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HomeMy WebLinkAbout; ; MASTER DRAINAGE PLAN; 1980-03-17MASTER DRAINAGE PLAN FOR THE CITY OF CARLSBAD MARCH 17, 1980 Prepared by: VTN Engineerss Architects, Planners 4845 Ronson Court San Diego, CA 92111 Engineers « Architects • Planners 4845 Ronson Court San Diago, California 92111 (714)292-1040 14 April 1980 Job No. 663-2 Mr. Les Evans City Engineer CITY OF CARLSBAD 1200 Elm Avenue Carlsbad, California 92008 Subject: Submittal of Final Draft Report for the Master Drainage Plan Gentlemen: VTN has contracted with the City of Carlsbad to prepare a Master Drainage Plan. At this time, we are pleased to submit the attached Final Draft of the Master Drainage Plan Report. Cost estimates, priorities and financing recommendations have been prepared for proposed drainage facilities required by existing deficiencies or new development. These backbone systems are estimated to cost $24,000,000; $21,400,000 of which is required for future development. Many of these facili- ties will be constructed by future development or financed through development impact fees or improvement district assessments. A portion of the City is under the present jurisdiction of the San Diego County Flood Control District. Implementation and financing of facilities in this area should be coordinated with the District. Drainage districts are proposed which group facilities in defined basins. These districts provide a framework for implementation of the Master Plan facilities within each district. We appreciate the opportunity to perform the study for the City and are grateful for the fine cooperation and assistance of the City Staff. Very truly yours, VTN SAN DIEGO I. Allan Cooper Vice President IAC:mlp Attachment _TABLE OF CONTENTS PAGE I EXECUTIVE SUMMARY 1-1 II INTRODUCTION A. AUTHORIZATION II-l B. SCOPE OF STUDY II-l C. DESCRIPTION OF STUDY AREA H-3 D« BASIS OF STUDY II-8 1. PREVIOUS STUDIES H-8 2. HYDROLOGY II-9 3. EROSION AND SEDIMENTATION H-10 4. GENERAL PLAN AND POLICY CONSIDERATIONS 11-10 III HYDROLOGIC AND HYDRAULIC CRITERIA A. STUDY APPROACH III-l B. HYDROLOGIC DESIGN CRITERIA III-l C. DESIGN RUNOFF METHOD HI-6 D. DESIGN PROCEDURE HI-6 IV DRAINAGE FACILITIES PLAN Ao BUENA VISTA CREEK BASIN IV-1 (Facilities AA-AE) B. A6UA HEDIONDA CREEK BASIN IV-3 (Facilities BA-BN) Co ENCINITAS CREEK BASIN IV-4 (Facilities CA-CM) D. SAN MARCOS CREEK/BATIOUITOS LAGOON BASIN IV-4 (Facilities DA-DT) V PRIORITY RATING SYSTEM AND MATRIX V-l VI FINANCING ALTERNATIVES VI-1 VII RECOMMENDATIONS VII-1 VIII COST ESTIMATES VIII-1 APPENDIX Model Erosion Control Ordinance A-l Erosion Control Devices - Schematics and Criteria A-6 Checklist for Site Evaluation A-16 Design Limitations on Dams A-27 Sediment Yield Charts A'30 Sediment Transport Chart A-31 REFERENCES A"33 PAGE FIGURES ~~ A STUDY AREA AND UPSTREAM WATERSHED I1-4 1 VELOCITY IN NATURAL VALLEY CHANNELS I11-10 2 NOMOGRAPH FOR DETERMINATION OF TIME OF CONCENTRATION III-ll FOR NATURAL WATERSHEDS 3 RAINFALL INTENSITY-DURATION-FREQUENCY CURVES FOR III-I2 COUNTY OF SAN DIEGO 4 GUTTER AND ROADWAY DISCHARGE-VELOCITY CHART 111-13 TABLES B PROPOSED FACILITIES - COSTS AND PRIORITIES VII-7 1 MANNING ROUGHNESS "n" VALUES II1-3 2 RATIONAL METHOD RUNOFF COEFFICIENTS III-3 3 PREVIOUS STUDIES III-3 4 DESILTING BASIN CAPACITY III-5 § UNIT PRICES A-5 6 COST ESTIMATES A-5 PLATES (I THROUGH) - EXISTING AND PROPOSED DRAINAGE FACILITIES EXECUTIVE SUMMARY 1-1 I. EXECUTIVE SUMMARY This Master Drainage Plan for the City of Carlsbad proposes drainage facilities costing an estimated $24,083,109 to be constructed in the study area in the future, About $2,708,938 worth of drainage facilities will remedy deficiencies in existing storm drain systems and developed areas lacking storm drains. These proposed systems may be financed by redevelopment funds, 1911 Act assessments, and/or new development. These facilities are generally of highest priority since they will reduce the potential for loss of life, property damage, nuisance flooding, and excessive erosion. The remaining about $21,374,171 worth of proposed drainage facilities are required by future development. These will be financed by future development in the following ways: ** le Proposed facilities located in a proposed development will be constructed by the developer, and right of way will be dedicated to the City. 2. Facilities offsite will be constructed by the developer or be paid for in part by the development and in part by future develop- ment. Right-of-way acquisition for offsite facilities will be funded by developers. 3. In areas requiring substantial offsite drainage facilities, Drainage Improvement Districts (or Multi-Purpose Assessment Districts where other facilities are planned) should be formed under the 1911 Act by property owners in each drainage district. 4. In lieu of districts, fees collected under the Subdivision Map Act will be used to construct offsite facilities. Based on the developable land minus open space, an average City-wide fee would be approximately $1720 per acre* For individual basins, the fees range from $44 to $8605 per acre .with an average fee of $2150 per acre. The proposed Drainage Improvement Districts are shown on Plates 1 - 4 along with existing and proposed drainage facilities. Table B tabulates priorities, costs and recommended methods of implementation. Priorities have been set for drainage facilities in areas of future development. These priorities are keyed to a growth management plan which directs near future development to areas with existing utilities, and defers proposed development in areas with no existing utilities. In addition to this report, nineteen orthophoto contour maps at a scale of 1" = 400' are provided to the City which show existing and proposed drainage facilities and the hydro!ogic data computed in this study. These sheets are intended to be updated by City staff as development occurs to maintain a current inventory of drainage facilities. Among the recommendations of this report is one to amend the grading ordinance to include a model erosion control ordinance as provided in the Appendix. This ordinance, along with a compatible City policy of enforcement of erosion controls will be largely responsible for preservation of the Lagoons from the impact of future development. INTRODUCTION 1L, __________ INTRODUCTION A0 Authorization This Master Drainage Plan has been prepared for the City of Carlsbad under a contract dated July 10, 1979 approved by the City Council of the City of Carlsbad on June 5, 1979, Resolution No. 5792= B0 Scope of Study The authorized scope of work involved the tasks outlined below. 1« General Investigation and Research Previous hydrology studies, a 1971 Master Drainage Plan, the various General Plan elements, and other relevant policy and design documents were reviewed. The findings were analyzed and incorporated into this report. Detailed descriptions of the various existing documents and the results of review are set forth in Chapter II Section D, Basis of Study. 2. To determine the adequacy of existing storm drains and the need for new storm drains, a detailed hydrologic analysis was performed on all basins except for major watercourses where previous studies had de- termined design flows. The methodology is described in Section III: Hydro! og i c and Hydrau 1 i c Cr i ter i a . Flows were determined at appro- priate places and storm drains were sized to match existing grades. This data is displayed on nineteen orthophoto sheets with a scale of 1" - 400'. The backup calculations were submitted to the City Engineering Department. 