notice"), attached hereto as Exhibit B, shall be mailed to each owner of real property to be included in the proposed District as shown on the assessment roll last equalized by Alameda County. The Notice shall be mailed first-class, postage prepaid, in the United States mail and postmarked not less than 20 days preceding the date of the Hearing. The Notice shall include a copy of the GRAD Petition and shall indicate where the Plan of Control may be reviewed or duplicated. The Notice shall also set forth the address where objections to the proposed formation may be mailed or otherwise delivered up to and including the time of the Hearing. . Page 1 of 2 Section 4. Objections to Formation At any time not later than the time set for hearing objections to the proposed formation, any owner of real property within the proposed District may make a written objection to the formation. Such objection shall be in writing, shall contain a description of the land by lot, tract, and map number, and shall be signed by such owner. Objections shall be mailed or delivered as specified in the Notice. If the person whose signature appears on such an objection is not shown on the assessment roll last equalized by Alameda County, the written objection shall be accompanied by evidence sufficient to indicate that such person is the owner of said property. PASSED, APROVED AND ADOPTED on the 19th day of July, 2011, by the following vote: AYES: Councilmembers Biddle, Hart, Hildenbrand, Swalwell and Mayor Sbranti NOES: None ABSENT: None ABSTAIN: None Mayor ATTEST: City Clerk Reso No. 115-11, Adopted 7-19-11, Item 4.4 Page 2 of 2 ~ e~~ - EXHIBIT A TO THE RESOLUTION GRAD PETITION - - - EXHIBIT - 3 To the Resolution . ~ ` 1~1 " PETITION FOR FORMATION OF THE FALCON Ci20SS1NG GEOLOGIC HAZARD ABATEMENT DISTRICT PURSUANT TO DIVISION 17 OF THE PUBLIC RESOURCES CODE OF THE-STATE OF CALIFORNIA TO: The City Clerk for the City of Dublin: The undersigned owners of land within the boundaries of the territory " . " proposed to be included in the Fallon Crossing Geologic Hazard Abatement " District ("District") hereby request that the City Council of the City of Dublin initiate proceedings for formation of the District to include the territory described in Exhibit B ("Legal Description") and Exhibit C ("Boundary Map"), attached hereto, pursuant to the provisions of Division 17 of the Public Resources Code sections 26500 et seq. Said owners are the owners of all the territory proposed for inclusion in the District. (a) This petition is made pursuant to Division 17 of the Public Resources Code with particular reference to Article 3 (commencing with Section 26550) and Article 4 (commencing with- Section . 26561). " (b) Opposite the signature of each petitioner is an indication of the lot; tract and map number or other legal description sufficient to identify _ the signature of the petitioner as that of an ownerbf land within the territory proposed to be included in the District. (c) Opposite the signature of each petitioner is an indication of the date on which said petitioner's signature was affixed to this petition. ~ l (d) The following documents are attached to this petition and are incorporated herein by reference as if set forth in full in the petition: i. A Plan of Control prepared by an engineering geologist certified pursuant to Section 7822 of the California Business and Professions Code, which describes in detail geologic hazards, their location and the areas .affected thereby, and a plan for the prevention, mitigation, abatement and control thereof (Exhibit A). ii. A legal description of the boundaries of.the territory proposed to be included in the District (Exhibit B ;and iii. A map of the boundaries of the territory proposed to be in I~ded in the District (Exhibit C); / Date ~ re of etiti ner Description of Property 2 ZQ , ~ ~4W ~ ~'r Date a e of P titio 'er Description of Property Z Z ~ r? 1 ~IC.?~. Date. Signature of Petitioner Description of Property ~ EXHIBIT A PLAN OF CONTROL I 1 STE~TEl®TS ~ i - ~~OCIA~'E~ I SOIL ENGINEERS ENGINEERING GEOLOGISTS- r I~ ~ i _ i . s . i-~ . i ~1 F Y - 6 ~ j 16 7 ' f ~ _ ' ~ . r T&8 ' PLAN OF CONTROL FALCON CROSSING GHAD TASSAJARA ROAD ' DUBLIN, CALIFORNIA FOR- - STANDARD PACIFIC HOMES May 25, 2011 Job No. 3058.000 BERLOGAR STEVENS & tLSSOCIATES BERI~~G1~R~~~ STEVENS & 1 Via Hand Delivery ASSOCIATES May 25, 2011 - ~ ~ Job. No. 3058.000 - . Mr. Aaron Ross-Swain Standard Pacific Homes 3825 Hopyazd Road, Suite 275 Pleasanton, California 94588 Subject: Plan of Control - Fallon Crossing GRAD Tassajaza Road Dublin, California Dear Mr. Ross-Swain: We are pleased to present herein Volume 1 of the Plan of Control for the Fallon Crossing Geologic Hazard Abatement District (GRAD) in Dublin, California. Volume 2 will include record drawings and as-built documents to be created at the completion of site development. This Plan of Control has been .prepared to satisfy Condition of Approval #26 for the Fallon Crossing residential development and in accordance with California Public Resources Code, Division 17, sections 26500 et seq. Should you have any questions regarding this document, please do not hesitate to contact us. Respectfully submitted, ~~E E~Si p,~~ BERLOG ST G\ CIATES ~ ~ ERA o rF~ P~ `N . ~ ~ ~Q~Plo. GE 142~9~' c~ ~ - - ~ERTI ~ C ~ ichael Claz ~ f0C fER' ~,G * Tank Ber cF~ GPI, CEG 1264 Misr GE 142 ~ s ~TECN~~ ~P 1 MC/FB:'mb ~ 9~°FeAUr-o~`'\P n~~FOF CAt,F~~ J ~ Copies: Addressee (2) Ruggeri-Jensen-Azar & Associates (1) . ~ Attention: Mr. Mark Falgout 3058.00021439.doc " SOIL ENGINEERS ENGINEERING GEOLOGISTS 5587 SUNOL BOULEVARD PLEASANTON, CA 94566 (925) 484-0220 FAX: (925) 846-9645 ~k ~ ~ .p1,~67 TABLE OF CONTENTS , GLOSSARY OF TERMS u~ I: AUTHORITY AND SCOPE 1 II. PROPERTY IDENTIFICATION• 1 )<II. BACKGROUND . 1 Permitting 1 . General Site Location And Existing Conditions 1 ` Proposed Site Development 2 Open Space 3 ~ IV. SITE GEOLOGY 4 Regional Geology And Seismicity 4 Site Geologic Units 5 Artificial Fill 5 Residual Soils And Coiluvial Deposits 6 F Alluvial Deposits 6 Landslide Deposits 6 Bedrock 6 V. GEOLOGIC HAZARDS 7 Slope Instability 7 Soil Creep 8 Erosion And Sedimentation 9 Seismic Ground Shaking 9 Creek Bank Instability And Erosion 9 Shrink/Swell Of Expansive Earth 9 - Compressible Soils 9 . Dispersive Soils 10 VI. FUNDING AND ACCEPTANCE OF RESPONSIBILITY BY GRAD 10 • Property Owner Assessments LO Transfer Of Responsibility To The District 10 VII. AREAS OF GRAD RESPONSIBILITY 10 _ Prevention, Mitigation, Abatement And/Or Control Of Geologic Hazards 10 Exceptions 11 Isolated Or Remote Slope Instability 11 Single Property 11 Geologic Hazard That Requires Expenditure In Amount Exceeding The Value Of The Threatened Or Damaged Improvement 11 GHAD Funding Or Reimbursement For Damaged Or Destroyed Structures Or Site Improvements 12 Earthquake Insurance 12 ' No Reimbursement Without Written Agreement 12 Property Not Located Within GHAD Boundaries 12 Protected Habitat Under Conservation Easement 13 Geologic Hazards In Open Space And Maintenance Of Open Space Areas 1~3 . VIII. GEOTECHNICAL TECHNIQUES FOR MITIGATING LANDSLIDE AND EROSION HAZARDSIQ IX. BIOTECHNICAL RECOMMENDATIONS FOR PRE VENTING AND MITIGATING EXISTING OR POTENTIAL EROSION HAZARDS 15 ~:1 BERLOGAR STEVENS & ASSOCIATES t ~ 167 1 ~ _ TABLE OF CONTENTS (continued) : • X. PRIORITY FOR GRAD-FUNDED REPAIRS 15 XI. RESERVE FUNDS 16 • XII. MAINTENANCE AND MONITORING SCHEDULE 16 ® XIII. LIMITATIONS ..................................................................................................:...........................:...............18 A Attachments: References Plate 1 -Vicinity Map Plate 2 -Pre-Development Geologic Map Plate 3 -Remedial Grading Plan i Exhibit A -Open Space Ownership and Maintenance Responsibilities Exhibit Af Exhibit B -Legal Descriptions of GRAD Boundaries and Maintenance Easement Exhibit C -Plats of GRAD Boundaries and Maintenance Easement Exhibit D -Deed Restriction Exhibit 1_ Appendix A - Detention/Water Quality Basin Operations and Maintenance Manual Appendix B -Fire Hazard Mitigation and Defensible Space Vegetation Management Plan Appendix C -Riparian Mitigation & Monitoring Plan 11 BERLOGAR STEVENS & ASSOCIATES l3 /67 _ GLOSSARY OF TERMS Board of Directors -The governing body of the Geologic Hazazd Abatement District., For the ` Fallon Crossing GRAD, the initial Board of Directors is the Dublin City Council. Fallon Crossing Site or The Site -The roughly 68-acre parcel of land including both the. development area of Tract 7617 and the undeveloped open space.' Refer to Plate 1. Geologic Hazard Abatement District (GRAD) - A district formed under California Public Resources Code 26500-26601 that is intended to handle long-term abatement and control of real property threatened by earth movement. Geologic Hazard - An actual or threatened landslide, land subsidence, soil erosion, earthquake, fault movement, or any other natural or unnatural movement of land or. earth. GHAD Boundaries -The limits of GHAD responsibilities as shown on Exhibit A. GHAD Maintenance Area -The area of GRAD maintenance responsibilities including Parcels A and H as well as the maintenance easement as shown on Exhibit A. GHAD Maintained Facilities -Facilities to be maintained by the GRAD, including concrete V ditches, drainage facilities, subdrain outfalls, ponds and basins. GHAD Ownership Areas -The areas that the GHAD will have ownership over shown as Parcels A and H on Exhibit A. Preserve -For the purposes of this document the preserve includes those areas within the Open Space parcel "Parcel A" and the Riparian Corridor located within Parcel H, except for the areas referred to as Water Quality and Detention Basin. GHAD Manager -The person in charge of overseeing GRAD related activities including budgeting, evaluation of assessments, contracting maintenance work, contracting technical consultant, and reporting to the Board of Directors. Plan of Control - A report prepared by an engineering geologist certified pursuant to Section 7822 of the Business and Professional Code or a firm of engineering geologists which describes in detail a geologic hazard, its location and the area affected thereby, and a plan for . the prevention, mitigation, abatement, or control thereof. BERi,OGAR STEVENS & 1~SSOCIATES iii May 25, 2011 ~4 ~ ~7 Job No. 3058.000 Page 1 TRACT 7617 -FALCON CROSSING _ . PLAN OF CONTROL I. AUTHORITY AND SCOPE Formation of the Fallon Crossing Geologic Hazard Abatement District (CHAD) is proposed under authority of the California Public Resources Code, Division 17, sections 26500 et seq. As required by Public Resources Code section 26509, an engineering geologist certified pursuant to section 7822 of the Business and Professions Code has prepared this Plan of Control which describes the potential geologic hazards within the Fallon Crossing CHAD boundaries. It also provides a plan for the prevention, mitigation, abatement, and control thereof. As used in this Plan of Control and as provided in Public Resources Code section 26507, "geologic hazard" means an actual or threatened landslide, land subsidence, soil erosion, earthquake, fault. movement or any other natural or unnatural movement of land or earth. II. PROPERTY IDENTIFICATION The GRAD boundaries, shown in Exhibits B and C to this Plan of Control, include 47 acres of land within the Fallon Crossing site (The Site). Exhibit A is a plan entitled Open Space Ownership and Maintenance Responsibilities Exhibit, Tract 7617 -Fallon Crossing, prepared by Ruggeri-Jensen-Azar (RJA), dated October 2007. The plan shows the areas of the site that will be owned and maintained by the GRAD and a 0.22-acre maintenance easement between the Fallon Crossing development and the adjacent Silvera Ranch development. The CHAD will have maintenance responsibilities over, but will not own the easement. The legal descriptions and Plats of the land within the Fallon Crossing CHAD are contained in Exhibits B and C, respectively. III. BACKGROUND PERMITTING Construction for Fallon Crossings will be carried out under permits issued by the City of Dublin, California Department of Fish and Game, National Fish and Wildlife Service, United States Army Corps of Engineers, and the Regional Water Quality Control Board. Certain conditions of these permits may survive construction and may apply to ongoing CHAD management activities. GENERAL SITE LOCATION AND EXISTING CONDITIONS The site is an irregularly shaped parcel including about 68 acres of land located on the northeast side of Tassajara Road, about 2`/4 miles north of Interstate Highway 580. Tassajara Road and Moller Creek, a tributary of Tassajara Creek, border the western and northwestern limits of the BERLOGAR STEVENS & ASSOCIATES ti-.~ ~ 6 ~ May 25, 2011 - Job No. 3058.000 Page 2 site. Moller Creek flows to the south-southwest into a culvert crossing under Tassajara Road. - , Grading for the Silvera Ranch residential development has been performed on the south and' southwest sides of the site. Open land borders the remainder of the site to the north and east. The site location is shown on the Vicinity Map, Plate 1. When this Plan of Control was prepared, the site was vacant and used for cattle grazing. A pond (labeled as "Lower Pond" on Exhibit A) is located adjacent to Moller. Creek in the northwest corner of the site. Another intermittent pond (labeled as "Upper Pond" - on Exhibit A) was created by a man-made artificial fill berm placed in a drainage Swale, upslope of the development. Additionally, there is an existing conservation easement at the site that includes the "Lower Pond" and a 200-foot wide radius around the pond. A ridge roughly 200 feet high trends east-west and dominates the northern portion of the site. This ridge slopes down to the development area at gradients as steep as about 2 horizontal to 1 vertical (2H:1 V) near the top, but generally slopes between 2'/zH:l V to 3H:1 V or less steep as shown on the Pre-Development Geologic Map, Plate 2. A shallow drainage course drains westerly along the toe of the ridge and into Moller Creek. A man-made berm is located across the drainage in the northeast portion of the site to form the "Upper Pond" about 450 feet east of the development area. Two. smaller west-east trending ridge spurs separated by a small drainage swale extend into the southern portion of the site from the east. The ridge spurs are between about 80 to 100 feet high with side slopes as steep as 2'/zH: l V along the northern slope of the northern spur and 3H:1V or less steep elsewhere. The spurs slope down to a relatively level plane east of Moller Creek. The plane ranges from about 100 to 300 feet wide. 1 Site topography ranges in elevation from 450 feet above mean lea level in Moller Creek in the southwestern portion of the site near Tassajara Road to about 705 feet on the top of the northem ridge. On-site vegetation consists of seasonal grasses on the slopes and in the valleys, and dense bushes and trees concentrated near the tributary creek. The site generally drains to the west. PROPOSED SITE DEVELOPMENT - The Fallon Crossing residential development is shown on the project grading plans prepared by RJA, dated May 2, 2008. The grading plans show that the site will be developed into 106 single- , ~ family residences. Grading will be limited to about the western half of the site and extending _ beyond the property line into partially graded ground within the adjacent Silvera Ranch development to the southeast and tying into an existing engineered fill slope of the Silvera Ranch development to the south. The roadways will include a main loop road that will connect to - Tassajara Road on the southwest side of the development and loop around the development in a clockwise direction tb connect to Cydonia Road to the southeast. Three cul-de-sacs will extend to the southeast from the western stretch of the loop. Site grading will steepen the lower portion of the slope in the eastern portion of the development. The spur ridges in the southern portion of the site will be modified by a combination of cuts and engineered fills. A water quality pond and two detention basins are planned ,next to Moller Creek. We understand that future development of adjacent properties (Moller Ranch) will include. rerouting Moller Creek to the south into a culvert to pass beneath Tassajara Road. The design of the creek realignment and culvert should be provided to the Fallon Crossing GRAD for review and acceptance. &~f BERLOGAR STEVENS & ASSOCIATES May 25, 2011 1(0 ~ 7 Job No. 3058.000 _ Page 3 OPEN SPACE Exhibit A of this Plan of Control shows the area of Fallon Crossing GHAD ownership as Pazcels A and H collectively referred to as the Open Space. Parcel A is located upslope of the development area on the north and northeast sides. Parcel A consists mainly of undeveloped open space and is bound by the Fallon Crossing and Silvera Ranch developments to the' south, Parcel H to the west, and open graze land to the north and east. Parcel H is located in the northwest portion of the Fallon Crossing GHAD-owned open space and is located along Moller Creek that is northwest of .the development area. The GHAD will maintain a 15-foot wide maintenance easement that is owned by the TR 7450 Home Owners Association (HOA). The maintenance easement i~s located in open space between the southeast side of the Fallon Crossing development and the upslope Silvera Ranch development. The maintenance easement will be transferred to the GRAD upon the turnover of Parcel A & H to the GHAD pursuant to Section a VI of this document. Parcels B, C, D, E, F, and G are HOA owned and maintained properties. Parcel B is a linear park located between the development area and Parcel H. There is a 15-foot wide access easement at the south end of Parcel B. Parcel C is a landscaped area along Tassajara Road. Parcel D is an open space located in the interior of the development area. Parcel D will consist of anorthwest-facing slope that is planned to be an irrigated vineyard. Parcel E is a neighborhood park located at the eastern edge of the development area. There is a 15-foot-wide access easement through this pazcel. Parcels F and G aze landscaped areas. . Open space within the Fallon Crossing GRAD boundaries (Parcels A and H and the maintenance - easement) shall be managed under the. terms .of the agreements between the developer and City of Dublin, this Plan of Control and any subsequent updates or amendments, the existing conservation easement that was recorded on the property in 2001 to satisfy biological mitigation measures, and the Fallon Crossing Riparian Mitigation and Monitoring Plan. A deed restriction will be recorded over Parcel A and a portion of Parcel H (excluding the detention basin and water quality pond) for the benefit of preserving the natural habitat; Exhibit D depicts the area covered by the deed restriction. The Deed Restriction will enable to the GRAD to conduct GHAD activities to protect the habitat area in an appropriate manner without interaction with the regulatory agencies. Within the areas .owned and maintained by the GHAD (parcel A and H), the GHAD's responsibilities may consist of, but are not limited to, the following: • Open Space maintenance _ Slope stabilization (landslides and erosion hazards) • Creek bank stabilization, when needed • Maintenance of the detention and water quality ponds including but not limited to . thinning/removal of vegetation and sediment • Subdrain outfall inspection and maintenance • Concrete lined V ditch maintenance, and repair or replacement - • Sediment removal {from concrete structures) . BERLOGAR STEVENS & ASSOCIATES 1 ~ 16`7 May 25, 2011 Job No. 3058.000 - Page 4 • GRAD monitoring program • Contracting technical consultants • Geotechnical instrument monitoring (if installed in the future) • Equipment maintenance-and operation in GHAD-maintained areas . - ' • Upper and Lower Pond repairs and rehabilitation (as discussed in Appendix B) • Vegetation control including revegetation and fire break mowing (as discussed, in Appendix C) RIPARIAN ENHANCEMENT As a part of the permitting process with the Regional Water Quality Control Board (RWQCB) and California Department of Fish and Game (CDFG), a small portion of Parcel H within the existing conservation easement (depicted in Exhibit D) will benefit from riparian enhancement. The general purpose of the proposed mitigation is to enhance and expand the width of the existing riparian corridor along Moller Creek and provide species access to the creek from an existing stock pond known to contain CRLF. The 0.17 acres (150-foot by 50-foot section of Moller Creek) of riparian habitat enhancementlrestoration work will consist of tree/shrub planting and the installation of temporary irrigation. Because this is a permit requirement, there will be maintenance and monitoring requirements associated with this enhancement work. For years 1 through 10, the maintenance and monitoring activities and expenses will be the responsibility of Standard Pacific Homes. Upon acknowledgement from the Agencies that the mitigation has reached its success criteria, management responsibilities which consist of reduced _ maintenance and monitoring will be turned over to the GRAD. These additional management activities that the GRAD will inherit will be incorporated into the GHAD's Engineers Estimate to generate funds to cover these additional activities. For details regarding the riparian enhancement work and for all maintenance and monitoring requirements, reference the Mitigation and Monitoring Plan incorporated herein as Appendix C and Section XII of this document IV. SITE GEOLOGY REGIONAL GEOLOGY AND SEISMICITY The site is located within the Coast Ranges geomorphic province of California: The Coast Ranges province is characterized by a series of northwest trending, folded and faulted mountain .ranges and valleys. In this part of the province, sedimentary bedrock units have been mapped as . - the Tassajara Formation by Dibblee (1980) and Crane (1988). Graymer ~et al, X1996) and Barlock (1988) include these rocks as part of the Livermore Gravels. These materials were deposited during the Pliocene to Pleistocene epochs of geologic time (approximately 0.01 to 5.3 million years before present). .The low-lying area at the site includes a Pleistocene alluvial terrace that has been incised by Moller Creek that crosses the northern portion of the site. - . BERLOGAR STEVENS & ASSOCIATES May 25, 2011 ~ o ' Job No. 3058.000 ® Page 5 The region has been folded and faulted during the past few million years due to oblique strike- slip relative motions between the Pacific Plate and North American Plate. The site. does not lie within an earthquake fault zone for active faults as defined by the State of California .(Bryant and Hart, 2007; Davis 1982). Major active faults in the region that influence the seismicity of the site include, but are not limited to, the Greenville fault located about 7 miles to the northeast, and the Calaveras, Hayward and San Andreas faults located about 4, '11 and 30 miles to the .southwest, respectively. The projected surface interception of the (blind) Mount. Diablo Thrust 1 fault is located about 2,000 feet south of the site. SITE GEOLOGIC UNITS Artificial Fill Existing Non-engineered Fills. There are two areas of non-engineered fill present at the site, as shown by~ the symbol "QaP' on the Pre-Development Geologic Map. The non-engineered fills consist of a stockpile in the northeastern portion of the planned development area and a berm forming the dam of the "Upper Pond". The existing stockpile of non-engineered fill located within the development area will be removed during mass grading of the site. The non- engineered fill berm at the "Upper Pond" is planned to remain. Off-Site Existing Engineered Fill. Grading for the Silvera Ranch development has altered the ground surface of the adjacent property to the south. Engeo Incorporated prepared two reports in 2005 and 2006 that documented the results of Engeo's observation and testing services during grading of the adjacent Silvera Ranch residential development. The Engeo reports discuss the location of landslide remediation, subdrain installation, and engineered fill placement. As a result of the Silvera Ranch grading, engineered fill has been placed against the southern limit and upslope of the southeastern limit of the site. These fills are outside the GHAD-maintained open space area and it is not expected that these off-site fills will require attention by the Fallon Crossing GHAD. Future Engineered Fill. To grade for the planned residential development at the site, the Swale areas are to be filled and spur ridges truncated by cuts. Engineered fill at the site will be constructed up to about 38 feet thick and will be placed on a properly prepared and geotechnically approved base. The geotechnical reports prepared . by Berlogar Geotechnical Consultants (BGC) in 2001 and 2003 include the recommendation that an engineering geologist map future cut slopes for the ` Fallon Crossing project during construction. Based on such observations, there is the potential that the engineering. geologist will recommend reconstructing selected portions of cut slopes with engineered fill. The limits of such future slope rebuilds cannot be predicted at the time of preparation of this Plan of Control; therefore, the project Remedial Grading Plan is provided as Plate 3. It is anticipated that the engineering geologist will document such locations of slope . rebuilds, if any, during construction. It is anticipated such construction-record documents will be available to professionals assisting the Fallon Crossing GHAD. BERLOGAR STEVENS & ASSOCIATES May 25, 2011 ~ ( I b / Job No. 3058.000 Page 6 Residual Soils and Colluvial Deposits . Residual soils, derived by in-place weathering of the underlying parent bedrock, are located , along ridgelines and spur ridges. The residual soils at the site consist of dark gray and dark gray- brown silty clay (CL-CH). Typically the thickness of residual soils ranges from about 2 to 4 ' feet. The residual soils have a moderate to high plasticity and are considered highly expansive (BGC, 2003). Colluvial deposits, generated by the downslope creeping of residual soils and/or their transportation by erosion, are located near the toes of slopes, in swales and near the upstream end of valleys. Areas underlain by deposits of colluvium are delineated by the map symbol "Qc" on the Pre-Development, Geologic Map. The colluvial deposits at the site consist of yellow-brown to dark brown silty clay (CH), have a high plasticity and are considered highly expansive (BGC, 2003).. Desiccation cracks up to about 3 inches wide and about 2 to 3 feet deep . have been observed at the site in the summer months demonstrating the expansive nature of these residual and colluvial soils. Alluvial Deposits Alluvium is material that has been trans orted and de osited b flowin w p p y g ater. Alluvial deposits were noted within and adjacent to Mollar Creek and its tributaries. The alluvial soils at the site generally consist 'of stiff to very stiff sandy clay and silty clay (CL-CH), medium stiff to stiff clayey silt (ML), medium dense sandy silt (ML), clayey sand (SC) and silty sand (SM) (BGC; 2003). The alluvial deposits are delineated by the symbols "Qoa" (older alluvium) and "Qal" on the Pre-Development Geologic Map. The clayey portion of the alluvial soils have moderate to high plasticity and are considered highly expansive (BGC, 2003). Landslide Deposits A landslide is a mass 'of rock and/or soil that has, because of the force of gravity, broken free from intact earth along some discrete surface and has moved downslope. Landslides have a variety of shapes, sizes, modes of movement, and material properties. They can consist of debris flows, earth flows, rotational slumps, or rock glides; there are~also other less common types. The _ landslides at the Fallon Crossing site appear to be a combination of soil slips, slumps and earthflows.. Regional landslide maps prepared by the California Division of Mines and Geology ~ , (Majmundar, 1991) and the U.S. Geological Survey (Nilsen, 1973 and 1975) show several suspected landslides within the site boundaries. The project's geotechnical reports (BGC, 2001 and 2003) have identified two landslides, designated as Landslides A and B that impact the' . development area. These two landslides will be completely removed and replaced .with engineered fill during site grading as shown on the Remedial Grading Plan for the site. There are additional suspected landslide deposits elsewhere on the site, but these are well outside (north ' and east) of the development area. The landslides identified at the site are delineated by the map symbol "Qls" along with their letter designation (A through H) .on the Pre-Development . Geologic Map. ~ ~ . 4 Bedrock Bedrock units of the Plio-Pleistocene aged (roughly 0.01 to 5.3 million years before present) Tassajara Formation underlie the site. In general, the Tassajara formation includes layers of sandstone, siltstone, claystone and conglomerate. These rocks are generally moderately to May 25,.2011 °2~ . ~ ~ 7 .Job No. 3058.000 Page 7 highly weathered, friable, and moderately to highly fractured. Commonly, the claystone beds and some of the clayey siltstone beds are moderately to highly expansive. The areas underlain by the Tassajara formation near the ground surface are delineated by the symbol "QTt" on the Pre-Development Geologic Map. V. GEOLOGIC HAZARDS Geologic hazards identified at the site consist of potential slope instability, soil creep, erosion and sedimentation, seismic (earthquake) ground shaking, creek bank erosion, shrink and swell of expansive earth materials, compressible soils and dispersive soils. The grading for the planned development is not expected to entirely eliminate the geologic hazards from the site. The geotechnical reports prepared by BGC (2001 and 2003) have identified the geologic hazards that impact the planned development. The Remedial Grading Plan shows the planned treatment of the geologic hazards and other geotechnical factors identified within the development area that pose a direct impact to planned lots and site improvements. It is anticipated that field-verified geologic mapping will be undertaken during site grading operations. The record documents showing subdrain locations and outfall elevations, bedrock structure, springs (if encountered), and landslide/unstable soil areas limits and repairs shall be provided to the Fallon Crossing ® GHAD when available as Volume 2 of this Plan of Control. A brief description of the geologic ® hazards within the Fallon Crossing GHAD boundaries is included below. 