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HomeMy WebLinkAboutSan Sevaine Channel Flood Control System LOWER SAN SEVAINE BASIN SAN_SEIAINE CHANNEL FLOOD CONTROL SYSTEM PRELIMINARY DESIGN AND ENVIRONMENTAL REVIEW ANALYSIS CITY OF RANCHO CUCAMONGA COUNTY OF SAN BERNARDINO Prepared by Bill Mann & Associates, Inc. 1814 Commercenter West, Suite A San Bernardino, CA 92404 April, 1987 TABLE OF CONTENTS Page SECTION I. INTRODUCTION 1 SECTION II. PROPOSED PROJECT 3 A. PROJECT DESCRIPTION 3 B. DAY, ETIWANDA AND SAN SEVAINE CREEKS 4 SYSTEM DRAINAGE PLAN C. SAN SEVAINE CREEK WATER PROJECT 5 D. HYDROLOGY 5 E. PRELIMINARY DESIGN OF THE BASIN 6 F. SOILS AND GEOLOGY 8 SECTION III. ENVIRONMENTAL SETTING AND FINAL ENVIRONMENTAL 10 ASSESSMENTS AND REPORTS A. ENVIRONMENTAL SETTING 10 B. PRIOR ENVIRONMENTAL ASSESSMENTS AND REPORTS 10 C. SOCIAL IMPACTS 12 SECTION IV. REFERENCES 16 APPENDIX 1. SAN SEVAINE CREEK WATER PROJECT - ENVIRONMENTAL ASSESSMENT - PROPOSED MITIGATION MEASURES i SECTION I. INTRODUCTION This report is proposed to develop the preliminary design plans and environ- mental review analysis for the Lower San Sevaine Basin located in the City of Rancho Cucamonga. The proposed basin is a vital part of the San Sevaine Creek Channel System, the regional flood control and water conservation system pro- viding protection, and a drainage outlet for the Cities of Fontana, Rancho Cucamonga and Ontario, and the Counties of San Bernardino and Riverside. The proposed basin is located in northeastern Rancho Cucamonga immediately north of the Devore Freeway and easterly of the community of Etiwanda. The proposed basin and immediate area around the basin is shown on Figure No. I, Vicinity Map. The proposed basin is planned to be a flood flow storage basin regulating flows from the upper San Sevaine Creek tributary system. The flood flow storage will allow the downsizing of flood control channels from the basin southerly to the Santa Ana River. The San Sevaine Channel System Drainage Plan and Hydrology Report is discussed in Sections II,B and D. The County of San Bernardino in conjunction with the Cities of Fontana, Rancho Cucamonga and Ontario, has applied for a low - interest loan from the U. S. Bureau of Reclamation. The funding for the "San Sevaine Creek Water Project" is being sought under the Bureau of Reclamation's Small Reclamation Projects Act of 1956. The Loan Application Report and Environmental Assessment have been prepared by the firms of Engineering- Science, Inc., and Bill Mann & Associates, Inc. The Lower San Sevaine Basin is a major water conservation element of the "San Sevaine Creek Water Project" to increase the percolation to the underground Chino Basin. The proposed Bureau of Reclamation project includes the major portions of the San Sevaine Channel System regional flood control project. 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FIGURE NO 1 ..., , ',' ,• • ._ Several environmental assessments and environmental impact reports have been prepared for the regional flood control and water conservation system. The prior reports are discussed in Section III,B. At the present time, in addition to the request for partial funding for the San Sevaine Creek Water Project through the Bureau of Reclamation, the County of San Bernardino and City of Fontana are presently reviewing other funding sources for construction of the overall flood control and water conservation project. Because of the necessity of new development in the area to mitigate the increased runoff that will be generated by development, an effort is being made to provide the mitigation by increasing the storage volume in existing water conservation basins or by developing new basins. The expansion of the Lower San Sevaine Basin is one of the major basins that is programmed for the mitigation of the increased drainage runoff. The excavation of the basin not only will support new development, it will at the same time provide a major element of the regional flood control system at a reduced cost. The proposed basin will provide a 2,350 acre -foot flood storage facility requiring a levee approximately 10 to 40 feet in height and approximately 2,130,000 cubic yards of excavation. Approximately 1,300,000 cubic yards of the excavated material will be placed in the levee. Although the overall flood control drainage plan has had prior environmental reports prepared, an additional environmental assessment has been recommended due to the height of the levee. The preliminary design and plan is necessary to provide the required data for environmental review. Therefore, this report has a dual purpose, to provide a preliminary design document for review by the cognizant agencies and to provide the format for a determination on environ- mental concern and significance. 