3. Recommended Fl ood Control _and Drainage Plan Where there are deficiencies in existing facilities or future development requires, storm drains are recommended as shown in Plates 1 to 4. _ "I _ 3. CONT'D " Debris basins are indicated in appropriate locations to preserve the lagoons. In addition to construction of faci1itiess methods of watershed management are recommended which will mitigate the impact of future development on the lagoons. These include requirements of developers for on-site erosion control and checklists for evaluation of development plans, 4. Preliminary Cost Estimates^ Preliminary cost estimates were determined for the recommended facilities based on approximate quantities and unit prices. These estimates are tabulated in Chapter VIII. 5. Prjority. jating Systern.j._nd_Matri x A system for prioritizing the implementation of the Master Plan was developed and is described in Chapter V. The system is tailored to the conditions existing in Carlsbad in terms of development policy and growth management. Facilities have been prioritized and grouped accordingly. Implementation of the Master Drainage Plan will therefore be in concert with implementation of other elements of the General Plan. 6. Methods andCon_cep_ts_ of Financing andjjanagernen t Methods available to finance the construction of recommended facilities are analyzed in Chapter VI. 7. Regort_ P rep arat i on This report, the nineteen 1" = 400' scale orthophotos showing the hydrologic analysiss and supporting mapss figures, tables, and reference is the product of the Master Drainage Study. This study will undergo Environmental Impact Assessment by the Carlsbad Planning Department. After approvals it would be presented to the City Council as a policy item of the Engineering Division. The Council would then enact a drainage and erosion control ordinance. II-3 ^' Description of Study Area The study area includes all the area within the current corporate boundary of the City of Carlsbad, and the unincorporated area which it surrounds, i.e., the vicinity of Palomar Airport and the north shore of Batiquitos Lagoon. This area is bounded on the north by the City of Oceanside and Buena Vista Creek, on the south by Batiquitos Lagoon, El Camino Real, and Encinitas Creeks on the West by the Pacific Ocean, and on the East by the Cities of Vista and San Marcos. The study area extends about eight miles north-south and five miles inland from the coast. The City lies on the coastal plain which rises to an elevation of 730 feet in the foothills to the east. Four major watercourses have carved watersheds in the coastal plain: 1. On the north is Buena VistaC^eek. "Buena Vista Creek originates in the San Marcos Mountains and flows westerly into Buena Vista Lagoon, which empties into the Pacific Ocean. The entire watershed lies within the County of San Diego and includes parts of the Cities of Vista, Carlsbad, and Oceanside. The Buena Vista Creek watershed is long and narrow in shape, with a distance of about 11 miles from the ocean to the highest mountain peak and an average width of about 2 miles. Total area for the watershed is about 22 square miles. Elevations range from Mean Sea Level (m.s.l.) at the Pacific Ocean to about 1,500 feet. Average slope is about 140 feet per mile." (Ref. 2) 2* South of Buena Vista Creek is AguaHedionda Creek. " AguaHedionda Creek originates in the San Marcos Mountains and flows westerly into Aqua Hedionda Lagoon which empties into the Pacific Ocean. The entire watershed lies within the County of San Diego and includes parts of the cities of San Marcos, Carlsbad, and Oceanside. The Agua Hedionda Creek C. CONTD H"5 watershed is long and narrow in shapes with a distance of about 13 miles from the ocean to the highest mountain peak and an average width of about 3 miles. Total area for the watershed is about 30 square miles. Elevations range from Mean Sea Level (M.S.L.) at the Pacific Ocean to about 1S700 feet. Average slope is about 130 feet per mile." (Ref. 1) A major tributary flows out of Oceanside into Calavera Lake, a manmade lake, and thence to the main creek. 3o The CandorLJeJ.as_jncinas watershed lies entirely with the study area nested between Agua Hedionda and San Marcos Creek watersheds. The creek extends easterly inland about 4 miles and drains about four square miles. Elevations range from Mean Sea Level to about 450 feet for an average slope of 110 feet per mile. 4. "San Marcos Creek originates in the coastal range of mountains north and east of San Marcos and empties into the Batiquitos Lagopj^ about 2.6 miles east of the Pacific Ocean. Encinitas Creek, a major tributary, originates in the mountains southwest of San Marcos and joins San Marcos Creek as it empties into Batiquitos Lagoon. The East Branch of San Marcos Creek originates in the mountains east of San Marcos and joins San Marcos Creek in the City of San Marcos. The entire drainage area totals 46 square miles and ranges in elevation from sea level to slightly over 1700 feet in the Merriam Mountain range northeast of San Marcos. "The stream gradient ranges from an average of 10 feet per mile near the mouth to about 600 feet per mile in headwaters. San Marcos Creek has a small and not well defined channel upstream from Lake San Marcos. Below that point, the channel is well defined., steep, and rocky to the La Costa development where it becomes small and not well defined again to Batiquitos Lagoon. The flood plain is broad upstream from Lake San Marcos. From Lake San Marcos Dam to the La Costa development, there is virtually no C. CQNT'D °"6 flood plain due to the steep, well defined channel. Through the La Costa development to the Batiquitos Lagoon, the flood plain is again broad. During large floods, flows exceed the channel capacity and inundate parts of the broad flood plain. "Batiquitos Lagoon extends from the downstream limit of San Marcos Creeks namely the Pacific Ocean, as far as El Camino Real Road, some 2.6 miles upstream. It comprises about 600 acres of area and would provide considerable storage during large floods. "The climate varies from warm summers to cool winters; extremes in temperature are rare. Mean seasonal precipitation for the drainage area ranges from about 10 inches near the coast to about 16 inches in higher mountains and averages about 13.5 inches over the total drainage area. Most of the precipitation occurs during the months of December through March." (Ref. 4) "Annual grasses dominate the coastal lowlands. Vegetation in the upper areas consist mainly of annual grasses and open brush with some broadleaf and narrowleaf chapparal in the San Marcos mountains and citrus and avocado orchards in the lower hills. "Soil particle sizes increase from fine sand and silt at the coast and low gradient reaches to decomposed granite with clay content as onemoves inland." (Ref. 1) Less than 20% of Carlsbad is urbanized. The City of Carlsbad proper lies between Buena Vista and Aqua Hedionda Lagoons extending from the coast to El Camino Real. Small clusters of development straddle San Marcos Creek upstream of Batiquitos Lagoon. The remainder of the study area is either undeveloped, in agriculture, or occupied by small clusters of development. II-7 c° The topography contributes to Carlsbad's unique character. The coastal plain extends inland several miles and gives way to foothills. Major water- courses have wide valleys with steep walls. Tributaries have carved steep side canyons in the alluvial sediments. Development occurs on the upper terraces and hillsides. Drainage is conveyed to the main watercourses along the tributary canyons. The tributary canyons are particularly sensitive to erosion. As development of the upper terraces occurs, impervious surfaces and concentration of flows increase the storm runoff to the canyons and accelerates the erosion process. This eroded material joins the silt generated by