1 SLOPE INSTABILITY Slope instability is common in the San Francisco Bay Area and is not unique to the site. In general, the stabilization of landslide masses and unsuitable materials on the slopes of the GRAD ownership and maintenance area will be performed during site grading only for slopes that could directly threaten improvements within the development area. It is considered neither practical nor desirable to remove all landslide deposits and/or unstable soil areas from the surrounding hillsides during site grading. In addition to areas of slope instability identified during geotechnical explorations, geologic reconnaissance performed before site development, .and geologic observations made during site grading, areas of slope instability and/or landsliding could become apparent during the life of the development. Since earth instability is the GHAD's primary geotechnical concern, this section describes several types of slope instability that are the GHAD's responsibility. See also Section VIII below under the heading Geotechnical Techniques for Mitigating Landslide and Erosion Hazards. Landslides located within open space are natural landforms that typically do not require mitigation. Where they do merit mitigation, it is where they could affect man-made ` improvements. GHAD maintenance will be important to provide and maintain adequate protection for the site improvements. See Section XII below under the heading Maintenance and Monitoring Schedule. Rainwater and artificial watering can raise pore pressures between earth particles and reduce the frictional forces holding the earth material together. Thus, water tends to reduce the strength of the earth material. For this reason, slope stability is -lower and landslides occur more frequently in the winter,.which is the rainy season in California. Intensive tunneling by burrowing animals can provide pathways for surface water to permeate into the ground, sometimes leading to BERLOGAR STEVENS & ASSOCIATES May 25, 2011 ~ J OS ob No. 3 8.000 Page 8 saturation of slopes and soil slips. Seismic ground shaking imposes forces on a slope that lowers slope stability and may increase landslide movements. The following table lists the areas of slope instability, their impacts to site improvements and the potential GHAD maintenance responsibilities. - SLOPE INSTABILITY AND GHAD MAINTENANCE TABLE - Location Potential Impact to . Potential GHAD Site Im rovements Maintenance Res onsibilities - Slopes above development If instabilities Slope monitoring required. Future . area develop in the fixture, instabilities, should they develop, they could threaten would likely require removal of the homes and site unstable mass and replacement with improvements engineered fill. Mitigation to be determined by technical consultant and based on site-s ecific characteristics. ' Slopes located in Open Potential to block Slope monitoring required. Impact to Space and not within drainage, be evaluated by technical consultants develo ment area Landslides A and B None after site Monitor reconstructed slopes. development. Landslide C Potential to block Monitoring required. Future landslide drainage. movement may require removal of soil and/or slo ere-contourin Landslides D, E and F Future landslide Slope monitoring required. Removal of movement could materials at the toe may be needed to block the flow of allow for drainage. Technical water resulting in consultants to determine extent of increased erosion and removal so that remaining upslope sedimentation in the mass is not destabilized. "U er Pond". Landslides G and H None Future landslide movement not expected to result in GRAD maintenance. Future grading of the _ off-site portions of these landslides shall be reviewed by the GHAD for potential impacts to the Fallon Crossing GHAD. SOIL CREEP - Soil creep is the gradual, diffuse downslope movement of surficial soil under the influence of gravity. Soil creep differs from landsliding in that creep does not involve a separation of earth material across any distinct surface. Creep moves at a speed imperceptible to the eye, on the order of a few inches per decade. Typically creep occurs in colluyial soil, though it can also occur in engineered fill, alluvium, and bedrock. ~ . . Soil creep has been observed at the site in the areas shown on the. Pre-Development Geologic Map and is generally outside the area of site improvements. The potential CHAD maintenance responsibilities of soil creep to the Fallon Crossing GHAD are low. ~t 1' BERLOGAR STEVENS & ASSOCIATES - May 25, 2011 p?o~ Job No. 3058.000 Page 9 ' EROSION AND SEDIMENTATION Erosion is the movement of soil particles down a slope or channel by the flow of running water as sheetwash or rivulets. The soil particles are suspended or otherwise entrained in the water, as . shown by the water's turbidity or cloudiness. Water usually does not flow in just a sheetwash mode for long and soon begins forming rivulets. Rills, which are tiny gullies, and then gullies are the result of concentrated water flow that remove soil on a slope. Where the slope gradient ' , decreases or.the water otherwise meets a barrier, the water slows and the soil particles settle out. The deposition of these soil particles is termed sedimentation. Vegetation can slow erosion, which will in turn reduce sedimentation.. Conversely; a lack of vegetation can speed erosion and lead to down-gradient sedimentation. Slope height and concentration of water, natural or artificial, are also factors that contribute to erosion and sedimentation. Sedimentation could impact drainage facilities and the ponds and basins at the site. Sediment removal and erosion control will be needed. SEISMIC GROUND SHAKING Future earthquakes of moderate to high magnitude are expected to occur in the region during the design life of the development. Strong ground shaking is expected to occur at the site as a result. ® To mitigate the shaking effects, structures will be designed under current building code l~ requirements and using sound engineering judgment. Slope stability is also lowered under seismic-shaking conditions. CREEK BANK INSTABILITY AND EROSION The channel of Moller Creek crosses the northern portion of the proposed GHAD boundary. The creek banks may be locally over-steepened and be susceptible to instability and erosion. Observation of creek bank conditions, as outlined in Section XII under the heading Monitoring and Maintenance Schedule, will be performed by the Fallon Crossing GHAD periodically. SHRINK/SWELL OF EXPANSIVE EARTH - Residual soils, colluvium, cla ey alluvial soils, engineered fill, and some bedrock layers at the Y - site could have a potential to shrink and swell with changes in moisture content. Such movements potentially would cause heaving and cracking of slabs-on-grade, pavements, and structures founded on shallow foundations. It rs anticipated that design and remedial grading under engineering control and the use of structural slab foundations will mitigate the potential for shrink and swell and reduce the potential hazard to low.. COMPRESSIBLE SOILS Colluvial deposits and alluvial soils are types of material that could be potentially compressible. Compression potentially would cause lowering and cracking of slabs-on-grade, pavements, and structures founded on shallow foundations, and sags in gravity controlled utility pipelines (storm and sewer). It is anticipated that some settlement of the thicker engineered fills will occur with site development but that those settlements will be within tolerable limits of the site improvements. It is anticipated that design and remedial grading under engineering control will mitigate the potential for soil compression and reduce the potential hazard to low. BERLOGAR STEVENS & ASSOCIATES May 25, 2011 'p Job No. 3058.000 I~7 Page 10 DISPERSIVE SOILS The northwest portion of the site located adjacent to Moller Creek appears to be. underlain by dispersive soils. The soils may contain dispersed clay .particles that go into suspension in flowing water (both surface and subsurface) and potentially contain soluble salt minerals. As a result, the areas underlain by the dispersive soils are highly erodible and sometimes form sinkholes. It is anticipated that design and remedial grading under engineering control will reduce the hazard of dispersive soils at the site to low. VI. FUNDING AND ACCEPTANCE OF RESPONSIBILITY BY GRAD PROPERTY OWNER ASSESSMENTS a The Fallon Crossing GHAD is funded in perpetuity by assessments that are paid by the residences. Subject to applicable law, an annual assessment must be promptly implemented on all residential parcels m the GHAD boundanes. The assessment v~nll be levied by. the Fallon Crossing GHAD on each individual residential parcel beginning the first fiscal year after the City issues a building permit for that parcel. Annual assessments will be based on the projected costs that are incurred from the implementation of the geotechnical scope outlined m this document. The actual assessments will be calculated in the Engineers Report that will be developed - subsequent to the approval of this document by the City Council. TRANSFER OF RESPONSIBILITY TO THE DISTRICT The party that, on the date that the City records the Final Map within the boundaries of the Fallon Crossing GHAD, owns the developable parcels shown on that Final Map has the responsibility to perform all the activities of the Fallon Crossing GHAD on property within that - Final Map. Such responsibility shall automatically transfer to the Fallon Crossing GHAD at 9:00 a.m. on the day exactly three years after the first residential building permit is issued by the City. This transfer date may be extended at the sole discretion of the project developer provided that the assessments continue to be levied during the extension period and that notice of such extension is delivered to the GRAD manager at least 30 days before the transfer date. The petitioners for formation of the Fallon Crossing GRAD intend that the approximately.three-year period between the levying of the GHAD assessment and the Fallon Crossing CHAD becoming responsible to perform activities on property within the Final Map will allow the District to accumulate reserve funds without incurring significant expenses. Such reserve funds are needed to address periodic major events that cannot be funded from annual revenues. VII. AREAS OF GHAD RESPONSIBILITY PREVENTION, MITIGATION, ABATEMENT AND/OR CONTROL OF GEOLOGIC HAZARDS Subject to the following exceptions, the primary mission of the Fallon Crossing GHAD shall be the prevention, mitigation, abatement, .and/or control of geologic hazards within its boundaries that have damaged or that pose a significant threat of damage to site improvements within the BERLOGAR STEVENS & ASSOCIATES May 25, 2011 ~Lf Job No. 3058.000 Page 11 development areas of the site. As used herein, the term-"site improvements" means buildings. and outbuildings, roads, sidewalks, paths, utilities, improved trails, swimming pools, tennis courts, gazebos, cabanas, basins, geologic stabilization features, drainage features, or similar improvements. The exclusions and limitations set forth herein do not apply to geologic hazards existing on open-space property owned by any homeowner's associations except for the maintenance easement from the upslope Siivera Ranch development, since these areas are not part of the responsibility of the Fallon Crossing GHAD. The secondary mission of the Fallon Crossing GHAD is to maintain the biological values of the open space by adhering to the conditions and restrictions set forth in the Resource Management . Plan and the deed restriction. EXCEPTIONS The Fallon Crossing GHAD is not responsible for open space tasks that will be provided by the City of Dublin or the homeowners association as set forth in Exhibit A or in any future memoranda or agreements. The Fallon Crossing GHAD's role is limited to overseeing and supervising the City's general physical maintenance of the open-space areas as may be required to prevent, mitigate, control, or abate erosion, sedimentation, and potential landslide hazards. The Fallon Crossing GHAD may decline to prevent, mitigate, abate, or control geologic hazards under the following circumstances: Isolated or Remote Slo a Instability P The Fallon Crossing GHAD will not have responsibility or may place a low priority on its responsibility to monitor, abate, mitigate, or control slope instability that does not involve damage, or pose a significant threat of damage, to site improvements, including residences. Sin le Pro e g P rt3' The Fallon Crossing GHAD will not prevent, mitigate, abate, or control geologic hazards that are limited in area to a single parcel of property unless the geologic hazard has damaged, or poses a significant threat of damage, to site improvements located on other property within the GHAD boundaries. The GRAD maintenance area (Parcels A and H on Exhibit A) shall not be considered a "single parcel of property" for the purpose of this limitation, regardless of whether it may actually comprise a single legal parcel. Geologic Hazard That Requires Expenditure in Amount Exceeding the Vaiue of the Threatened or Damaged Improvement The Fallon Crossing GHAD will not prevent, mitigate, abate, or control a geologic hazard where, in the GHAD manager's sole discretion, the anticipated expenditure required to be funded by the Fallon Crossing GHAD to prevent, mitigate, abate, or control the geologic hazard will exceed the value of the structure(s) and site. improvement(s) threatened with damage or loss. _ BERLOGAR STEVENS & ASSOCIATES ~ May 25, 2011 -7 Job No. 3058.000 / . Page 12 GHAD Funding or Reimbursement for Damaged or Destroyed Structures or Site Improvements In the event a residence or any other private structure, site improvement, or landscape feature is .damaged or destroyed as a result of a geologic hazard, the Fallon Crossing GHAD may fund or reimburse the property owner for the expenses necessary to repair or replace the damaged or destroyed structure, site improvements, or landscaping, with the exceptions noted above. Unless otherwise authorized by the board of directors, the dollar amount of the Fallon Crossing GHAD funding or reimbursement may not exceed ten percent (10%) of the costs incurred by the Fallon Crossing GRAD in preventing, mitigating, abating, or controlling the geologic hazard causing the damage.. In the event the geologic hazard damaged or destroyed a structure, site improvement or landscaping that violated any provision of the City of Dublin Building Code or City of Dublin Municipal Code applicable at the time of its installation or improvement, the Fallon Crossing GRAD may decline to provide any funding or reimbursement to the property owner for repair or replacement of the damaged structure, improvement, or landscaping. Earthquake Insurance The Fallon Crossing GHAD is not intended to serve or provide "in-lieu" earthquake insurance for private property owners. Obtaining the adequate level of earthquake insurance is the sole responsibility of the individual property owners within the Fallon Crossing development. No Reimbursement without Written Agreement The. Fallon Crossing GHAD will not be obligated to reimburse a property owner for expenses incurred by the property owner for the prevention, mitigation, abatement, or control of a geologic hazard absent a written agreement between the property owner and the Fallon Crossing GHAD to that effect, executed before the property owner incurs said expenses, and following an investigation conducted by the Fallon Crossing GHAD'. Property Not Located Within GHAD Boundaries - Except as .herein provided, the, Fallon Crossing GHAD shall not prevent, mitigate, abate, or. control geologic hazards located on.property that is not located within the GHAD boundaries. In ~ . the event, however, that all or any portion of a geologic hazard existing on property located outside the GRAD boundaries has damaged or poses a significant risk of damage or site or other physical improvements located on property within the GHAD boundaries, the Fallon Crossing GHAD .may prevent, mitigate, abate, or control the geologic hazard. Any work conducted on property located outside of the GHAD boundaries shall tie strictly limited to that necessary to prevent, mitigate, or control the, damage, or threat of damage, to property located within the boundaries of the Fallon Crossing. GHAD. Should the Fallon Crossing GHAD be required to respond to a geologic hazard outside the GHAD boundaries, the Fallon Crossing GHAD may take such actions as may be appropriate to recover costs incurred as a result of preventing, mitigating, abating, or controlling such geologic hazards from the responsible party, if any. ~ - ~ BERLOGAR STEVENS & ASSOCIATES i ~ May 25, 2011 ~ ~~7 Job No'. 3058.000 Page 13 Protected Habitat under Deed Restriction , Geologic Hazards that occur within the Open Space that do not damage or threaten improvements, homes, or biological features (including the upper and lower stock ponds), will not be mitigated for. GEOLOGIC HAZARDS IN OPEN SPACE AND MAINTENANCE OF OPEN SPACE AREAS The Fallon Crossing GHAD may prevent, mitigate, abate, or control the geologic hazards in open space areas and other unimproved areas within the GRAD boundaries if the geologic hazards have damaged or have the potential to damage site improvements located on properties within the GHAD boundaries or result in a major adverse biological impact if not corrected or rehabilitated. All such prevention, mitigation, abatement, and control shall be done in a manner consistent with the Detention/Water Quality Basin Operations and Maintenance Manual and the Resource Management Plan. Due to the sensitive biological nature of the open space within the Fallon Crossing GHAD ownership and maintenance areas, procedures for mitigating geologic hazards are set forth in the Detention/Water Quality Basin Operations Manual and Resource Management Plan are provided in Appendices A and B hereto. No management activities can be performed within the deed restricted areas which result in the loss of habitat or impacts to any special-status species without required agency permits. The Fallon Crossing GHAD will be responsible for slope stabilization, including major landslide events that meet the criteria for repair listed above for the potential to impact site improvements. This also includes repair of minor landslides and debris flows which have the potential to affect both the upper and_lower ponds. The Fallon Crossin GRAD is also authorized to monitor erosion and sedimentation in open g space areas that affect developed tots and/or improvements. In addition, the Fallon Crossing GHAD is authorized to repair erosion gullies, etc. in open space areas if they pose an immediate threat to improvements, or wildlife habitat. Repair activities conducted within the Preserve will be coordinated with the California Department of Fish and Game and/or US Fish and Wildlife Service. The Fallon Crossing GHAD is responsible for sediment and debris removal from concrete V ditches and open space catch basins. The Fallon Crossing GHAD is further authorized to maintain surface and subsurface drainage facilities and improvements located in the GRAD maintenance area, either by ownership or easement, including, but not necessarily limited to, concrete V ditches, storm drain inlets and outlets in open space and ,drainage corridors and subdrain outlets. Occasionally, portions of V ditches may require repair or replacement due to cracking caused by expansive soils, .and this will be the responsibility of the Fallon Crossing GHAD. The GHAD's creek channel maintenance responsibilities are limited to repairing substantial bank failures that directly damage or threaten actual site improvements (buildings, roads, utilities, trails, basins, etc.). Landslides that block the flow of water resulting in flooding of the site improvements may require immediate treatment. Downstream sedimentation resulting from creek bank erosion is considered a natural geologic process and is not the responsibility of the Fallon Crossing GHAD. Drainage channel improvement projects armoring channels with rock BERLOGAR STEVENS & ASSOCIATES May 25, 2011 ~C / ~ b 7 Job No. 3058.000 . Page 14 or other materials may be undertaken by the Fallon Crossing GHAD as required. Creek repairs -will be required to obtain agency authorizations prior to undertaking such activity. The Fallon Crossing GRAD is responsible for routine clearing of the firebreak and general maintenance of Parcels A and H (other than geologic hazard abatement). The Fire Hazard _ Mitigation. and 'Defensible Space Vegetation Management Plan discusses the procedures for firebreak mowing and is included herein as Appendix C. The Fallon Crossing GRAD should review such activities for their potential to damage or interfere with the operation of any GHAD- _ maintained improvements, to cause an increase in erosion andlor sedimentation, or in any manner aggravate or increase the potential of a landslide. Equipment maintenance and operations includes items of equipment related to geotechnical stabilization within the open space areas could include items such as sump pumps. - GHAD operations will include monitoring. of geotechnical instruments (e.g., piezometers, inclinometers, settlement monuments, etc., if any) within the GHAD boundaries, including open space area asrequired. - The Fallon Crossing GHAD may review and has the right to approve or disapprove physical construction, maintenance, or repair activities proposed within the GHAD maintenance area that, at the discretion of the GHAD manager, could increase erosion or sedimentation or otherwise impact or affect the geologic stability of the area. Furthermore, no management activities can be performed within the deed restricted areas which result in the loss of habitat or impacts to any - special-status species without required agency permits. Should the Fallon Crossing GHAD be required to perform maintenance activities that are the responsibilities of others, the Fallon Crossing GHAD shall take such actions against the responsible party as may be required to recover costs incurred as a result of such activities. - VIII. GEOTECHNICAL TECHNIQUES FOR MITIGATING LANDSLIDE AND EROSION HAZARDS . Techniques the Fallon Crossing GHAD may employ to prevent, mitigate, or abate landslide or adverse erosion damage include, but are not limited to, the following: 1. Agency authorization, if applicable. 2. Removal of the unstable earth mass. s 3. Stabilization by either partial or total removal of the landslide, and safely stockpiling of V material near the excavation and replacement with engineered fill provided with subdrainage. - 4. Construction of structures to retain or divert landslide material or sediment. f, 5. Construction oferosion-control devices or materials such as gabions, rip-rap, geotextiles, or lined ditches. 6. Placement of drained engineered buttress fills. 7. Placement of subsurface drainage devices, e.g., subdrains or horizontal drilled drains. BERLOGAR STEVENS & ASSOCIATES i May 25, 2011 Job No. 3058.000 I~7 Page 15 i . 8. Slope correction such as gradient change, biotechrucal stabilization, and slope trimming or contouring. , Construction of additional surface ditches and/or detention basins silt fences sediment 9 , traps, or backfill of erosion channels. 10. Re-vegetation of slopes by planting or hydro-seeding. Potential landslide and erosion hazards can best be mitigated by controlling soil saturation and water runoff and by maintaining surface and subsurface drainage systems. The Fallon Crossing GRAD should use techniques to mitigate.individual events of slope instability or erosion that are based on the recommendations of licensed professional technical consultants contracted by the Fallon Crossing GHAD. Maintenance shall be provided for lined surface drainage ditches and benches and drop inlets. IX. BIOTECHNICAL RECOMMENDATIONS FOR PREVENTING AND MITIGATING EXISTING OR POTENTIAL EROSION HAZARDS Fill and cut slopes within the GHAD boundaries are expected to be erodible. Therefore, the maintenance of vegetative cover is especially important. Vegetation provides a protective function on soil and exposed rock. Vegetation absorbs the impacts of raindrops, reduces velocity of runoff, and retards erosion. In man instances ade uate erosion rotection for.slo es can be accom lished with carefully Y ~ q P P P selected and placed biological~elements (plants) without the use of structures (e.g., brush layering and willow wadding). In other areas, biotechnical slope protection may involve the use of mechanical elements or structures in combination with biological elements to provide erosion control ,and help prevent small-scale slope failures. Locally, crib walls, welded-wire .walls, gabion walls, rock walls, rip- . rap, and reinforced earth walls used in combination with carefully selected and planted vegetation can provide high-quality slope protection.. The vegetation may be planted on the slope above a low retaining structure or toe wall, or the interstices of the structure can be planted. . . X. PRIORITY FOR GHAD-FUNDED REPAIRS Emergency response and scheduled repair expenditures are to be prioritized by the GHAD manager, at his or her discretion, based on available funds, a prudent reserve, and the approved operating budget. Should available funds not be sufficient to undertake all of the identified remedial and preventive stabilization measures; the expenditures shall be prioritized as follows in descending; order of priority: 1. The prevention, mitigation, abatement, or control of geologic hazards that have either damaged or pose a significant threat of damage to critical structures, residences, critical underground utilities, basins or paved streets. BERLOGAR STEVENS & .ASSOCIATES May 25, 2011 w4 Job No. 3058.000 lb7 Page 16 2. The prevention, mitigation, abatement, or control of geologic hazards that have either damaged or pose a significant threat of damage to community buildings. 3. The prevention, mitigation, abatement, or control of geologic hazards that have either damaged or pose a significant threat of damage to private or community recreation facilities (e.g., park structures, pools, spas, tennis courts, etc.). 4. The prevention, mitigation, abatement, or control of geologic hazards that have either _ damaged or pose a significant threat of damage to loss of landscaping or other similar nonessential amenities. 5. The prevention, mitigation, abatement, or control of geologic hazards located entirely on . . open-space property and which have neither damaged nor pose a significant threat of damage to any site improvements. 6. As part of the standard GRAD budgeting practices, funds shall be allocated annually for the purpose of routine maintenance and management over the detention and water quality basins to ensure that they are operating as designed. ' In performing any of the duties described above, the Fallon Crossing GHAD may seek reimbursements from public and private entities including, but not limited to, FEMA, City and County agencies, insurance companies, etc. XI. RESERVE FUNDS Based on the Engineers Report as well as subsequent Engineers Reports, the GHAD manager - will evaluate the appropriate amount of funds to be reserved for emergency and long-term capital replacement projects that have costs in excess of the annual maintenance and repair budget. The reserve funds may be evaluated annually based on the most recent costs of GRAD projects at the site. XII. MAINTENANCE AND MONITORING SCHEDULE Geologic features and GRAD-maintained facilities shall be inspected on a regular basis and as necessary. Inspections shall be scheduled to occur a minimum of three times per year in normal years and four or more times per year in years of heavy rainfall as determined by the GRAD manager. The inspections shall be scheduled to take place prior to the middle of October before the first significant rainfall, midwinter as appropriate during heavy rainfall years, and in April at about the end of the rainy season. The operations and maintenance of the basins shall be conducted pursuant to Operations and Maintenance Manual (Exhibit D, Appendix A). The ~ frequency of the inspections shall be increased in years of higher-than-average rainfall intensity and/or occurrence. The following table summarizes the inspection schedule recommended herein. BERLOGAR STEVENS & ASSOCIATES May 25, 2011 c~© 167 - Job No. 3058.000 Page 17 ITEM SUGGESTED TIMING OF INSPECTIONS - Fall Winter S rin Site Slopes Annual for fast S years post Annual development Creek Banks Annual After si nificant rainfall events Annual Basins Annual After si nificant rainfall events U er Pond Annual Concrete Annual After significant rainfall events Structures Drainage Annual After significant rainfall events Facilities The Fallon Crossing GHAD shall review its inspection schedule annually and assess the effectiveness of its preventive maintenance program on a regular basis. CHAD staff shall prepare an annual report to the board of directors with recommendations for maintenance and/or- repair projects. If necessary, consultants will be retained to undertake the needed studies. The district geotechnical engineer and/or engineering geologist retained by the Fallon Crossing GHAD shall prepare an annual inspection report for presentation to the GRAD board of directors. Slo~es• Site slopes shall be observed during scheduled site visits by a State of California certified geotechnical engineer (GE) or certified engineering geologist (CEG) for indications of slope instability, seeps, or unusual erosion. The schedule shall be two times per year for the first five years post-development and annually thereafter or as determined by the GRAD manager. Creek Banks. AGE or CEG shall inspect the banks of the tributary creek on a regular schedule. The inspections -would check for indications of potential instability and significant erosion. The inspections shall be performed prior to winter and during or shortly following significant rainfall events budget permitting: - Upper Pond. The GRAD Manager shall inspect the pond annually. The inspections would - check for indications of potential instability, significant erosion, sediment deposition, vegetation accumulation, signs of trespass and human disturbance. The pond shall .undergo sediment removal once every fifteen years or on an as needed basis as determined by the GHAD manager. Basins. AGE or CEG shall inspect the detention and water quality basins for over vegetation or sedimentation that would decrease the geotechnical functions intended. Maintenance may include thinning of vegetation and sediment removal. If maintenance is required, such methods shall adhere to. the Detention/Water Quality Basin Operations and Maintenance Manual in Appendix A. The operations and maintenance of the basins shall be conducted pursuant to - - Operations and Maintenance Manual (Exhibit D, Appendix A). Concrete Structures. AGE or CEG shall inspect the surfaces of concrete-lined drainage ditches - within the GRAD boundaries on a regular schedule: Inspections will be scheduled twice each year. One inspection should be in the fall before the onset of winter rains. The professional should check for sedimentation, cracking or shifting of the concrete-lined ditches. Repairs and maintenance should be performed on a regular schedule. Excess silt or sediment in ditches shall be removed and cracked or broken ditches should be patched or repaired as required before the .beginning of the next rainy season. BERLOGAR STEVENS & ASSOCIATES May 25, 2011 ~Jt 16 7 Job No. 3058.000 Page 18 Drainage facilities. Culverts, storm drain inlets, outfalls or trash racks, if used, must be kept free of debris and spillways maintained. Attention should be given to plantings or other obstructions that could interfere with access by mechanized equipment. . Subsurface drain outlets shall be inspected on a regular schedule. Water flowing from these outlets should be measured and documented during each inspection. Inspections shall be scheduled twice each year, preferably in the fall and spring. Suspicious interruption of flow should signal a need to unplug or clean by flushing the affected drain. It is anticipated the project professionals observing the installation of subsurface drains and geotechnical instrumentation (if any) will document their locations and provide such documents to the Fallon Crossing GRAD for use in their maintenance and monitoring tasks. Instrumentation. Although no geotechnical instrumentation, such as piezometers, inclinometer casings, and settlement monitoring devices, are planned in the Fallon Crossing development, they could be installed depending on future recommendations made by project professionals. If installed, the Fallon Crossing GRAD shall monitor such instruments on a regular schedule. BIOLOGICAL RESPONSIBILITY TABLE Fallon Crossin - Parcel's A & H - Annual Pre- Monitoring / Acceptable Annual Acceptable Construction Annual Inspection Monitoring Maintenance Maintenance Survey Agency permit Report Area Parcel Re uirement Methods Activities Methods Ra uirement Notification Re uirement Re uirement Additional information Identified as Assumed to occur Stock Pond Upper pond; NA NA once every 15 TBO None Yes Yes NO ahero Ha a auenc ppN fa the located wfin years. Or on an as- to conducting the sediment poor Parcel A needed basis. removal from the pond. - Annual maintenance may No -However, ' inGude maintenance Yes - puarterly. clearinglmaintenan Hand labor 8 must be InspeIX outlet ce of Inlet and wheelbarrows ~ conducted in - structures, access ~ Outlet Structures, within the accordance Aii Maintenance activities to_ road, basin banks, access road basin, with the remove vegetation and/or Detention Fencing. Ouarterty Visual repairs, basin mechanized Operations Basin Basin Area Monitoring Report Inspection embankment - equipment Yes - No and ~ No . sediment shall be pertormed template wn be repairs, fencing positioned Maintenance between August i and found in the O&M repairs, desilting of from the Manual September 30. Manual attached basins; and maintenance prepared by . hereto es en exhbit. mosquito rd. ~ ~ RJA, attached abatement. See hereto as an 08M Manual for exhibit. more detail. Yes; puarterly for years 1J, with Vandalism Portion of reduced levels for inspections, weed Parcel H; years 4 and on. conVOl, plant an0 Riparian within Detailed breakdown Visual irigation Hand labor No No No Yes Corridor existing of maintenance and Inspection maintenance, litter - conservation monitoring removal, and Easement obligations can be erosion control found in the MMP maintenance. (Appendix C). Y 1' BERLOGAR STEVENS & ASSOCIATES . May 25, 2011 ~ .Job No. 3058.000 Page 19 XIII. LIMITATIONS The conclusions and recommendations presented in this document are based on information provided to us regarding the proposed improvements and other aspects of site development, the results of the geotechnical investigations at the site, available published regional geologic data and professional judgment. This document has been prepared in accordance with current standards of the engineering geology profession. No warranty is expressed or implied. 