2 SECTION II. PROPOSED PROJECT A. Project Description The proposed project as far as this report is concerned is the excavation, levee placement and construction of the concrete spillway, ungated 10'x 8' RCB basin outlet, 48 -inch RCP Etiwanda Channel turnout, and 36 -inch RCP basin drain for the Lower San Sevaine Basin. Figure No. II, Sheets 1 thru 3, are reduced sheets of the preliminary plan and cross - sections for the basin. Following are the major pertinent construction features of the project: Basin excavation = 2,130,000+ yd3 Fill required for levee = 1,300,000+ yd3 Estimated Cost = $5,725,000 The height of the south levee of the basin will vary from 10 to 40 feet above existing terrain. Due to the higher existing ground along the north side of the basin, the height of the north levee will vary from 0 to approximately 10 feet above the existing terrain. There is an existing elongated basin on the site at the present time. The existing basin is approximately 250 feet wide and 20+ to 30 feet deep. The existing basin will be widened to an approximate maximum width of 950 feet. The basin excavation, along with the levee construction, will provide the necessary storage volume of 2,350 acre -feet. Due to the need to minimize the amount of excavated material that will have to be hauled away from the site, the proposed levee has been designed with a wider top width and flatter slopes than may be necessary. Due to the expense of disposing of any excess excavated material, it is proposed to place as much 3 t • h i, , e o _ S QQ Q ` �- 25 2S w . \ , .., `..\\.,,,s,„--,-;, 2 in 1 _ 1C?�83H0' ,.:,--- .,\., fo, :,— .,.._ , .,,,..- f .. y_ _ :, ...,,,.,\ ,-,-,-_.'s 's • , \" \! •-:.- ,,:._ , ,,,z,.,,... 1.\.c\.\, . \ o \, . �\ � � w cn Q U o ra U - d Q W 4. Z Z . V- ' ' - - ,',. ', 1 - -- 'N* -, \ s • s • .'• ' '4 ),. cc 0 ' ,1\ ,,:''' :N2 ,,'. , ' , 3 5 w r-- ;-- a t- L � < X85 rn ,� r :t ,: ,,� ' 4 • . •'- v4 ^ - \ •i. 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The proposed levee, based on the preliminary design, will have a 30 -foot top width and 3:1 side slopes. A spillway approximately 200 feet in width is proposed to pass a major flood without topping the levee. The design criteria for the preliminary plan is discussed in Section II,E. The environmental setting for the site is discussed in Section III,A. The estimated cost of $5,725,000 can be reduced significantly if the major part of the excavation can be removed through the development process. B. Day, Etiwanda and San Sevaine Creeks System Drainage Plan The proposed Lower San Sevaine Basin is a part of the San Sevaine Creek Drainage System. A master plan was prepared for the Day, Etiwanda and San Sevaine Creeks System in 1983 by Bill Mann & Associates. The major elements of the master plan were the Day, Etiwanda and San Sevaine Creek Channels. The San Sevaine Creek Drainage System comprises the easterly portion of the master plan drainage area. The Day, Etiwanda and San Sevaine Creeks System Drainage Plan is shown on Figure No. III. The drainage master plan development was a joint effort by the Cities of Rancho Cucamonga, Fontana and Ontario, and the Counties of San Bernardino and Riverside. The drainage plan was accepted by all the agencies involved in 1983. Lower San Sevaine Basin serves two purposes as an element of the drainage plan. Because of inadequate, existing, improved flood channels in Ontario and Riverside County and the need to downsize the proposed channels southerly of the basin, the basin was designed as a flood flow storage basin. Addi- tionally, the drainage plan included a "Water Conservation Report ". The water conservation report recommended 11 basins within the 90 square -mile watershed area for water conservation purposes. 4 Lower San Sevaine Basin will provide 2,350 acre -feet of flood flow storage and at the same time, provide available water conservation facility. The water conservation element is discussed in more detail in Section II,C. C. San Sevaine Creek Water Project The Technical and Steering Committees of the Cities of Fontana, Rancho Cuca- monga and Ontario, and the County of San Bernardino recommended the preparation of an application for a low- interest loan from the Bureau of Reclamation to assist in funding the San Sevaine Creek System. The Loan Application Report and Environmental Assessment have been prepared by the firms of Engineering- Science, Inc., and Bill Mann & Associates, Inc. The report requests a low- interest loan of approximately $27,000,000 for an