runoff from graded construction sites and is carried to the lagoons and deposited. The accelerated siltation of the lagoons is a matter of increasing concern to agencies responsible for pre- servation of the crucial wildlife habitat provided by Lagoons. With a few exceptions, development in Carlsbad has avoided areas of potential inundation since suitable high ground is plentiful. With the commencement of the Federal Flood Insurance Program, the subsequent mapping of the floodplains of major waterways and the enactment of floodplain management ordinances by the City, the floodplains of Buena Vista, Aqua Hedionda, and San Marcos Creeks have been defined and development in the floodplains has been precluded. These areas provide open space corridors between areas of potential develop- ment. The City has developed a General Plan Land Use Element which connects these east-west open space corridors with inter-connecting open space and park corridors following north-south tributary canyons. Development in these areas will be minimal and natural watercourses are desirable. The Master Drainage Plan therefore focuses on drainage deficiences in exist- ing development and on facilities in tributary canyons which will be developed according to the Land Use Plan. Flood plain management eliminates the need for channelization of the major watercourses. II =8C. CONTJD Tributary canyons in designated open spaces are left natural yet may require drop structure stabilization to mitigate erosion. To protect lagoons from accelerated siltation, sedimentation basins are proposed at strategic locations. D« Basis of Study This Master Drainage Plan is based upon information derived from previous studies, existing topographical and soil data, the City's Land Use Plan, and considerations of current policy of various agencies with jurisdiction in the study area 1. Previous Studies (The Previous Studies are listed in Table 3) a) A Master Drainage Plan was prepared in 1971 for Carlsbad by the consulting firm of Shuirman and Simpson. (Ref. 5) This study compares with the 1971 Shuirman and Simpson study as follows: (i) This plan covers the entire present City plus unincorporated areas which will probably be annexed. The Shuirman & Simpson study did not cover portions of the La Costa and South Carlsbad areas; (ii) This plan reflects land uses stipulated in the 1977 Land Use Element of the General Plan. The 1977 General Plan calls for open space along many of the major watercourses. Therefore, natural conditions were assumed along alignments where Shuirman and Simpson proposed storm drain pipes and channels; (iii) The hydrologic design criteria has changed since 1971, The Federal Flood insurance program mandates 100 year flood protection and most municipalities and local governments conform to this criteria. This Master Plan recommends facilities with 100 year runoff capacity whereas Shuirman and Simpson used 50 and 10 year criteria; and (iv) The hydrology method used in this report differs somewhat from that used by Shuirman and Simpson. Although the Modified Rational Method was 11=9 D. COjTPD used in both studiess the time of concentration value was computed differently. This study utilizes criteria for time of concentration found in the San Diego County Flood Control District Design and Procedure Manual. (Ref. 7) b) Zone 1 of the San Diego County Flood Control District had Koebig, Inc. prepare a Comprehensive Plan for Flood Control and Drainage (Ref. 6) which covers the southern portion of Carlsbad and La Costa. Some of the proposed facilities in the Plan are located along watercourses which are now in the Carlsbad General Plan designated open spaces. These watercourses were assumed to be left natural in this Master Drainage Plan. c) Hydrology and Floodplain mapping studies have been completed by the Corps of Engineers and/or the County of San Diego for Buena Vista, Aqua Hedionda, and San Marcos Creeks. (Ref. 1, 2, 34) The hydrology has been reviewed and is incorporated in this Master Plan. Since these streams are zoned for floodplain, no channelization is proposed. d) The inflow and outflow from Calavera Lake has been studied in the 1976 County Floodplain mapping hydrology study and the 1971 Shuirman and Simpson Master Drainage Plan. Both studies determined the 100 year inflow to be 2300 cfs but the outflows calculated are very different, 900 cfs and 1440 cfs respectively. The difference is due to methodology. The T4"4G cfs outflow was utilized in this report because the methodology conforms to the Modified Rational Method used in this analysis. 2. Hydrology The hydrologic analysis was performed using County of San Diego standard .criteria. This is detailed in Chapter III, Hydrologic and Hydraulic Criteria. This criteria conforms to that used previously in the City of Carlsbad for subdivision design and is appropriate for the study area. 11-10 D. CONTD Topographic data was derived from 1" = 400' scale orthophotos with 5 foot contour interval topography. These were reduced and composed from 1" = 200' scale orthophotos provided by the County of San Diego. Soil and ground cover information came from 1969 Soil Conversation Service Soil Survey Maps updated with projected land uses. 3. Erosion and Sedimentation As discussed previously, the erosion of tributary watercourses and the subsequent accelerated siltation of the lagoons concerns various agencies. The City of Carlsbad addresses this problem in the Land Use, Open Space and Parks and Recreation Elements of the General Plan. The stated goals of the City are to preserve these bodies of water for visual, recreational and wildlife habitat resources. The Coastal Commission., in implementing the Coastal Act, conditions developments adjacent to the lagoons to effect measures which reduce siltation yet provide for beach replenishment. The State Fish and Game Department and U.S. Fish and Wildlife Service require mitigating efforts from developments which impact water-oriented wildlife habitats. The Environmental Protection Agency has sponsored preparation of the Erosion and Sedimentation Control Handbook by the State of California (Ref. 8). This document provides techniques for analysis and design of erosion/siltation controls. This Master Drainage Plan is consistent with the intents and goals of the various agencies with jurisdiction in the study area regarding preservation of the lagoons and watercourses. Facilities and management policies are proposed to mitigate the impact of development in these areas. 4. General Plan and Policy Considerations To determine requirements for storm drains in areas of future development the 1977 Land Use Element of the Carlsbad General Plan was utilized. The type of ultimate land use designated for a particular area influenced selection of hydrologic parameters. In addition, the type of facility was 11-11 D. CONT'D selected to conform to the nature of development. For example, in open space or low density residential areas, natural watercourses or grass- li!?®d channels are specified. In more dense developments storm drains and rip-rap lined channels are specified. 