3058.000/21439.doc BERLOGAR STEVENS & ASSOCIATES 33 1~7 , * ~ REFERENCES Barlock, V.E.; 1988; Geologic map of the Livermore Gravels, Alameda County, California: U.S. Geological Survey, Open File Report 88-516. Berlogar Geotechnical Consultants; September 19, 2003; Design level geotechnical investigation, Mission Peak property, Tassajaza Road, Alameda County, California. Berlogar Geotechnical Consultants; September 13, 2001; Report, feasibility-level geotechnical investigation, Mission Peak property., Tassajara Road, Alameda County, California. Bryant, W.A. and Hart, E.W.; 2007 (Interim Revision); Fault-rupture hazard zones in California, Alquist Priolo Earthquake Fault Zoning Act with index to Earthquake Fault Zones maps: California Geological Survey Special Publication 42. Dublin Cit of• 2007• A room i v y pp g a s to de elopment review and Vesting Tentative Map 7617 within existing PD-Planned development district known as "Fallon Crossing" at the northeast intersection of Tassajara Road and Fallon Road, PA 04-016, APN 985-00021-001: Planning Commission Resolution No. 07-59. . Davis, J.; 1982; State of California Special Studies Zones, Livermore, Official Map; California Division of Mines and Geology. Dibblee, T.W.; 1980; Preliminary geologic map of the Livermore Quadrangle, Alameda and Contra Costa Counties, California; U.S. Geological Survey, Open File Report 80-533B. Engeo Incorporated; September 28, 2006; Final report, observation and testing services during grading, Silvera Ranch, Tract 7441, Dublin, California. Engeo Incorporated; May 2001; Preliminary Geologic Map, SilveralHaight Property, Dublin, California. Graymer, R.W., Jones, D.L. and Brabb, E.E.; 1996; Preliminary geologic map emphasizing bedrock formations in Alameda County, California: a digital database:. U.S. Geological Survey, Operi-File Report 96-252. Nilsen, T.H.; 1975; Preliminary photointerpretation map of landslide and other surficial deposits of the Livermore. 7'/z' Quadrangle, Alameda County, California: U.S. Geological Survey, Open File Map 75-277-26. Nilsen, T.H.; 1973; Preliminary photointerpretation map of landslide and other surficial deposits • of the Livermore and part of the Hayward 15-Minute Quadrangles, Alameda and Contra Costa counties, California: U.S. Geological Survey, Miscellaneous Field Studies .Map MF- 519. Majmundaz, H.H.; 1991; Landslide hazazd in the Livermore Valley and Vicinity, Alameda and Contra Costa Counties, California, Landslide Hazard Identification Map No. 21: California Division of Mines and Geology, Open File Report 91-2. m~.._ BERLOGAR STEVENS & ASSOCIATES i~~ REFERENCES (continued) Ruggeri-Jensen-Azar; May 2, 2008; Grading Plans Tract 7617 -Fallon Crossing, City of Dublin, Alameda County, California. _ ,State of California; February 27, 2008;_ Seismic hazard zones, Livermore Quadrangle, Preliminary Map: Califoiia Geological Survey. BERLOGAR STEVENS & ASSOCIATES ~ ~S ~6~ f~_ ~ ~ ~ a 1 , ' ; ' ' °~v c~( lei y i urJ ~ ` c ~ ~l, ~~i ~ ' j 1 ~1_ 1 \i /,r o ~ f ~ 7 \ ; ~ ~`(p SITE. r r ac M _ _ aF~~ i ~ Q'~ O ~ ~ U • ~ ~ I,I \ 1/ ~ ' ,O ~r~Ca. lL~r' /a/,G,r~'~~ ~,"~l\ . 1~~/~41/~''l ~ _ ~sSAJ~ ~ ; -J ,r i• ~ ~r~...~~-.', 1,~~-- J ' 11~` ~ r~ .f m'il` - fit." 'RECTLS]V~ li ~a i~~ cam,\;~I /~~i~.--J~l r-~-J~ 1~%~~~~I~, \ a t 1 - III f 1. ( J ~ t C- % 15~ 1,~ • \ .^/'~/"1 0 2000 ~ °=2000` ` ..t:. *7 VICINITY MAP FALCON CROSSING TASSAJARA ROAD DUBLIN, CALIFORNIA tsA ' FOR STANDARD PACIFIC HOMES ~F . S~~ ' BASE: PORTION OF U.S.G.S. 7.5 MINUTE TOPOGRAPHIC QUADRANGLE, DUBLIN, CALIFORNIA,.PHOTOREVISED 1983, AT A SCALE OF 1:24,000. PLATE 1 SP 35aobltP'j / ~ N .l ~J , ' V Y1 1 I / I /.n. r~~ - ~ ~ .\l ~ ~ ~ \ j ~c l EXPLANATON 1 R tt ~Tt . \C \.;~/~,~7i~oai,~~ 0 sky \ ~F \ \ ~~~~j~~i/ ~ ~ ~~t~\ \ aa~ ,y 1 r " } ~J/'// / ~ /7/J,),/ ~ oar. n J - " ''F ~ta~'~ F ~.k ,ry' ~ \ mac. : ~p //1~~~~)~r ~7J~~1~~~1 ( ~ j oal l j~ ) } ~ Lr h . J~ ~ F F. ~ , tar F ~ ~ J----; - - . - ~ ~ ,,u, . ~ ~ - ~ ~ PRE DEVELOPMENT \ \ I/\\ ~ ~ GEOLOGIC MAP \a\ \ - ~ \\\f I ~ / I ~1 ~ \ FnL*ObN~CR0941NO 35b l~l i / i I . _ / _ aEaatioa~NFaa~L~.~.Lao~.NL ,.F~,LSG~G~NNO~NL crry , O _ is E ~ _ ~ a~ naE ..o ~ I r 4 _ - _ Y ` ' ~ i _ oa s II ~~hjr4 , u e ~ ~ ~~-r~~ ~''v°: `,F`a r . ; ~e~ - ~ J_ ~ I 1 -/i/ - ° wrumrr ~ ~ / _ `oars - ~L~ 'ate".:" ~~Nr ~ # / s ~~~^I J,- ( _ an I ~ - ° a.E,o.: ism ~.'°`.~N i ~ - a ~ ~ ~1Oe..w°1BU a r _ __wnF~,. ».o~e°:~..r' a°:a~.~«~na~.w nox~ue. ~ a~u ~ i 1 ~ s~.. ~ »onm wrw Lo E. .a~~ow 3 D ~ ~ ~ oab ~ _ Sy~l~ . I' 1~ l~k SILVERA RANCN~~ ! - --_-arem+awmnam / _ ~ _ DEVELOPMENT _ an~c ~ ~ ro _ ~ ro . - ~ ~ ~~ouae~N~rFS .~..roEa.~,m~nF a:oaa;a REMEDIAL GRADING PLAN wve.wy.m...m~.m.i...~w.o. wnorc ~riwieor¢vrw ~'rvuo ~~u[x[~woxo S:J•=} wuo¢.cnumurtn FALLG~ACROSSING ~ - un• - - ~ - - _ 5~ .__.u i`~i~ we - .mrxarta sartnrav~r.m~~.~~.n ~ e v Duna ~ t~~ 1. I EXHIBIT A OPEN SPACE OWNERSHIP AND MAINTENANCE RESPONSIBILITIES EXHIBIT 1 BERLOGAR STEVENS & ASSOCIATES ' I ~ ~ ~ 37 a1 )bl I ~ m _ ~ 4~ r ~ 19''! L - i; 4C~; _ _ -m+~ n ' 1 e _ ~ 4 f ti, ~ fa I rug _N_ Q r.v~re ~ J ra w ~ OPEN SPACE OWNERSHIP AND ~ ~ ~ ~ MAWTENANOE RE$PON8181LITIEB EXHIBIT TRACT 7817 -FALCON CROSSING RI~~lAS iam 7w ~ ~ 1 EXHIBIT B LEGAL DESCRIPTIONS OF GRAD BOUNDARY AND MAINTENANCE EASEMENT BERLOGAR STEVENS & ASSOCIATES . 3~ Standard Pacific Corporation City of Dublin County of Alameda Exhibit "B" Legall~escription - ~ GH.AD Parcel 1 ;ip Real property situate in the City of.Dublin, County of Alameda, State o.f California, .described as follows: Being a portion.of the Parcel. described in the deed.recorded on April 14, 2005 to Standard Pacif c Corporation in. Document No. 2005146527, Official'Reeords o.f the ~ County.. of Alameda, State of California, described. as follows: Beginning at the northeaste.?~. comer of said Parcel; thence along the eastern .line of. said ` Parcel, South O1 °04'38"West, 1264.53 feet. to the southern line of said Parcel;. thence South 60°19'01"West, 133.5.2 feet; thence.North 83°40'59"West, 135.30 feet; thence North 64°10'59"West, 528.00 feet; thence ~lorth 87°i0'S9"West, 473.88 feet; thence, ~ South 34°49'01 "West,. 576.18 .feet; thence .North 89°25'5.9"West, 725.1:8 feet to a: non- tai~gent curve to the right having a radial which bears South. 69°08'38" West, a radius of 1066'.00 feet, a delta of 17°39'41"; thence leaving said southern line, northwesterly along said curve an arc length of 328.59 feet; thence North 03°11.'41 "West, 121.68; thence North 33°23'01 "East, 83.52; thence North. ] 3"02'00"West, 227.15 feet to the northwestern line of said parcel; thence along said northwestern line, North 31 °01'01" East, 9,53.44 feet to the northwest corder o.f said Parcel; thence along the northern line of said Parcel, South. 89°20'13"East, 1866.0.4 feet to,the Point of Beginning. Containing 66.4 Acres t ~ ~ f ~,Alv~ SU . Charles Sellman L.S. 518'6 Ut~''~~R~"- ~y~o 0 ~~.2 3"iZ00a No. 5186 . Date ~ Ezp.06-30-09 ~~'9 P~ . TF ~F C A`~F4 ~ J Created on 6/12/2008 4:11 .PM G:\AdniinUolis-03\0310061S~irveyCNew .DeedslGl=aAD A & H.doc ~~r=:. . " ~n ~7 ~ . Pfeiffer Ranch tn.vestors IL 1.nc City of;Dublin County of Alameda Exhibit "B" Legal Description ~ " GHAD Parcel 2 " Real pioperty situate in the City of Dublin; County o:f Alameda; State of California, described as follows: Being a portion of Lot."A3'' as.shown on the snap entitled "Tract 7441" filed:in Book:279 " of Maps at Page 68, Records of the County of Alameda; State of California, described as follows: Beginning at an angle point on the northern line of said Lot, said point.being the southwestern terminus of the course shown as "N34°49'01"E 576.1.8"'; thence, South 44°22'05"West, 50.43 feet to anon-tangent curve to fhe right having a radial which bears South 32°49'52" West, a.radius of. 25.00 feet; a delta of I 1°32'13"; thence, northwesterly along said curve an arc length of 5.03 feet; thence Noith.45°3755"West, 48.12 feet to said northern line; thence along said northei7i line, South 89°25'59"East, 73:60 to the Point of Beginning. Containing .03 Acres t Charles Sellman L. .5186 O t'p'N~ S~!9 =S~~S SE L~.. Ocl-Z3-2oob v~~~' Date J No. 5186 Exp. 06-3009 ~ \Q' N~9TF'OF GAS-\F~~~ Created on 9/23/2008 2:03.PM ~ G:~ldminUobs-03\031006~Survey\New Deeds\GHAD parcel 2.doc ~t! 6 - . . ~i ~ Pfeiffer Ranch. Investors II Inc _ City of.Dublin .County of Alameda Exhibit "B" Legal.Dcscription GRAD Parcel 3 Real property situate in the City of Dublin, County of Alameda, State ofCalifornia, described as follows: Being Lot "A4" as shown on the map.eutitlecl "Tract 7441" filed in Book 279 of Maps at Page 68, Records of the County of Alameda, State of California, described as follows: Containing .0.1 Acres f Charles Sellman L.S. 5186 Date ~t~, v No, 5186 Ezp.06-30-09 N~T~ F~~~er - Ofi CA~-\ - - Created on.9/23/2008 2:45 PM G:~AdmnUobs-031031006..\.Survey\Netiv DecdslGI=IAD parcel. 3,doc pia ~ ~-7 1 1. .1 1 - _ EXHIBIT C PLATS OF GRAD BOUNDARY AND MAINTENANCE EASEMENT 1 BERLOGAR STEVENS & ASSOCIATES » tad R1CH~Y / HUNTER p 58970'13'£ 1866.04' ' H ~ G° ~ ~ bra ' -~r r.~ , , ~r } u° Q l t~'U~r ftlw~yy~ s n ~y . iIy ~ -^+~8'? ° ' . f f r ta~. ate 'x~ 4 .v . "mod ~ ~ ~ 3~~~~1 'y t .y'f`~~ tb t A' dts~ ~ ~ ° k r t'. '3 Q Z, v ~ 9~ } t~~~ fSL 'U~ k S' rfL 14.~' 1w -Yr1{fi yy~ Y4 ~'i{. ~ ~ 1 P ~ '~H 3 P~yn ~k ^ ~s -1 lr ~ y ,a~ ~p Rt~~k' ~ t r G I P Y J ~ ~ ~ O' S/ 5~~~.~~~4" .3ti~'~;k~ a Pin -r~C ~'+,Zi° ~ ~ { S . ~ ~ ~~M € °'i~ ~i~ ~ q ~ 1-5-1 O ~ . a ~k ~ ~ ~ t ~'r > i dm . ' t ~ FT-1 ~ m Y~y '~.~~M1fX ~Yny a'l ¢3 t€~7 ~ ~~3Lm~ i l ~1 1--1 m r~~~ ~ ~ ~ k ~°`,~as~`'~- r s ~t~ ~ W y ~ Sri o Cam] y g ~ ~ ~ ~ °4~ i~r~ "h ~ °y~' 1~ IT~.°+~ '3t(:z ;N ,.Fib' . ' ~ l 1 G7 ~ ~~Ir t~ ~f ~ N . ~ ' { L~~ y~2t~ W fi ~ ~ R.~, ~ 1. 9. d ~ >ti4 ~'~C`n ~A ~t y~P~ 'aJ F~ - ~ s ~ fi ! ~~~~b a A l 5dF CrJ ~ ' ~.7 lrf~" : ' f tip' ~x. 3 t p w p ° '+{yy4 ,kl 'C S ~ :r~ 5 " 7 . ~2`#k2"'J(' ~ A z G",~,°N i~t~~ 11~' 3~ ~3 6 5 d I S~y& ~,~~~,n i ~ t , , r{~-r 3~, : d~~ z yyG 55 ~ y~€jty~a~ ~~u~'~~ z~:~'w"~ ~~~'`,~'Q~ f .~+,~QrC ~~.Y ~ ~ ~ 1~~'~ ,~y.~ ~I'~' " s~,~'~ 3" ` ~ !9 •t~~y`~II~ 4 -sK Y y ~ 1 -y2S,¢~ ~ :,~/~p~y•~~ , Y.. / ~/'S A:ll'.~ N 7 3~' rY.. 7,ii ~ i;~` c {r+{, k,~~ y~ ~ ~ r th ~.K ,irf 3 u t~ r A~ ~ ~ Q E~ ~ ~~~t ~c~'~ ,r~~,£+?~ k"o t: ~ ,s ~~~9~. ~~ry ~gy,~~ y,~y~~~ { ~'~r• ~ y~~! 7..i yXyi a 5 x~.~ 2tgr... ~°~A=, 'it ,~s• r vb'w 1~7t,~ r>l+'te~ °'1~'a,~d1~J:L*~~ ~vs~y~ 5 tr~~. F~~RI ~ ~ ~ t ~I 6 6 „ L~. ,y~y p g A, x ~~'E' ~'14 r ~ ~l~i ~ ~ r ~5 '°S S~I+N~ [~~.J{ .~flC~tvy~~Gti~3~~ jr, 's $..rz ~4 ~ iee"~f~ F~'~ y F~ 5 g1 1 ~ F~S~~a~ -A~.l ~h •q-£~'G ~~'~d•~y~~ F 5~~~~ ~ys fit ' ~~~~7Q~jr `~kY ~f3,s nom' P ~"t`~ $ ~ .~y 7a+ ~~r,7'p T 1 a~ »n s~{""D~ ' ''~a tli y Q~ "~,'~},~,,qa ~ t °:~'~'~;+~fT~ ~ ~ ~ ~ U w m ~ ` . ' A3y'~. ~ Safi ~,s~_?'`~ ~ v ~ ~ Fe " ~ = ~ .t . `N~815' f5$,~~k~725~18 5~~ ~F~N a i ~ $ =M ~ ip ~~w~ ~ v ~ N ~ ~ 7RA C7 7'44 1 r ~ s~aZ ~ o ~ ~ ~ ~~.~I ~ ~ ~ ~ Ov uu ~~~by ~ n ~ 10 $z n O ~u v,t~ ~w r*t ~ ~ W v t" N. ~ _ . 1 UNE TABLE UNE BEARING DISTANCE L1 N34 49'01 E 57.61' . L2 N044756°E 34.Oi' L3 N007T39°W 210.60' - L4 N6078'13"W 52.63' L5 N6134'05°W 47.51' L6 N5934.;36°W 50.00' CURVE TABLE L7 N62~T31 "W 51.44' CURVE RADIUS DELTA LENOTN L8 N6577252"W 52.17 Cf 200.00' 217623° 74.84' L9 N70'46'S3"W 51.50' C2 125 00' 2935 38" 64.56' L 10 N6931'14 "W 95.00' C3 44:00' 54270 29 ° 41.48' L 11 N69275 47"W 49.38' C4 121.00' 4273'28° 89,1 T L 12 N&4 3323"W 47.61 ' C5 21 i.00' 2074'45° 75.1 T U3 N5927T40"W 46.83' C6 104.00' 264128° 48.45' L14 N5735'14°W 50.01' C7 f61.00' 144900° 41.63' L 15 N5575'40"W 47.55' C8 304.00' 2774 06 ° 145.39' L16 N5817902"W 71.54' C9 111.00' 19723° .38.66' L 17 N762?5'13°W 7.82' C10 59.00' 15'42'21 " 16.1 T L 18 SO4279 06"W 28.49' Cll 100.00' S7T34 ° 9.24' L19 S33'44'44"W 65.05' C12 29.00' 187711° 9.34' L20 54143'13°W 14.49' . C13 100.00' S7T11 ° 9.23' L21 52936'12"W 55.14' L22 531 X146 °W 28.98' L23 51579'25"W 14.51' L24 S203659"W 12.63' L25 568^51'33"W 89.14' L26 S74278'44"W . 25.93' L27 N037141"W 104.23' L28 N3373'01 E 83 52' L29 N1327200"W 227.15' SHEET 2 OF 2 ' GnJob2003\031006\MAPPING~PLATS~UND.tlvg 7/31ROOR &57N6 Ph POT EXHIBIT C _ PLAT TO ACCOMPANY LEGAL DESCRIPTION 1 ~ FOR RUGGERI-JENSEN-AZAR ~ . ENGINEERS • PLANNERS • SURVEYORS ' ~ 4690 CHABOT DRIVE, SUITE 200 PLEA9ANTON, CA 9458H ' GHAD PHONE: (925) 22]-9100 FAX: (925) 227-9J00 SCALE: GATE: JOB NO.:' ~ CfPY OF DUB[1li. ALAl~DA WIIN'PY, CAI,II+ORNIA N/A 7-31-08 031006 l ~ X15 167 -N- P.0.6. S8770'59°£ 17.69' 0 100 200 - Q { IN .FEET } p4' 1 inch = 100 ii~ ~ ~ MAINTENANCE EASEMENT ~1U ~~~'Q ~ REQUIRED FROM 1RACT 7540 Q,~V 1~ ~p ~ - , ~ AREA = 9,937 SQ. FT. 4~(JZV .;,~6 4.44 ' Gj ~p.? ~ ~ ~ LO 7 A 3 ' - 7 R A C 7 7 4 4 i ' i _ N44 22'05"E . , 50.43' - S4422'05"W S32 49 52 W R 42.19 LEGEND - ; N0845'43°wR P.O.B. POINT OF BEGINNING R=25.00' S4, FT. SQUARE FEET d=4135'35" L=18.15' EXHIBI'~ C ~ S'Voh2R03\031006\RAPPING\PI.ATSV7RINTENANCE ESMTArg 7/31/2008, &5b12 AH VRT i E;. PLAT TO ACCOMPANY LEGAL DESCRIPTION _ 1 1~'' FOR RUGGERI-JENSEN-AZAR ENGINEERS ¦ PLANNERS • SURVEYORS MAINTENANCE EASEMENT 469° ~«~°T OR"~. 200 PLEASANTON, CA 94588 PHONE: (82S) 227-9100_ FAX: {g25) 227-9300 SCALE: .DATE: JOB NO.: CITY OF DUBLIN, AWd[;DA COUNTY, C~L1FnRNIA 1 "=100' 7-31-08 031006 1: ~ 1~ 1- EXHIBIT D ~ _ .DEED RESTRICTION EXHIBIT a~ . o BERLOGAR STEVENS & ASSOCIATES L1 ~ \ HOLLER PROPERTY ~ \ ~ ~ f I l I ~ ,f v~~f . .FPAPoAN FTtIA1CF3iERT v„ \ ~;f /f~/ r~~ j' ~ /f nit "r~'/~j / . i~j ~ ~~rr. DEED RESTRICTED ~ t ,f ~ f~!~ " ~ / / r'.' AREA j/ fi"~'~ ~j /%j r~ ~ii''•/ ~//.~1•i•~ T' rw- -<V 1, f,' ,;/j f~`i'~~ l :i' r f'~~ i'`~/ / ~ 3 /j DEE/RESTRICTED AREA ~ ~~r / ~r' ~ ~ iii jf~~/~ j:F// `,r~ . • , i, / / ~ . . GRADING ~ r" t ii % ` f~ EASEMENT ~ ~ ~ ~ ~ " r; PER'Ar:fdEtdT D!_V'ELOP'V'vN i j/ ~ ~uuRmS;wcE ~mAO , ` I i r ~ l,r`,,F''„~,' 5 ~ ~ g~ / ~ ~ ag ~ . l ~ StLYCRA RANCH ~ ~ ` GRAPFIIC SCALE ~ o zoo Goo Iv_ DEVELOPMENT AREA EXHIBIT ~ M ~ FALCON CROSSING i min .zoo tt ~ o~.e+. aAearonraA PATE: FE6Rt1ARY 55, 21777 .108 40. OJ5008 _I ~ . l 1 ~1 1~ APPENDIX A DETENTION/WATERAUALITY BASIN OPERATIONS AND MAINTENANCE MANUAL Prepared By: Ruggeri-Jensen-Azar and Associates - _ ' C BERLOGAR STEVENS & ASSOCIATES -0: GRAD Management DetentionlUllater Quality Basin Operations and Maintenance Manual Tract 7617 Fallon Crossin 9 Dublin, Alameda County, California Prepared by: 1\ 11 RUGGER[-JENSEN•QZAR [NG~N(ENS PIANNI NS • SUN VE YON6 4690 Chabot Drive, Suite 200 ~ ~ _ Pleasanton, CA 94588 (925) 227-9100 •''F\E~ • P R OFFS II~t\ INI~ S'O / ~`I ~ I ~ 'r1~1 - I ( ~ 1 ~ ~ ` ~ ; ~ - rU ~ 3 ~ ; Z Mark Andrew Falgoui;' i ' No. 0566 fi; ~'•s~•, , . JP~ . M ..-Q February 15, 2011 WATER - Updated April 13, 2011 r .5"0 ~ FOREWORD The purpose of this document is to provide a manual for the management and maintenance of the Fallon Crossing Detention/WaterQuallty Basin. The Fallon Crossing project is located at the intersection of Tassajara Road and Fallon Road in the City of Dublin. The two Water Quality Ponds are in the western portion of the site and treat runoff from the entire site. Stormwater runoff from the northern and eastern portion of the development is collected. and treated by filtration though 18 inches of sandy loam in the Upper Water Quality Pond before outletting to the. detention basin through a storm drain. The southern and western portion of the site drains to the Lower Water Quality Pond where it is also filtered through 18 inches of sandy loam, then outletted to the detention basin: The water quality ponds are located along Tassajara Creek and are within an area which has been recognized as habitat for both the federally protected California red-legged frog and California tiger t salamander. All maintenance activities are to be performed in a manner which does not result in the "take" or harm to either of these species. Maintenance activities will be performed in a manner which avoids, to the maximum extent practicable, impacts to these species. Maintenance of the Water Quality Ponds and Detention Basin will initially be performed by Standard Pacific Homes and will remain their responsibility until the Geologic Hazard Abatement District (GRAD) assumes the maintenance duties. The Basin Operations and Maintenance Manual provides policies, responsibilities, authorities; and procedural guidance for management and maintenance of the Water Quality and.Detention Basins. The GRAD Manager will provide to regulatory agencies. requesting them, annual reports on maintenance activities and will comply with ail applicable State of California and federal laws and requirements governing the maintenance activities. Maintenance activities may generally be summarized as follows: GRAD Mana ement Task O en S ace Maintenance 1 DetentionNVater Quali Basin O eration and Maintenance Erosion Re airs Reve etation Sediment Removal from Ponds Access Road Maintenance ' Basin Operations and Maintenance The basin maintenance responsibilities include monitoring and maintenance so that Detention and Water Quality Basins function within the intended purpose. The Basin Operations and Maintenance Manual may be modified from time to time at the discretion of the GRAD Manager, subject to applicable laws and rules. i Page 1 l 6 1 . BASIN. OPERATIONS AND MAINTENANCE MAN UAL Procedures and Guidance for Implementation of Policies . , ~ r6 ~ _ ~ ~ OVERVIEW - The procedures in the following chapters are applicable to the identified organizational elements. Chapter 1 presents Procedures for General Basin Maintenance. Chapter 2 presents procedures for Maintenance of Basin Water Height and Facilities. Refinement of the O&M Program should be expected based on the recommendation and agreement of the GRAD Manager, GRAD, the Regional Water Quality Control Board and other applicable public agencies. General Maintenance and Monitoring Sediment accumulation measurements will occur quarterly, with the exception of monitoring during the wet season, the rate of sedimentation in the Detention/Water Quality Basins and identify the need for removal. Some sedimentation is expected within the basin; removal is planned only to the extent necessary to maintain proper basin function and performed in a manner which reduces impacts to wildlife. The Detention/Water Quality Basins will be monitored to assure that they are self-draining with a residence time that does not significantly exceed the design criteria. Quarterly monitoring during January, April, July and October is planned with additional monitoring within two working days after significant storm events, i.e., one inch of rainfall in a 12-hour period. The DetentionNllaterQuglity Basins . should drain within five days. All inlet structures will be monitored to ensure proper function. Remedial procedures for the inlets should be taken immediately if the water level overtops an emergency overflow structure. Overtopping of the basin, or a drain Time in excess of five days would be indicative of silt built- up or an inoperable basin outlet structure that should be maintained/repaired to prepare for subsequent storm events. As the Detention/Water Quality Basins fill, the rate of discharge from the basin should increase with increased water depth. The basin outlet structure should be monitored for proper function during significant storm events. Vegetation that does not preclude the proposed function of the Detention/Waier Quality Basins should be allowed on the floor of the basins to aid in the trapping of sediment. Herbicides will not be used in the Fallon Crossing Detention/VVater Quality Basins unless absolutely necessary. Pesticide use wilt be limited and only used if absolutely necessary for mosquito control, with input from Alameda County Mosquito Abatement Di§trict, and in conformance with all applicable rules and regulations. All herbicides/pesticides used in the management of the Fallon Crossing Detention/INater Quality Basins will be selected from a California Department of Fish and Game (CDFG) approved list. Policy Implementation 1. GRAD Manager maintenance and monitoring procedures will include: • Inspection and repair of inlet and outlet structures. • Stabilization and/or repair of eroded areas or failures of the embankment surrounding the Detention/Water Quality Basins. . .Pruning/cutting of the vegetation within and surrounding the Detention/UVater Qualify Basins. • Maintenance of all access roadways. • Monitoring any perimeter fencing for public safety, if present. Measurement of DetentionNVater Quality Basin water levels. • Mosquito abatement. Page 1 - . 5.~ I b ~ Technicians retained by the GRAD Manager will carry out the quarterly site inspections and utilize the Monitoring Report Form included at the back of this manual. The GHAD Manager will ultimate) be Y responsible for determining the need for more frequent monitoring. Personnel and subcontractors involved in Detention/ Water Quality Basin management will be trained on reading the staff gage, proper running/cutting techniques, and inspection measures by the GHAD Manager. A sample Inspection Report is included at the end of this manual. An annual review shall be made by the GHAD Manager to assess the effectiveness of the maintenance program and to make recommendations as to which measures should be undertaken in the next fiscal year. The GRAD Manager should submit an annual Program Review report to the GRAD verifying that O&M Program performance goals are being attained. Any appropriate site-specific study or request for remedial repair shall be determined at that time. Consultants, if necessary, wiH be retained to undertake the needed studies/repairs. Emergency Response and Scheduled Remedial Repair Emergency response and scheduled repair expenditures are to be prioritized at the discretion of the CHAD Manager, based upon available funds and the approved operating budget. When available funds are not sufficient to undertake all of the identified remedial and preventive stabilization measures, the expenditures ale to be prioritized as follows in descending order or priority: A. Prevention, mitigation, abatement or control of hazards that have either damaged or pose a significant threat of damage to the Detention/V1later Quality Basin levees or overflow structures. B. Prevention, mitigation, abatement or control of hazards which have either damaged or pose a significant threat of damage to ancillary struc#ures, including but not limited to the inlet and outlet pipes. C. Prevention, mitigation, abatement or control of geologic hazards which have either damaged or pose a significant threat of damage to the Detention/Water Quality Basins. The techniques which may be employed by the GRAD Manager to prevent, mitigate, abate, or control hazards include, but are not limited to, the following: 9. Repair, maintenance or replacement of inlet or outlet control valves structures. 2. Stabilization (either partial or total) of levee embankments by removal and replacement with compacted, drained fill. 3. Construction of erosion control measures. Whenever, feasible, bioengineering techniques will be utilized and are preferred over hard armor. 4. Placement of subsurface drainage devices {e.g., underdrains, or horizontal drilled drairi~). S. Slope correction (e.g.,.gradient change, slope trimming or contouring). 6. Construction of additional surface ditches, sediment traps, or backfill of eroded. channels. Page 2 . 5~ CHAPTER 1 PROCEDURES FOR GENERAL. BASIN MAINTENANCE II-1-1 Procedures. The GRAD Manager provides technical guidance for the O&M Program process and promotes management practices with. standards and guidelines. The GRAD Manager is responsible for providing effective and efficient use of staff and subcontractors. Procedures for the following maintenance items are presented in the following sections of this chapter: • Inlet and outlet structures • Maintenance of access roads • DetentionlWater Quality Basin Embankments • Fencing repair • Desilting and clearing of basin • Mosquito abatement • Vegetation control 11-1-2 Inlet and Outlet Structures. Maintenance of inlet and outlet structures will involve the clearing of t debris and repair of the trash rack structure, as required to allow passage of storm flows. 'The outlet structure iri the Upper Water Quality Pond is a 48-inch-diameter riser pipe with 2-inch- diameter holes as shown on the Fallon Crossing Stiorm Water Treatment Plan. The outlet structure in the Detention Basin is also a 48-inch-diameter riser pipe with 3-inch and 4-inch diameter holes. The inlet and outlet structures should be visually inspected during or immediately after large storm events to avoid prolonged blockage. The holes on the outlet structure should be clear of debris and observed during each maintenance check. Any observed damage or apparent inoperability of the structures. will be reported to the GRAD Manager immediately. In the event that the primary DetentionNVaterQuatity Basin outlet is rendered inoperable during a major storm event, the emergency overflow structure should be allowed to operate as designed to pass the storm flows. Emergency maintenance of the inoperable outlet structure should be undertaken at such time and with the equipment that the GRAD Manager deems appropriate. II-1-3 Maintenance of Access Road. Maintenance of access roads, as shown on the attached improvement plans, will involve_repair of excessive bumps, cracks and depressions such that maintenance vehicles can easily navigate the roads. The roadways will be inspected on a quarterly basis and repaired as needed. Any damage to or failures of the embankments near the road will be reported to the GHAD .Manager immediately. Pavement repairs should be performed in accordance with the general repair practices of the City of Dublin's Public Works/Maintenance Department. I1-1-4 DetentionNVater Quality Basin Embankments. Maintenance of the Detention/Water Qualify Basin embankments shall involve visual inspection of the Detention/WaterQuatity Basin embankments and slopes. Observations should occur on a quarterly basis in conjunction with the inlet and outlet structure inspections. The betention/WaterQuatity Basin slopes should be inspected for obvious signs of vertical and/or horizontal displacements. Embankment sides should be free of erosion, rills, slumps or landslides. Any observed slope displacement should be reported to the GRAD Manager immediately. II-1-5 Fencing Repair. Fencing installation on the. eastern side of the DetentionNUaterQuatity Basin will occur with the development of Fallon Crossing. Maintenance of fencing involves repair of all gaps, tears, sags and breaks such that public safety is provided. Alf perimeter fencing will be monitored quarterly and maintained in good condition without breaks or damage. Page 1 55 ~ b ~ II-1-6 Desilting and Ciearing of Basin. DetentionlWatec Quality Basin floors should be regularly cleared of excess sediment and excess ve etation to enable ro er flow characteristics. Failure to d g p p o so - can create flood hazards; however, a vegetative growth of less than 5 feet in height contributes to sediment trapping within the basin. Although vegetative growth, is generally encouraged, excess vegetation (defined. as shrub and tree growth in excess of 5.feet in height} should be removed from the basin floor by pruning. Aggressive, non-native species such as bamboo may need total removal with shovels. The floor of the Detention/Water Quality Basin should be moni#ored by GHAD Manager on a quarterly basis. !f sediment in excess of 18 inches or 10 percent of the storage capacity, whichever is greater, has accumulated above design grades, the sediment should be removed. Vegetation in excess of 5 feet in height and grass exceeding 4-inches in height will require removal. Sediment accumulation will be measured with installed staff gages. Vegetation accumulation will be measured with a tape measure in at least four locations within the basin floor. Vegetation removal would be restricted to the period of August 1 #hrough September 30. Prior to sediment removal or vegetation pruning, the procedure should be reviewed and authorized by the GRAD Manager. If sediment in excess of 18 inches or 10 percent of the storage capacity, whichever is greater, has accumulated above design grades during a quarterly sediment monitoring event, sediment removal shall be undertaken before the next wet season. Sediment removal shall be restricted to the period of August 1 through September 30. Sediment removal for routine main#enance will be with hand labor, lawn mowers and wheelbarrows as much as possible within the pond and mechanized equipment working from the maintenance road for heavier work to maintain compliance with regulatory agency requirements. Emergency repairs may require use of larger equipment including, but not limited to, excavators and dump trucks. Sediment will be removed in small sections, with as little disturbance to existing vegetation as possible. No heavy equipment will be used within the Detention/Vllater Quality Basin without permission from the GHAD Manager. Prior to any mechanized removal of silt or vegetation, apre-construction survey shall be performed by a biologist having direct knowledge of local flora and fauna to remove wildlife species and assure that all speaal-status species including but not limited to the California red- legged frog {CRLF) are not impacted by the maintenance activity. Standing water should not remain in the Water Quality Ponds for more fhan five days. If water is visible in the Water Quality Ponds #or longer periods with no evidence of sediment on the surface, _ the sandy loam should be removed and replaced with a soil mixture meeting the Alameda Countywide Clean Water Program soil specifications included in appendix G of the Stormwater Management Pfan. The sediment shall be off-hauled to a landfill or other suitable disposal site with no biological restraints. a. Vegetation maintenance will be accomplished by hand pruning, unless aggressive, non-native species become a problem, in which case other me#hods of removal can be initiated at the discretion of the GHAD Manager. Pruning will only involve the cutting and removing of vegetation.above the ground, e.g., mowing, rotary cutting, and chain-sawing, where the activity neither substantially disturbs the root system nor involves mechanized pushing, dragging, ar other similar activities. No heavy equipment will be used within the Detention/Water Quality Basins for routine maintenance. Pruning debris will be removed from the basin in burlap or canvas bundles and trucked to an authorized dumpsite reviewed and approved by the GHAD Manager. Vegetation removed or destroyed during maintenance will be allowed to re-establish naturally without replanting. ` f ~ - Page 2 . I'~ ' . b. The sides of the Detention/VVaterQualhy Basins are to be monitored on a quarterly basis. Plantings and other vegetation are to be inspected for health and vigor. All embankmen# sides should be free of erosion, rills, slumps or landslides. Embankment slope irregularities should be reported to the GHAD Manager in the monitoring report. Irrigation systems, if present, are to be monitored for proper function. Leaking or malfunctioning irrigation systems will be repaired within two days of inspection. II-1-7 Mosquito Abatement. As part of DetentionNVater Quality Basin maintenance, the GHAD Manager will coordinate with Alameda County Mosquito Abatement District to monitor for the potential presence of mosquito vectors as necessary. Should mosquito populations be detected in the basin, the GHAD Manager will coordinate with Alameda County Mosquito Abatement District to employ techniques to control mosquito production that are acceptable to the applicable regulatory agencies: 1 _ i ~ ~ . 1 . Page 3 . 