approximate $42,000,000 project. The Bureau of Reclamation Project will be funded under the Bureau's Small Reclamation Projects Act of 1956, as amended. The "San Sevaine Creek Water Project" is a water conservation project designed to capture and recharge approximately 25,000 acre -feet into the Chino Underground Basin on an average annual basis. The project area facilities, including the proposed water con- servation basins, are shown on Figure No. IV. The proposed Lower San Sevaine Basin is the major water conservation element in the project, designed to provide 2,350 acre -feet of flood storage and a recharge capacity of 234 acre -feet per day. D. Hydrology At the time the Day, Etiwanda and San Sevaine Creeks System Drainage Plan was developed, preliminary hydrology for the three flood channels was provided. Because of the significant development occurring in the Fontana area, the updating of the hydrology for the entire San Sevaine Creek Watershed became necessary. 5 An updated hydrology analysis and report entitled "Hydrologic Analysis and Modeling of the San Sevaine Creek Watershed" was prepared by the firms of Bill Mann & Associates, Inc., and Hall & Foreman, Inc. The computer modeling has been approved by the Flood Control District. The hydrology report text dated January, 1987 (revised), has been submitted in final form for review and approval by the Flood Control District. The major significance of the Lower San Sevaine Basin to the watershed area is the flood flow storage. The basin will provide 2,350 acre -feet of storage volume. The storage reduces the 100 -year frequency peak flow of the San Sevaine Creek tributary area from 12,300 to 2,650 cfs. The reduction in peak flow has allowed the downsizing of the channel below the basin at significant savings in construction costs, and has reduced the channel flow in Riverside County to the point where channels already constructed are adequate in size. The San Sevaine Creek watershed hydrology map is included as Figure No. V for reference purposes. Table I shows the 100 -year peak flow at certain points within the watershed, including the Lower San Sevaine Basin. E. Preliminary Design of the Basin Sheets 1 thru 3 of Figure No. II show the preliminary design of the basin. It should be emphasized the plans included herein are provided primarily to prepare a reasonable cost estimate, estimate the approximate excavation required to develop the basin capacity, and estimate the cubic yards of material necessary to construct the levee embankment. The preliminary plan is also necessary to determine the environmental significance and whether an environmental impact report will be necessary. The basin will fall under the jurisdiction of the California Division of Dams and Safety. Therefore, the basin plan will have to be reviewed and approved by the State Division of Dams. Because of the requested funding under the Bureau of Reclamation's Small Reclamation Projects Act of 1956, the final plans will have to be approved by the Bureau. 6 11 I Table I 1 Unit Hydrograph Peak Flow Rate (cfs) 100 -Year Event li (Nodes) Watershed Location li Point Number 1983* 1986 1r UPPER ETIWANDA CREEK 2 3,077 4,821 1 3 5,287 7,385 4 - 7,996 or 7 = 8, 1 14 8 8,209 Ir UPPER SAN SEVAINE CREEK 1 1,967 2,921 1 401 ** - 7,425 403 * ** - 6,068 (12,330 * * * *) t 4.1 (spillway) 4,100 2,651 ir SAN SEVAINE - ETIWANDA CREEKS 5 8,200 4,600 i r 7 12,200 7,258 8 8,530 ir 8' 12,200 14,958 9 15,550 18,218 ir 11 18,850 22,860 12 18,850 23,722 I * Day, Etiwanda and San Sevaine Creeks System Drainage Plan (March, 1983) I ** Flow at San Sevaine Basin No. 1 * ** Flow at Hawker Crawford at San Sevaine Basin No. 3 * * ** Combined flow at San Sevaine Basin No. 3 The watershed locatio1i point numbers (Nodes) are shown on Figure No. II as 1 6A Various aspects of the preliminary plan are briefly discussed below. 1. Basin Capacity The San Sevaine Creek watershed hydrology analysis and report is based on a flood flow storage volume of 2,350 acre -feet and a basin regulating 10'x 8' RCB ungated outlet. The preliminary basin plan, with the basin flowline and elevation of top of levee as shown, was developed with the intent to minimize the levee height and the amount of excavation. The conceptual plan developed in the Day, Etiwanda and San Sevaine Creeks System Drainage Plan was followed very closely because of the prior approved Environmental Impact Report. The flowline of the ungated 10'x 8' RCB was established to provide 350 acre -feet of dead storage below the outlet in accordance with the water conservation requirements of the Bureau of Reclamation San Sevaine Creek Water Project. 