5« History of Drainage Problems The current City drainage complaint file was reviewed to determine chronic nuisance drainage problems. In certain areas, facilities are proposed to up- grade the existing system and should remedy the problems. JJJ •JYDHOLOGJC AND HYDHAULJC CHJTEHJA 111. HYDRpLgGIC_CRITERIA ~ A. STUDY APPROACH The approach of this project was to utilize previous hydrology studies for the major watercourses and to analyze tributary areas where storm drain deficiencies occur. Storm drain facilities are recommended where existing facilities are inadequate or where projected development will require drain- age facilities. B. HYDROLOGIC DESIGN CRITERIA The design criteria, as found in the San Diego County Flood Control District Design and Procedure Manual, specifies the 100 year frequency storm for design runoff for facilities draining areas greater than one square mile. For areas less than one square mile, the storm drain system must have 100 year flow capacity within the street up to right-of-ways 50 year flow capacity to top of curb, and where storm drains are required, minimum 10 year capacity in the drain. For this study existing drainage systems were analyzed with respect to the above criteria and recommendations made accordingly. In undeveloped areas, where future street alignments and grades are unknown, the recommended storm drain lines are sized for 100 year flow capacity, based on the grades-of existing flowlines. However, when these areas are developed the drainage system may actually carry the 10 year storm underground, the 50 year to top of curb, and the 100 year to right-of-way. Drains at sumps should convey 100 year flows. The design flows were computed based on the following assumptions and data: (1) Ground cover data was derived from S.C.S. 1969 Survey Maps updated with ultimate development data corresponding to the 1977 Land Use and Circulation Element Map of the General Plan, except as noted below. III-2 (2) For the area generally southwest, west and northwest of Palomar Airports shown hatched on the City's Land Use and Circulation Map the Land Use was assumed to be industrial at the direction of City Planning staff. (3) Hydrologic Soil Groups were determined from Soil Conservation Service 2000 scale Soil Survey Maps published in 1969. The soil types were derived from the "San Diego Soils Interpretation Study for Hydrologic Soils Groups in San Diego County. Soil Types were segregated into groups as a function of their probable infiltration capacity. The group designations include: Group A - Low Runoff Potential: Soils having high infiltration rates even when thoroughly wetted, consisting chiefly of deep, well to excessively drained sand and/or gravel. These soils have a high rate of.water transmission and would result in a low runoff potential. Group B - Moderate Runoff Potential: Soils having moderate infiltration rates when thoroughly wetted, consisting chiefly of moderately deep to deep, moderately well to well drained soils with moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission. Group C - High Runoff Potential: Soils having slow infiltration rates when thoroughly wetted, consisting chiefly of (1) soils with a layer that impedes the downward movement of water, or (2) soils with moderately fine to fine texture and a slow infiltration rate. These soils have a slow rate of water transmission. Group D - Very High Runoff Potential: Soils having very slow infiltration rates when thoroughly wetted, consisting chiefly of (1) clay soils with a high swelling potential: (2) soils with a high permanent water table; (3) soils with clay pan or clay layer at or near the surface; and (4) shallow soils over nearly impervious materials. These soils have a very slow rate of water transmission. (4) The following coefficients were used: III-3 Table I Manning Roughness Vs Values PIPES Ve Corrugated Metal Pipe 0.024 Reinforced Concrete Pipe 0.012 Cast in Place Concrete Pipe 0.015 Asbestos Concrete Pipe 0.011 OPEN CHANNELS Revetment 0.040 Concrete lined 0.015 Natural Grass 0.035 Reinforced Concrete Box Culverts 0.015 LAND USE Single Family Multi Units Rural Commercial Industrial Table 2 Rational Method Runoff Coefficients GENERAL PLAN DESIGNATION Medium, Low-Medium Density Residential High, Medium-High Density Residential Low density Residential, Open Space Commercial Industrial, Government, Schools COEFFICIENT. C SOIL GROUP A i £ D. .40 .45 .50 .55 .45 .50 .60 .70 .30 .35 .40 .45 .70 .75 .80 .85 .80 .85 .90 .95 II1-4 (5) Rainfall intensities for the Rational Method hydrology computations were taken from the San Diego County Flood Control District Design and Procedure Manuals Appendix XI. (6) Watershed boundaries and grades for proposed storm drains were derived from 400 scale topography reduced from 200 scale orthophoto maps prepared by the County of San Diego. (7) Flows for major watercourses have been determined by pre- vious studies as shown in the following Table 3. III-5- STREAM BUENA VISTA CREEK CALAVERA LAKE INFLOW and OUTFLOW AGUA HEDIONDA CREEK SAN MARCOS CREEK SAN MARCOS CREEK, ENCINITAS CREEK TABLE 3 PREVIOUS STUDIES STUDY HYDROLOGY REPORT FOR BUENA VISTA CREEK DECEMBER 1976 FLOOD PLAIN INFORMATION JULY 1973 MASTER DRAINAGE PLAN CITY OF CARLSBAD APRIL 1971 HYDROLOGY REPORT FOR AGUA HEDIONDA CREEK DECEMBER 1976 HYDROLOGY REPORT FOR AGUA HEDIONDA CREEK DECEMBER 1976 FLOODPLAIN INFORMATION APRIL 1971 COMPREHENSIVE PLAN FOR FLOOD CONTROL AND DRAINAGE - ZONE 1 SAN DIEGO COUNTY FLOOD CONTROL DISTRICT JULY 1976 AUTHOR COUNTY OF SAN DIEGO CORPS OF ENGINEERS SHUIRMAN SIMPSON. CIVIL ENGINEERS COUNTY OF SAN DIEGO COUNTY OF SAN DIEGO CORPS OF ENGINEERS KOEBIG, INC. III-6 C. DESIGN RUNOFF METHOD The hydrologic analysis utilized for design of facilities recommended in this report is the Rational Method. The Rational Formula is Qp = CiA where: Qp s The peak discharge in cubic feet/sec.* * 1 Acre in/hr. - 1.008 cubic feet/sec. C - Runoff Coefficient (Dimensionless) i - Rainfall intensity (inches/hour) A ~ Tributary drainage area (Acres) If rainfall is applied at a uniform rate to an impervious area, the runoff attributed to this area would eventually reach a rate equal to the rate of precipitation* The time required to reach this equilibrium is term- ed the time of concentration. For small impervious areas one may assume that if precipitation persists at a uniform rate for at least as long as the time of concentration the peak discharge will equal the precipitation rate. D. DESIGN PROCEDURE The following procedure was used in calculating quantity of storm flow at various locations along the route of the proposed storm drains. Whenever the term "Manual" is used, it refers to the "DESIGN AND PROCEDURE MANUAL OF SAN DIEGO COUNTY FLOOD CONTROL DISTRICT" dated December 1969. The general procedure was developed by Los Angeles County Flood Control District and has been modified herein for use in San Diego County. I. On the drainage map divide the runoff area into subareas of from 20 to 100 acres. These divisions should, if possible, be based on the topography, soil type, and the land development. The size of the initial area should be chosen such that the length of travel for the water from the ni-7 most remote point to the point of concentration should not exceed 1,000 feet and if possible be near 500 feet and be of a generally uniform slope. 