51 ~6 7 CHAPER 2 MAINTENANCE OF BASIN FACIIITlES . II-2-1 Procedures. Procedures for the following maintenance items are outlined in the subsequent .chapter sections. • Monitoring stormwater height in the Detention/Water Quality Basin. • Cleaning of all debris racks. • Maintenance of basin outflow structures. • Repair tasks. • Embankment stabilization. II-2-2 Monitoring stormwater Height & Cleaning Debris Racks a. The DetentionlWater Quality Basin inlets will be inspected quarterly and maintained in good condition without obstructions. It is of utmost importance that the inlet functions properly, substantially free of debris or other obstructions. Special attention should be given to whether erosion is occurring around the edges of the inlet structures as well as at or immediately downstream from the discharge point into the basin. Litter and obstruction removal should be undertaken during routine maintenance visits. b. The DetentionNllater Quality Basin outlets and the emergency overflow structure will be inspected quarterly and after all storm events generating more than 1.0 inch of rainfall in any 12-hour period. The overflow structure should be additionally inspected after any event that causes flow over the overflow structure. Any debris accumulating on trash racks is to be removed. All trash racks and the emergency overflow structure will be maintained and repaired as necessary to allow proper function. c. The basin should drain wi#hin 72 hours of significant precipitation. The water level should not be significantly higher than the maximum elevation of the outlet control structure, or less than one feet below the level of the emergency overflow structure. 11-2-3 Maintenance Discharges. Water removed from the DetentionlWater Quality Basin facilities for maintenance will be directly released into the 24-inch storm drains. Maintenance discharges are limited to those approved by the GHAD Manager. Before approving the removal of water or sediment from the Detention/_Water Quality Basins, the GHAD Manager wilt consider the following factors: • The size and age of the facility. • The construe#ion quality of the facility. . • The maintenance history. Whether the facility has been functioning at capacity and for how long. - Present vs. original stormwater control needs: • Whether sensitive/unique functions and values may be adversely affected. II-2-4 Repair Tasks. In determining the need for repairs to the DetentionlWater Quality Basin's embankments, overflow structures, inlets or outlets, the GRAD Manager will consider• the following factors: • Any original mitigation required. • The current environmental setting. • Any adverse effects of the repair project including those to wildlife species utilizing the basin. Page 4 r.~ 1. ~ ~ 1~ The GRAD Manager will immediately undertake maintenance for completion of any basin repairs, .provided that the GRAD Manager establisheda schedule for the identification, approval; development, construction and completion of the required repair in accordance with City policy. {I-2-5 Embankment Stabilization. The embankment of the basins should be maintained in a stable condition and are designed to remain stable throughout the life of the project; however; if areas of weakness are noted during the monitoring process, stabilization should be undertaken in a timely fashion. The following guidelines are applied to all grading accomplished for non-emergency construction of stabilization measures: - - • Both an Engineering Geologist and Civil Engineer should be consulted on significant embankment repairs. • Soil removal/placement should be limited to the. minimum needed for erosion/flood protection. No material should be placed in any special aquatic site, including wetlands, without proper 1 resource agency permitting. • Preference will be given to soft-armor and bioengineering techniques whenever possible. • No material should be placed in any location, or in any manner, so as to impair surface water flow into or out of.any wetland area without proper resource agency permitting.. No.material should be placed within a surrounding open space area without the consent of the GHAD. • No material should be placed in a manner that will be eroded by normal or expected high flows. _ _ . _ r. Page 5 • MONITORING REPORT Fallon Crossing ' Alameda County, California Fallon .Crossing DetentionlWater Quality Basin Operations and Maintenance Site Monitoring and Maintenance Report f=orm {to be completed quarterly In January, April, July and October and as necessary during heavy rainfall, and submitted In the semi-annual sediment accumutatfon and hydrologic function reports in February and August, and in the Stormwater Maintenance and Monitoring Report by December 31 of each year) . Inspector: Date: Weather Conditions: Days since last rainfall: Dry season? Wet season? Basin Water Level: ~ Sediment Accumulated since Last Monitoring Event: MONITORED YES NO N/A COMMENTS! SUGGESTED MAINTENANCE CONTROL 1, Are inlet and outlet s#ructures functioning properly, allowing the • basin to drain and are they in satisfactory condition? 2. Are all holes on the outlet structure clear of debris and allowed to function ro eri ? 3. Are access roads in . satisfacto condition? 4. Is all perimeter fencing (if present) in good condition without breaks, a s or dama e? 5. Have the debris racks been cleaned and are - the in ood condition? 6 Are embankments surrounding the basin in good condition without rills or failure? 7. is the vegetation less - than 5 feet in hei ht? 8. Are embankment slopes . protected with mulch or ve etation? 9. Has water removal been undertaken in the last 3 months? If so, describe rocedure? ~o ~ ~ 6i MONITORED YES NO NIA COMMENTS/ SUGGESTED MAINTENANCE ' CONTROL 10. Has sediment removal been undertaken In the last 3 months? 11. Do any basin devices require maintenance to provide more effective function? 12. Are there any signs of leaking irrigation s terns? _ 13. Are there any signs of vandalism?. 14. Are mosquitoes evident? - 15. Has mosquito abatement been undertaken since the last monitoring event? ' 16. Are there remedial/repair tasks that should be undertaken in the near future? 17. Is there evidence or information received in the last 3 months to indicate a lengthy drain time? "No" answers to Items 1-9 or "Yes" answers to Items 10-17 require a correc#ive action. f 16~ - FALCON CROSSING DETENTION/WATER QUALITY BASIN OPERATIONS AND MAINTENANCE. SITE MONITORING AND MAINTENANCE" REPORT FORM {CONTINUED) CORRECTIVE ACTIONS UNDERTAKEN {If none required, enter date and "none") - DATE ACTION REQUIRED CORRECTIVE ACTION TAKEN ~ a 167 1 1. _ DATE ACTION REQUIRED CORRECTIVE ACT10N TAKEN 1 - ~~3 APPEN®IX . RUGGERI-JENSEN-AZAR & ASSt?CIATES Fallon Crossing Stormwater Treatment Plan Alameda County, California . . . ' 67 Stormwater Management Plan Fallon Crossing -Tract 7617 Dublin, Alameda County, California ' Prepared for: Standard Pacific Homes Pre ared b P Y * ~ 1~~ 1 ® RUGGERI-JENSEIV-AZAR ENGINEERS PLANNERS SURVEYORS 1 Project No. 031006Il' September 19, 2008 Updated July 30, 2009 Updated April 13, 2011 l ' 65 .~67 . Table of Contents Introduction 1 Purpose and Scope 1 Water Quality 2 Water Quantity 3 . . Site Location and Description 3 Soils Conditions 3 Climate 4 Ground Water and Surface Water 4 . Project Description....: 4 Drainage Management Areas 5 Detention Design Guidelines 5 Additional Source Controls 5 Maintenance , 5. References.... G Appendix A Vicinity Map ....................................................................................................................:..B Storm Water Treatment Plan . C Water Quality Sizing Calculations .........:...............................................:............................D Pond Volume Calculations . E BAHM Report F Alameda Countywide Clean Water Program Soil Specifications...................... G i Introduction The Fallon Crossing Residential project (Project) is a planned development in the City of Dublin, Alameda County, California. The stormwater runoff generated,by the Project site is subject to Provision C.3 of the NPDES permit issued to the local municipality by the California Regional Water Quality Control Boac•d (RWQCB) for the San Francisco Bay Region. The regulations require treatment of the post construction runoff from new developments and significant redevelopments before the runoff is discharged to the municipal stom? drains to the Maximum Extent Practicable {MEP). In addition, many projects must also control the rates and durations of runoff flows to match pre- development levels for a particulaa• range of storm events. RWQCB staff monitors each municipality's implementation of permit requirements. Each municipality must report on its development review process, number and type of projects reviewed and what Integrated Management Practices (IMP) were utilized in projects. Development and redevelopment activities can degrade water quality during constructian with erosion and sedimentation as well discharge of other pollutants. Since 1999, a . Storm Water Pollution Prevention Plan (SWPPP) has been a standard part of grading plans to be used to winterize jobs where the hardscape and landscaping has not been completed prior to the rainy season. In addition to these short term source pollutants, long term pollutant sources can degrade the water quality being discharged to receiving streams; lakes, estuaries and bays. While stormwater runoff is a natural part of the hydrologic process, urbanization and agricultural land uses have altered the natural drainage patterns and added pollutants to receiving waters. Project applicants are required to incorporate IMPS into the site to offset the negative impacts of urbanization. This plan addresses both water quality and flow control measures at the planning level of detail to show compliance with the post-construction,. long term requirements of Provision C.3. A SWPPP will be prepared as a separate document to control short term, construction related discharge pollutants as required by the California State Water Resources .Control Board Order No. 99-08-DWQ. Purpose-and Scope The puipase and scope of this plan is: l . Determine the existing hydrologic, topographic, soils, and drainage features of the site. 2. Identify site constraints and opportunities for selection of heatment and flow control facilities. 3. Utilize these features to design water quality treatment facilities for removal of pollutants. . 4. Utilize existing site features described above and proposed site features to design . hydrograph modification facilities, if needed, using the Bay Area Hydrograph Model {BAHM): 1 A. Acheclczai G:~AdminVoln•07W7fOD4~Stomrva~crManagemrnf Pkadoc ~7 ~ 67 5. Document design decisions within this report to quantify the benefits achieved by the site design. This stormwater Management Plan (SMP) has been developed using guidelines provided by the Alameda Countywide Clean Water Program (ACCCWP) C.3 stormwater Technical Guidance, the California stormwater Quality Association (CASQA) stormwater Best Management Practice Handbook, the Bay Area Stoi-mwater Management Agencies Association (BASMAA) Using Site Design Techniques to Meet Development Standards for stormwater Quality and past experience in the design, of stormwater quality facilities. Water QualitX Impervious surfaces in developed areas such as roofs, ibads, parking lots and sidewalks prevent stormwater from infiltrating into the soil. Most of the rainfall remains on the surface which is designed to drain as quickly and efficiently as possible. The surface .flow washes debris, dirt, oil and other vehicle fluids, chemicals and other pollutants into the storm drain system .which eventually outlets into receiving waters such as streams, t7vers or bays. Approximately 80% of annual rainfall occurs in more frequent, low intensity sto~~nns that produce less-runoff. The goal of the SMP is to remove pollutants from the stormwater { runoff during these low intensity storm events while still providing flood protection for the infrequent high intensity events. CASQA lists the following pollutants of concern and their impacts on water quality in their 2003 handbook; • Sediment -nutrient transport and interferes with aquatic life • Nutrients - excessive or accelerated growth of algae • Bacteria and Viruses -health concerns for humans at recreational facilities • -Oil and Grease -toxic to aquatic organisms at low concentrations • Metals -toxic to aquatic organisms, bioaccumulation and drinking water contamination • Organics -synthetic organic compounds are environmentally harmful to water quality • Pesticides -environmental, wildlife and human health concerns through bioaccumulation • :Gross Pollutants -includes trash, debris and floatables that creates an eyesore in waterways • Vector Production -mosquitoes, flies and ro_ dents are attracted to areas of standing water and can. spread disease 2 • A. Acheckzai ' G:V.dminVobo-O?WJ1006\Siatmvatcr Matmgcmem Plan.doe ' . _ 167 Water Quantity Hydrograph modification is the change in timing and volume of stozmwater runoff when a site is developed. In August 2006, Provision C.3.f in the stormwater National Pollutant Discharge Elimination System (NPDES) permit requires municipalities to manage increases in peak runoff flow and volume from all projects that create or replace an acre or more of impervious area (Group 1 Project) where the increase in flow or valume is likely to cause increased erosion in creek beds and banks, generate silt pollution or otherwise impact beneficial uses of water bodies. Larger volumes and faster flaw rates in unprotected creeks. or channels increase erosion. As the channel enlarges due to erosion, damage to habitat, water quality and.pzoperty occuzs. TraditSonal detention designs have not adequately addressed this problem in the past due to the fact that relatively low flows can cause erosive damage. For this reason, ACCWP requires continuous simulation using record rainfall data to evaluate Hydrograph Modification for the storm event range of 10% of the 2 year storm to the 10 year storm. ACCWP has parrticipated, along with San Mateo County, Santa Clara County and Clear Creek Solutions, Inc. in developing a computer model for this purpose. The Bay Area Hydrograph Madel.(BAHM) is the result of this collaboration and is used in this plan to evaluate Hydrograph Modification for the site. Projects are subject to Provision C.3.f unless they can show that the project will not cause erosion or other significant effects to beneficial uses in~the receiving waters. Site Location and Description The Project site is a 67~ acre undeveloped parcel located at the intersection of Tassajara Road and Fallon Road in -the City of Dublin as shown on the vicinity map (Figure 1). The Project is situated on a city black that does not yet have fully developed streets. Bordering on the north is an undeveloped parcel owned by Charles Richey and Charles Hunter. The westezn boundary is Tassajara Road, which connects Alameda County and Contra Costa County. To the south and east borders Silvery Ranch, a recently developed residential development. Solis Conditions Based on the design level geotechnical investigation report by Berlogar Geotechnical Consultants, zesidual soils, colluvial deposits, and alluvial deposits were encountered in . boring logs performed: The residual soils encountered consisted of dark gray and dark gray-brown silty clay (CL-CH). colluvial deposits were also found to consist of dark gray to dark gray-brown to dark brown silty clay (CH). Alluvial deposits were located within and adjacent to Tassajara Creek. The.alluvial soils consisted of stiff to very stifl'sandy clay and silty clay (CL-CH), medium stiff to stiff clayey silt (ML), medium dense sandy silt (ML), clayed sand (SC) and silty sand (SM). 3 A. Acheckzai . G:1AdminVobs•03W3100b~5tornmatta Managcn>cm Plm.doc~ ~ . V 1 6 Climate Dublin has a climate characterized by wet winters and dry summers receiving a mean annual precipitation of 16 inches (ACCWP, Attachement-6). The typical wet season is from October to April with occasional, uncharacteristic rainfall during the other months. Ground Water and Surface Water Groundwater conditions at the site are expected to vary significantly depending on weather conditions during the time of year, water level in the creek, and irrigation practices. It is not anticipated that groundwater will interfere with stotmwater facilities on this site. Surface runoffbegins when .the soils reach their saturation level and additional rainfall - begins overland flow. The surface water begins as overland flow down the hillside - eventually makes its way to Tassajara Creek. Project Descri t~ - The Project is planned to be composed of 106 single family homes. The development consists of 3 private driveways, 3 cul-de-sacs, and one street which runs through the entire site. A 3f acre trail/landscaping area is-.planned to be centrally located and landscaping areas are planned to maximize the green areas of the site. 100% of storm water runoff will be treated in the proposed Upper and Lower Water Quality Ponds which will have 18" of sandy loam meeting the ACCWP soil specifications (Appendix G) on the bottom surface to filter stormwater prior to discharge to a detention basin designed using BAHM to meet the hydt•omodification standard. The detention basin discharges into the Tassajara Creek through a storm drain pipe and energy dissipater. - The property fronts on existing Tassajara Road which is cun~ently not treated for stonnwater quality. The project will construct curb, gutter and sidewalk on the existing road and replace existing pavement with the ultimate road section. The portion of the existing street that drains toward the new curb, gutter and sidewalk will be treated in two 6 feet by 10 feet Filterra units. The total area contributing to these Filterra units is 0.74 acres (Areas 4 and S in the table below). The number and size of the Filten•a units has been designed to treat double the contributing area. - - . 4 A. Acheckzai G:1AdminUoln-OJlOJ 100GlStumavala' Mae~gemcnt Pt~a.doc 1 . ~ 1- Draina eg Management Areas For the purpose of this report, the project has been divided into Drainage Management Areas (DMA) as shown in Figure 2. The table below describes the treatment method , used for each DMA. Area Impervious Required Volume ID SurfACe Arca (SF) BMP Used Volume Provided Treated Ac-ft Ac-ft Area 1 Roof/Paving/SWK/DWY 186,250 U er Water Qualit Pond* 0.18 0.25 Area 2 Roof/Pavin SWK/DWY 22G,347 Lowe"r Water ualit Pond* 0.2G 0.30 Area 3 O en S ace 0 Seif Treatin - - Area 4 PavinP/SWK offsite 23,565 Filtration Unit - - Area 5 Pavin SWK offsite 8,837 Filtration Unit - - *Water quality pond sized using 80% capture method described in. Alameda Countywide Clean Water Program {see appendix) Detention Design Guidelines Flow control for this site is planned to be addressed prior to connection to the existing City storm drain system. The BAHM model described earlier in this report was used to determine the amount of storage required and the outlet structure needed to meet the HMP standard (see appendix}. Additional Source Controls - In addition to the water quality pond, education is an important factor to water quality. Education includes printed material available from ACCWP that should be provided to all buyers and tenants as they move in. The printed materials have information regarding 1 the damaging effects of spilled oil, car washing, paint products and many more common sources of pollution from developments and how to minimize or eliminate them. In addition to this, stenciling "NO DUMPING, DRAINS TO CREEK" on alI storm water inlets is another way of informing the public. The use of drought tolerant planting will reduce irrigation requirements thereby reducing the potential for polluted runoff. Maintenance - . Maintenance of the ponds will be the responsibility of the owner until it is delegated to the Geological Hazard Abatement District (GRAD). The focus of the maintenance is to keep the ponds in the condition to provide the services required to meet water quality and flow control standards. Primary maintenance of detention basins. and water quality ponds should include managing vegetation annually during the summer, trimming vegetation at the beginning and end of the wet season and inspecting on a month to month basis to prevent establishment of woody vegetation and for aesthetic.and mosquito control reasons. ,The 1 5 A. Acheckzai _ o:VtdntinUolx•OJ1011000\Storntwatcr Mmagemcnt hlan.doc . ~ ~ ~ 7r .1~ . ~ 7 basins and ponds should be regraded every ten years or when the accumulated sediment vaIume exceeds ten percent of the basin volume. A separate and more detailed Operations and Maintenance has been prepared for the ponds. The Filtecra units will be maintained by Filterra for the first year, then by Standard Pacific Homes until such time as the City of Dublin accepts the right of way dedication. Once the dedication is accepted, maintenance will be performed by the City or its designee. Filterra will provide an Operations and Maintenance manual for these units. References 1. Alameda Countywide Clean Water Program, C.3 Stormwater Technical - Guidance: Ahandbook foz~ developers, builders and project applicants, August 31, 2006. 2. Alameda Countywide Clean Water Program, C.3 Stormwater Technical Guidance: A handbook for developers, builders and project applicants, October 19, 2010. 3. Bay Area Stormwater Management Agencies Association, Using Site Design Techniques to Meet Development Standards for Stormwater Quality, May 2003. 4. California State Water Resources Contxol Board, August 19, 1999, General Permit No. CAS000002, State Board Order No. 99-08-DWQ, WDID No. 2075313525. 5. California Stormwater Quality Association, Stormwater Best Management Practice Handbook, January 2003. 6. Contra Costa County Clean -Water Progc•am, Stormwater C.3 Guidebook, 3'`' Edition, October 2006. 7. United States Department of Agriculture, Urban Hydrology for Small Watersheds: Technical Release 55, June 1986. 8. United States Department of Agriculture, Web Soils Survey, http://websoilsurvey.nres.usda.~ov/app/. 6 A. Acheckzai GMdminUo6s•OJW310061Swmn~our Muugcnkm Plan.doc ~ . i6~ i t 0 e t t e t t s 0 p 73 X67 ~NN MOLCER CONGA p COUP ~Y:{F~~~.':K:,~: ~osTn ~ PROJECT A1.A~~ `Gf~t3~s71VG~~' SITE LIN ,`Y`r. . _ 5~L I~fIPA RANCH MN ilN _N^ ~ o ~ ~ ~ ~~y ~ Q a~ASON oRrt~' :c ~ PKtfy . ~ lRA OUBL LYD . 1NIERSTAYE 580 ~~A~ ~ ~pP Q~~P ~ oe pig gA d VICINITY MAP NOT R7 SCALf - _ - jc~ l r , _ ~ J ciR9.iSN lam` J ~ ' ~ : ~ , sd , 4 ..w~ t,tk rte.,, r Y~~~~~~~~```~ ti.._ ; „ , ~ +t...,t '.Y ~ Syr ~ / ) • _ d -1 ~ »s. ' ~ r ~S\ 1 _ ,~,s _ , W ///~/f~ we »~f _ l ei~.~ ~~Y ~ ~ F~.c~)d.. ~C-«vey: 9'_ ~ ' , - .n..aml+,on..e.nov .w. . w.u . ~ ~ ~ . • r ~r. a~ nip NR 3npfRn mrRw+w. Y ~ ~j/"~d ~ jj a,.:_ .~k _ `t 1r` ' _ - ~ - _ ~ xnren auauMrr,_roa~ aeaz~ j~ lVb&3ta3f~PN7rti or... a C~~~ „ .ww..e.~w. RU68ERNEN9CN•AZAR STORM WATER TREATMENT PLAN FALCON CROSSING ,;„=-y;,;;',_ ~5 `6~ FALCON CROSSING Water Quality Sizing Calculations - 80% Capture Method (ACCVVP) Total DrainageArea(WQP1)= 7.91 AC {UPPER). Total Drainage Area(WQP2)= 12.77 AC (LOWER) ` Avera e T ical Pervious' Flows to Lot No. Lot Area Roof Area'' D area Total DCIA % DC1A Area LOWER WQP. 1 4,790 1,760 234 1,994 42% 2,796 LOWER WQP 2 4,651 1,907 283 2,190 47% 2,461 LOWER WQP 3 9,266 2,140 288 2,428 26% 6,838 LOWER WQP 4 8,643 1,919 276 2,195 25% 6,448 LOWER WQP 5 4,159 1,760 243 2,003 48% 2,156 LOWER WQP 6 4,361 1,760 190 1,950 45% 2,411 LOWER WQP 7 5,210 1,907 410 2,317 44% 2,893 LOWER WQP 8 5,633 1,527 614 2,141 38% 3,492 LOWER WQP 9 5,603 1,760 304 2,064 37% 3,539 LOWER WQP 10 7,183 1,907 357. 2,264 32% 4,919 . LOWER WQP 11 5,431 2,134 277 2,411 44% 3,020 LOWER WQP 12 4,277 1,501 589 2,090 49% 2,187 LOWER WQP 13 5,229 2,134 325 2,459 47% 2,770 LOWER WQP 14 4,621 1,907 398 2,305 50% 2,316 LOWER WQP 15 5,637 1,501 592 2,093 37% 3,544 LOWER WQP 16 5,378 1,919 359 2,278 42% 3,100 LOWER WQP 17 5,119 2,127 333 2,460 48% 2,659 LOWER WQP 18 4,762 1,907 357 2,264 48% 2,498 LOWER WQP 19 2,950 857 175 -1,032 35% 1,918 LOWER WQP 20 2,493 543 215 758 30% 1,735 LOWER WQP 21 4,000 1,919 357 2,276 57% 1,724 LOWER WQP 22 3,889 .1,502 579 2,081 54°l0 1,808- LOWER WQP 23 4,837 1,760 252 2,012 42% 2,825 LOWER WQP 24 4,318 2,134 256 2,390 55% 1,928 LOWER WQP 25 4,211 1,502 575 _ 2,077 49% 2,134 LOWER WQP 26 5,966 1,919 312 2,231 37% 3,735 LOWER WQP 27 5,937 2,127 240 2,367 40% 3,570 LOWER WQP 28 5,244 1,907 463 2,370 45% 2,874 LOWER WQP 29 4,763 1,501 594 2,095 44% 2,668 - LOWERWQP 30 5,000 1,907 357 2,264 ' 45% 2,736 LOWER WQP 31 5,334 1,760 304 2,064 39% 3,270 LOWER WQP 32 6,381 2,140 371 2,511 39% 3,870 , LOWER WQP 33 2,633 843 ' 214 1,057 40% 1,576 LOWER WQP 34 2,465 887 175 1,062 43% 1,403 LOWER WQP 35 3,800 1,527 589 2,116 56% 1,684 LOWER WQP 36 4,000 2,127 288 2,415 60% 1,585 LOWER WQP 37 4,000 1,919 357 2,276 57% 1,724 - LOWER WQP 38 3,939 1,501 596 2,097 53% 1,842 LOWER WQP 39 4,161 1,7$0 316 2,076 50% • 2,085 .LOWER WQP 40 4,926 -1,907 359 2,266 46% 2,660 LOWER WQP 41 4,476 2,134 253 2,387 53% 2,089 LOWER WQP 42 5,598 1,527 663 2,190 39% 3,408 LOWER WQP 43 4,125 1,760 279 2;039 49% 2,086 a 76 ~d ~ Averas~e Tvpica! Pervious Flows to Lot No. Lot Area Roof Area' Dw area Total. DCIA %DCIA -Area LOWER WQP 44 4,587 1,907 331 2,238 49% 2,349 1 LOWER WQP 45 4,417 1,760 249 2,009 45% 2,408 LOWER WQP 46 4,498 1,502 580 2,082 46% 2,416 LOWER WQP 47 4,427 2,140 .288 2,428 55% '1,999 ' ~ LOW ER W QP 48 4,299 1,501 589- 2,090 49% 2,209 LOWER WQP 49 4,726 1,907 387 2,294 49% 2,432 , . LOWER WQP 50 5,202 2,134 354 2,488 48%. 2,714 LOW ER WQP 51 4,533 1,502 .571 2,073 46% 2,460 LOW ER W QP 52 3,238 857 161 1,018 31 % 2,220 LOWER WQP 53 2,083 843 201 1,044 50% 1,039 Streets ' 118,162 S F Totals 246,619 , 89,140 19,045 108,185 ~ 92% 138,434 C (Ala Co. Clean 0.7 NA 0.75 0.8 NA NA 0.1 Water Program) Open Space 199,940 SF Weighted C* 0.39 Correction Factor= 1.11111111 Unit Basin Stor 0.22 in Corr UBS= 0.24 in WQv= 0.26 Ac-ft At 3.5' max WQ depth; need area= OA8 ac Averas~e Tvpica) Pervious Flows to Lot No. Lot Area Roof Area* D area Total DCIA %DCIA Area UPPER WQP 54 3,992 1,760 304 2,064 52% 1,928 UPPER WQP 55 4,115 1,919 356 2,275 55% : 1,840 UPPER WQP 56 4,052 1,502 579 .2,081 51 . 1,971 UPPER WQP 57 3,909" 1,760 255 2,01.5 52% 1,894 UPPER WQP 58 4,025 1,907 387 .2,294 57% 1,731 UPPER WQP 59 3,825 1,501 589 2,090 55% 1,735 UPPER WQP 60 4,075 1,907 357 2,264 56% 1,811 UPPER WQP 6.1 4,107 1,760 311 2,071 50°Jo .2,036 ' UPPER WQP 62 4,217. 2,134 310 -2,444 58% : 1,773 UPPER WQP 63 3,227 889 231 1,120 35% 2,107 UPPER WQP 64 2,791 843 271 1,114 40% 1,677 UPPER WQP 65 3,871 1,760 324 2,084 54% 1,7$7 UPPER WQP 66 3,982 1,501 604 2,105 53°l0 1,877 UPPER WQP 67 4,307 1,907 409 2,316 54% 1,991 UPPER WQP 68 4,082 1,502 570 2,072 51% 2,010 UPPER WQP 69 4,242 2,127 265 .2,392 56°10 1,850 UPPER WG~P 70 4,263 1,919 334. 2,253 53% 2,010 UPPER WQP" 71 3,953 1,527 574. 2,101 53°k 1,852 UPPER WQP 72 4,013 1,501 354 1,855 46% 2,158 UPPER WQP 73 3,872 1,501 610 2,111 55% 1,761 UPPER WQP 74 4,187 1,907 425 2,332 56°Io 1,855 UPPER WQP 75 4,226 2,134 337 2,471 58% 1,755 UPPER WQP 76 4,054 1,501 614 2,115 52% 1,939 UPPER WQP . 77 3,927 1,760 25Z 2,017 51% 1,910 UPPER WQP 78 5,505 1,919 407 2,326 42% 3,179 UPPER WQP 79 6,410 2,127 476 2,603 41% 3,807 . ~7 .1~7 Average TygiCal Pervious Flows to Lot No. Lot Area Roof Area° Dw area Total DCIA % DCtA Area UPPER WQP 80 5,440 1,527 574 2,101 39% 3,339 UPPER WQP 81 5,919 1,907. 338 2,245 38% 3,674 UPPER WQP 82 5,805 1,502 565 2,067 36% 3,738. UPPER WQP $3 5,950 1,760 241 .2,001 34% 3,949 - UPPER WQP 84 6,219 1,919 384 2,303 37% 3,916 . UPPER WQP 85 5,999 .2,134 344 2,478 41% 3,521 UPPER WQP 86 5,761 1,907 434 2,341 41°/a 3,420 UPPER WQP 87 5,252 1,501 619 2,120 40% 3,132. UPPER WQP 88 5,276 .1,907 380 2,287 43% 2,989 UPPER WQP 89 4,984 1,527 582 2,109 42% 2,875 UPPER WQP 90 5,086 1,760 296 2,056 40% 3,030 UPPER WQP 91 5,474 1,919 341 2,260 41% 3,214 UPPER WQP 92 5,347 2,140 274 2,414 45% 2,933 UPPER WQP 93 4,115 2,127 342 2,469 60% 1,646 UPPER WQP 94 3,848 1,527 559 2,086 54% 1,762 UPPER WQP 95 4,036 1,907 387 2,294 57% 1,742 UPPER WQP 96 3,951 1,501 589 2,090 53% 1,861 UPPER WQP 97 3,907 1;760 257 2,017 52% 1,890 UPPER WQP 98 4,058 1,919 357 2,276 56% 1,782 UPPER WQP 99 3,800 1,760 304 2,064 54% 1,736 UPPER WQP 100 3,800 1,502 579 2,081 55% 1,719 UPPER WQP 101 3,900 1,760 307 .2,067 53% 1,833 UPPER WQP 102 4,132 1,907 361 2,268 55% 1,864 UPPER WQP 103 3,975 1,527 593 2,120 53% 1,855 UPPER WQP 104 4,004 1,907 360 2,267 57% 1,737 UPPER WQP 105 3,852 1,501 592 2,093 54% 1,759 -UPPER WQP 106 4,065 2,127 316 2,443 60% 1,622, Streets 71848 SF Totals 235,184 92,617 21,785 114,402 79% 120,782 C (Ala Co. Clean 0.7 NA .0.75 0.8 NA NA 0.1 Water Program) Open space 31258- Weighted C* 0.45 Correction Factor= 1.11111111 Unit Basin Stor 0.25 in Corr U85= 0.28 in WQv= 0.18 Aaft At 3.5' max WQ dep#h, need area= 0.05 ac ~'g 167 ~ ' Falbn Crossin Pond Volume Calculations g Lower WQ Pond e Contour Areas Volume (cfl Volume (Ac-Ft) 472.7 0.0 597.8 0.01 473.2 2391.0 2318.8 0.05 .474.0 3406.0 8728.0 0.20 476.0 5322.0 1081.7 0.02 - 476.2 5495A TOTAL 0.29 Upper WQ Pond Contour Areas Volume {cfl Volume {Ac-Ft} 477.5 0.0 i 369.5 0.01 478.0 1478.0 4038.0 0.09 480A 2560:0 4560A 0.10 481.5 3520.0 ' TOTAL 0.21 / ! b1 . Bay Area Hydrology Model PROJECT REPORT Project Name: Fallon crossing. ' Site Address: Tassajara/Fallon Rd City Dublin .Report Date : 9/19/2008 Gage LIVERMORE Data Start : 1959/10/01 ' Data End 2004/09/30 Precip Scale: 1.07 SAHM Versions PREDEVBLOPED LAND USE Name Pre-Developed Bypass: No Groundwater: No .Pervious Land Use Acres C D,Grass,Very(>20~) 103.5 Impervious Land Use Acres $lement Flows To: Surface Intezflow Groundwater Name : Lower Development Bypass: No Qroundwater: No Pezvi.ous Land Use Acres C D,Urban,Flat(0-5~) 3.18 C D,Vrban,Very(>20~) 4.39 Impervious Land Use Acres Roada,Flat(0-5~) 1.2 Mod (5-10~) . ~ 1..51 Roof Area 2:05 Mod(5-10$) 0.94 Y~ 8lement Flows ~o: Surface interflow Groundwater rt ~ ~ • 1 1 ~6~ 1 . LOWER WQP, LOWER WQP, Name : Upper Developi?fent Bypass: No Groundwater: No Pervious Land Uae Acres C D,Urban,Flat(0-5$) 2.77 C D,Urban,Very(>20sk} .86 Impervious Land Use Acres Roads,Fiat(0-5~) 0.5 Mod (5-lORs) ~ 1.15 Roof Area 2.13 Element Flows Tor • Surface Snterflow Groundwater - UPPER WQP, UPPER WQP, ( _ Name LOWER. WQP Bottom Length: 63ft. Bottom Width: 4oft. Depth 5.f t. Volume at riser head s 0.3078ft. Side slope l: 3 xo 1 Side. slope 2: 3 To 1 . Side slope 3: 3 To 1 Side slope 4: 3 To 1 .Discharge Structure. Riser Height: 3.5 ft. Riser Diameter: 198 in. Orifice 1 Diameter: 2 in. Elevation: 0 ft. Biament Flows To: • Outlet 1 Outlet 2 Detention Pond, Pond hydraulic Table 8taae(£t) Area(acr) Volume(acr-£t) nschrg(cfa} InCJ.lt(c_£st o.aoo o.osa o.ooo o.ooa . o.ooo 0.056 0.059 0.003 0.025 0:000 0.111 0.059 .0.007 0.035 0.000 0.167 0.060 0.010 0.043 0.000 0.222 0.061 0.013 0.050 0.000 0.278 .0.062. 0.017 0.05.ri 0.000 ~ ~i i~~ 0.333 0.063 0.020 0.061 0.000 0.389 0.063 0.024 0.066 0.000 " 0.444 0.064 0.027 0.070 0.000 0.500 0.065 ~ 0.031 0.074 0.000' 0.556 0.066 0.034 0-.078 0.000 0.61I 0.067 0.038 0.082 .0.000 0.667 0.068 0.042 0.086 0.040 0.722. 0.069 0.046 0.089 0.000 .0.778 0.069 0.049 0.093 0.000 0-.833 0.070 0.053 0.096 0.000 0.889 0.071 0,.057 0.099 0.000 0.944 0.072 0.061 0.102 0.000 1.000- 0,073 0.065 0.105 0.000 1.056 -0,074 0.069 0.108 0.00 0 1.111 0.075 0.073 0.111 0.000 1.].67 0.076 0.078 0.1].3 0 , 000 " 1.222 0.076 0.082 0.116 0.000 - 1.278 0.077 0.086 0.119 0.000 1.333 0.078 0.090 0.121 0..000 - ' 1.389 0.079 0.095 0.124 0.004 1.444 0.080 0.099 0.126 0.000 . 3.500- 0.081 0.104 0.129 0.000 ' 1.556 0.082 0.108 0.131 0.000 1.611 0.083 0.113 0.133 0.000 1.667 0.084 0.117 0.136 0.000 1.722 0.085 0.122 0.138 0.000 1.778 0.086 0.127 0.140 0.000 1.833 0:087 0.132 0.142 0.000 .1.889 0.088 0.136 0.149 0.000 1.944 0.089 0.141 0.146 0.000 2.000 0.090 0.X46 0.149 0.000 2.056 0.091 0.151 0.151 0.000 2.111 0.091 0.156 0.153 0.000 2.167 0.092. 0.161 0.155 0.000 2.222 0.093 0.167 0.157 0.000 2.278 0.094 0.172 0.159 0.000 2.333 0.095 0.177 0.160 0.000 2.389 0.096 0.182 0.162 0.000 2.444 0.097 0.188 0..164 0.000 2.500 0.098. 0.193 0.166 0.000 2.556 0.100 0.199 0.168 0.000 2.611 0.101 0.204. 0..170 0.000 `2.667 0.102 0.210 0.172 0.000 t 2.722 0.103 0.216 0.173 0.000 2.778 0..104 0.221 0.175 0.000 2.833 0:105_ 0.227 0.177 0.000 2:•889 0.106 0.233 0.179 0.000 2.944 0.107 0.239 0.180 0.000 3.000 0.108 0.245 0.182 0.000 ' 3.056_ 0.109 0.251 0.184 0.000 3.111 0.110 0,257 0.185 0.000 3.-167. 0.111 0,263 0.187 0.000 3.222 0.112• 0.269 0,189 0.000 , 3.278 0.113 0.276 0.190 0.000 ' 3.333 0.114 . 0.282 0.192 0.000 3.389 0.115 0.286. 0.193 0.000 3.494 0.117 -0.295 0.195 0.000 1 - ~ ~ h~ 1 . 3.500 0.218 0.301 0.197 0.000 3.556 .0.119 0.308 2.302 0.000, 3.611 0.120 0.314 6.151 0.000 3.667 .0.121 0.321 T,1.13 0.000 3.722 0.122 0.328 17.04 0.000 _ 3.778 0.123 0.335 23.73 0.000 1 ~ 3.833 0.124 0.342 31.13 0.000 3.889 0.126 0.348 39.18 .0.000 3".944 0:127 0.355 47.82 0.000 4.000 0.128 0.363 57.02 0.000 4.056 0.129 0.370 66.75 0.000 4.111 0.130 0.377 76.98 0.000 9.167 0.131 0.384 87.68 0.000 4.222 0.132 0.391 98.84 0.000 t 4.278 0.134 0.399 17.0.4 0.000 9.333 0.135 0.406 122.5 0.000 9.389 0.136 0.414 134.9 0.000 4.444 0.137 0.421 147.7 0.000' 4.500 0.138 0.429 160.9 0.000 4.556 0.140 0.937 174.5 0.000 4.611 0.141 0.445 186.4 0.000 4.667. 