2. Basin Levee Embankment The basin levee height was established to provide the required volume of flood flow storage (2,350 acre -feet) discussed above. Dams and levees can usually be designed with a minimum slope of 2:1 to 2.5:1 with the onsite soils prevalent in the general area. The minimum top width of the levee is usually 20 feet to provide an access roadway as well as the necessary structural requirement. However, in this case, it is intended to place as much of the required excavation in the levee as possible to reduce the cost of having to haul the basin excavated material off site. Therefore, a 30 -foot top width and 3:1 side slopes are proposed for the levee. The final design of the levee will depend upon a detailed geological and soils investigation, seismic criteria, the possible need for a core in the levee, and criteria established by the State Division of Dams and Bureau of Reclamation. 7 3. Spillway Design As indicated in Section II,D, Hydrology, the hydrology for the San Sevaine Creek watershed and the proposed basin has been established. The basin will be designed to regulate a 100 -year frequency flood utilizing the basin storage and the ungated 10'x 8' RCB outlet. The basin and outlet will reduce the 100 -year flood flow of 12,330 cfs above the basin to a 2,650 cfs outlet flow. However, the spillway has to be designed for a much higher flood flow to protect the integrity of the dam and prevent overtopping the structure. The State Division of Safety of Dams requires the design of "dam" spillways to pass the "maximum probable flood ". The spillway consists of a 200 -foot wide rectangular spillway sized to pass a 37,200 cfs flow without overtopping the dam. This flow corresponds to the "Creager" formula with C = 100. The final design of the spillway will be based on new hydrology for the spillway based on the maximum probable flood criteria. The channel down- stream of the spillway and levee embankment will continue to be based on a 100 -year frequency storm flow. 4. Outlet Works The outlet works will be similar to the Los Angeles County Flood Control District standards and will be uncontrolled. It will consist of a 10'x 8' RCB conduit that passes through the dam discharging into the downstream San Sevaine Channel. F. Soils and Geology The onsite soil is predominantly cohesioness sand, gravel, cobbles and some boulders. The site is a part of a boulder- strewn, sand and gravel alluvial fan (wash) created over the eons by outflow from the San Gabriel Mountains. 8 The embankment will be constructed exclusively from reservoir excavation from the site. If it is determined a core is needed for the embankment, it may be necessary to import some fine material for the core. If this is the case, the fine material will be excavated from other basins owned and operated by the Flood Control District. A detailed geological and geotechnical investigation and analysis will be necessary for the final design. 9 SECTION III. ENVIRONMENTAL SETTING AND PRIOR ENVIRONMENTAL ASSESSMENTS AND REPORTS A. Environmental Setting The proposed basin area consists of an existing elongated basin approximately 250 feet wide, 4,000 feet long and 20 to 30 feet deep. A concrete spillway is located at the lower end of the existing basin. The basin outlets into a concrete lined channel that passes under Highland Avenue and the Devore Freeway. A grouted rock spillway also exists at the upstream end of the existing basin that inlets flows from the San Sevaine Basins located immediately northeast of the basin. Sheet 1 of Figure No. II shows the existing basin, channels and Devore Freeway. According to the Environmental Assessment provided for the Bureau of Reclama- tion Loan Application Report, the site is composed of alluvial scrub, coastal sage scrub and grassland with some Eucalyptus trees dispersed within the basin. An old growth of alluvial fan woodland dominated by holly - leafed Cherry is located at the western end of the site. In recognition of the value of the holly- leafed Cherry woodland at the west end of the site, the proposed levee will be designed to avoid as much of the woodland as feasible from an engineering standpoint. This is a recommended mitigation measure in the Environmental Assessment. There have been several environmental assessments and impact reports prepared for the drainage plan and proposed Bureau project. These reports are referenced for a detailed analysis of the environmental setting. B. Prior Environmental Assessments and Reports There have been several prior environmental impact reports and /or assessments on the overall flood control and water conservation projects. These reports are listed below for reference. 