2. Determine the quantity of water for the initial area. a« Estimate the initial time of concentration. This can be obtained from appendix X-A of the "Manual" (Figure 2). b. Determine the type of soil from "Hydrologic Soil Groups - Runoff Potential" maps of the County Soils interpretation study. c. Determine the ultimate land use from the Carlsbad General Plan, do Obtain the runoff coefficient "C" from Table 2. e. Obtain the intensity (i) from Appendix II "Rainfall Curves for County of San Diego" of the "Manual" (Figure 3). f. Calculate the quantity of water (Q) from the "Rational Equation", Q = CiA. *3. Determine the quantity of water for subsequent subareas as follows: a. Determine the water route from the point of concentration of the previous subarea to the point of concentration of the subarea in question. b. Calculate the time necessary for the quantity of water arriving at this subarea to pass through to its point of concentration by the above route. The physical properties of this route must be considered and the velocities obtained from the following: (1) If traveling in a street the velocity can be figured from Appendix X-D, "Gutter and Roadway Discharged - Velocity Chart" of the "Manual" (Figure 4). (2) If traveling in a ditch, pipe or other regular section calculate the velocity from the actual section. III-8 (3) If traveling in a natural watercourse the velocity can be derived from Figure 1 , Velocity In Natural Valley Channels. c= Measure the length of flow to the point of inflow of the next subarea downstream* From the velocity compute the time of flow and add this time to the time for the first area to determine a new time of concentration. When determining the time of concentration (Tc), the ex- pected future drainage facility and route is used to determine velocity and travel time (Tt). Wherever junctions occur, or there is a change in slope or drainage facility, it is necessary to calculate the velocity and .travel time for the preceding reach. The slope of the Hydraulic grade line is generally assumed to be parallel to the grade slope. d. Calculate Q for the second subarea, using the new time of con- centration and continue downstream in similar fashion until a junction with a lateral drain is reached. e. Start at the upper end of the lateral and carry its Q down to the junction with the main line. 4. Compute the peak Q at each junction. Let QA, T^, 1^, corres- ponding to the tributary area with the longer time of concen- tration. Let QB, Tg, IB, correspond to the tributary area with the shorter time of concentration and Qp, Tp correspond to the peak Q and time of concentration when the peak flow occurs. a. If the tributary areas have the same time of concentration, the tributary q's are added to obtain the Peak Q. QP S QA + % b« If the tributary areas have different times of concentration, the smaller of the tributary Q's must be corrected as follows: III-9. (1) The usual case is where the tributary area with the longer time of concentration has the larger Q. In this cases the samller Q is corrected by a ratio the intensities and added to the larger Q to obtain the peak Q. The tabling is then continued downstream using the longer time of concentration QA= QA + QB ^ ip - TA 1B (2) In some casess the tributary area with the shorter time of concentration has the larger Q. In this cases the smaller Q is corrected by a ratio of the times of concentration and added to the larger Q to obtain the peak Q, The tabling is then continued downstream using the shorter time of concentration. 5 % • VA - T P ' TB TA 111-10 p:i' JaJtij. fip-jriBy. j-if uaLujaJL' -yUaiuiiylJ •Mo ' ' BjBfthatgg in e.X.«. TSLQCXXX XS FIGURE 1 \. c /tftf/ Jc a 7//j?e» of concert f/TaJ-Saff effective 5/<?/3<£ tine (See dppendix. X-&) L 9OO £06 \ »$00 \ -406 4- \ \2- \ \ - — 40 ZD /G NOTES: 1. ADD TEN MINUTES TO COMPUTED TIME OF CON- CENTRATION. 2. THIS NOMOGRAPH IS INTENDED FOR USE PRI- MARILY IN NATURAL, UNDEVELOPED WATER- SHEDS, 4 3 \ \ \ \ 2OOO \ - /G009OO80 O £06 — •300 240 SO — 40 20 — /* -/O — 9 — S H FIGURE 2 P. VII-7 SAN DIEGO COUNTY DEPARTMENT OF SPECIAL DISTRICT SERVICES DESIGN MANUAL APPROVED -'P'A NOMOGRAPH FOR DETERMINATION OF TIME OF CONCENTRATION (Tc) FOR NATURAL WATERSHEDS DATF APPENDIX X-A —d dodo «3d S3HONJ - C093IQ NVS) AirSN31Nl 2 O ^^H <ec <D O otf \ » o « h_ Q ev» «. »= O O in<c r» N FIGURE 3 RAINFALL INTENSITY - DURATION- FREQUENC' CURVES O « Illl COUNTY OF SAN DIEGO r i ' i o s 0 2 o o o mo o o o ui Us Io — > o a • >«• —p. YII-8 S.D.F.C.D. APPENDIX in-13 f RESIDENTIAL STREET ONE SIDE ONLY EXAMPLE: Given. Q= 10 I 1 I II I * S 6 7 8 9 10 DISCHARGE (QFS.) \ S= 2.5% I 20 I 30 ! I 4O 50 Chert gives; Depth = 0.4, Velocity = 4.4 tpus. FIGURE p. VII-9 SAN DIEGO COUNTY DEPARTMENT OF SPECIAL DISTRICT SERVICES DESIGN MANUAL APPROVED __^J GUTTER AND ROADWAY DISCHARGE-VELOCITY CHART DATE APPENDIX X-D J DRAINAGE FACl.JTJEiS PLAN IV-1 DRAINAGE FACILITIES JLAN The master drainage facilities required to remedy deficiencies in existing development or required by future development are displayed on plates 1 - 4 and are described below. Design criteria and the basis for selection of facility types has been discussed in Chapters II and III while priorities and implementa- tion recommendations are discussed in Chapters V and VII, This chapter describes the proposed drainage facilities basin-by-basin, The older city has an existing storm drain system which was designed for low flow drainage and is inadequate for 50 or 100 year storms, A review of drainage complaints revealed numerous instances of chronic street flooding during major storms. Remedial facilities are proposed to upgrade the pro- tection level and eliminate nuisances. ** In the newer developments, storm drains exist which, in combination with street capacity, provide adequate protection. Facilities are proposed to complete the system through the areas of future development. In undeveloped areas, future development may require storm drain facilities on-site or downstream. Where the Land Use Plan designates open spaces on canyons, the watercourses are assumed to be left natural with provision for grade stabilization with drop structures. These areas may be managed by requiring the areas of inundation by the 100-year flood to be determined during the engineer- ing of new developments and by requiring that development be kept out of these areas. If such open space areas are later proposed for development, appropriate modifications of onsite and downstream facilities must be required of the developer. A. Buena Vista Creek Watershed (Facilities AA - AE) Facilities AA, AA-1, AA-2, AA-3 An existing storm drain system drains the Carlsbad downtown business district along State Street, Washington Street, Laguna Drive and Grand Avenue. Complaints of flooding along these streets have been received by the City. IV-2 A. CONT'D A stonn drain system of adequate capacity is proposed as facilities AA, AA-1s AA-2S and AA-3. The alignments are initially proposed within existing street right-of-way. However, during final design, the costs of relocation of utilities, disruption of business,, or convenience may dictate an alternative alignment of the State Street System, line AA. Such an alternate would require acquisition of right-of-way through private property and along the railroad right-of-way. These facilities could be implemented during redevelopment of the business district and thus be elegible for redevelopment funds or be constructed by an improvement district. Facility AB Facility AB is a storm drain proposed to be constructed under Highland Drive with an outfall from the cul-de-sac to Buena Vista Lagoon. The street provides the only conveyance for drainage and is of inadequate capacity by current standards. The upstream area is partially undeveloped and higher density development will aggravate the drainage deficiency unless a drain is constructed. Facilities AC and AD Facilities AC and AD will complete existing storm drain systems as future development fills in. The existing systems are in newer development and have adequate capacity. Facility AE The drainage area tributary to debris basin facility AE is undeveloped and the watercourse is designated as open space. Future development in the watershed may accelerate siltation of Buena Vista Lagoon. Therefore, a debris basin is proposed in the location shown on Plate 1 to mitigate this development impact. - 2 IV-3 Agua Hedionda Creek Watershed (Facilities BA - BN) Facility BA Line BA is a 60" diameter storm drain which parallels the railroad and will intercept existing tributary storm drains. It replaces a ditch from Walnut Avenue to Juniper Avenue and parallels an existing 60" RCP from Juniper to Tamarack. Both 60" pipes are required due to the very mild slopes. This