0.142 0-.452 202.7 0.000 4.722 0.143 0.460 217.4 0.000 4.778 0.145 0.468 232.3 0.000 4.833 0.19G 0.476 247.6 0.000 ' 4.889 0.147 0.485 263.3 0.000 4.944 0.148 0.493 279.2 0.000 5.000 0.149 .0.501 295.4 0.000 S.OSb O.1S1 0.509 312.0 0.000 .Name t UPPER WQP Bottom Length: 60ft. Bottom Width: 25ft. Depth 5.5ft. Volume at riser head s 0.2079£t. 83de elope 1:. 3 To 1 . Side-elope 2• 3 To 3 5~.de .elope 3: 3 To 1 Side slope 4~ 3 To 1 Aischarge Stzucture Riser. Heights 3:5 ft. .Rises Diameter: 48 in. Ori£ioe 1 Diameter: 2 in. Elevation: 0 ft. 8lement F1owe.To: Outlet 1 Outlet 2 Detention Pond, Pond Hydraulic Table 8ta4e(ft) Arsa(acr) Volume(acr-ft~ Dachrg(cfs) "Tnfiltfcfa) 0.000 0.034 0.000 0.000. 0.000 0.063 0.035 0.002 0.026 0.000 - A.122 0.036 0.004 0.037 0.000 ~ i F~ 3 t~~ 0.183 0:037 0.00') 0.045 0.000 0.244 0:037 0.009 0.052 0.000 0.306 0.038 0.011 0.058 0.000 .0.367 0.039 0.013 0,064 0.000 0.426 0.040 0.016 0.069 0.000 0.489 0.040 0.018- 0.073 0.000 0.550 0.041 0.021 0.078 0.000 0.611 0.042 0.023 0.082. 0.000 0.672 0.043 0.026 0.086 0.000 , 0.733- 0.043 0.'029 0.090 0.000 • 0.794 0.044 0.031 0.094 0.000 0.856 0.045 0.034 0.097 0.000 0.917 0.046 0.037 0.101 0.000 0.978 0.047 0.040 0.104 0.000 1.039 0..047 0.042 0.107 0.000 1.200 0.048 0.045 0,110 0.000 1.161 0.049 0:048 0.113 0.000 1.222 .0.050- 0.051 0.116 0.000. 1.283 0.051 0.054 0.119 0.000 1.344. 0.052 0.058 0.122 0.000 • 1.406 0.053 0.061 0.125 0.000 1.467 0.053 0.064 0.127 0.000 1.528 0.054 0.067 0.130 0.000 1.589 0.055 0.071 0-132 0.000 1.650 0.056 0.074 0.135 0.000 1.)11 0.057 -0.077 0.137 0.000 _ 1.772 0.058 0.081 0.140 0.000 1.833 0.059 0.085 0.142 0.000 1.694 0.060 0.088 0.14"5 0.000 1.956 0.060 0.092 0.147 0.000 2.Oi? 0.061 0.096 0.149 0.000 2.078 0.062 0.099 0.151 0.000 2.139 0.063 0.103 0.154 0.000. i. 2:200 0.064 0.107 0.156 0.000 2.261 0.065 0.111 0.158 0.000 2.322 0.066 0.115 0.160 0.000 2.383 0.067 0.119 0.162 0.000 2.444 0.068 0.123 0.164 0.000 2.506 0.069 0.127 0.166 0.000 2.567 0.070 0.1.32 0.168 0.000 2.628 0:071 0.136 0.170 0.000 ; 2.689 0.072 0.140 0.172 0.000 2:750 0.073 0.145 0.174 0.000 2.811 0.074 0.149 0.176 0.000 " 2.872 O.D75 0.154 0,178 0.000 2.933 0.076 0.158 0.180 0.000. - 2.994 0.07? 0.163 0.182 0.000 3.056 0:078 0.168 0.184 0.000 3.117 0.079 0.173" 0.185 0.000 3.178 ~ 0.080 0.177 0.187 0.000 3.239 0.081 0.182 0.189 0.000 3.300 0.082 0.187 0.191 0,000 3.361 0.083 0.192 0.193 `0.000 ' 3.422 0.084 0.197 0.194 ~ 0.000 3.483 0.085 0.203 0.196 0.000 ' 3.544 0.0$6 0.208 0.563 .0.000 3.606 0.087 0.213 1.535 0.000 . t 3.657 0.088 0.219 2.852 0.000 3.728.. 0.090 0.224 4.438 0.000 3.789 0.091 0.22 9 6.253 0.000 3.850 0.092 0.235' 8.272 0.00 0 3.911 0.093 0.241 10.48 0.000 3.972 0.094 0.246 12.85 0.000 4.033 0.095 0.252 15.38 0.000. 4.094- 0.096 0.258- 18.07 0.000 4.156 0.097. 0.264 20.89 0.000 4.217 0.098 0..270 2'3.85 0.000 , 4.278 0.100 0.276 26.94 0.000 4.339 0.101 0.282' 30.15 0.000 4.400 0.102 0,288. 33.48 0.000 ' 4.:461 0.103 0.295 3b.93 0.000 4.522 0.104 0.301 40.49 0.000 4.583 0.105 0.307 44.15 0.000 4.694 0.107 0.314 47.92 0.000 ' 4.706 0.108 0.320 51.79 0.000 4.767 0.109 0.327 55.76 0.000 4.828 0.110 0.334 59.83 0.000 1 4.889 O.lll 0.340 64.00 , 0.000 4.950 0.113 0.347 68.25 0.000 5.011 0.114 0.354 72.60 0.000 5.072 0.115 0.361 77.03 0.000 5.133 0.116 0.368 81.'56 0.000 5.194 0.118 0.375 Sb.16 0.000 5.256 0.119 0.383 90.86 0.000 5.327 0.120 0.390 95.63 0.000 5.378 .0.121 0.397 100.5 0.000 5.439 0.123 0.405 105.4 0.000 5.500 0.124 0.412 110'.4 0.000 5.561 0.125 0.420 115..5 0.000 Name Retention Pon@ Bottom Length: 172ft. Bottom Width: 20ft. . Depth 7.7ft. volume at riser head : 1.0826ft. Side slope l: 3 To 1 Side slope 2: 3 To 1 aide slope 3: 2 To 1 Side slope 4: 11 Ta 1 . Discharge Structure Riser Haight: 6 ft. Riser Diameter:_ 48 in. _ NotchType : ReCtangu3.ar Notch Width : 2.000 ft, Notch Heights 1.000 ft. Orifice 1 Diameters 3 in. $lavations 0 ft. Orifice 1 Diameter: 4 in. 8lavationr i ft. Orifice 1 Diameters 18 in. Elevation: 3 ft. Element Flows 1'os Outlet 1 Outlet 2 ~5 ~6 ~ Pored Hardzaulic Table - 8ta4e(ft) Areatacr) Vo__lwne(acr-f t) Asohrg(efe) InFSlt(cfe) 470.0 0.079 0.000 0.000 0.000. 470.1 0:-081 0.007, 0.069 0.000 470.2 0.083 .0.014 0.098 0.000 470.3 0.086 0.021 0.120 0.000 470.3 0.088 0.029 0.138 0.000 470.4 0.090 0.036 0.155 0.000 470.5 0.093 0.044 0.169 0.000 470.6 0.095 0.052 0.183 0.000 470.7 0.098 0.060 0.196 0.000 470.8 0.100 0.069 0.207 0.000 470.9 0.103 0.077 0.219 .0.000 470:9 0.105 0.086 0.229 0.000 471.0 0.108 0.095 0.308 0.000 471.1 0.110 0.105 0.390 0.000 471.2 0.113 - 0.114. 0.446 0.000 971.3 0.115 0.124 0.491 0:000 - 471.4 0.x18 0.134 0.532. 0.000 471.5 0.120 0.144 0.568 0.000 471.5 0.123 0.155 0.602 0.000 471.6 0.126 0.165 0.634 0.000 471.7 0.128 0.176 0.664 0.000 471.8 0.131 0.187 0.692 0.000 471.9 0.134 0.199 0.719 .0.000 472.0 '0.137. 0.210 0.795 0.000 ' 472.1 0.139 0.222 0.770 0.000 472.1 0.142 0.234 0.794 0.000 472.2 0.145 0.246 0.818 0.000 472.3 0.148 0.259 0.840 0.000 472.4 0.151 0.272 0.862 0.000 472.5 0.154 0.285 0.884 0.004 472.6 0.157 0.?.98 0.905 0.000 472.7 0.160 0.311 0.925 0.000 472.7 0.163 0.325 0.945 0.000 472.8 0.166 0.339 0.965 0.000 472.9 0.169 0.354 0.984 0.000 473.0 0.172 0:368_ 1.002 0.000 473.1 0.175 0.383 3.428 0.000 473.2 0.178 0.398. 4.501 0.000 473.3 0.181 0.413 5.321 0.000 473.3 0.184 0.42 9 6.012 0,000 473.4 0.187 0.445 6.621 0.000 473.5 0.191 0.461 7.172 0.000 973.6 0.194 0.478 7.680 0.000' , s 473.7 0.197 0.494 8.153 0:000 473.8 0.200 0.511 8.597 0.000 473.9. 0:204 0.529 9.019 0.000 - 473.9 0.207 0.546. 9.420 0.00.0 - 474.0 0.210. 0.564 9.803 0.000 474.1 0.219 0.582 10.1'1 0.000 '474.2 0.217 0.601 10.53 0.000 479.3 0:220 0.619 10.87 0.000 - 4?4:4 0.229 0.638 11.20 0.000 474.4 0.227 0.658 11.52 0.000 - E'"- 1 ~ . ~6 . ~ 474.5 0.231 0.677 11.83 0.000 • 474.6 0.234 0.697 12.14 0.000 474.7 0.238 0.717 12.43 0.000 474.8 0.241 0.738 12.72 0.000 474.9 0.245 0.75 8 13.01. 0.000 1 475.0 0.248 0.780 13.28 0.000 475.0 0.252 0.801 13.62 0.000 475.1 0.256 0.823 14.13 0.000 475.2 0.259 0.845 .14,73 0.000 475.3 0.263 0.667 15.38 0.000 475.4 0.267 0.890 16.08 0.000 475.5 0.270 0.913 16.81 0.000 475.6 0.274 0.936 17.56 0.000 475.6 0.276 0.960 18.33 0.000 475.7 0.282 0,984 19.11 0.000 475.8 0.286 1.008 19.90 0.000 475.9 0.289 1.032 20.69 0.000 476.0 0.293 1.057 21.48 0.000 476.7. 0.297 1.083 22.57 0.000 476.2 0.301 1.108 24.49 0.000 476.2 0.305 1.134 26.95 0.000 ' 476.3 0.309 1.160 29.85 0.000 476.4 0.313 1.187 33.11 0.000 476.5 0.317 1.214 36.71 0.000 976.6 0.321 1.241 40.60. 0.000 476.7 0.325 1.269 44.77 0.000 476.8 0.37.9 1.297 49.20 0.000 476.8 0.333 1.325 53.88 _ 0.000 • 476.9 - 4.338 1.354 58.78 0.000 477.0 0.342 1.383 63.91 0-.000 477.1 0.346 1.412 69.24 0.000 477.2 0.350 1.442 74.78 0.000 477.3 `0.354. 1.472 80.51 0.000 477.4 _0.359 1.503 86.43 0.000 477.4 0.363 1.534 92.53 0.000 477.5 0.367 1.565 96.80 0.000 477.6 0.371 1.597 105.3 0.000 477.7 0.376 1.628 111.9 0.000 Name s Self treating area Sypaaa: Yes Groundwater: No Pervious T,and Uae Acres C D,GZasa,Very(>20~) 82.82 Impervious Land IIae Acres 8lement Flows To: ~ . Surface. Interflow Gzoundwater • • g~ i6~ ~ ' MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped._ POC #1 Return Period Flow(cfe) 2 year 22.4682 5 year 38.689691 10 year 51.572878 25 year 58.506461 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfe} 2 year 19.7132 S year 35.535061 10 year 46.202422 25 year 53.526793 Yearly Peaka for Predeveloped and Mitigated. POC #1 Xear Predevelo~ad Mitigated 1961 19.106 15.672 - 1962 11.523 9.304 1963 24.571 ~ 19.713 1964 27.930 26.662 1965 6.526 9.664 1966 18.543 14.884 196% 16.321 13.156 1968 90.595 80.928 1969 22.468 22.075 1970 34.124 32.458 1971 30.374 24.734 7.972 29.421 23.902 1973 0.185 0.775 1974 55.450 50.917 1975 37.786 30.977 1976 19.376 15.865 1977 0.009 0.338 1978 0.021 0.300 1979 33:759 27.511 1980 36.187 29.512 1981 24.023 23.994 , 1982 6.999 b.408 1983 51.821 45.619 1984 38.941 36.390 tt~~ 1985 _20.796 16.922 1986 10.587 8.853 1987 52.343 48.169 ~ ' 1988 14.127 13.922 1989 1 .261 1.].43 ' 1990 3.835 3.133 1991 13.391 12.390 1992 18.223 16.617 1993 21.669 17.606 + _.r-• ~ ~ ' 1. 1994 24.365 23.361 2995 10.582 8.654 1996 42.572 41.953 1997 51.441 45.925 1998 27.877 26.500 1999 47..043 39.,975. 2000 27.254 22.002 2001 17.061 16.229 2002 3.115 2.532 .2003 10.946 8.956 2004 29.769 27.763. 2005 47.274 46.722 Ranked Yearly Peaks for Pzedeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 90.5951 80.9280 2 55.4504 50.9171 3. 52.3432 48.1588 4 51.8209 46.7224 5 51.4406 45.9251 , 6 47.2739 45.6185 7 47.0434 41.9528 8 92.5719 39.9749 9 38.9408. 36.3898 10 37.7857 32.4580 11 3F.1866 ~ 30.9768 12 34.1237 29.5121 13 33.7592 27.7634 14 30.3743 27.5114 15 29.7692 26.6622 16 29.4212 26.5000 17 27.9299 24.7336 18 27.8772 23:9019 19 27.1544 23.3614 20 24.5705 22.0753 . 21 24.3646 22.0022 22 24.0229 21.9936 23 22.4682 19.7132 24 21.6691 17.6057 25 20.7964 16.9222 26 19.3761 16.6167 27 19.1056 16.2291 28 18.5430 15.8649 29 18.223 15.6718 30 _ 7.7.0614 14.8841 31 16.3206 13.9221 3214.1269 13.1556 33 13.3908 12.3895 34 1.1.5229 9.6845 35 10.9464 9.3037 D 36 10.5866 8.9559 37 10..5823 8.8535 38 6.9988 8.654 5 39. 6.5259 6.4083 40 3.8352 3.1326 4J. 3.1155 2.5323 . _ ~i 6 42 1.2611 1.1430. 43 0.1851 0.7752 44 0.07.09 0.3382 45 0.0093 0.3000 POC #1 The Facility PASSED • Th@ FaCility PASSED. 1 Flow(CFS) Predev. D@v P@rc@ntage Pass/Fail .2.2468 1522" 1513 99 Pass 2.7451 1353 1312 96 Pass 3.2433 1212 1157 95 Pass 3.7415 1107 1033 93 Pass 4.2398 1017 928 91 Pass. _ 4.7380 931 847 90 Pass 5.2363 850 755 88 Pass 5.7345 777 685 88 Pass 6,2328 701 623 88 Pass 6.7310 651 566 86 Pass 7.27.93 598 529 88 Pass 7.7275 554 486 88 Pass 8.2257 514 442 85 Pass 8.7240 487 396 81 Pass 9.2222 450 367 8'1 Pass 9.7205 410 341 83 Pass 10.2187 381 310 81 Pass 10.7170 354 281 79 Pass 11.2152 334 -258 77 Pass 11.7134 308 238 77 Pas$ . 12.2117 290 212 73 Pasa 12.7099 272 201 73 Pass 13.2082 253 187 73 Pass 13.7064 234 173 73 Pass 14.2047 218 162 74 Pass 14.7029 202 152 75 Pass 15.2011 189 142 75 Pass 15.6994 177 130 73 Pass 16.1976 166 119- 71 Pass 16.6959 154 106 6B Pass 17.1941 145 100 68 Pass 17.6924 133 94 70 Pasa 18.1906 1.26 88 69 Pasa 18.6888 117 83 .70 Pass 19.1871' 109 77 70 Pase 19.6853 97 75 77 Pass 20.1836 94 65 69 Pass 20,6818 90 64 71 Pass. 21.1801 86 64 74 Pass 21.6783 79 61 77 Paes. 22..7.765 77 55 71 Pass 22.6748 72 54 ?5 Pass 23.1730- 65 53 81 Pass • 23.6713 62 52 83 Pass '24.1695 60 50 83 Pass - r sssd 5Z t 6 bZLS't5 Q _ ssrd OZ i S 94L0'TS _ ssed 04 Z. S 49L5'OS • ssed 04 Z S t8L0'05 ssed Ofi Z S 66LS'66 ssed 09 £ S Lt80'64 ssed 09 £ 5 4£85'86 ssea oe 4 s zsso•a6' ssed 08 6 S 6985'L6 ss8d 99 6 4 L880'L6 sssd tL S L 4065'96 ssed iL S L ZZ60'94 99ed L8 L 8 0665'54 ssed LS L 9 LS60"56 . flflL'd LL L 6 SL65' 6i~ ssed 98 $ 6 Z660'6b ssed 88 8 6 Ot09'£4 • ssed 88 8 6 LZOi'£4 _ ssed 88 8 6 5409'Z6 ssed. 08 8 OT £90t'Z4 ssed £8 Ot Zt 0809't4 ssed £8 Ot Zt 860i'i6 ~ , ssed. £8 Oi Zi Stt9'Oi~ ssed OOt ZL Zt ££tt'04 ssed Z6 £t 4t OSt9'6£ SflE~j £6 6t Si 89it'6£ ss8d ZS 6Y Lt 9819'8£ ssed Z8 6t Lt £021'8£ ssed l: 6t 8t 1229' L£ sssd LG 6i' St 8£zt'L£ ssed LL 6t St 9SZ9'9£ ssed 68 Li 6I £LZL'9£ ssed S8 LT OZ 1629.'5£ ssed GL Gt ZZ 60£1'5£ ssed 6L 6T 4Z 9Z£9'6E ssed 9L 6i 5Z 44£1'4£ ssed L9 6t 8Z 19£9'££ ssed XL OZ 8Z 6GEt'££ ssEd it OZ 8Z 96£9'2£ SsEd 8L ZZ SZ bt4t'Z£ .ssed 9G £Z 0£ Z£49't£ ssed 08 4Z o£ 646i't£ ssed £8 SZ 0£ L949'0£ • ssed L8 LZ t£ 6841'0£' ssed t8 LZ 2059'62 ss12d Z8 8Z 6£ 6i5i ~ 6Z j- ssed Z8 8Z 6£ L£59'8Z ssed 5L. 8Z L£ SSSi'8Z ssed Z8 Z£ 6£ ZL59'LZ -ssed £L S6 065i'LZ ssed 5L ~ 4£- 54 L099'9Z ssed LL L£ 84 SZ9t'9Z ssed 08 Z4 ZS Zb99'SZ ssed 98 5b Z5 099L'SZ saes 98 94 £5 8L99'4Z i L~~ ~ p ~ . b ~ 1 t ~6~ This program and accompanying documentation are provided 'as-is' without warranty of any kind. The satire risk regarding the pertormnnae end results of this program is assumed by Bad User. Clear Creek Solutions Inc. and the governmental licensee or aubliaenaeea . disclaim all warranties, either expressed or implied, lnaluding but not limited to implied warranties of program and ac~emopsnying doaumentation. in ao event .shall Cleai Creak SolutionB Inc, Applied tdaris?e Soiencea Incorporated, the Alameda County Flood Control and Mater Conservation Diatriot, imh Inaorporated, member agenoies of the Alameda Countyxifle Clean Mater Program, member agencies of the San liateo Countywide Mater Pollution Prevention Program, member agencies o! the 8nnta Clara Valley Urban Runott Pollution Prevention Program or nny other LOU Partioipante or authorised representatives of LOU Participants ba liable for any damages whatsoever (inoluding without limitation to damages !or loos of business profits, loas.ot business iatosmatioa, business interruption, and the like! ariaiag out o! the use o!, or inability to use this program even it Clear Creek solutions Inc., Appiied Marine saienoes Incorporated, the Alameda County Hood Control and Mater Coaaesvation Distriot, 1011 Inaorposated or any member agenaiee of the IAU Partiaipanta or their authorised representatives have been advised of the possibility o! sash damages. software Copyright ~ by CUer Creek solutions, 2no. 1005-10071 A12 Rights Reserved. 51.57 A~ n 39.2 - 26.91--~ a J 14. , 2.2 ~DE•4 1~•3 t0E•2 10E•1 1------ 10 100 ' For-oe~nt Time Exo~e3din~ i i I - i . ~.~i~ Alameda Countywide Clean Water Program A Consortium of Local Agencies SOIL SPECIFICATIONS FOR STORMWATER TREATMENT MEASURES ' The Alameda Countywide Clean Water Program's New Development Subcommittee is providing these specifications to its member agencies for use in non-proprietary, . landscaped-based stormwater treatment measures. The purpose of these specifications is to help applicants specify soils that will provide suitable growing conditions for appropriate plantings and meet the percolation .requirements identified in Chapter 6 of ACCWP's C.3 stormwater Technical Guidance for the specific types of landscape-based treatment measure proposed in their .projects. Some requirements may vary from one jurisdiction to another. Project applicants should check with the jurisdiction having authority over the project regarding applicable local requirements. The, specifications refer specifically to treatment measures for which technical guidance is included. in the Alameda Countywide Clean Water Program's C.3 stormwater Technical Guidance (August 2006). The specifications identify planting soils to be used (Section I), requirements for compost amendments in the- planting soils (Section 11), and a top dressing layer of mulch (Section III). I. PLANTING SOIL Planting soil is to be placed for the purpose of providing a soil for plants to be established in the treatment measure. ACCWP previously provided specifications for dewatering soils for use in vegetated swales. The dewatering soil option has been removed, however, in preparation to implement the requirements of the Municipal Regional stormwater Permit's (MRP) Provision C.3.c.i(2)(b)(vi) requirements for biotreatment soils with a long-term infiltration rate of 5 to 10 inches, anci a biotreatment measure surface loading area no small than what is required to accommodate a 5 inches/hour surface loading rate. Project proponents may meet these requirements using the treatment soil mix specified below.. . Treatment Soils. (high percolation planting soils, such as loamy sands) shall be used for filtering of a volume of water in the treatment measures, such as flow-through . planters -and bioretention areas. These treatment measures shall treat runoff by passing it through the surface layer of high percolation planting soil, then saturating a zone of crushed drain rock and finally in most cases, entering a perforated sub-drain. A. IMPORTED MATERIAL FOR TREATMENT (LOAMY SAND); Planting soil material for treatment shall consist of high organics soil (no gravel) with a high percolation rate, supplied from previously tested and approved sources, and shall conform to the following specifications and requirements: runaa~numu~nai ws n.a..rt~i..`.do:....u,e...mw.pu wetwtrti cfum~.~.u_a,..;m+....rns..,~..a.~+r.~xme.e _ . . Page 1 NDS Approved May 8, 2007 (Dewatering soil option removed Sept 2010) °~3 ~~7, ACCWP Soil Spectficat~ons for Stormwater Treatment Measures r 1. All materia! shall be free of trash and debris; expansive clays or any other deleterious materials, and shall be subject to the approval and acceptance of the Authority Having Jurisdiction. ~ , 2. The contractor shall designate their proposed import sources in advance and shall provide source samples of materia! to the jurisdiction having authority. 3. Material shall be free of seeds. „ ' 4. The treatment planting soil shall fiave documentation from the supplier _ showing conformance to the following gradation guidelines: Screen Information Percentage a. Maximum particle size 2 millimeters {0.078 inch) b. Percent passing No. 10 screen {2mm) 100 (coarse sand or finer) c. Percent passing No. 200 screen (0.074mm) 10 to 15% d. The overall dry weight percentages shall be 85-90% sand, less'than 5% clay, and less than 5% silt. The range of clay and silt and organics should be 10-15% of total volume. 5. The treatment planting soil shall have 4 to 6% by dry weight organic compost mixed in. Organic compost percentage may be lowered by the jurisdiction of authority for varying plant species in the treatment measure. Native in-situ . loamy sand soils can be used, with 4 to 6% of organic compost mixed in. This mixed soil must be certified to meet the imported planting soil requirements. Organic compost shall meet the specifications stated in Section II -Organic Compost Amendment. The soil shall have a salt concentration less than 500 mg/L. The pH shall be between 5.5 and 7, unless directed otherwise by the . jurisdiction of authority. 6. One' test shall be conducted by the supplier per each 500 cubic yards supplied. Testing shall be conducted for the above gradation requirements, salt contents and pH range.. 7. Contractor shall demonstrate the in-situ percolation of each treatment measure for design storm flows through the installed soil to the satisfaction of - the Authori#y Having Jurisdiction. The material shall have an onsite tested percolation rate of 5 to 10 inch per hour. In-field percolation test shall consist _ of a 1-foot diameter pipe, 2.5 feet long pipe, driven 1.5 feet deep into treatment soils. Pipe shall be filled with 1 foot of wafer after the treatment measure has been wetted. The pipe should empty 1 foot of water above the wetted soil layer in no less than 1 hour and 12 minutes, and no longer than 2 hours and 24 minutes. Contractor shall provide records of percolation tests to city inspector. 8. Soil shall be placed in lifts of $-10 inches. . 9. Standard compaction to a minimum of 85 percent shall be used when placing . the mixed material The method to achieve 85% compaction shall be approved by the local jurisdiction before the soil is' placed in the treatment measure. fiAl0.UL9/~tlY'.1Ui.011y,5 M1daHf.Jln'1.uJ (iwlNV l'pt'e JdlAy tA('1: tY71'ra11n1A1'IJ.SrI,K~r.w_~~~,pwa lly_t,JO~A.. ' Page 2 NDS Approved May 8, 200? (Dewatering soil option removed Sept 2010) ~ w ~ lbl ACCWP Soil Specifications for Stormwater Treatment Measures II. ORGANIC COMPOST. AMENDMENT An organic amendment per Attachment 1 is to be mixed into the planting soil for the purpose of providing organic material to be utilized by plantings placed within the treatment measure. The following specifications are for amendments used in bioretention areas, flow through planters, vegetated buffer strips, vegetated swales, and extended detention basins only. A. COMPOST SPECIFICATIONS Organic compost shall meet the requirements of the Alameda County Bay Friendly Landscape program. Provide a lab analysis of proposed material performed by either. ~(1) a certified US Composting Council Compost Analysis Program (CAP) laboratory or (2) a laboratory approved by the local jurisdiction, using approved Test Methods for the Evaluation of Composting and Compost (TMECC). Verifying current participation in CAP can be achieved by visiting www.comaostingcouncil.or4. The- TMECC methods are explained at www.tmecc.org/tmecc. Check with local jurisdiction for a list of approved .laboratories. See the attached Bay-Friendly Landscaping (BFL) Soil Preparation Specifications, Part 2.1.8.1,, Section 02920: Soil Preparation 'for approved testing ranges of attributes for compost amendments. Organic content may be lowered by the jurisdiction having authority for varying plant species in the treatment measure. This mixed soil must be certified by the laboratory - to meet the imported planting soil requirements. III. TOP DRESSING MULCH A three-inch thick layer of top dressing mulch shall be placed in all designated planting areas for the purpose of retaining moisture, preventing erosion arid minimizing weed growth. Keep top dressing six inches away from tree trunks for tree health except where approved by the jurisdiction having authority. The following specifications are for top dressing soils used in bioretention areas, flow through planters, vegetated buffer strips, vegetated swales; and extended detention basins only. A. MULCH SPECIFICATIONS Any of the following materials may be used as top dressing for any of the treatment measures listed above, subject to :the jurisdiction of authority's approval. Options for . top dressing material include: ^ Arbor Mulch: Arbor Mulch shall be wood waste from tree trimming and not contain eucalyptus. Local tree companies may have material available free of charge. Submit a minimum one-quart sample of proposed material to be used, to jurisdiction with authority. . - Wood Chip Mulch: Wood Chip Mulch shall be a coarse wood mulch .made from salvaged kiln dried lumber and be color enhanced with mineral pigments that have a runw~nnosWUr.o~xoa ndwre~T.e~.:,yaw.a.We+.ror~w~.wecwrrti.aoR.vru.sw_~.are.:m. *ms_sn...e_~~~oare: _ Page 3 NDS Approved May 8, 2007 (Dewatering soil option removed Sept.20T0) ~5 ~1 ACCWP Soil Specifications for Stormwater Treatment Measurd.S demonstrated color longevity of one year. Mulch material shall pass a two inch . screen. Organic Compost: Organic. Compost may be used as mulch as determined by the jurisdiction having authority. Organic compost shah meet the specifications. stated above in Section I I -Organic Compost Amendment. The following are specifications for the above dressing materials: 1. The top dressing soil material shall not float when three inches or more of water has ponded in the treatment measure. ~ . 2. Natural compaction is adequate for top dressing layer soil. 3. The 3 inches of top dressing. mulch shall be placed in a single lift. IV. SOURCES/DOCUMENT PREPARERS These specifications were•prepared under the guidance of the New Development Subcommittee. BKF Engineers prepared the specifications with substantial input from Design, Community and Environment. Organic compost amendment specifications in . Sec#ion II were based on Bay-Friendly Landscaping specifications prepared by Stopwaste.org. As the permit compliance consultant, EOA, (nc. coordinated work group meetings, reviews of draft specifications, and subcontracts with the consulting engineer and landscape architect. • V. DEFINITIONS • 1. Lift -Depth of soil placed before compaction is necessary 2. Expansive clay soils -are in-situ clay soils. These soils must be amended to be used in the treatment measures. 3. Stormwater treatment measure -Any engineered system designed to remove pollutants from Stormwater by simple gravity settling of particle pollutants, filtration, biological uptake; media~adsorption or any other physical, biological, or chemical process. Sometimes called a treatment control, • treatment. control measure, treatment best management practice (BMP), or treatment facility. 4. Wetted soil -soil that has been irrigated until the water has penetrated soil to a minimum of 4 inches. l.~AMM1,99\D~iA1.91.01 rS1A 11Nwi~<;.)M•,rift(wdt.[rt:~.leiNAgy..A('fM•fI'ie.IOPNTLia1SMfMra~~05.,ry9rwN.jtq.l tOC).Oe: Page 4 NDS Approved May 8, 2007 (Dewatering soil option removed Sept 2010) . ~ ~ 1~ r ACCWP Sail Specifications for Stormwater Treatment Measures r Attachment 1 BFL Soil Preparation Specifications Part 2.1.B.1 Section 02920: Soil Preparation 1. Organic Amendment Compost shall be a well decomposed, stable, weed free organic matter source.l'heproduct shall be certified through the US Composting Council's (USCG) Seal of Testing Assurance Program (S'1"A) Program (a campost testing and information disclosure program). It shall be, derived from agricultural or food waste or yard trimmings.l'he product shall contain no substances toxic to plazits, shall possess no objccdonable odors and shall not resemble the feedstock (the original materials from which it was derived. Before delivery of the compost, the supplier shall submit. a copy of lab analysis performed by a laboratory that is enrolled in the US Composting Council's CAP and using the approved 'l'est Methods for the Evaluation of Composting and Compost ('1'ME(:C). 'The lab report shall verify: A. Iieedstock Materials shall Ue specified and include one or more of the following: landscape/yard trimmings, grass clippings, food scraps, and agricultural crop residues. B. Organic 1Vlatter Content: 50% - GO% by dry wt. preferred, 35-70% acceptable. C. Carbon and Nitrogen Ratio: C_:N < 25:1 plus at least one measure of stability and at least one measure of toxicity. ll. Maturity/Stability: shall havc a dark brown color and asoil-like odor. Compost exhibiting - a sour oe putrid smell, containing recognizable grass or leaves, yr is hot (120I) upon delivery or rewetting is not acceptable. in addition any one of the following is required to indicate stability ' a. Oxygen 'Test < 1.3 Oz/unit TS / hr ' b. Specific oxy. 'Test, < 1.5 Oz /unit BT~S / hY i c. Respiration test < 8 C /unit VS /day ' d. llewar. test < 20 Temp. rise (°C) e. Solvita~ > S Index value Ts. 'Toxicity: any one of the following measures is sufficient to indicate non-toxicity. a. NH4- : NOa-N < 3 b. Ammonium < 540 ppm, dry basis c. Seed Germination > 80 % of COnirol d. Plant Trials > 80% of conlrol ' e. 5olvita®> 5 Index value I~. Nutrient Content: provide analysis detailing nutrient content i~lcluding N-P-I{, Ca, Na, Mg, S, and Ii. a. Total Nitrogen content 0.9% or above preferred. ` b. Boron: 'Total shall be <80 ppm; Soluble shall be <2.5 ppm. G. Salinit :Must be re ported; ma va but < a.0 mmhos/cm referred. Soil should also be Y 1 Y rY P tested: <2.5 mmhas/cm is preferred for soil/compost blend but may vary with plant species_ , H. pN: pH shall be between 6.5 and 8. May vary with plant species. , 1':`AMMJ1Lt1 XISAI.>).01 ~0111w7w.fC.)i'FYwil11~4r.l:pa/MAY(n:ACf.MT IieH IJ9.AITJ. SSG,YIrvfiaein. ~~K,ga...J \1ay,~ }L71~: Page 5 NDS Approved May 8, 2007 (Dewatering soil option removed Sept 20I0) 7 67 ACCWP Soil Specifications for Stotmwater Treatment Measta4•es I. Particle size: 95% passing a 1/2" screen. J. Bulk density: shall be between 500 and 1100 dry Ibs/cubic yard . I{. Moisture Content shall be bet\veen 35% - 55% of d solids. , ry Inerts: compost shall be relatively frc;e of inert ingredients, including glass, plastic and paper., < 1 % by weight or volume. M. Weed seed/pathogen destruction: provide proof of process to Further reduce pathogens (I'1~RP). For example, turned windrows must reach min. 55C for 15 days with at least 5 . . turnings during that period. _ N. Select Pathogens: Salmonella <3 M1'N/4grams of'1'S, or Coliform Bacteria <10000 MPN/gram. U. 'l race Contaminants Nfetals (bead, Mercury, rte.) Product must meet US EPA, 40 CFR 543 regulations. 2. Additional amendments and/or fertilizers as required in the soils report. a. Additional amendments and fertilizers that ace approved for use by the Organics Materials Research Institute (UMRI) for use in crop production are approved for use. See www.omri.org. Fertilizers that are not approved or are restricted for use by OMRI shall be applied only after review and written approval Uy the Chvner. Noses: 1) Solvita is a registered trademari< test. Please see http://solvita.com/ 2) 'TS is Total Solids;l3VS is Biological Volatile Solids, VS is Volatile Solids, MPN/gram is Most Probable Number per gram, ppm is parts pee million. - . F, ~ - _ i ` 'The 2007 version of this specification indicated a <0. I % threshold for allowable inerts. In September 2010, this was changed to <1 % for.consistency with the US Composting Council's Seal of Testing Assurance Program. rwoon~.v~ aarv.w.m ~»s nw~: r..~aw+icw,.rr i~rRa na~a•r n.a uxnnv. wa.-s,.Yx....., a»s ,~..~..a u.y_a, iema.: Page 6 NDS Approved May 2007 (Dewatering soil option removed Sept 2010) - ~ 1 ~ ~6 i~ 1~~ 1 1: APPENDIX B FIRE HAZARD MITIGATION AND DEFENSIBLE. SPACE VEGETATION MANAGEMENT PLAN Prepared By: . . Ralph J. Alexander & Associates r r BERLOGAR STEVENS & ASSOCIATES 1~1 FIRE HAZARD MITIGATION AND DEFENSIBLE SPACE ~iEGETATION MANAGEMENT PLAN - FALCON CROSSING Prepared for: Standard Pacific Homes 3825 Hopyard Road, Suite 195 Pleasanton, CA 94588 Prepared by: Ralph J. Alexander 8~ Associates 1020 Railroad Avenue, Suite C Novato, CA 94945 X415) 898-8722 May 29, 2007 ~ ~ 1~~ 1. TABLE OF CONTENTS PAGE LIST OF FIGURES iii EXECUTIVE SUMMARY iv EXISTING SITE DESCRIPTION ~ 1 VEGETATION RESTORATION AND MANAGEMENT CONCEPT 1 . RECOMMENDED METHODS OF VEGETATION MANAGEMENT 1 DEFENSIBLE SPACE ZONES 3 0-3' CRITICAL ZONE 3 Ground Covers 3 Perennials 4 Maintenance Standards 4 4'-14' 8~ 4'-24" DEFENSIBLE SPACE ZONE 4~ Ground Covers ~ - 4 Perennials ~ 5 Shrubs 5 Trees 6 1 Maintenance Standards 6 15'-30' 8~ 25'-55' DEFENSIBLE SPACE ZONE 7 Ground Covers 7. Shrubs g Trees g Maintenance Standards g . 55'-100' DEFENSIBLE SPACE ZONE 9 Grasses and Wildflowers 10 Trees 10 Maintenance Standards 10 DESCRIPTIONS OF MAINTENANCE PROCEDURES 1 1 GRASS MOWING 11 SHRUB MANAGEMENT 12 PRUNING OF OAK SAVANNA /WOODLANDS 13 SUMMARY.OF FREQUENCY OF RECOMMENDED MANAGEMENT 14 ACTIONS TO BE TAKEN DURING HIGH FIRE DAN ER G ]4 ii i~ ~ ~6~ LIST OF FIGURES Drawing F-l . Fire Hazard Mitigation and Defensible Space Vegetation Management Plan - 1 "=50' - 0" L a ~6~ EXECUTIVE SUMMARY ` The City of Dublin requires the preparation arid submittal of a Wildfire Management. Ptan prior to any development approval. The Plan includes both a text description of the management concepts, defensible space zones and maintenance procedures, .and a graphic plan delineation of the Defensible Space Zones. The graphic plan, Drawing F-l , is attached to this report: t This Plan lays out the criteria for design, management and maintenance of the landscape to achieve afire-safe landscape installation that. will achieve the proper gaps and spacing of landscaping to prevent the :spread of fires. to the development areas.. Trees and vegetation with a high fire risk, including pyrophytic species, .such as California Bay and Eucalyptus; are prohibited within the 0'-30' zone surrounding all project .buildings. The existing trees of other species to remain must be limbed up, cleaned up and cleared underneath, as specified in this report. No new trees of these species shall be planted. 1 This plan describes the Vegetation Restoration and Management Concepts; the Defensible Space Zones, which include the 0-3' Critical Zone, and the 4'-14', 4'- 24', 15'-30', 25'-55', and 55'-100' Defensible Space Zones; the Maintenance Procedures for Gross Mowing, Shrub Management and Pruning of Oak Savanna/Woodlands; the Frequency of Recommended Management; and Actions to be Taken During High Fire Danger. A map is included that delineates each of the above zones. The criteria for which zones are applicable are: upslope - to 30', sideslope - to 30' and downslope - to 30' or 100'. In addition, all grass must be mown to a 2" height within 10' of any road or driveway. The areas shown on the Plan will be planted and irrigated, using plant materials. specified in this report. The private yards will be planted and irrigated by the homeowners purchasing the affected houses. The CC&R's will, specify that the installation will be complete within 6 months of occupancy of the home, and that maintenance must be carried out as specified in this plan. References used in the. preparation of this plan include "Pyrophytic vs. Fire . Resistant Plants" by Ray Moritz and Pavel Svihra, obtained from the Marin County Fire Department, and "Fire-Safe Plant Selections, Landscape Restoration in Inverness Park" by Ray Moritz, and "Fire-Safe Landscape Database" by UCFPL. i~ ' - iv . 03 - ~ ~ /6 EXISTING SITE DESCRIPTION Fallon Crossing is a 66.9 acre site consisting of both flat and hillside topography, at the intersection of Fallon and Tassajara Roads. There are no existing structures on the site, and it is currently used for grazing. The existing vegetation consists of primaril introduced and native rasses. Y g There are no trees within the development area. The only, trees occur within the creek area, and consist of native, riparian trees. VEGETATION RESTORATION AND MANAGEMENT CONCEPT There will be four zones delineated in the Defensible Space. Vegetation Management plan, as required by the City of Dublin. 