10 1. A "Draft Environmental Impact Report /Statement" was prepared for the Day, Etiwanda and San Sevaine Creeks Drainage Plan in February, 1984. The EIR was approved by the County Environmental Review Board on June 7, 1985, and was certified by the Board of Supervisors on June 10, 1985. The EIR was prepared by The Planning Network and Bill Mann & Associates. The EIR included the proposed Lower San Sevaine Basin. 2. An "Environmental Assessment" was prepared for the San Sevaine Creek Water Project to support the Loan Application Report submitted to the Bureau of Reclamation. The assessment was prepared by Engineering- Science and dated March, 1987. A detailed biological survey of the San Sevaine Creek Water Project was conducted by Karlin Marsh in 1983. A supplemental survey of the water project area and a special survey for Federal candidate and proposed endangered species was conducted by Karlin Marsh in May, 1986. The Environmental Assessment is presently being reviewed by the County, Bureau of Reclamation and other Federal and State agencies. The EA covered the proposed Lower San Sevaine Basin in detail and listed several concerns and mitigation measures. The concerns and mitigation measures are discussed in Section III,C, "Social Impacts, Cultural and Biological Resources ". An EA was also prepared for the Bureau of Reclamation "Day Creek Water Project" by The Planning Network and Bill Mann & Associates. Although the assessment did not cover San Sevaine Creek, it is listed because of the similarity in projects and some of the assessments were done for both projects at that time. 11 C. Social Impacts 1. Water Conservation As indicated above in Section II,C, the proposed basin is a major element of the proposed San Sevaine Creek Water Project. The basin will assist in capturing annual local runoff flow and storm flow for percolation into the Chino Underground Basin. The local and major storm flow will flow through the valley area to the Santa Ana River if sufficient water conservation basins are not developed to store and percolate the flows for recharge purposes. The basin has an estimated recharge rate of 3 feet per day. The 100 -acre recharge basin has an estimated recharge capacity of 234 acre - feet /day or approximately 7,000 acre - feet /year based on a 30- day /year period. The basin will have water in it on an average annual basis. In addition, the California State Division of Water Resources and the Metropolitan Water District of Southern California have reviewed the use of basins in the Chino Basin area for their Conjunctive Use Program. The agencies propose to recharge water into the underground basin during periods of excess rainfall for retraction during dry years. The proposed Lower San Sevaine Basin is one of the basins proposed for spreading of State imported water. Reference is made to the Water Conservation Report of the Day, Etiwanda and San Sevaine Creeks Drainage Plan and the Bureau of Reclamation San Sevaine Creek Water Project application report for details on water conservation in the proposed project. 2. Flood and Drainage Control As indicated above, the proposed basin is an integral part of the regional flood control system described in Sections II,B and C. The basin will 12 provide 2,350 acre -feet of flood flow storage and regulate a 12,330 cfs, 100 -year flood flow down to 2,650 cfs. The proposed basin storage has allowed the downsizing of the San Sevaine Channel downstream because of the storage and peak flow reduction. Several reaches of the channel have been constructed and /or designed with the reduced flow in both San Bernardino and Riverside Counties. Therefore, the project will provide direct benefits through improved flood control at reduced costs to the general area. 3. Aesthetics The proposed basin will have a levee varying from 10 to 40 feet above natural ground on the south side of the basin. However, there are already a series of fill areas between the Devore Freeway and the basin and between Highland Avenue and the basin. The existing fill areas are 30 to 40 feet above the level of the Devore Freeway. There are also several fill areas south of the freeway that are the same height. The existing mounds are fill that was placed at the time the Devore Freeway was constructed for the future Interstate Route 15 /Route 30 freeway to freeway construction. There is also an additional 200,000 yd3 to be placed by Caltrans for a ramp immediately south of the basin. The ramp is part of the proposed interim interchange access construction proposed for the 1987/88 Fiscal Year. The fill material for the ramp will come from the basin excavation. In