improvement would alleviate nuisance ponding and reduce the potential for mosquito breeding. It would connect to a 72" existing pipe5 thus completing a major system draining into Agua Hedionda Lagoon. FacrHtyJSB This proposed storm drain will complete a drainage system by connecting upstream and downstream existing facilities. Drainage complaints have been recorded along the existing watercourse. Severe erosion occurs on downstream reaches of the existing gully and the resulting silt plugs downstream storm drains and necessitates dredging of the Shelter Cove Marina. The proposed facility will alleviate the nuisance flooding and erosion problems. Continued residential and commercial development will occur in the basin, and should bear a portion of the cost of improvement through assessments or fees. Facility BC Storm drain line BC protects against erosion of the east side of El Camino Real and will reduce siltation of Agua Hedionda Lagoon. This should be constructed with road maintenance funds since the primary benefit is road protection. Facilities BD - BN Facilities BD through BN are required by future development and will be constructed by future development or be financed by assessments or impact fees paid by new developments in the tributary areas. Five debris basins are located to mitigate siltation of Agua Hedionda Lagoon accelerated by - 3 - IV-4 B- CONT'D new developments in these areas. C. Canyon De Las Encinas Watershed (Facilities CA, ± CM) Storm drain lines CA through CM are required by future development. Line CM also completes an existing storm drain system. No debris basins are proposed on the premise that no lagoon is threatened and that transport of silt to the beach is vital to beach sand replenishment. Several bridge and culvert structures on Encinas Creek may require more frequent maintenance due to siltation. These facilities will be constructed or financed by future development through assessments or impact fees. D. San Marcos Creek/8atiquitos Lagoon Watershed Facilities DA - DU Facilities DA through DU are required by future development.Line DA also upgrades an existing system in certain reaches downstream of the railroad. Lines DB and DG complete existing systems. Ten debris basins are proposed at various locations to control siltation of Batiquitos Lagoon. This basin is within Zone 1 of the San Diego County Flood Control District. A Comprehensive Plan was prepared for Zone 1 in 1976 by Koebig, Inc. This Master Plan differs from the Zone 1 Comprehensive Plan as follows: 1. The 1977 Carlsbad Land Use Element of the General Plan designate many watercourses as future open space which does not require pipe or channel storm drains. 2. Debris basins are proposed in this Master Plan as part of the facilities for individual drainage areas. These are required to mitigate the impact of siltation of the _ 4 - IV-5 D. Cont'd lagoon due to grading of new development. PRIORITY ATING SYSTEM AMD MATRIX V-l V. PRIORITY RATING SYSTEM AND MATRIX A priority rating system and matrix has been developed to provide a schedule for implementation of the Master Drainage Plan. The primary function of drainage facilities is to protect public health. Additional functions may be cited according to specific needs for a facility. For the City of Carlsbad, the following priority list of functions has been identified: Priority Rating Function of Drainage Facility 1 (Protects Life (Protects Property (Enhances Transportation Safety 2 (Reduces Vector Problems from Ponding (Reduces Nuisance Flooding (Reduces Erosion/Lagoon Sedimentation 3 (Upgrades Existing System to Higher Protection (Completes Existing System (Required By Future Development a. Areas developing within 5 years b. Areas developing within 5 to 10 years c. Areas developing after 10 years Priority 1. Protects Life and Property As stated previously the primary function of a drainage facility is protection of public health, and prevention of loss of life is of highest priority. Pro- tection of property is another high priority function of storm drains. Property damage may be caused by inundation of low areas by storm waters overflowing existing drainage facilities; by erosion of banks which may undermine found- ations or cause loss of cropland; by deposition of silt and mud by receding « floodwaters. If not f1oodproofed, buildings may suffer damage to walls and * floors with residual effects of rotting of timbers and fouled utilities. JU Contents may be damaged by only flooding of floors. Businesses are particularly hard hit by contents damage and loss of business due to repairs. V-2 Priority 2 Enhances Transportation Safety, Reduces Vector Problems from Ponding, Reduces Nuisance Flooding These functions are grouped secondary to protection of life but are nevertheless at very important and provide a tangible basis for determining benefits versus costs « for a particular project. „ Transportation safety is enhanced on heavily travelled roads when adequate catch * basins and storm drains provide lanes free from deep, flowing water and eliminate * the need for parallel ditches which may erode-shoulders. >» Areas with poor drainage may pond water and create a breeding place for mosquitos and other vectors. Nuisance flooding may occur in residential areas at poorly drained sumps, or drains plugged with debris, for example. Downtown areas may experience inadequate drainage which discourages auto and pedestrian traffic. *» •m Priority 3 Reduces Erosion/Lagoon Sedimentation, Upgrades existing System to Higher Protection, Completes Existing System Facilities reducing erosion and lagoon sedimentation are measures designed to •* implement the preservation of the lagoons as called for in the Carlsbad General * Plan and the/State Coastal Act. 41 Storm drain systems exist which were designed under different criteria and may * m adequately handle annual storms but not 50 or 100-year storms. These systems require upgraded facilities to provide protection up to current criteria. Some '* proposed facilities connect upstream and downstream of existing facilities to ~ • complete the system. These functions are grouped in third priority due to a lesser degree of urgency relative to the first two priorities. ••* m V-3 Priority-4 Required by Future Development^ Proposed facilities located in currently undeveloped areas will be required by future development which was assumed will proceed in accordance with the current land use plan. These facilities will primarily constructed by developers or financed by impact fees or improvement districts as development occurs in the drainage basin. The priority of implementation in these areas is affected by the available public facilities and growth management policies of the city. Therefores secondary priorities have been established as follows; 4a. Proposed storm drains located in areas expected to develop in the near term, that is within 5 years will have higher priority in implementation. 4bc Proposed storm drain located in areas of anticipated develop- ment in the mid-term, that is within 5 to 10 years will have next priority in implementation. 