0-3' Critical Zone 4'-14' 8~ 4'-24' Defensible Space Zone 15'-30' & 25'-55` .Defensible Space Zone 55'-100' Defensible Space Zone The sub'ect ro erf re wires the followin Fire Hazard Miti ati J p P Y q g g on and Defensible Space Zones. Up Slope to 30 Cross Slope to 30' Down Slope to 30' or 100' Recommended Methods of Vegetation Management Several methods of vegetation management are feasible. In fact, there are environmental benefits to occasionally changing the method used. The maintenance actions in the vegeta#ion management guidelines can be .categorized by vegetation types. Grass must be mowed, shrubs will be pruned of dead material, shortened or removed altogether. Trees and tree-like shrubs will not be removed, but pruned of lower branches when grasses under them are not mowed. Fire resistant, water conserving, landscaping will be installed near the structure, in the Defensible Zones, and along roads. All newly .installed landscaping will be irrigated. All NEW .LANDSCAPED AREAS SHOULD BE MULCHED, BUT THE USE OF "MONKEY HAIR "OR "SHREDDED REDWOOD BARK" IS . PROHIBITED. Cut material may be left on the site only if it has been mechanically chipped. t p ~ ~~6~ Removal of brush. and dead shrubs vviil take place .throughout the site before construction begins, as construction itself can be an additional risk of ignition. Shrubs which will remain after the entire project has been completed will be identified in the field:, marked and preserved. Other shrubs will be removed before construction begins: Pruning of any existing trees to be retained throughout the site is advisable, as is mowing the grass where pruning to a height higher than three times the. unmowed grass height is undesirable: Understory shrubs will need to be removed and shrub clusters formed in open shrubby vegetation. There are several advantages to fuel treatment before construction begins. The cost of fuel modification in a wildland setting is many times .less expensive than when improvements are even partly in place. The desired vegetation will have at least one season to re-grow and become visually appealing. Lastly, the chance of a damaging fire caused by construction itself is reduced. The frequency of vegetation management is linked to the vegetation type, and is described in this plan. Grass will need to be mowed annual) when 30% of the rass cover has cured Y g (any time from April 15-June 1). The. grass will be cut within the week when 30~ of the grass cover is determined to be cured, and no later than June 1. This may require re-mowing if late season rains promote grass growth after the first cutting. This will apply during construction and prior to occupancy, as all of the Defensible Space Zones will be irrigated, and not contain native grasses. The expected frequency of treatment of shrubs should be as necessary to meet .the requirements 'of this plan, but in no .case less than five years. Shrubs may need to be. pruned of dead wood, shortened; shrub groupings minimized, in size, or new .shrubs removed under tree canopies. Shrub removal or pruning may be done any time of year. Application of a herbicide to prevent re-sprouting may be more effective in the spring; but will follow recommendations. i . Because trees typically grow from the top ends of branches, subsequent pruning needs to occur only every five years or so, depending on the rate of growth, 1 and significant events which may cause dead. wood to develop or breakage to occur. Pruning of oaks, other trees and tree-like shrubs can be done at any time of the year, depending on recommendations from a professional arborist. Trees and large tree-form shrubs shall be pruned to provide clearance of three -times .the height of the understory plant material, or 8 feet, whichever is higher. Limbs which are smaller than 3 inches in diameter are to be pruned up to 8 feet . off the ground, and in-young trees, the lower one-third of the height of the tree. Thus, if a tree is 10 feet tall, the lower 3-4 feet will be pruned up and understory 2 4 ~ ~b7 plant material kept to less than 6 inches in height. Then as it grows to 24 feet in height, 'the 8-foot distance from ground can be achieved, and the understory plant material is allowed to reach 2.5 feet in height. The tree canopy will not be disturbed or thinned, since this promotes growth of more flammable vegefation. Removal of a litter layer which is deeper than the guidelines allow is expected to be necessary only once every ten years. Creation of "ladder fuel situation" (where a fire can climb from-one vegetation layer to the next) will be avoided. Thus shrubs may be near, but not under, trees. Individual plants or shrubs masses will create "shrub islands" with adequate horizontal spacing. Shrub islands are distinct groupings of shrubs designed to help control the spread of fire. Islands will be small enough to provide adequa#e horizontal separation between groupings and to ensure proper maintenance; shrub islands will be no wider than two times the shrub height, or 120 square feet in area. The space between islands would be greater than three times the height of the shrub or a 12 foot .minimum. Emerging trees will have a spacing of 12 feet cleared from the edge of the canopy. As an alternative to "shrub islands", shrubs may be placed in sinuous single rows of varying length, but not more than 7 feet in width, and with spacing of at least 12 feet to other rows and/or "islands" of shrubs. Trees may be planted singly or in clusters, but the crowns should be separated by at least 10 feet. This does not apply to trees within clusters, but does apply to crowns between clusters. The crowns should also be separated at least 10 feet from any flammable structures. An additional 5 feet shall be added to the above spacings for every 10 (1 Oho) percent increase in slope. DEFENSIBLE SPACE ZONES 0-3' Critical Zone The zone 0-3' around the buildings is either hardscape, or irrigated and landscaped with plant material that is low growing and nonflammable, as well as deer resistant. Limited trees are proposed in this zone. Groundcovers: Arctostaphylos 'Hookeri' Monterey Car et p Ceanothus gloriosus Pt. Reyes Ceanothus Coprosma kirkii Creeping Coprosma Festuca longifolia .Hard Fescue Liriope gigantea Giant Turf Lily Monardella purpurea Coyote Mint 3 " . ~ n~ ~1 Myoporum parvifolium Myoporum Salvia sonomensis Creeping Sage Trachelospermum jasminoides .Star Jasmine - Perennials: 1 . Coreopsis species Coreopsis Dieter bicolor African Iris ' Hemerocallis hybrids Daylify Iris douglasii Douglas Iris Lantana montevidensis Lantana Lavandula species. Lavender Polystichum munitum Sword Fern Tulbaghia violacea Society Garlic Maintenance Standards: The following standards will be used as uidance for maintenance as it a lies g pp to the zone between 0-3' from buildings. . A!I dead lants and combustible .materials shall be removed to p establish and maintain a defensible space. Removal of combustible ' materials includes keeping the ground, roofs, decking and balconies free of dead leaves, needles or other plant debris, and removing dead material that drapes over ground cover- yearly, before June 1. This includes leaves, bark, and branches. 4'-14' or 4'-24' Defensible Space Zone The zone 4'-14' or 24' around the buildings will be irrigated and planted with a variety of low and medium growing groundcovers and herbaceous shrubs that are fire-resistant, and deer resistant. Individual plants or shrub masses will create "shrub islands" with adequate horizontal spacing. Some clusters of trees are being proposed for screening. All landscaping will be irrigated. Groundcovers: Ajuga reptans Carpet Bugle " 1 Arctostaphylos `Hookeri' Monterey Carpet Armeria maritime Common Thrift Ceanothus gloriosus Pt. Reyes Ceanothus t Cerastium tomentosum Snow-in-Summer Cistus salvifolius Sageleaf Rockrose . Coprosma kirkii Creeping Coprosma j: Cotoneaster spp. Cotoneaster 4 f ~6~ Epilobium canum California Fuchsia Festuca longifolia . Hard Fescue Fragaria chiloensis Beach Strawberry Liriope gigantea Giant Turf Lily Monardella purpurea Coyote Mint Myoporum parvifolium Myoporum - Osteospermum fruticosum Trailing African Daisy . Salvia sonomensis Creeping Sage Teucrium chamaedys Prostrate Germander Thymus praecox articus Creeping Thyme Verbena peruviana Perennial Verbena Perennials: - Achillea species Yarrow Coreopsis species Coreopsis Dietes bicolor African Iris Erysimum linifolium Wallflower Hemerocallis hybrids Daylily Iris douglasii Douglas Iris Lantana montevidensis Lantana Lavandula species Lavender - Limonium perzil Sea Lavender Lupinus species Lupine Polystichum munitum Sword Fern Sidalcea hickmanii Marin Checkerbloom Tulbaghia violacea Society Garlic Zauschneria californica California Fuchsia .Shrubs: Ceanothus 'Dark Star' Ceanothus Cistus spp. Rockrose _ Correa 'Carmine Bells' Australian Fuschia - Corylus cornuta 'Californicq' California Hazelnut _ Elaeagnus pungens Silverberry - Eriophyllum lanatum Wooly Sunflower _ Garrya elliptica -Silktassel Heteromeles arbutifolia Toyon Lonicera involucrata Twinberry Mimulus aurantiacus ~ Sticky Monkey Flower Myrica.california Wax Myrtle Polystichum munitum Sword Fern Prunus ilicifolia Holly-Leafed Cherry Rhamnus californica 'Eve Case' .Coffeeberry 5 . C I~ b7 ~I Ribes sanguineum Red-Flowering Current Salvia greggii Autumn Sage Solanum xantii Chaparral Nightshade Trees: Aesculus californica California Buckeye Alnus rhombifolia White Alder Arbutus unedo Strawberry Tree Cercis occidentalis Western"Redbud Crataegus phaenopyrum Washington Thorn Pistachia chinensis Chinese Pistache Quercus coccinea Coast Live Oak Quercus ilex Holly Oak Quercus lobata Valley Oak Quercus rubra Black Oak 1 Quercus suber Cork Oak Schinus molle California Pepper t Maintenance Standards: The following proposed set of maintenance standards will be used as guidance for work performance for maintenance as it applies to the zone between 0-30' from buildings. 1. All dead plants and dry vegetation shall be removed to establish and maintain a defensible space. The following actions will provide the equivalent level of fire safety as removing all combustible material. a. Cut grass and weeds to less than 2 inches yearly when 30% of the grasses have cured. The. grass will be cut within the week when 30~ of the grass cover is determined to be cured, and no later than June 1. This may require re-mowing if late season rains promote grass growth after the first cutting. All cut grass shall be raked and removed from the site. This will apply during construction and prior to occupancy, as all of the Defensible Space Zones will be irrigated, and not contain native grasses. b. Keep the ground, roofs, decking and balconies free of dead leaves or other plant debris. 6 ~ ~ 61 - c. Leaves, bark arid humus will be cleared every year under trees and shrubs. At no time will a buildup of leaves and humus exceed 1 inch in depth anywhere in a landscaped area. However, bare earth will not be exposed in over 50% of the site. d. Dead materia I that drapes over ground cover wail need to be removed yearly, before June 1. This includes leaves, bark, and branches. e. Remove all dead branches from within live ground covers, vines and.shrubs, immature and landscape trees. - 2. Mechanically chipped materials can remain on the -site provided the mulch layer is no greater than 2 inches in depth. 3. Creation of "ladder fuel situation" (where a fire can climb from one ' vegetation layer to the next) will. be avoided. Thus shrubs may be near but not under trees. If there is a choice, place trees downhill and shrubs uphill where the structure is above the open space. 4. No stacked wood piles will be located in this zone. 15'-34' or 25'-55' Defensible Space Zone A portion of the zone 15'-55' from the buildings will provide additional defensible space. Most of this area will be irrigated, and will be landscaped with groupings ` of low and medium height, fire resistant plant material, and will be aggressively maintained. There will be a few random tree groupings for screening. Groundcovers: Arctostophylos `Hookeri' Manzanita Ceanothus gloriosus Pt. Reyes Ceanothus Cistus salvifolius Sageleaf Rockrose Coprosma kirkii Creeping Coprosma Cotoheaster spp. Cotoneaster - ~ Epilobium canum California Fuschia Festuca longifolia Hard Fescue Monardella purpurea Coyote Mint Myoporum parvifolium Myoporum . Salvia sonomensis Creeping Sage . 7 ~ . ~ ~ 1~ /6 Shrubs: Ceanothus 'Dark Star' Ceanothus Cistus spp. Rockrose Correa 'Carmine Bells' ~ Australian Fuschia ' Corylus cornuta 'Californica' California Hazelnut Elaeagnus pungens Silverberry Garrya elliptica Silktassel Heteromeles arbutifolia Toyon Mimulus aurantiacus Sticky Monkey Flower Myrica California Wax Myrtle e Prunus ilicifolia Holly-Leafed Cherry Rhamnus Californica 'Eve Case' Coffeeberry Ribes sanguineum Red-Flowering Current Salvia greggii Autumn Sage I Trees: Aescvlus Californica Buckeye Alnus rhombifolia White Alder. Arbutus menziesii Madrone Cercis occidentalis Western Redbud Pistache chinensis Chinese Pistache Quercus coccinea Coast Live Oak Quercus Ilex Holly Oak Quercus lobata Valley Oak .Quercus rubra Black Oak Quercus suber .Cork Oak . . Schinus molle California Pepper Maintenance Standards: The following proposed set of maintenance standards will be used as guidance for work performance for maintenance as it applies to the zone between 15'-55' . from the home. ' ~ l . All dead plants and dry .vegetation shall be removed to establish and maintain a defensible space. The following actions will provide- the equivalent level of fire safety as removing all combustible material. a. Cut grass and weeds to less .than 2 inches yearly when 30% of the. r grasses have cured. The grass will be cut within the-week when 30% of the .grass cover is determined to be cured,. and no later than June 1.. This may require re-mowing if late season rains promote grass growth after the first cutting. All cut grass shall be raked and 8' - all removed -from the site. This will apply during construction and prior to occupancy, as all of. the Defensible Space Zones will be irrigated, and not contain native grasses. b. Leaves, bark and humus will be cleared every year under trees and shrubs. At no time will a buildup of leaves and humus exceed 1 inch in depth anywhere in a landscaped area. However, bare earth will not be exposed in over 50% of the site. c. Dead mat r' h r v v e ial t at d apes o er ground co er will need to be .removed yearly, before June 1. This includes leaves, bark, and branches. d: Remove from mature trees all vines, loose papery bark, dead branches and live branches smaller than 3 inches in diameter; to 8 feet above ground. e. Remove all dead branches from within live round covers, vines g and shrubs, immature and landscape trees. 2. Remove and safe) dis ose of all cut ve etation and hazardous refuse. Y p 9 3. Mechanically chipped materials can remain on the site provided the mulch layer is no greater than 2 inches in depth. 4. Creation of "ladder fuel situation" {where a fire can climb from one vegetation layer to the next) will be avoided. Thus shrubs may be near but not under trees. If there is a choice, place trees downhill and shrubs uphill where the structure is above the open space. 5. No stacked wood piles will be located in this zone. 55'-100' Defensible Space Zone A portion of the zone 55'-100' from the buildings will provide additional downslope defensible space. Some, but not all of this area will be irrigated, and will be encouraged to revert to a natural landscape fabric. Landscaping will consist of hydroseeded annual- grasses and wild flowers with .strong slope stabilization qualities and low fuel volume. Some random tree clusters will be created for screening and aesthetic appeal, and- reforestation. All vegetation will be aggressively maintained. . 9 ~ ~ ~ Grasses and Wildflowers: Seed Mix by weight Botanical Name Common Name 25% Festuca rubera cv. Molate Red Fescue - 25% Hordeum brachyantherum Meadow Barley 15% Melica imperfecta Coast Range Melic 15~ Nassela pulchra iStipa) Purple Needlegrass 7% Mimulus aurantiacus Monkeyflower . 6% Artemisia californica California Sage 3% Lupinus succulentus. Succulent Lupine 2.50% Eschscholzia californica California Poppy J5% Layia platyglossa Tidy Tips _ .50% Clarkia amoena ssp. Godetia ' . .25% Achillea millefolium Yarrow Trees: Aesculus californica Buckeye Alnus cordata Italian Alder Alnus rhombifolia White Alder Cercis occidentalis Western Redbud Heteromeles arbutifolia Toyon Prunus ilicifolia Holly-Leafed Cherry Quercus coccinea Coast Live Oak ' Quercus lobata Valley Oak Quercus rubra Black Oak Quercus suber Cork Oak . Maintenance Standards: The following proposed set of maintenance standards will be used as guidance for work performance for maintenance as it applies to the zone between 55'- 100' from buildings. Creation of "ladder fuel situations" (where a fire can climb from one vegetation layer to the next) will be avoided. In openings between trees, shrubs may remain.. Maintain individual plants or shrub masses to create "shrub islands" with adequate horizontal spacing. The crown cover of shrubs will not exceed 30% shrub, withremaining vegetation ideally comprising 50% -grass and 20% other herbaceous plants. The maximum dead-to-live ratio would be 20% in the fuel modification zones. Those shrubs ® which readily reseed (poison oak and coyote bush) wilt be preferentially cut ¦ before those shrubs which depend upon seeding for replacement. r 0 l I~ i 1. All dead .plants and combustible materials shall be removed within 100 feet of the structure to establish and maintain a defensible space. The following actions will provide the equivalent level of fire safety as removing all combustible material. a. Cut grass and weeds to less than 4 inches in height under short trees (trees under 24 feet in-height) to preclude excessive .pruning. This will be done yearly before May 1. Cutting ,of native grass and . wildflowers maybe delayed under after seed set provided they do not form a means of rapidly transmitting fire to any structures. b. Remove from mature trees all vines, loose . ,papery bark, dead branches and live branches smaller than 3 inches in diameter, to 8 feet above ground. c. Remove all dead branches from within live ground covers, vines and shrubs, immature and landscape trees. 2. Trees and large tree-form shrubs shall be pruned to provide clearance of three times the height of the understory plant material or 8 feet, whichever is higher. 3. Mechanically chipped materials can remain on the site provided the _ mulch layer is no greater than 2 inches in depth. 4. Remove and safely dispose of all. cut vegetation and hazardous refuse. DESCRIPTIONS OF MAINTENANCE PROCEDURES Grass Mowing Grass will be mowed with a n Ion cord weed whi er or razed with oats. The Y pP 9 g control that is afforded by manual or goat herds, as compared to mechanical equipment, is advantageous to avoid harming new and existing oak seedlings, as well as damaging rock formations. Weeds will be removed with manual labor using a weed whipper or applying herbicides on a spot basis. Weeds, grass and removal of any oak leaf litter or other dead material in the critical zone will similarly need to be done manually, possible with a rake. This will apply during construction and prior to occupancy, as all of the Defensible Space Zones, except for the 55'-100' zone, will be, irrigated, and-not contain native grasses. 11 1 ~ ~ ? ~ ~ ~b Shrub Management Shrubs that need to be removed will be cut with weed whips that have a cutting . . blade attached, or grazed with a goat herd. Branches which are larger than can be handled by the weed whip, or consumed by goats will be.cut with a chainsaw. When manual labor is used, special precautions will be needed in poison oak: To avoid re-cutting or otherwise re-treating undesired shrubs, spot, application of a .Category 3 or 4 herbicide will be applied to the foliage or stump, depending on the recommendation provided by a licensed Pest Control Advisor (PCA), If goat grazing were used, dead material which was not broken .up or consumed will need to be cut manually with toppers and saws. Oak seedlings . and small oaks will need to be .protected from goat grazing, as the animals will browse and girdle the trees. Protection may take the form of "cages" made from fencing or temporarily wrapping the tree trunk. If manual labor is used, dead material wi{I need to be cut with toppers and/or saws. Pruning and shortening shrub height will need to be accomplished with the same method. ' The debris. of the shrubs can be cut and hauled away, or mechanically chipped and left in place. Following the initial treatment, manual labor or a goat herd :will be used to remove incipient shrubs in the grasslands before they flower. While the plants need not be removed the first year they appear (since the shrubs would provide some improved, deer browse), they will be cut or grazed before they are old enough to set seed and spread (this is approximately three years). . While the initial treatment is likely to be substantial, subsequent maintenance will require significantly less effort. Application of herbicides to undesired shrubs will further diminish subsequent maintenance requirements, as it will prevent re- sprouting. In addition to reduction of fire hazards, hand. crews will be used for the removal of undesirable and hazardous plants such as poison oak, artichoke thistle, purple and yellow star thistle, and Russian thistle. These species will be removed with a combination of repeated manual cutting, spot application of a Category 3 or 4 herbicide, and mowing at the time of flowering. The open space will need to be monitored ,through the year, every year, in order. to eradicate these weeds before they become dominant and constitute a significant fire hazard. 12 r ' f ~ ~ ~~7 Pruning of Oak Savanna/Woodlands Pruning of lower branches of oaks, other trees and tree-like shrubs wherever they occur will need to be performed by hand crews, using toppers, hand saws, chain saws and chain saws on poles under supervision of an arborist. Similarly, dead material in the tree crowns will need to be accomplished in ,the same manner. Where leaf litter has accumulated to a depth which triggers management action, hand crews with. rakes will need to be used to remove the material. Debris of the pruning operation can be hauled away, or mechanically chipped_ and left in place. . 13 ~ ~c b ~ i SUMMARY OF FREQUENCY OF RECOMMENDED MANAGEMENT . Ahnuat Management • mow, graze grass near structures and under trees and shrubs during construction, prior to occupancy and along roads and driveways • hand crew cut shrubs and weeds in grasslands • monitor site for weed and shrub encroachment inspect trees for deadwood, vertical clearances • re-establish vertical clearance in Landscape Zone _ remove weeds, all dead material in Landscape Zone Management That Will Occur Every S Years, Or More Frequently As Necessary To Meet The Plan • thin shrubs into groupings • remove new understory shrubs • prune trees of lower branches to re-establish vertical clearance ACTIONS TO BE TAKEN DURING HIGH FIRE DANGER i In times of very high fire danger, extra precautionary procedures should be instituted by the facility. ~1 14 1 1~ ~ 6~ r APPENDIX C RIPARIAN MITIGATION & MONITORING PLAN a i i ~ERLOGAR STEVENS & ASSOCIATES 1 ` lig~ r~~ f REVISED RIPARIAN MITIGATION AND MONITORING PLAN 1 FOR THE FALCON CROSSING DEVELOPMENT PROJECT ALAMEDA COUNTY, CALIFORNIA Prepared for: L STANDARD PACIFIC HOMES 3825 Hopyard Road, Suite 27S Pleasanton, California 94588 Prepared by: OLBERDING ENVIRONMENTAL, INC. Wetland Regulatory Consultants 3170 Crow Canyon Place, Suite 260 San Ramon, California 94583 Phone; (92S) 866-2111 ~ FAX (92S) 866-2126 Contact: Jeff Olberding ¦ MAY 2011 lid ~ TABLE OF CONTENTS 1.0 PROJECT DESCRIPTION FOR WHICH MITIGATION IS REQUIRED ........................1 1.1 Brief Summary of Overall Project ..........................:................................................1 1.2 Location of Project ...:...............................................................................................2 13 Responsible Parties: ............................................................................................:....2 1.4 Habitat Types and Functions,of the Jurisdictional Areas Impacted ............:.:.........3 2.0 GOAL OF RESTORATION AND MITIGATION PLAN .................................................3 3.0 IMPLEMENTATION PLAN ................................................4 3.1 Plan and Permit Check ..................................:..........................................................4 _ ~ 3.2 Install Protective Flagging for Preservation and Pond Construction Areas ............4 . 3.3 Installation of Exclusion Fencing ............................................................................5 ' j 3.4 Site Grading ............................................................................................................5 3.5 Weed. Control .......................................................................5 3.6 Augering of Holes for Trees and Shrubs $ . „ 3.7 Planting ...........................................................................................................:........5 3.8 Installation of Irrigation ...........................................................................................7 3.9 Complete Erosion Control Measures ...................................................:...........:.......7 3.10 Prepare As-Built Drawings and Construction Report ..............................:...............7 4.0 MAINTENANCE DURING MONITORING PERIOD .....................................................7 4.1 Maintenance Activities „-g 4.1.1 Yandalism .................:..................................:...............................................8 . 4.1.2 Weed Control .........................................:.....................:...............................8 4.1.3 Plant Maintenance ....................................................:................................1 l 4-1,4 Irrigation Maintenance and Monitoring .......................:.....:......................11 4.1. S Litter Removal ............................................................................................1 l 4.1.6 Erosion Control .............:...............................'.....................:......................11 4.1.7 Maintenance Records ...........................................................:.....................12 4.2 Responsible Parties.. .:...........................................................................................:12 4.3 Schedule ....................................................................:............................................12 4.4 Long-term Maintenance .........................................................................................13 5.0 FINAL SUCCESS CRITERIA ..........................................................................................I4 . ' S.1 Overall Mitigation Objectives .....................................:..........................................14 5.2 Conditions Proposed for the Site that Will Insure Success ....................................14 5.3 Quantitative Mitigation Success Criteria ...........................................:...................15 6.0 MONITORING PLAN I S 6.1 Performance Criteria ..................................................................................:...........16 6:1.1 Number. Remaining from Original Planting l 6 i. b~ i 6.1.2 Site Maintenance ..............:.......................................:.................................16 b.1.3 Plant Vigor and Health/Abundance and Diversity ..................................:..16 6.2 .Monitoring Methods and Schedule ...................:....................................................17 6.2.1 Number Remaining from Original Planting.:,..., .......::...................:..........17 b.2.2 Site Maintenance .....................................................::..:..............................17 ' 6.2.3 Plant Vigor and Health/Abundance and Diversity ..............................:.....17' 6.2.4. Photo-Documentation ............:..:.:....................:.........................::.....:...:....18 6.3 Data Analysis 18 6.3.1 Number Remaining from Original Planting .................18 6:3.2 Site Maintenance ....:...18 b.3.3 Plant Vigor and Health/Abundance and Diversity ....................................18 6.4 Annual Reports ......................................................................................................19 6.5 Schedule ..............................................................................:............................:.....19 7.0 COMPLETION OF RESTORATION ...............................................................................ZO ~1 7.1 Notification of Completion .........................................:..........................................20 7.2 Confirmation ..20 8.0 CONTINGENCY MEASURES ........................20 8.1 Initiating Procedures e ....................................................................:.......20 List of Tables Table 1 Sequence of Habitat Construction Tasks .........................:..............:...........................:..4 Table 2 Proposed Riparian Plants and Estimated Number Required ........................:................6 Table 3 Maintenance Activities by Year .........................:.....................................:..........:......12 Table 4 Long-term Maintenance Activity Beyond Year 10 ........................................'.............13 Table 5 Plant Vigor and Health Ratings .....................................:.............................................17 ii lal ~ 6~ ATTACHMENTS ATTACHMENT 1 FIGURES Figure 1 Regional Map Figure 2 Vicinity Map Figure 3 USGS Quadrangle Map for Livermore Figure 4 Aerial Photograph Figure 5 Fallon Crossing Development Site Plan Figure 6 Mitigation Area Map Figure 7 Riparian Planting Plan Figure 8 Deed Restriction Area Map b This report should be cited as: Olberding Environmental, Inc. May 2011. Revised Riparian Mitigation and Monitoring Plan jor the Fallon Crossing Development Project, Alameda County, California. Prepared for Standard Pacific Homes, Pleasanton, California. r_ iii . 