addition, an existing series of basins located west of Cherry Avenue and upstream at the proposed Lower San Sevaine Basin has levees in the 20 -foot range. There will be limited visual contact of the proposed levee from the Devore Freeway (Interstate 15) due to the existing freeway ramp fill. The existing freeway fill will also limit visibility of the basin levee from the area south of the freeway. Highland Avenue crosses over the freeway 13 on a fill and therefore will limit visual contact of the basin levee from the south. The westerly part of the basin levee and spillway will be visible from the area north of Highland Avenue and west of the existing Etiwanda Channel. The area north of the basin is for the most part at the same elevation as the top of the north basin levee. There will be a levee approximately 10 feet in height along a portion of the north levee. It is proposed to infill between the south basin levee and the proposed freeway ramp to dispose of material. The California Department of Transportation has considered the concept and has included it in their project report due to its safety feature relating to the freeway ramp. If the area between the proposed levee and ramp is filled in, it will assist in softening the visual impacts of the levee. The basin plan view, Devore Freeway, Highland Avenue, existing future freeway ramp fills, and existing Etiwanda and San Sevaine Channels are shown on the preliminary plans, Figure No. II, Sheets 1 thru 3. Due to the existence of the 20 to 30 -foot high future freeway ramp fill, the Devore Freeway, elevated Highland Avenue and the existing basins east of the proposed basin, it would appear the visual impact of the basin levee will be minimal. The basin area is a part of the hiking trails pro- posed for the area by the City of Rancho Cucamonga. Subject to compatibility and arrangements made for maintenance and operation, it may be possible to landscape the basin to some degree to further soften the aesthetic impact of the levee. 4. Cultural and Biological Resources A Class III cultural resources inventory and impact evaluation, including a field survey, were conducted as a part of the Environmental Assessment for the Bureau of Reclamation San Sevaine Creek Water Project.. No prehis- toric archaeological sites were identified within or near the proposed basin. The inventory is listed in Section IV, References, and discussed in detail in the Environmental Assessment. 14 A biological assessment of the proposed Lower San Sevaine Basin was made by Karlin Marsh for the San Sevaine Creek Water Project. The studies are listed in Section IV, References, and discussed in the above mentioned Environmental Assessment. The County of San Bernardino, in support of the Loan Application Report and Environmental Assessment submitted to the Bureau of Reclamation for request of project funding, has committed to certain mitigation measures for the Bureau San Sevaine Creek Water Project. For information purposes, Section 7 of the Environmental Assessment is included in the Appendix. Table 7 -1 lists a Summary of Mitigation Measures. Mitigation Measures 1, 2 and 8 apply directly to the proposed Lower San Sevaine Basin. 15 SECTION IV. REFERENCES Bill Mann & Associates, Day, Etiwanda and San Sevaine Creeks System Water Con- servation Report, March 1983. Bill Mann & Associates, Day, Etiwanda and San Sevaine Creeks Drainage Plan, Volumes 1 and 2, March, 1983. Cottrell, M.G. (Archaeological Resources Management Corp.), 1983, Archaeo- logical Resources Assessment Conducted for the Day /Etiwanda /San Sevaine Creeks Drainage Plan and the Day Creek Channel Debris Basin, May. Lerch, M.K., 1986, Class III Cultural Resources Inventory, San Sevaine Creek Water Project, San Bernardino County, California, August. Marsh, K.G., Day Creek Flood Control Project Biological Resources Assessment, March, 1983. Marsh, K.G., Biological Resources Assessment Physical Setting Reconnaissance San Sevaine and Etiwanda Creeks for Proposed Channel Improvements, Levee Rein- forcements and Debris Dams, prepared for The Planning Network, May, 1983. Marsh, K.G., Results of Survey of Upper Etiwanda Creek Debris Dam and Spreading Basin Site, Upper San Sevaine Creek Debris Dams and Spreading Basin and Lower San Sevaine Basin for Federal Candidate and Proposed Rare /Endangered Biota Species, June, 1986. Marsh, K.G., Supplemental Information Attachment to Biological Resources Assessment, Physical Setting Reconnaissance, San Sevaine and Etiwanda Creeks for Proposed Channel Improvements, Levee Reinforcements and Debris Dams, August 21, 1986. Moore & Taber, 1981, Reconnaissance Geotechnical Investigation, Debris /Reten- tion Basins, Day and East Etiwanda Creeks, Western San Bernardino County, California, July 8. The Planning Network /Bill Mann & Associates, 1984, Draft Environmental Impact Report /Statement Day Creek Water Project /Day, Etiwanda and San Sevaine Creeks Drainage Plan /Master Plan for the San Sevaine Channel, February. The Planning Network /Bill Mann & Associates, 1984, (Preliminary Draft) Environmental Assessment, Day Creek Water Project, prepared for County of San Bernardino, submitted to U. S. Department of Interior Bureau of Reclamation, August. The Planning Network /Bill Mann & Associates, 1985, 1986, Draft Environmental Assessment, Day Creek Water Project, prepared for County of San Bernardino, submitted to U. S. Department of Interior Bureau of Reclamation. 16 APPENDIX 1. San Sevaine Creek Water Project - Environmental Assessment - Proposed Mitigation Measures r ✓ DRAFT ✓ ENVIRONMENTAL r ASSESSMENT ✓ SAN SEVAINE CREEK - WATER PROJECT r PREPARED FOR COUNTY OF SAN BERNARDINO 11 California n SUBMITTED TO n U.S. DEPARTMENT OF TH E INTERIOR f BUREAU OF RECLAMATION n n MARCH 1987 n ENGINEERING - SCIENCE DESIGN • RESEARCH • PLANNING n 75 NORTH FAIR OAKS AVE. • P.O. BOX 7107 • PASADENA, CALIFORNIA 91109 ri / • ri SECTION 7 ENVIRONMENTAL COMMITMENTS 1 Twenty -eight mitigation measures are proposed to reduce potential adverse impacts to environmental resources in the project area. These 1 measures are summarized in Table 7 -1. The agency that would be responsible for these mitigation measures is the contracting agency, most likely the County of San Bernardino. Some mitigation measures are part of the project design, would be part of project specifications, or 1 are standard practice, while others would require the commitment of the project sponsor. Some mitigation measures are contingencies and might be required as a result of construction activities. Preliminary cost estimates for those mitigation measures that are not design elements, specifications, or standard practice are provided in the accompanying Loan Application Report. TABLE 7 -1 SUMMARY OF MITIGATION MEASURES Mitigation Measure No. Brief Description WATER QUALITY 1 Develop and conduct water quality monitoring program for urban runoff BIOLOGICAL RESOURCES 2 Limit construction work to avoid and /or minimize disturbance to alluvial fan scrub habitat 3 Revegetate temporary construction staging areas and roadways r -I R 133 _ 7 -1 1 ripir TABLE 7 -1 (Contd) Mitigation Measure No. Brief Description 4 Salvage native needle grass Stipa cernua prior to excavation of Lower San Sevaine Basin 5 Use low smooth- wire - topped fencing for the western end of 9111 Lower San Sevaine Basin to avoid disturbance by ORVs 6 Provide water to Etiwanda Creek woodland SOILS 7 Stockpile excavated construction material, sediment, and rill debris to prevent erosion 8 Use excavated material from project area for fill LAND USE 9 Set aside a major portion of existing Etiwanda Spreading Grounds as open space PUBLIC SERVICES rill Submit plans to utility companies 11 Have local agencies review development projects TRAFFIC /TRANSPORTATION 7 11( 12 Plan construction to minimize number of roads to be closed 13• Schedule construction to minimize amount of time each road is to be closed 14 Post notice to motorists of road closure and alternate routes 15 Circulate railroad closure notice and construct temporary bypass SAFETY /NUISANCES 16 Fence facilities to minimize unauthorized entry 17 Conduct mosquito /vector inspection and treatment R 133 7 -2 T • . [ TABLE 7 -1 (Contd) Mitigation Measure No. Brief Description I n 18 Limit construction to 7 a.m. to 7 p.m. in residential 1 rml areas 19 Develop access routes for trucks that avoid residential i areas i 20 Temporary storage of excavated materials below debris dam ni , and basins; transport discarded household items to Milliken Landfill ill CULTURAL AND PALEONTOLOGIC RESOURCES 21 Avoid historic site on high ground near transmission lines in San Sevaine Spreading Grounds 22 Monitor construction during initial grading of northern - portions of project area (i.e., at canyon mouths) ill 23 Have site evaluated by archaeologist if artifacts or historic resources are found during construction 24 Have site evaluated by paleontologist if fossil remains uncovered during construction 0 VISUAL RESOURCES 25 Fence construction storage areas n - 26 Remove unneeded construction material and equipment h AIR QUALITY 27 Time clearing and excavation to minimize exposure of cleared areas 0 28 Water cleared areas, compact soil, and pave, seal, and /or oil access routes and parking areas to prevent fugitive irl dust 0 (I R 133 . 7 -3