4c. Proposed storm drain located in areas where development is not anticipated within 10 years will have least priority. The recommended facilities have been prioritized based on primary functions, need, and geographical location with respect to the criteria discussed above. The results are displayed in Table B, Chapter VII. V FINANCING 3'NATjy VI-1 VI. FINANCING ALTERNATIVES In this period of municipal financing of public works projects, there is a significant amount of uncertainty and change. The passage of Proposition 13 and the most recent passage of Proposition 4 have seriously impacted both the financing options available to a community and the extent of work which can be reasonably undertaken within legal limitations. Proposition 13 has had a strong negative impact on the use of ad valorem methods of financing with special negative emphasis on the ability to use tax investment financing or general obligation bonds to finance public projects. The passage of Proposition 4, which sets a limit on the amount of appropriations by state and local governments and ties increases in that amount to population and cost of living changes, has created uncertainties which have yet to be resolved by the state legislature. Until the state acts to define how Proposition 4 will be implemented, the question regarding the viability of using multipurpose assessment districts with 1911 Act financing, developer impact fees and user fees will be unanswered. Beyond the question of the current practicality of previous financing methods, there is a growing awareness of the need to develop local capital improvement plans which are designed to manage community growth and development in a manner consistent with the wishes of the citizenry. This philosophy takes the various service requirements of VI-2 water, sewer and drainage and combines them into an all-encompassing growth management policy which clearly defines how development will be > 4- allowed, what will be required to provide the necessary infrastructure, and how the financing of these improvements will be achieved. *• An important aspect of this total plan is the determination of what primary method should be used for financing capital facilities. The HUD publication Local Capital Improvements and Development Management lists the following available methods of pricing capital facilities: 1. Incremental Budget Pricing—in which a developer is charged only for increases in the governmental budget directly related to his development. 2. Incremental Budget Pricing with Payback—in which the de- veloper is repaid for excess capacity as additional users develop within his service area. 3. Average Incremental Pricing—in which capital costs associ- ated with increased service are averaged over the total expected number of service users and the developer pays the costs associated with his development. 4. Average Incremental Zone Pricing—similar to item 3 above, txcept that the costs of services are averaged over par- ticular areas of a city permitting isolation of expensive service areas. VI-3 5. General Revenue Pricing—in which the costs of service expansion are allocated across the entire community. 6. General Revenue Zone Pricing—in which the costs are allo- cated to residents or property owners within zones drawn to isolate high-cost (as well as low-cost) areas. Each of these approaches has advantages and disadvantages, and each system may be more appropriate for one particular capital facility than another. Incremental budget pricing, for example, may work well and be most fair where facilities are involved that will primarily serve one development, such as short sewer extensions and on-site services; average incremental pricing may best serve to finance a large facility such as a fire station that will serve a whole area. Zone pricing policies are best used to discourage development in high-cost areas. In developing a comprehensive local capital improvement plan these methods of pricing must be clearly incorporated into the management strategy. With these thoughts in mind, we present the following analysis of financing methods. Financing methods which were considered are: A. Improvement Districts B. Development Impact Fees C. Corps of Engineers Project Funding VI-4 D. User Fees EC Flood Control District / F. General Obligation 6. EDA/HUD Funding ^° Improvement Districts Improvement Districts are established by local ordinance through 1911 or 1913 Act proceedings and provide for the implementation of master- facilities plans which benefit the district. An advantage is the flexibility provided in cost distribution, i.e., areas directly bene- fitted ma- pay proportionately more than other areas within the district. Bonds are sold through 1911 or 1915 Act proceedings for construction and acquisition and are retired by assessment revenues collected on the pro- perty tax bill. The 1911 Act enables property owners to establish a local improvement district to issue bonds, assessing themselves for the costs. The 1913 Act provides a modified assessment procedure. The 1915 Act modifies the bonding procedures. Generally, the 1911 Act is used along or in combination since each provides only part of the funding procedures. Typically, improvement cost estimates and designs are prepared by the City or County staff and, after public hearings, the district forma- tion and assessments are approved or disapproved by the affected owners. If approved, the contractor bonds for the improvements and the improvement district retires the bonds in 5 to 40 year periods. VI-5 Proposition 13 has caused confusion regarding formation of improvement districts. Prior to passage of Proposition 13, use of the Improvement Bond Act of 1915 appears to be the most desirable form of financing for multi-purpose assessment district. However, the 1915 Act requires assumption of a limited liability by the City in the event of default (equivalent to $.10 on the property tax rate). Mow that cities no longer are in a position to commit property taxes, 1915 Act bonds cannot be sold unless the bond market will accept other revenue sources as sufficient guarantee. Development impact fees held in reserve are a possible source. The Improvement Act of 1911 provides for issuance of bonds that are a direct lien on each parcel within an assessment district instead of the district as a whole as in the 1915 Act. Either the bonds must be paid off prior to subdivision, or the holders of the bonds must agree to permit bond splits. If the bonds are split, the bond still would have to be paid at the time of sale unless the institution providing take- out financing is willing to make loans with an existing assessment lien. Even if a home buyer could leave a 1911 Act bond against his property, it may be to his advantage to pay it off and assume the cost as part of the mortgage. Because 1911 Act bonds usually mature in 10 to 15 years and have equal annual installments of principal, the annual bond service is high and is approximately twice the amount in the first year as in the last year. Inclusion in the home loan would result in a higher rate of interest but lower monthly payments. VI-6 Pending definitive outcome of test cases, many municipalities, such as the City of San Diego5 are pursuing 1911 Act district formations in belief that such beneficial special assessments are not included in the intent of the vaguely-worded proposition. Bond opinions and ratings are jeopardized in the meantime. Additionallyt until the enabling legislation for Proposition 4 is developed the area of financing is further confused. B. Development Impact Fee^ The Subdivision Map Act (Section 66483) provides the authority to collect fees for "Planned Local Drainage Facilities" from developers as conditions of approval. The Act requires that a Master Plan exists which estimates the costs of proposed facilities and that a local ordinance be passed which provides for collection of such fees. The fees are apportioned on a uniform cost per acre basis, thus precluding any other cost distribution based on degree of benefit within the fee area. Fees are collected in the subdivision map and permit approval process and are not considered subject to Proposition 13 restrictions. However, Proposition 4 looks at user type fees as an offset against other sources of revenue. Funds for construction or acquisition may be advanced from the City general fund and reimbursed by fees. Only new facilities are eligible for funding by fees. The Fees collected are spent for facilities in the benefiting area, and related administrative and engineering expenses. Fees are commonly used by the County and most municipalities in the County to provide for public capital facilities such as drainage improvements. VI-7 C. Corps of Engineers Project Funding The U.S. Army Corps of Engineers has constructed numerous flood control projects throughout the nation. The projects are typically financed through a combination of Federal and local funding. A proposed project must have a favorable benefit/cost ratio justifying Corps funding. 