1a~~ 167 1.0 PROJECT DESCRIPTION FOR WHICH MITIGATION IS REQUIRED 1.1 Brief Summary of Overall Project The Fallon Crossing Property (Property) consists of 66.9 acres of gently rolling hills primazily ~ . vegetated with non-native annual grassland habitat (Attachment 1, Figures 1-4). A segment of a degraded incised creek channel (Moller Creek)-flows across the northern portion of the Property. Proposed development of approximately lOb single family residential units, interior streets, utilities, a storm water detention basin and two water quality basins will result in permanent impacts to 21 acres of the Property (Attachment 1, Figure 5). An additiona19.8 acres (ti.l acres located on-site and 3.7 acres located on an adjacent property) will be temporarily impacted by grading in order to stabilize the hillsides above .the development Project. All areas temporarily impacted for geotechnical rehabilitation purposes. will be restored back to grassland habitat upon completion. The Development Project .will involve the construction of an outfall structure within Moller Creek with impacts to the bank of Moller Creek above and -below the ordinary high water (OHW) line. The outfall will consist of a 9x20x 12 foot concrete structure (180 square feet) or 0.004 acres of impact along a degraded creek embankment. Sheet pilings will be installed just above the OHW line to provide a footing for the outfall. Three concrete chambers have been designed to dissipate water velocity from storm water discharges. Work includes placement of 1/4 ton rock rip rap to slow water flow as it enters the creek. The rock rip rap protection apron and coir fabric will be positioned at the base of the outfall. The bank protection material will be installed over a 15-foot wide length. of channel and extend 5 feet below the OHW line. The dimensions of the rock rip rap are I Sx5x3 feet for a total of (75 square feet). Permanent impacts within the creek total 255 . square feet (0.006 acres). Additionally, a detention basin and the two storm water quality basins (water quality ponds) will be constructed to treat water that will flow from the development site into Moller Creek. The detention and water quality basins will be located between the development and Moller Creek and managed for water quality purposes. The outfall will discharge stormwater which collects within the detention basin and two water quality ponds. These facilities will be maintained by the Geologic Hazard Abatement District (GRAD), as described in the Stormwater Management Plan which has been. submitted under separate cover. Additional work in Moller Creek consists of the placement of the discharge. culvert from the water treatment basin within an excavated trench through the bank of Moller Creek. This activity includes the excavation of a trench 15x4 feet from the edge of the riparian dripline to the outfall structure for a total of 60 square feet. Finally, an additional 18-inch sfonn drain line will be installed along Tassajaza Road. The stone drain will tie into the existing culvert located under the Tassajaza Road Bridge. This activity involves the excavation of a trench 47x5_ feet along the edge of the creek bank with a portion of the trench located in the riparian dripline for a total of 235 square feet of impact. In both cases, the utility trench accommodating the stone drain lines - will be backfilled and restored. Temporary impacts within the creek total 295 square feet (0.007 acres). . - l 1 A total, of 550 square feet _(0.013 acres) of impact (255 sgft permanent and 295sgft temporary) would occur along a combined total of 33 linear feet of the Moller Creek channel and _ embankment, to install an outfall structure and riprap and allow for trenching work to accommodate storm drain lines. The outfall structure is positioned between a break . in the willow riparian vegetation, but construction may require the trimming of trees to accommodate equipment access to the work area. Native material will be removed for the placement of the storm drain lines, gravel will be installed in the trenches, and native soils will be replaced. The on-site mitigation area proposed for project related impacts to Moller Creek and associated riparian habitat is approximately 150 feet long by 50 feet wide, 7,500 square feet. (0.17 acres) and occurs between Pond 2 (lower pond) and Moller Creek (Attachment 1,.Figure b). The mitigation calls for the installation of 82 native riparian trees .and shrubs that .will provide additional.. cover for CRLF. The expansion of riparian habitat will enhance the existing setback ' buffer between planned residential development, the Creek and the lower pond. 1.2 Location of Project The 6b.9-acre Property is located on the east side of Tassajara Road, northeast of the city of Dublin. The Property is found approximately 2.5 miles north of the Highway 580 and Tassajara Road interchange. The Property is situated at the first bend in the roadway where it curves east to cross over Moller Creek in Alameda County, just south of the Contra Costa/Alameda County line. Moller Creek forms the northwestern boundary of the site, Tassajara Road forms the western border, Pirui Brothers Silvera Development is located along the southern boundary and fence lines and undeveloped lands form all other boundaries. Attachment I, Figure 2 illustrates the vicinity of the Property iri relationship to the City of Dublin. Attachment 1, Figure 3 identifies the location of the Property on the USGS 7.5 Quadrangle Map for Livermore. An aerial photograph of the Property is contained in Attachment 1, Figure 4. The development Project is depicted in Attachment 1, Figure 5. 1.3 Responsible Parties The applicant for this project is: This riparian mitigation plan is being prepared by: Standard Pacific Homes Olberding Environmental, lnc. 3825 Hopyard Road,, Suite 275 1370 Crow Canyon Place, Suite 260 . Pleasanton, California 94558 San Ramon, California 994583 Contact: Mr. -Aaron Ross-Swain Contact: Mr. Jeff Olberding Telephone: (925)-730-1375 Telephone: (916)-985-1188 Fax: (949) 789-9601' Fax: (916) 985-2288 E-mail: arossswain@sfanpac.com E-mail: Jeff@olberdingenv.com 2 ~ : ~a~;~ 1b~ 1.4 Habitat Types and Functions of the Jurisdictional Areas Impacted Moller Creek is defined by a very deeply incised bed and bank. Approximately 1,460 linear feet of the channel occur along the northwestern property line. The active channel =averages approximately five feet wide and lies approximately 20 feet below the top of the bank. A narrow . ~ flood terrace is also located along portions of the Creek adding an average of nine additional feet . to the channel. The slopes of the banks approach vertical, however, a few locations occur that are less steep allowing access to the channel. Scour is ongoing along the banks of the channel and there is a lack of channel vegetation. The portion of the channel in the property area and directly downstream appears to suffer from .a very high erosion rate. Arroyo willow (Salix lasiolepis) and valley oak (Quercus lobata) are found along theactive portion of the channel and up to the top of the bank. Elderberry (Sambucus mexicana) and coyote brush (Baccharis pilularis) were also observed as secondary species in the comdor and were the only understory components along the channel. Several mature blue gum (Eucalyptus globulus) occur on the top of the east bank and within the channel. Fine gravel material and silt are found in the bed of the Creek. Where Tassajara Road crosses the Creek, a large corrugated metal culvert transports flows beneath the roadway. Approximately 1,200 feet southwest from the property, Moller Creek.joins the main, channel of Tassajara Creek. A stock pond is located along the east bank of Moller Creek in "the northwestern corner of the property. This pond was restored in the spring of 2001 and planted with freshwater marsh and riparian ,species such as .cattails (Typha latifolia), three square (Scirpus americanus), arroyo ~ willow, western sycamore (Platanus racemosa), and cottonwood {Populus fremontii). The pond- is approximately 9,280 square feet (58 feet by 160 feet) in size. Pond depths range from several inches along the edge of the pond to 13 feet deep near the center. Both the pond and the creek channel provide habitat for the California red-legged frog (Rana draytonii (CRLF). , 2.0 GOAL OF RESTORATION AND MITIGATION PLAN The goal of this document is to set forth a riparian planting plan to enhance/restore 0.17 acres of riparian habitat along a 150-foot by 50-foot section of Moller Creek fully mitigating impacts to 0.013 acres of non-vegetated creek bank associated with outfall construction.. and utility trenching. The general purpose.of the proposed mitigation is to enhance and expand the width of the existing riparian comdor along Moller Creek and provide species access to the creek from an existing stock pond known to contain CRLF. 3 j _ ~5 ~ ~ 6 7 3.0 IMPLEMENTATION PLAN The general sequence of construction tasks is shown in Table 1 below. 1. Plan and permit check. 2. Install protective flagging for preservation areas (riparian comdor and oak trees). _ 3. Installation of exclusion fencing. 4. Site grading. 5. Weed control. 6. Augering of holes for trees and shrubs. 7. Planting. - 8. Installation of irrigation. 9. Erosion control measures. 10. Prepare as-built drawings and construction report._ All tasks will be overseen by an Ecological Monitor (EM), a qualified ecologist with experience. m the areas of habitat development, hired by the. applicant. Vehicular access to the restoration - area will be restricted to restoration construction and later to emergency and. maintenance purposes (estimated to occur twice per year or less). 31 Plan and Permit Check Plan check requires an on-the-ground survey of all work detailed in the restoration plan. Permit checks require ensuring that all work complies with State, and local permits. The EM must identify in the field the preserve, weed control zones, access routes and materials and equipment storage. . 3.2 Install Protective Flagging for Preservation and Pond Construcfion Areas Prior to any site modification, all existing habitats within the general work- area that will be protected (tlie riparian vegetation along the creek and preserved valley oaks) shall be staked and flagged by the EM. Flagging will consist of four-foot red or orange construction fencing and be replaced as necessary to be continuously in place during construction activities. Flagging shall extend around the protected area perimeters or along their entire lengths to prevent any wanted . intrusions and/or damage: Accidentally damaged plants or areas will be replaced or repaired and the damage and corrective action reported in the first monitoring report. If flagging proves an insufficient barrier° to protected areas, .fencing will be required. Fencing and flagging will be removed at the end of construction work. Garbage, including old barbed wire fences, on the restoration site or discovered during initial .mobilization shall be removed to an approved disposal. site. 4 _ 1a,6 16~ i~ 3.3 Installation of Exclusion Fencing A split rail or similar type of fence, to be field located by the landscape architect, will be .permanently installed between the riparian mitigation area and the development. The location of the fence will roughly correspond to the outer edge of the 100-foot riparian setback buffer and the 200 foot setback around the constructed pond feature at the north boundary. of the mitigation site. 3.4 Site Grading No grading is anticipated within-the riparian mitigation area. A truck mounted augur will be used in the establishment of tree and shrub planting. Shallow watering basins will also be placed around each of the new plants. . 3.5 Weed Control Invasive non-native plants within the mitigation .area will be removed prior to any revegetation work. Treatment involves the mowing, disking, or removal of the.primary plant, all roots, and any seed that could contaminate the site. These opportunistic species are known to out-compete California natives for light, water, nutrients and space. An aggressive eradication effort prior to revegetation will give the natives amuch-needed competitive edge and significantly reduce ' future maintenance efforts. _ Areas of noxious weeds shall be disked, watered to encourage seed growth, and disked again. The cycle may be repeated until. weed growth is extremely sparse. Areas with little or no grading will require at least a thorough mowing so that debris will not hamper construction. A flail-type mower should be used, and all debris thoroughly mulched. 3.6 Auguring of Holes for Trees and Shrubs Holes will be augured to a de th re uired for ro er installation of restoration st e P q p P ock. Tr es will be excavated to a width of 24 inches greater than that of the root ball, and to the depth of the root ball. Shrubs and vine will be excavated to a width of 12 inches greater than the width of the root . ball, and to the depth of the root ball. Subgrade material in the holes shall be Ioosened to a depth of three inches. 3.7 Planting A mix of riparian trees and shrubs is proposed to .be planted to enhance the existing riparian corridor and to increase the area of the riparian habitat of the Moller Creek corridor. The species composition is detailed in Table 2 below. 5 lad 167 Common Name Botanical Name Size * uanti California Bucke e Aesculus tali ornica 1$ aUl ai+ - ~3 Western S camore Plantanus racemosa 1$ aUl al 6 Coast Live Oak uercus a ri olia 1$ aUl al 3 California Ba Umbellularia tali ornica 1$ aUl al, 3 . ~;~~f Co ote Brush Baccharis ilularis • 1 al' 10 Mule Fat Baccharis salici olia 1 al $ Blue Blossom Ceanothus s . ~ 1 al ~ California Wild Rose Rosa call ornica 1 al 14 California Blackbe Rubus ursinus 1 al 21 y; Mexican Elderbe Sambucus Mexicana 1 al 6 Snowbe S m hoica os alblus 1 al $ TOTAL a~~~ ~ 82 * ] 5% of all trees shall. be 15 allon containers, remainin trees shall be 1 allon containers. The species have been selected based upon presence near the site. Unless specifically noted below, it is the goal of this program that all plant materials -container stock, seeds, and plugs are to be planted from stock gathered in the immediate vicinity of the Project site. As a result, only genotypes of locally native species should be planted. Generally, plant material may be installed as container stock, bare root seedlings, cuttings, canes, plugs or seed. Viability and growth of different species varies by stock type, however; and the form chosen for this plan is based on the authors experience with these species. The trees specified for planting shall. meet .the following minimum standards. The form shall be standard with the main scaffold branches established and properly distributed, preferably with a ~ . full skirt of branches. For 15 gallon container size trees, the minimum trunk caliper at six inches in height should be between one and 1.2$ inches. The minimum height should be seven to eight feet, and the minimum canopy spread should be between two and three feet. Prior to planting, all planting areas. will be tilled to loosen soils to a minimum depth of eight .inches. Plant material shall be free from damage, disease, insects and weeds, not be rootbound, and identified correctly to genus and species. Plants shall be sufficiently rooted to the edge of the container to maintain.the root ball when removed. The planting azea should be free of weeds, trash and other debris. Plants will be placed according to the plans of the landscape architect, . using a .triangular spacing method. The root collar will be placed at one inch above the surrounding grade. All holes shall be backfilled by the end of that same workday. Backfill material will include one part existing soil (or approved topsoil) and one part nitrolized fir . shavings or nitrolized half-inch minus fir bark. Soils shall be completely saturated to promote 6 't ~~~16? settling of excavated soil, Slow-release fertilizer such as agriform or osmocote will be added to ® each planting hole prior to planting. A After planting ammonium sulphate should be applied at a rate of five pounds per 1000 square feet to all planting areas. All. areas with. ground cover and shrubs shall have two-irich shredded i ~ bark mulch applied as well. All new plantings shall be watered deeply and thoroughly. All trees shall be .staked, and trees and shrubs shall have watering basins... All. plants will have deer protection such as screening for foliage and collars for the.root structures if browsing is evident. All trees shall be guaranteed for a nunimum of one full year from the date of final acceptance. . Shrubs and ground cover plantings will be guaranteed for a minimum of 6 months from the date of final acceptance. The landscape contractor, to be named by the property owner,, shall be responsible for maintaining the.plantings for 60 days from the date of final acceptance. The EM will oversee maintenance during this interval. 1 The trees and shrubs installed will ev n 11 v' e tua y pro ide higher quality habitat and additional cover for CRLF than what currently exists on the site. It is estimated that it will take at least three to five years for. the understory species and eight to ten years for tree species to provide habitat ' functions similar to those located along Moller Creek. It can be assumed that this habitat will provide food, cover, and nesting materials to a wide variety of riparian wildlife species once established. 3.8 Installation of Irrigation The contractor shall provide sho drawin s of the irri ation s stem whic P g g y h shall be reviewed. by the landscape architect prior to installation. Imgation shall be temporary for the first three years. After three years the imgation system will no longer be utilized. 3.9 Complete Erosion Control Measures 1 All graded slopes will be revegetated and seeded as noted above, and the Project will be sub'ect - J J to State and local erosion control regulations. 3.10 Prepare As-Built Drawings and Construction Report Within six.rnonths of completion of the construction project, the EM shall sign a copy of the construction log and as-builts for the Project. The as-builts will include Project topography and planting zones and shall be used in the future as the base map. for the monitoring report. At that time, the applicant will send a copy of the signed as-builts to the City and request, in writing, - . _ inspection of the Project. 4.0 MAINTENANCE DURIN G MONITORING PERIOD Inspection .and !maintenance activities will be undertaken by a contractor hired by Standard . . , Pacific Homes with oversight by the EM. Inspection and maintenance activities will ..be I~ 161 y undertaken each year for a period of 10 years according to the schedule presented in, Table 3 below. -The monitoring schedule will be broken down into three categories: 1) Years 1=3 Plant . Irrigation Period; 2) Years 4 & 5 Plant Establishment Period; and 3) Years 6-10 Extended Monitoring Period. 4.1 Maintenance Activifies Most native plants such as those proposed for the restoration site are pre-adapted to their normal . regional growing conditions and do not .require substantial maintenance. "Pre-adapted to their growing conditions" means simply, that they will occur only where conditions are: relatively _ optimal for their growth. However, the species to be planted pursuant to this plan will not have - sprouted naturally. ' Restoration is an artificial process undertaken in anticipation that a native plant community, one adapted to the site conditions, will develop. Maintenance activities will therefore be rieeded to ' ensure that (1) the community. develops as a native plant community without the introduction of harmful non-native species, (2) the community can naturally regenerate and sustain itself in perpetuity, and (3) the development of this native community does not create potential hazards for the adjacent neighborhoods. At -the same time, maintenance shall not require significant modifications to the site. The guidance provided in this section describes maintenance activities that do not require further permitting actions. Maintenance activities shall be guided by defined treatments and restrictions. 4.LI Vandalism Maintenance activities will be conducted quarterly during Years 1-5 and then annually during Years 6-10. Site inspections shall be performed by the contractor for any evidence of vandalism. -Given the proximity of the mitigation sites to a residential neighborhood, it is possible that damage may occur from vandalism. The site will also be monitored for signs of excessive or. . uncontrolled human disturbance such as off-road vehicle use, presence of brush and litter and human foot traffic. Presence of human disturbance will be recorded along with suggested remedial action. 4.1.2 Weed Control In most cases, careful design and pre-planting weed control procedures will reduce the burden of weed abatement. However, afreshly-graded construction site is a haven for. weeds which may blow in from off-site.. Additionally, misapplied cultural efforts (irrigation during the warm season in an area known to contain warm season weeds) may actually promote weed growth in - . the restoration area. The EM shall. make a distinction between ruderal species that are part of natural succession and those species that will impede development of the target vegetation association. This latter group, particularly non-native and aggressive species, can be controlled using manual or chemical methods, bearing in mind that simply removing -the weed is no guarantee that another will not replace it. 8 - 13~ (61 The EM must also ensure that the appropriate native species replace the weed species and the conditions which resulted in' weed growth will not re-occur. This step is best addressed prior to construction through development of a weed control program that emphasizes prevention followed by containment and'elirnination/reduction. It is necessary to weed plant basins to control invasive non-native species that can reduce water or light availability. During the first one to two years after planting, it will be possible for weedy plants to grow as tall as or taller than the planted shrubs and to compete with the native species for water or nutrients. While some of these weeds will be native plants that might not compete with the planted species (they may .simply appear due to the relatively high fertilization rates or presence of disturbed soils), few people aside from experienced horticulturalists or plant ecologists will recognize the difference between native plants which may be relatively benign and those weeds which, can harm the restoration success. Consequently, this plan .espouses manual and/or chemical removal of all weeds within the planting basins that compete with the planted species. A desirable objective is to remove all non-natives prior to planting. This gives the natives the competitive edge needed to capture the site. Freshly graded soil from site preparation provides a perfect seedbed for. windblown seed from invasive non-native species. The success of initial eradication efforts may strongly influence maintenance requirements. Invading non-natives shall be removed before they are allowed to seed or become well- ' established on the site. Invasion of the restoration area by non-native species and weeds shall be noted in the .monitoring reports and prescriptions for removal shall-be provided in the maintenance manual Post-construction weed control must take into account the following steps: 1.. Identify and address the conditions which allowed or encouraged the exotic to. become established. ' 2. Remove the exotic. 3. .Replace the exotic with the appropriate native plant. 4. Maintain the site such that further opportunities for the exotic to become re- established are limited. Manual controls consist of either hand removal of the entire plant or cutting the plant above- ground. Hand removal of the entire weed is almost always possible but also labor-intensive and is best suited for woody plants. The advantage of hand removal is that the area of impact is usually~quite small; less specific weed control activities can create the type of disturbance which results in more weed growth. It is often much less expensive to cut the weed and then spot-spray the stump with an herbicide (see below far herbicide cautions). -For conditions that militate against the use of chemical controls, an array of tools are available from suppliers that can be • used to selectively remove even mid-sized trees without disturbing the adjacent land or plants. Cutting can include hand-pruning or chopping, weed "whips"- or similar hand-held but gas- powered tools; and tractor-driven or floating- mowers. Hand pruning or chopping is labor- - 9 intensive. and costly unless the weeders are volunteers. Prior to selecting this method, the ecologist shall personally weed a specific area for at least two hours and develop an estimate of the amount of person-hours then required, multiplying this by the cost of the labor. Where .weeding will occur in dense growth or where only. a few plants among many are to be ~ eliminated, this method is the most productive. ~ . . Weed. whips and similar tools are very useful for clearing annual or soft perennial growth over large or small areas where tractors cannot be driven (slopes, marshes, etc:). These shall not be used near planted trees and shrubs or above-ground irrigation lines as even an experienced practitioner can inadvertently girdle a plant or chop up a poly line. Mechanical mowers are .the most efficient means of cutting large areas of vegetation. They cannot run on steep slopes (although some have mowing "booms" which can reach out and cut limited areas) and to operate need a certain distance between trees and shrubs which are to remain uncut. It also is important to consider these issues during the design phase. An easily maintained project is generally subject to fewer disturbances and may prove to be more successful. Surveys for weed control needs shall start as soon after the construction as the growing season begins. Timing is often crucial in manually controlling weeds, especially annuals. Because . cutting does not remove the root systems, it is generally important to cut the plant just prior to seed set to maximize the likelihood of complete control. Even this technique may not always work. Chemical controls are often the least expensive means of eradicating or reducing weed growth. Application of a herbicide to the lowest portion of the tree provided good control for trees under 18 inches in diameter at the .base while cutting and application to the stump was required for _ larger trees. Few chemicals are licensed for use in wetlands and a licensed technician is often required by local regulations. Further, environmental conditions, e.g:, wind speeds, must be carefully monitored to avoid damage outside the target area. Chemical controls include "pre-emergents" _ that are applied to the ground prior to the emergence of the weeds in the spring or "post- - emergents" that kill or stunt plants during their active growth stages. Pre-emergent are most useful when applied adjacent to' newly planted propagules as they limit the growth of competing weeds adjacent to the propagule. Post-emergent controls are most useful for bioad areas • completely dominated by weeds; areas where no plants are proposed (firebreaks, for example); or spot-spraying of individual weeds. On this site, spot spraying of a post -emergent. broadleaf _ may be needed once fo twice per year during the spring growing season with two additional applications latter in the summer. Tree and shrub basins should be maintained quarterly during the first five years and then annually in Years 6-10, removing weeds by hand pulling if possible to prevent overspray on the installed plants. The placement of mulch or wood chips within the: planting basins will also reduce weed growth. Mulch should be checked on a quarterly basis during Years 1-5 and annually in Years 6-10. 10 4.1.3 Plant Maintenance All new tree and shrub plantings will be checked by the EM on a quarterly basis for deer . browsing, proper functioning of irrigation, healthy rootball; application of fertilizer, repair of water basins, and other pest damage during the first five years and annually thereafter up to Year 10. Imgation shall be checked only for the first three years, after which plantings will no longer , be irrigated. Hand clearing of .weeds around the base of the installed plants will also be . conducted on a quarterly basis. Once trees have become well-established, and if deemed necessary, some pruning of trees may be conducted to compensate for irregular growth due to excessive browsing or broken branches. Dead plants will be replaced annually in the late fall. 4.1.4 Irrigation Maintenance and Monitoring Irrigation will be used during the first three years to assist in plant establishment. The irrigation system shall be checked quarterly during the three year imgation period and as much as weekly ' immediately following plant installation, for malfunction and vandalism. All drip lines and filters shall be flushed as needed. Emitters must be checked regularly for. malfunctions, position of emitter over root ball, and vandalism. Flushing end caps must also be checked regularly. Irrigation for plantings is a temporary tool to help establish the constructed vegetation association. Water shall be decreased every year, and ideally shall not be needed after the third ' year. Caution shall be exercised not to create lush plants, which would become dependent on regular watering. Deep watering, spaced at the longest time possible before plants show signs of stress, shall be used. This type of watering will encourage plant roots to travel downward into ' the appropriate water zones in the soil. . 4.1.5 Litter Removal Litter can impede the growth of propagules or seedlings, and increase the cost of plant care maintenance efforts. Therefore, it is recommended that each site be thoroughly policed, and all litter and debris removed from the site at least quarterly dunng the fast five years and annually in Years 6-10. Adjacent construction especially generates large numbers of small snack bags which lodge among plants. Construction projects.which are near or within residential areas generally collect the most trash. - 4.1.6 Erosion Control The site will be inspected for signs of erosion quarterly during the first five years and annually in Years 6-10. Visual inspections of the restoration site will be conducted to ensure that there is not • . - erosion or downcutting from broken irrigation. lines or surface hydrology. The EM will determine if woody vegetation has become .established. If it is determined that erosion is occurring; measures will be taken.to divert or slow runoff prior to remedial actions. 11 9 _ 133 I6~ 4.L 7 Maintenance Records ' Documentation of all maintenance activities. will be prepared by the applicant during the five- . year monitoring period, then annually in Years 6-10. Photographs documenting the progress of the plantings will betaken at each visit. Photographic reference points will be pre-determined during the as-built survey. These points will include the outfall, riparian plantings, and. the new swale feature. A record of maintenance -activities by date will be submitted in a monitoring report. All monitoring reports will include information on type of activity, frequency and dates of maintenance activities and a summary of repairs and remedial actions and any other ' maintenance activities. 4.2 Responsible Parties Maintenance of the restoration area during the 10 year maintenance period will be the responsibility of the applicant with coordination from the EM. Maintenance, monitoring, and compliance reporting activities will be financed and carved out by the applicant through a contracted landscape maintenance company until mitigation has been determined to be successful by the EM and verified by the regulatory agencies. This mitigation plan is. being - designed so that restored riparian habitats are self-sustaining and will not require maintenance to assure continued viability. Maintenance may be required, however, to respond to disturbance by humans. For example, if unauthorized dumping were to occur within the restored area, maintenance would be required in order to properly dispose of the garbage or debris and clean up the site. 4.3. Schedule For the first one to two years, most projects will require awalk-through by an ecologist or maintenance technician every month. The variation in the number of visits depends on the size . of the site, its proximity to disturbance and the time of year. Visits may reasonably be required every week for the first year and twice monthly for the .next two years. Smaller sites, for example those less than ten acres, can reasonably be visited once every two-weeks during the first year, and monthly in subsequent years. The maintenance schedule determined for the site is " - listed in table 3 below. Maintenance Activi Years 1-3 Years 4 5 and 6-10 ' Vandalism Ins ection uarterl Years 4&5 uarterl ,Years 6-10 tAnnuall ' Weed Control Ins ection uarterl Years 4&5 uarterl' ,Years 6-10 Annuall A 1 re-emer ent uarterl Years 4&5 uarterl ,Years 6-10 Annuall ' - Add Mulch uarterl Years 4&S arterl ,Years 6-10 Anriuall - Weedin uarterl Years 4&5 uarterl ,Years 6-10 Annuall . - Plant Maintenance ' - In ection uarterl Years 4&5 uarterl ,Years 6-10 Annuall 12 . 13~ lb~ Maintenance Activi Years 1-3 _ Years 4 5 -and 6-10 - Re lace Dead Plants Annuall Annuall - Water Basin Re airs uarterl Years 4&S uazterl ,Years 6-10 Annuall - Fertilize Plants uarterl Years 4&5 uarterl ,Years 6-10 Annuall Irri ation Maintenance Ins ection uarterl - - Ad'ustments/re airs uarterl - Litter Removal uarterl Years 4&5 uarterl , Yeazs 6-10 Annuall Erosion Control Ins ection uarterl Years 4&5 uarterl ,Years 6- ] 0 Annuall Maintenance Records - Photo a h Site Annuall Annuall - Pre are Re ort Annuall Annuall 4.4 Long-term Maintenance The EM would be responsible for the coordination of site maintenance with the applicant and monitoring of the restoration site for ten years or until success criteria have been met and the regulatory agencies have provided a letter of release. Following the ten years of monitoring and maintenance the property own will incorporate- passive long-term. maintenance to ensure that the restoration site is functioning according to design and that vegetation is maintaining with minimum competition from invasive exotic plants . or disturbance from public access or trash build-up. Long-term maintenance will include regular inspections for exotic plant species, to be periodically eradicated, and removal of trash. Y: - . , Maintenance Activi Be and Year 10 Vandalism Ins ection Annuail Weed Control - Ins ection Annuall = A 1 re-emer ent Annuall Weedin Annuall Litter Removal - - Annuall Erosion Control In ection Annuall - - i~ - 4~ 13 . ~ 3S ~ 5.0 FINAL SUCCESS CRITERIA _ The final success criteria will be used to determine if the applicant has met the obligations outlined in this plan. Attainment of the final success criteria will indicate that the restoration-site is well on its way toward meeting the long-term habitat goals of the site with, little chance of failure. Success criteria will be evaluated each yeaz that monitoring is conducted with a final _ assessment performed the last year for which monitoring is required. Results of the final evaluation will be compared to the established success criteria and described in table format in the final report. Restoration of the functions lost as a result of the impacts to riparian habitat is a primary goal of this plan. This will be measured through the successful establishment of riparian habitat on the restoration site. Attainment of final success will be determined .by the regulatory agencies, which will verify success of the restoration site after being notified of attainment of the established criteria in the final report. Success criteria will be quantitatively evaluated by monitoring the restoration site annually during the 5-year monitoring period, then every other yeaz until Year 10. 5.1 Overall Miti ation Obeectives g J F Proposed mitigation will have the following overall objectives for mitigation of permanent impacts: ¦ To create 0.17 acres of self-sustaining riparian habitat; ¦ To attain 70 percent survival of planted trees and 80 percent survival of planted shrubs, evaluated individually for each planted species. ; ¦ Should the survival rate fall below 70 percent for tree species and 80 percent for shrub species at any point during the monitoring period (5 years for shrubs, and ten years for trees) until the success criteria in this plan are achieved, remedial planting shall be conducted and the monitoring period shall start anew. 5.2 Conditions Proposed for the Site that Will Insure Success ¦ The restoration area will be maintained in as natural a state as possible. The riparian habitat will not be mowed, burned, grazed or otherwise maintained, except as part of a regulatory agency approved long=term plan should such a plan be prepared, to maintain or enhance the natural values of the established habitats. ¦ No construction will occur in areas under regulatory agency jurisdiction outside the permitted mitigation project footprint; ¦ Unless authorized by the regulatory agencies, no work will be conducted within ..the restoration area that may modify the hydrologic regime of the riparian habitat orice established; 14 _ ?36 l6~ ¦ No farming or farming activity will be allowed within the restoration area; ¦ No grazing will be allowed within the restoration area; ¦ No off-road vehicle use will be allowed within the restoration area. 5.3 Quantitative' Mitigation Success Criteria The 0.17 acre mitigation area will be evaluated based on the following quantitative success criteria. Once the site has met these criteria and the circumstances on site have been confirmed by the regulatory agencies, the monitoring requirements will be considered satisfied and there will be no further obligation .for this site. It is anticipated by the applicant's biological consultant that_these criteria will likely be met within ten yeazs. If the site has not met these criteria and ten years have past, monitoring and maintenance shall continue until the conditions are met or an alternate mitigation plan is approved by the regulatory agencies. 1. Non-native plant species identified by the EM as "nuisance- species" shall not be greater . than 10% of the total vegetation cover (cumulative for all s ecies of nuisance lants P p ) within the riparian mitigation area; 2. The restoration area shall demonstrate natural hydrology. This shall be indicated b the Y lack of artificial irrigation for at least. two years (with no loss of vegetation); and 3. Restoration tree stock will remain alive at the end of the annual five year rowin season g g (and every .other year until year 10) with 70 percent survival of all planted trees. Restoration shrub stock will remain alive at the end of the annual five year growing . season with 80 percent survival of all planted shrubs. All trees and shrubs planted in the restoration areas. shall exhibit medium to high health and vigor and demonstrate new vegetative growth on an annual basis. 6.0 MONITORING PLAN The restoration site will be monitored over afive-year (and ultimately ten-year) period to ascertain whether the performance and success criteria aze met. Vegetation monitoring will be conducted annually for the first five years, then every other year until Year 10. By Year 5, the restoration site should be sufficiently well established to determine if it will reach the long-term goals, summarized below, with little chance of failure. The results of vegetative monitoring in Year 5 will be compared to the f nal success criteria to determine if these criteria have been met. If the final success criteria have not been met at the end of the monitoring period, monitoring will continue until they have been met. Additionally, creek monitoring will take place at the outfall location in order to evaluate any hydrogeomorphological changes associated with outfall ..construction: Three repeatable transect lines will be established across Moller. Creek.. One each up and downstream (50 feet) and the third at the outfall location. Measurements will be taken to demonstrate the location of top-of--bank, midpoint on the embankment, ordinary high water mark 15 - ~3~ ~6~ and thalweg or bottom of the channel. Data collection will follow the vegetative monitoring schedule. Photo points will also be established at each transect line location. 6.1 Performance Criteria This section contains the performance criteria for the restoration site. Monitoring of performance criteria will evaluate the extent to which original plantings remain so that the restoration site continues to meet the established final success criteria. The performance criteria are quantitative benchmarks against which the success of restoration will be tracked. 6.1.1 Number Remaining Jrom Original Planting At no time during the monitoring period, should the number of riparian plant species remaining from the original planting be lower than 70 percent survival for trees during the ten year monitoring period and 80 percent survival for shrubs during the five year monitoring period. If fewer than 70 percent of the original tree plantings and 80 percent of the original shrub plantings remain, replanting shall be conducted so that the original plantings are replaced. Percent survival must be evaluated individually for each planted species. If these success criteria are not achieved, dead plants must be replaced in kind, unless the Applicant demonstrates that the site is not conducive to the survival of a specific plant species, in which case alternate native riparian plant species may be-used. Replacement plantings must be made within one year of survival - .rates failing to meet the specified success criteria. Replacement shrubs shall be monitored for five years from the date of replanting. Replacement tress shall be monitored for ten years from the date of replanting. Replacement plants are subject to the same performance criteria as the - initial plantings Irrigation should only be conducted, during the .first three years unless replanting occurs. If • replanting is needed imgation shall be utilized for an additional 3 years to allow establishment of the newly planted stock. ' 6.1.2 Site Maintenance - Site maintenance is included in the performance criteria because of the critical importance of . proper maintenance during the plant establishment period. Site maintenance will be monitored to assess weed control, irrigation adequacy, trash removal, and vandalism. Site maintenance will be monitored during the ten-year monitoring period. 6.1.3 Plant Vigor and Health/Abundance and Diversity The health and vigor of each dominant native riparian species occurring in the restoration area will be qualitatively assessed. The following factors will be taken into consideration iri this determination: plant color, seed development, new growth, herbivory, drought stress, fungal/insect infestation, and physical damage. Overall health and vigor of each dominant riparian species will be rated as high, medium, or low (Table 5). 16 11 _ ~ ~ r~~ ' ~ . 4~ al _ _ ~ •SyN- 1 rbj faY,h~ , ~ .'i'q t'S°~'F "'YqM .2., " rra ~ 'thy ; ~ ~ ,q ? r, ~ ~ , 1 7~ ~ Safi.C4r~~3.}uh+f ~,~i`i~ N. ~Y } a+^T ~i'-'+„`YL~yC~4'~' 4 ~ `V1. l1, "~71L f~'A_', n ~ t ~ v ~ ~th~and~~gor~ w ~ .t ercentaHe.~lth{~ o'liaQe E ' ' u ~ ~'r, n s'!~.e-w'-.n. s4 -sYc !'~_ur~!~I~b . _1w~vaRlri~! _ High 67-100% Medium 34-66% Low 0-33% ' 6.2 Monitoring Methods and Schedule The restoration area will be monitored using the sampling techniques described below until the performance criteria described above have been met or exceeded, and it is demonstrated that the restored habitats have become self-maintaining. Permanent photo points that provide views of the restoration area would be established during the construction of the riparian habitats. :i Monitoring will be conducted between February and June of each monitoring year. Monitoring reports will be prepared by the EM following .data collection and will be ,submitted to the permitting agencies by December 31 of each monitoring year. 6.2.1 Number Remaining from Original Planting The percentage of remaining plant species from the original planting at the restoration area will be measured by counting the number of individuals of each species of tree and shrub remaining. • Sampling will be conducted at random locations throughout the restoration area site. 6.2.2 Site Maintenance Site maintenance will be assessed during .percent cover estimates and during general site monitoring as specified in the maintenance schedule. Pertinent information derived from visual observations, reports from site maintenance crews, or from other sources will be included in the ' summary for site maintenance. . 6.2.3 Plant Vigor and Health/.46undance and Diversity A rating of plant vigor and health will be assigned to all dominant plant species observed in the restoration area.. An explanation of each rating.will be provided in the text giving details of the rational for each rating. The qualitative assessment will be conducted at each data point; then an assessment that characterizes the entire site will be determined based on the average rating of the species. ® Abundance and diversity will be assessed by qualitatively analyzing the total number of plant `I species observed at the mitigation site. This information will. be recorded on the data sheets by documenting each species encountered. 17 i3~ X2.4. Photo-Documentation Photo-documentation. of the site will be conducted from fixed permanent locations along the creek channel. Photographs will also be taken to record any events that may have a significant effect on the success of restoration, such as flood, fire, or vandalism. Photos will be taken to document the success of plantings and. erosion control measures. These locations will be predetermined during the as-built survey. Additional photos will be taken if it is determined that the initial photo points are not sufficient to track riparian plantings along Moller Creek. A minimum of four photo points would be established along the restoration area. 6.3 Data Analysis L The yearly monitoring,results will be compared with results from previous years to evaluate site progress. 6.3.1 Number Remaining from Original Planting The number of remaining individuals of each species will be tabulated each year. Number of remaining species will be compared to the number at the time of the original planting. 6.3.2 Site Maintenance Success or failure of site maintenance will be analyzed and included in the monitoring report. Any recommendations will be provided based on yearly findings. 6.3.3 Plant Vigor and Health/Abundance and Diversity - Plant vigor and health will be r orted as hi h medium or low for each dominant s ecie . ~ g > p s Health and vigor ratings will be compared between years. The vigor and health rating for each dominant species will be included for discussion in the report. The abundance and diversity of the site will be qualitatively discussed in reference to the dominant species. 6.4 Chanel Stability Monitoring Creek. monitoring will be performed along three repeatable transect lines established across stationary points on Moller Creek. Measurements will be taken to demonstrate the location ofl top-of--bank, midpoint on the embankment, ordinary high water mark and thalweg or bottom of the channel on each transect line. Information would be collected to assess the stability of the channel and determine if the outfall has had an impact on the channel feature. Observation and data comparisons will be used to document channel slumping, bank erosion, channel incision, undercutting of the banks and loss of vegetation due to increased scour or erosion. Data J collection will follow the vegetative monitoring schedule. Photo points will also be established at 4 each transect line location. fit. 18 1 ~ 6.5 Annual Reports Annual reports will be completed and submitted- by the EM that present vegetation and channel stability monitoring results for the year monitored. These reports will assess both attairunent of yearly vegetation performance criteria and trend characteristics that demonstrate progress toward ~ final success criteria. The reports will also include specific information collected from stationary/repeatable transect lines at the three locations across the channel to document channel stability characteristics. The report will include documentation of .observed conditions, attainment of success criteria and. an assessment of any identified changes. Data sheets and photo documentation developed from the .monitoring effort would be combined with a compliance report summarizing monitoring results. This information will be submitted on an annual basis in the form of a mitigation monitoring report during the month of December or until success is achieved by meeting the final success criteria listed above: As required, these reports will include a list of names, titles, and companies of persons preparing the report, as well as all participants in the monitoring activities; a copy of the Corps permit, Special Conditions, and subsequent Letters of Modification; analysis of quantitative monitoring data; prints of all included monitoring. photographs; and maps identifying monitoring areas, transects, planting zones, etc. Annual monitoring reports ,will be sent by December 31 of each monitoring year. Annual monitoring reports will include a brief description of the project, the methods used to collect and analyze the data, the results of the data analysis, a discussion of the results, and conclusions regarding the present condition of the site. The report will also include a remedial action section - that will discuss any additional actions required to ensure that the site meets the success criteria. 6.6 Schedule Monitoring to determine the successful attainment of the performance criteria shall be tied to the actual implementation date of the restoration effort rather than to predetermined .years. It is anticipated that mitigation will be completed in 2011. _ The proposed monitoring schedule is outlined below: 1. Conduct baseline vegetation and channel stability monitoring in the fall of 2011. 2. Conduct annual site vegetation and channel monitoring to determine restoration- success and channel stability between February and June 2012-2016, then every other year until 2021. The monitoring period will restart for any new plantings installed, should the survival rate fall below 70 percent for trees during the ten year monitoring period or 80 percent for shrubs during the _initial f ve years of monitoring. _ . 3. Submit an annual compliance monitoring report which includes data sheets, photo documentation and a .report summarizing monitoring results in 2012-2016, 2018, 2020, and 2021. 19 7.0 COMPLETION OF RESTORATION 7.1 Notification of Completion When the initial .monitoring. period is complete, and/or the applicant believes that the final success criteria have been met the applicant will notify the regulatory agencies when submitting the f nal annual report that documents this completion. 7.2 Confirmation Upon submission of the above-mentioned final report, the regulatory agencies will conduct a site inspection (if needed), and upon determining that mitigation success has been achieved will provide a letter of release from further mitigation monitoring requirements. 8.0 CONTINGENCY MEASURES a If the number of restoration plants fails to met the identified success criteria in a given year, additional planting will be require to bring the total number back to the original number planted with site monitoring starting over. If the identified success criteria are not achieved, dead plants must be replaced in kind, unless the Applicant demonstrates that the. site is not conducive to the survival of a specific plant species, in which case alternate native riparian plant species may be used. These actions would be coordinated with the regulatory agencies. - - Channel stability characteristics will also be evaluated each year reporting is required. In. the event that instability problems are observed within the channel during monitoring events, an assessment will be made as to the appropriate action to be taken. This will include consultation with a hydrologist experienced in geomorphology. Recommendations will be assessed and evaluated and the problem convected. Corrective actions may require permitting and oversight from resource agencies in order to conducted work in the creek channel. 8.1 . Initiating Procedures - Subsequent to the first year's monitoring result of any subse uent ears of the re uired to - e q Y q n y ar monitoring period, corrective actions will be taken to correct unforeseen deficiencies in the - t establishment of riparian vegetative conditions. Analysis of the cause of site failures will be ` made and remedial actions will be recommended to correct the problem if a performance criterion or a final success criterion is not meta 20 1 i~~ie, 1 1 1 0 1 1 i ATTACHMENTS 1 143 b ATTACHMENT 1 FIGURES Figure 1 Regional Map Figure 2 . Vicinity Map Figure 3 USGS Quadrangle Map Figure 4 Aerial Photograph Figure 5 Fallon Crossing Development Site Plan Figure 6 Mitigation Area Map y Figure 7 Riparian Planting Pian Figure 8 Deed Restriction Area Map 1 ivv b 1 1 1 1 1 1 ' Figure 1 Regional Nlep 1 9 - I~ ~ 16~ _ Stroec Atlas USA~~ 2006 I 1~ ~_Z et ~ i i-- i ~ Vista ~ lileton - ( _ 37 ~ ~ /1 ~BlydaLanding - ~ i'~ ~ -f l i ~ ..M1 1.' - 'f mkix ~ ,!".~.,s`'~•,ln/s(ane' - ~(j-, r ~i"^. ,r _ G at _ • o „ \ I ! ' ~ • ~ ° J~ snits falind j r +T'a+ f ? eo Port' . - J - 1 'ro`. ~ ~1eHn0 - 1 J ham- et r' C'fyde ~ - ~ - t-. ~e~~~. • / r,iit ~ _ t\ - _ - Vltie M Mattb ~ ~ ILo`s'7VIe ~ - _ Beth llalagd; `S °l - 1 R II ftekl -.r -'i_~~"'!-i'_-. i ~~.Oakley _ '"i~ ~ ~ tia ,1 Concord ~ . ° ; - ~ ~ ' - °PleaienrHl0 1 t `Cowell' ~ L.-- ~ ( ? ~ . ,~jtT;'.77°~x_. "'r y:T : : ~ - Clayton I ut+i _ oad --3~--_-_._. 1 2C _ ~4.. ~ '`a i~.. r.... ~P ~ . o ~ _ - 11 . .~.Bir e e - ONritfti ` ~ - alttut Hdghts_ ~ , t - .t.. i eimV3tlegi s-; ~ ---•~Byron dmc~ ..Ca~9n? ..~Noraga Alame s:_ ~ _ fir- ~ J . t , ~1 nyt1~ R anville ~ ' ®~~~i . and . -~a `~\a ~ ~ . '~e~ ~S`= . ~•rr- ~ e \ ` SanRarrlon - ~ - ~ ',.~•L , - da...,.. -deddnrois ~ - - - y? ~ • Part ~ • ' ~ ~ P.Havg , ~ ~ 1 i • ~ . i • Fallon'~rgssing Propert ~°'t~ i ~ ~ ~ + j _ ~ Komandersk), Village ~ ~ `-''mil I V ' ( ~ tiritrEden - ~ ~ / - ~ ~K11 re Woods j• 1 IH-~UnlonClry~ ol~ ' ,`-Y~, ~ va 1. - ~ rerifont 1 \ e4 p + He k 1 \ , ont A ~ 'Ga oo C ~ O ~ ~ ~ `t ~ / ~•Attia `o$:~~.•~,--!-~ teal-d,Ak4o~,t~:~.. - ~a1l"r7~cs i .C I .uClra CbvrY r ice, ~ \ :&u~•ooi?'• 1,, _ r: dslad ~"~fa;a ~ Hne , - _ 1~,. , i Portol VaH6y~ 1 . ~-i i,, L-ee- i ,1 - 3 ~i.l_ l _ . . ~`1 t. sAkoi-H ~3~-~ e ' ~ .Alum Rook, } t _ ~,LOS.Traneos Of1E. ~ i• ~ ~ ~ ~T~ i ~ -i~ ~.~J~rlew of P~ ricua . \ ~ I I-_ i9~~,' t . p•~FS.~ena pare ~ ~ 'La Horida Monts I u aio 'GMs rllan_ o 1~7 . -Data use subject to license. © 2005 DeLorrne. Street Atlas USAF 2006. 0 2 4. 6 8 10 ml - rnvw.delorme.com MN (14.4' E) Oats Zoom 8-0 ° Olberding Environmental, Inc. 3170 Crow Canyon Place, Suite 260 ` San Ramon, California 94583 Figure 1 Phone: (925) 866-2111 Regional Map of the Fallon Crossing Development Project This document is not intended for detail design work, Alameda Coun , Califomia . . i - I~ ~ b t - t U Figure 2 Vicinity Map 1 _ _ - . ~ 7 X67 sh..e ads: usa~:~ 2ooe i f ji l l ry i~ . ' J • ~ ' ' ~3:~ ~ ~ ~ _ 11'~ I - .Tusagjmc bssk ~ ~ / ~ . Failon Crossing Property 1 kb t: ~ 8 I - y~ T ~2' X 'I ~ ~ ~ ca-p~ ~ ~ i - FI C TOE 1 ~ - - B~ ~ - ~ _ I ~MILIBLJ CT J r \ ~ I+I G,~ STILL~7 j~C7 `~y ~1LN ~ ~ I n l Data use subject to license. ~ , h ©2005 DeLorme. Street atlas USAr~ 2006. 0 400 800 1200 1600 200D www.delorme.com MN (14.4' E 1 Data Zaom 14-0 Olberditig Environmental, Inc. 3170 Crow Canyon Place, Suite 260 San Ramon, California 94.583 Figure 2 Phone: (925) 866-2111 Vicinity Map of the Fallon Crossing Development Project This document is not intended for detail design work. Alameda Count ;California s: - Iu~ Q lb~ - l l - . ~ - 1 1 Figure 3 USGS Quadrangle Map for . Livermore 1- ~ . - - _ I ~ I~~ li' :'4. ti,-, ~•'I , ~ _ _y i_- T1 1 1l l' yea ~ •I ~ =-;1_ ,~~i~ ! -x,11-0-~~.~95 • 9~_, ~ `e 1 ~ ~ ~ ~ `t~i~ ~ +r+Q'~~: ~~i7 l ~ - •ti _ ~r ~ ' ~ a /f 700 1 l T~~T !r_ • y ~(I~ t-:' ~ , o- ~i+` _ ~ . cc11 t. t ~.~r /t % ~ - 1 • ~ r Q~:~~~ ' ~jh.')t ~/off J-.:SpO ~,•Il•~ 1 f. 1 p +`~!Q.,~ ,,t 1 ~ 1 t\l I K-~'/i i ~11~'•/ _ ,•j I .lj-. 1 ~ .`.l 1 _ \ ~ ` J p ~ J~~•' I~F-. ~ 1 ~ to l/'s>~./1 ~':l`i • ~ I, / ~ ( G, .y. /r\'L.J • ) 1 ..r'-+~\~i/ ei ~ 11' r~lf, Ij ` w ~~3 ~ 1~ ; 'r• ~ ; ! • i ~~,~f y 1;•s~ r`'" .J ~ .!t ' r -w,, ~ ~ ?~~,6. r~ ,1~ ii(r- 511 ~~1.~ ~i ~ , 1~ a-'tl , 11.'~0C i+l~.R'' ~ $I'I` ,•1.'~r/ ~ '~il a . ~ ~.d.,........~ , Oiberding Environmental, Inc. 3170 Crow Canyon Place, Suite 260 Figure 3 San Ramon, California 94583 USGS Quadrangle Map of the Fallon Crossing Phone: (925) 866-2111 Development Project Livermore Quadrangle This document is not intended for detail design work. Alameda Count ,California 4~ _ ' 1 ~aqa rb~ 7 1 i 1 1 1 1 Ae Figuref rial Photograph 1 I 1 1 1 1 1 i 1 M l~ ~ . • Olberding Environmental, Inc. 3170 Crow Canyon Place, Suite 260 San Ramon, Califomia 94583 - Phone: (925) 866-2111 Figure 4 Aerial Photo of [he Fallon Crossing Development Project This document is not intendcd for detail desi n work. Alameda Count Califomia - 0 i5a l~1 Figure 5 , Fallon Crossing Development Site Plan e t ~ _ _ _ . o - _ ~ ~ - . ; I ~d ~ - c I _ _ . _ t Y ~ Ff' t _ ` t ~ ~ ~ p ~ t 1~ ~ I 1 . ~ ~ o . 1 _ . - ~ - - i 1.. ~s~ ^ , ~ _ ~ meeenr_nruax ~vm wA~.m~.~cII® ~~..~r .~vmwm~ FALIO~ ORr 033M0] -BITE PL•~N E,~N~ (4Rl'g$"'- l1 CJ ~1, Olberding Environmental, Inc. ff 3170 Crow Canyon Place, Suite 260 San Ramon, Califomia 94583 Phone: (92S) 866-211 I Figure 5 Site Plan of the Fallon Crossing Development Project d~ This document is not intended for detail desi n work. Alameda Count ,Califomia ..J i isa~ i6i 1 1 1 0 1 1 a FiGUr<6 M11i[igalion Area Map N %A FALCON CROSSING PROPERTY i F.ristmg~Pond~Lbcatlons 'R+P~'Falmeta,~ FroPnt7Dmwdary. Deed Rertrittion Area . CAPPro»rate) ~ , Olberding Environmental, Inc. 3170 Crow Canyon Place, Suite 260. ~ San Ramon, California 94583 Phone: (925) 866-2111 Figure 6 Mitigation Area Map st the Fallon Crossing . This document is not intended for detail desi n work. Development Project - ~ Alameda Count California J X56_ ~ 16'1 1 1~ t 1 ~ 1 Figure 7 Riparian Planting Plan 1 , 1 - . . .r ~ ~ ~ ~ ~ s. ~ ~ . . . s it . r r ~ as sY~a~ c x~,, • c.;~ oar ~,rfi„,~, t~~ oor~.lldabe`r~. O • ~ • • ~ Fat '13fhcJmory Olberding Environmental, Inc. 3170 Crow Canyon Place, Suite 260 San Ramon, California 94583 Phone: (925) 866-2111 Figure 7 Riparian Planting Plan at the Fallon Crossing ^ Development Project ~ This document is not intended for detail deli n work. Alameda Coun California J 1 issa s 1 1 1 i i 1 1 ' Figure B Deetl Reetriclion Area hfep 1 1 1 1 •w ~e -~w .aw .ter , .e , ,e .w .air ~w -.e e ~ diisTgio;~~•~ CON9FAVATOIN `~~'•EA9EMENT~ OEEO RESTRICTED AREA OEEO R~ TRIOTED AREA aRADO~Iti EASEIdENT !LENT DEVELOPYEpIT eirou aura t ~ ~ mew mzn d GRAPHIC 3CAi.E. i~ "I?- DEVELOPMENT AREA EXpIg1T fn, t m ~ ~ FALLDN CA0991N3 ' m°° " aao " av.a~ ouaawN o~tc gomev ,a amo aa3 uo. onaoa Olberding Environmental, Inc. _ 3170 Crow Canyon Place, Suite 260 San Ramon; California 94583 Phone: (925) 866-2111 , Figure 8 Deed Restriction Area Map at the Fallon Crossing ~ This document is not intended for detail desi n work. Development Project S Alameda Coun ,California ~ EXHIBIT B LEGAL DESCRIPTION - . - ~ l~lr ~'~1 - Standard Pacific Corporation ' City of Dublin County of Alameda _ Exhibit "B" Legal Description GRAD Parcel 1 Real property situate in the City of Dublin, County of Alameda, State of California, - described as .follows: Being a portion of the Parcel described in the deed recorded on Apri] 14, 2005 to Standard Pacific Corporation in Doctm~ent No. 2005.146527, Official Records of the County of Alameda, State of California, described as follows: Beginning at the northeastern corner of said Parcel; thence along the eastern line of said Parcel, South O1 °04'38"West, 1264.53 feet to the southern line of said Parcel; thence South 60°19'01"West, 133.52 feet; thence North 83°40'59"West, 135.30 feet; thence ~ - North 64°10'59"West, 528.00 feet; thence North 87°10'59"West, 473.88 feet; thence, South 34°49'01 "West, 576.18 feet; thence i'~Iorth 89°25'59"West, 725.18 feet to a non- tangent curve to the right having a radial which bears South 69°08'38" West, a radius of 1066.00 feet, a delta of 17°39'41 thence leaving said southern line, northwesterly alo~ig said curve an arc length of 328.59 feet; thence North 03°1. ].'41 "West, 121.68; thence North 33°23'01"East, 83.52; thence North 13°02'00"West, 227.15 feet to the _ . northwestern Line of said parcel.; thence along said northwestern line; North 31°01'01" East, 953.44 feet to the northwest. corner of said Parcel; thence along the northern line of said Parcel, South 89°20'1.3"East, 1866.04 feet to the Point of Beginning. Containing 66.4 Acres t O ~pN~ SU ~l~GI~L~~ S SEA 9~F Charles Sellman L.S. 5186 ve;,'~'U,~~ ~ ~ o ~ 2.3`~o0g No. 5186 Date Exp. 06-30-09 - N~gTF ~F C A~\~OQ~ Created on 6/12/2008 4:11 PM G:\Admin\Tobs-03\031006\Survey\New T~eeds\GIIf1D A & H.doc ~~'b1 . .Pfeiffer Ranch Investors II Inc ~ ~ - , City of Dublin County of Alameda ~ _ Exhihit "B~' Legal Description ' GHAD Parcel 2 . Real property situate in the City of Dublin, County of Alameda, State of California, described as follows: ' Being a portion of Lot "A3" as shown on the map entitled. "Tract 7441" filed in Book 279 of Maps at Page 68, Records of the County of Alameda, State of California, described as .follows: Beginning at an angle point on the northern line of said Lot, said point being the southwestern terminus of the course shown as "N34°49'01"E 576.18"'; thence, South 44°22'05"West, 50.43 feet to anon-tangent ciilve to the right having a radial which bears South 32°49'52" West, a radius of 25.00 feet, a delta of 11 °32' 13"; thence, northwesterly . along said curve an arc length of 5.03 feet; thence North 45°37'55"West, 48.12 feet to said northern line; thence along said. northern line, South 89°25'59"East, 73.60 to the Point of Beginning. Containing .03 Acres f Charles Sellman L.. , 5186 ~ O ~N~ SV9 ' ~G,~ ~yEB SF G~-L ~cl"-Z3-2oo~ ~ v ~s ~ Date No.5t86 74' Exp. 06-30.09 ~ .Q" i cn~q~ OF C AL\~~P= i I Created on 9/23/2008 2:03 PM G:\AdminUobs-03\031006\Survey\New Deeds\GHAD ,parcel 2.doc 1~ , Pfeiffer Ranch Investors II fiic City o.f Dublin County of Alameda ' Exhibit "B" Legal Description ~ GRAD Parcel 3 Real property situate in the City of Dublin, County of Alameda, State of California, described as follows: Being Lot "A4" as shown on the snap entitled "Tract 7441" filed in Book 279 of Maps at Page 68, Records of the County of Alameda, State of California, described as follows: Containing .O1 Acres t ~~-''v Charles Sellman L.S. 5186 IAN S Date ~ ~ o No. 5186 A Exp. 06-30-09 9~ OF C A~-\F~Q` i Creaied on 9/23/2008 2:45 PM ' G:\Ad.minUobs-03\031.006\SurveylNew DeectslGFIA.U parcel 3.doc . ~ J ~ - ~ EXHIBIT C BOUNDARY MAP ' ~ ~ a n a W ~ \e~ ~ • ~ i" w"' hoa O ~ zo N ~ ~ O , O ~n am o, 3~~~U ^xN cv ~ ~1`~~ m;~ o N ~ C Q:. 00 ~ gN. e °~~;3 3~ IVW~a l bbd 1-~7?11 ~~~z ~ p ~ . z,q 0 Z i 8 0 ' v,~ ~ ~ Wjsg ~N ' ` "Blr~ll'? iN;6~5, 97..~6BN"~a~~ ~5 ""ii ~ ' ' 0 ~%tia3gttj.'iL~}c'~Stt `ID~m 'l'1°,`.~ ~i`r~J J'~'# ~ ~ ~ c~ ~*ri~'~"~~i ~,~t~aw~N59 y` P~~"~~.~. ~ . W a o~ . ' ,r""~.'s ,stiJ1 t~~ 3 s s~t ~`8`u'a QxS jy~i ~x~s~ O gg ~ _ ~ ..rkR Y r,~ yysf'r W~ u*Q ~ j <+..,,~t~ hY }~ip, ~a~ +!c v,.~yt ~ fi,.~•pi ad ~ ' +~J ° '~A~~sS~j~ij ~ > ~ t p~'i 'D~ N3~5~ ~ ~s 'yEk ~.F25cF~+ ~ `J' ° ° .u+rY tit ~ tt{ ~ .'r~+'e~~S`' . ~;~r, ~ "r"v`s~~;r;~~t a"''~ ` f i'Y<~ ~p .,1~,-i " - ~ v, ~ - . ~~~~'g ~g ,Y«'~c6sy ~~titcOi w Iv ~~.~SVa ~~i~ f/ct-~... x...:_K G'+~F w$ s•"r~"~~vu7'vS 0~5t~9,jN ~ mo rJ~ ; c ~ `'rh' ~°M {ut~~', rti ; 1 xrZp~,t: y. rh 98 £Lt /1.r~ s' a w,cv ~ ~ 3 ~,~s~ 'r~al~ ni- Ys s. O~L9M ~t i , ~ a~ +i}'~i~YffG~f fr~ .~'{~u.~r - ~ E r''~ip~'Swt~.?t~ 5 ' P;~ x y O b ~~f5 ~ 62 ~ M s di ~ ~c x`31€ 3rd ~I[~l~f d~. s--~ r 'Y, L t S 0 O Z n, l f' b d d 2 r> ,mss x Vii. G1, r~.t~c~~~r~+ z~,'~~:R L Z 5 r' l S 0 ,0 2 -~7 0 U: !,~{3, ~'c~~~ ~ a " f ~F}' L ~ U c~~ d '_d ~ ~ f ~ 7' d 4 b 7 Q FJ 7 J 6 z ~ ' ''~fi'~1~'~f ~~~c~t~{~'a~ rr?~ ~`Y~y. y7p ~ _ t' ~t~~f~~' ~Q Z ~ U ~ ~~^~~3^i~~~> ~ ~SV,~~ t ~v'd~Y.7;~~s~ t;f~~~~~! W tM'1 GY, Q' e ~n~t 4w 4.~~ >;'xr ~~xs~ ~gSa~t ~ ~ '`rq '°Y4~fr~~;l 4; ~+"~"f~~~"~»~<4 m Y-i O war s~€~4 r~ ! ~ % c^i a 4- ~ s ri ~i't,*. /''}l' ns~y, li ' 1---1 fit' 1 Ci„ ft ~ kr3r a14~' t33..t~"} y ^ ~ L~ 'c~. 4~c { r iy .J,~ 9 ~ < rs~t >.R i~ , yu,+~`x~,r hi ~ f ~ *'~'~0 O ;11~~ Y ..f ~.Y r ~ t~„ x ~.~~.~`f~x~i'.~I T, ,u' '~h:l. `~~`a ~t '.v~' w`r~, s's f~'"A ~ ~ v ~r~ '~.a~ ~ t~1 s at<~& ~t.r cD ~ g~b~,o-.ji`rs4~sr ~~u' ~ `C ~ ~ O w O Sln~~~ ~~I~ rPvE~ b hd r P~s~ ~ fl ~4 ~ ! r-cs» ~ zt tra r~'"' ~ •~l 1a~1 U Gl 1 t r~ET tt3~ ^~'"F'~~~3 ~L5 '~L~ - ~ i a x 2 1~ ' a 1>f3i r~.W~f~ a ~ Y to J ~ 8'!'i ~:s c r ~ ~ ~ ' l aewd ak gf e~S if 4` r,8 ~r ~r„ca Fi it ~ t `L~ Y t.~ > 1~~ c«~n.. ~Y~. ,?ar,'tJsi.'.r~d'~s .~~°k~'ry`.i.'.^:. ~~IYa~tt~,if~f ~1a1P ~.'S~',4'~''yy~~r'*`s t x„1~ t ~3 t s Y'.-r x ~ O Ei . ,r.€ ~,w'a fi., r$ $~"S~. .aA..a Y7 a~yc~_. '':E~ ikW"t-";1 ~ ~ ,ro'ssar 3 rr,ozsas O E, 213.LNf1H / ,~3H~f2! a ~ EXHIBIT B TO THE RESOLUTION NOTICE OF PUBLIC HEARING 4 '!6'~' ' X61 NOTICE OF PUBLIC HEARING ON FORMATION OF THE FALCON CROSSINGS GEOLOGIC HAZARD ABATEMENT DISTRICT You are hereby notified that on August 16, 2011 at 7:00 p.m. in the City Council Chambers at 100 Civic Plaza, Dublin, California, 94568, the City Council of the City of Dublin will consider the formation of the Fallon Crossings Geologic Hazard Abatement District ("Fallon Crossings GHAD") pursuant to the attached "Petition for Formation of the Fallon Crossings Geologic Hazard Abatement District Pursuant to Division 17 of the Public Resources Code of the State of California" (the "Petition"). . The territory proposed for inclusion in the Fallon Crossings GHAD is located in the area generally known as Fallon Crossings, and is described in detail in the Petition. The formation of the Fallon Crossings GHAD will require the levy of an assessment to pay for the costs and expenses of the activities described in the plan of control for the Fallon Crossings GRAD ("Plan of Control"). The Plan of Control can be reviewed at City Hall at the address set forth below. The Plan of Control may be duplicated at cost upon request. The purpose of this hearing is to receive and consider any and all objections to the formation of the Fallon Crossings GRAD. Valid objections can be made in writing, not later than the time set for hearing, by any owner of real property within the boundaries of the territory proposed for annexation. Objections shall contain a description of the land by lot, tract and map number, and shall be signed by the owner of such property. Objections must be mailed or delivered to the address set forth below and must otherwise comply with the provisions of Public Resources Code Section 26564. For further information contact Mark Lander, City Engineer, at 100 Civic Plaza, Dublin, California, 94568, or (925) 833-6635. City Clerk, City of Dublin ~x b~-~ ~3