100% construction costs are borne by the Corps except in areas which are removed from the Federal Insurance Administration-designated floodway. These areas can then be developed and must therefore pay a portion of the directly benefitting construction cost. Right of way acquisition and utility relocation costs are borne by local government. Typically, up to 75% of right of way costs and up to 90% of utility relocation costs are reimbursed by the State. Implementation of project proposals may take up to ten years from conception. "Large" projects require congressional approval and take 10 years from authorization study to construction funding. "Small" projects with less than $3 million Federal Share require approval only within the Corps, and may be implemented within the three years of inception. The Environmental Impact Review, economic analysis, design approval, and budgeting processes are time consuming at the Federal level. Q. User Fees The user fee concept until recently provided a viable alternative to property assessment to generate revenue for construction acquisition, VI-8 and maintenance of public works facilities. However* the passage of Proposition 4 has clouded the extent to which user fees may be imple- mented and the City may require State legislative clarification to establish the extent user fees may be utilized. The 1976 "Benefit Charge Study for San Diego Flood Control District, Zones ls 2, 3, 4 and 5S" Stone & Youngberg Municipal Financing Consul- tants analyzed the user fee concept and its application in Boulder, Colorado and Bellevue, Washington. Their conclusions were as follows: "It is our conclusion that drainage fee systems work best in those communities in which several conditions are present. First, there must be a broad-based concensus in the community that the levy of ad valorem property taxes for financing flood control and drainage is inequitable. Secondlys there must be an awareness among local residents of the poss- ibility of flood damage to their property. Thirdly, if flood hazards are not present, then there should be strong community support for and the willingness to pay for the maintenance of natural flood control channels to preserve or restore the "natural" environment. Lastly, the drainage fee system must be coupled with an effective method for collect- ing and enforcing payment of fees." Fees for drainage were collected on the water and sewer bill. For Carlsbad, in areas the City provides water and/or sewer, collection of fees for drainage facility maintenance could be feasible if Proposition 4 does not preclude it and the political realities support it. VI-9 E. Flood ControLMltrjct The San Diego County Flood Control District is a special purpose district formed to construct and finance drainage and flood control facilities within five zones. Significant portions of Carlsbad are not currently within the Flood Control District. The District finances facilities as follows. Bond issues approved by 2/3 majority within the District Zones are retired through ad valorem property taxes and development impact fees. The District Act has authorization to do work or improvements under 1911s 1913 and 1915 Acts, and to charge user fees. The County Board of Supervisors directed District Staff to implement an annual drainage charge for FY 79-80, however, public opposition forced postponement of the implementation for an indefinite period. The Flood Control District is pursuing State legislation to form a new Zone in the North County watersheds presently excluded. Annex- ations to the new zone require elections if protests are received from over 25% of the population. If formed, cities such as Carlsbad could annex by popular vote as subzones under the City inclusion alternative. Revenues raised by the subzone would be spent entirely within the subzone for implementing a capital facilities plan and for District services. Subzone taxes would be received as an allocation of the }% tax revenue in the county. Upon completion of the imple- mentation, the subzone could dissolve, ceasing its obligations to the District. Services such as maintenance could be assumed by the City or contracted to the District. VI-10 Advantages to joining the District as a subzone include the use of user fees for financing capital projects, bonding capability of the District, the possibility of the District loaning improvement funding with later reimbursement by fees or assessment, the availability of maintenance service, and the potential for a city to exert planning influence over neighboring unincorporated areas. Additionally, the expansion of the Flood Control District in Carlsbad would increase the District's pop- ulation service area and should allow for a District budget increase under Proposition 4 beyond the allowable cost of living increase. This budget increase could allow the District to finance facilities in Carlsbad and/or increase the level of maintenance for Carlsbad's storm drain system. F. General Obligation Bonds Capital projects improving services or benefitting the municipality as a whole are commonly financed through General Obligation bonds, retired through ad valorem property taxes. Storm drain and flood con- trol projects funded in such a manner are subject of the budget priori- tizatfon along with the police, fire and other municipal services. In the past the likelihood of budget cut survival for drainage projects depended upon the intensity of concern for flood control. Proposition 13 has reduced property tax revenues an average of 60%. Services will probably remain the high priority budget items while funding for capital projects will diminish. Unless a project can offer very attractive benefits, such as greatly increased tax base, revenues, and/or jobs, general obligation bond funding for drainage improvements is unlikely. 6. EDA/HUD^Financing Qualifications for Economic Development Administration (EDA) and Housing and Urban Development Department (HUD) are constantly changing, becoming more restrictive and in the case of EDA regulations have still not been enacted. However, because of the increasing restrictions or uncertainties placed on other local financing options, federal funding for capital improvements must not be overlooked. There are four major programs which may be of benefit to Carlsbad. 1* Title I Publ_ic_Mor_ks Program The Public Works Program (Title !) of the Economic Development Ad- ministration (EDA), through the PUblic Works Impact Program (PWIP), funds projects that create short-term and construction jobs. Con- struction assisted under the impact program must be completed in 12 months, and most of the PWIP grant funds must be spent in the project area. States, cities or organizations representing an EDA-designated area are eligible for Title I frants and loans, which may be used to buy, contruct, or improve land, buildings and equipment. (Funds for land acquisition are usually a small part of a larger construction grant.) Forty percent of the current regular Title I grants are funding indus- trial projects, such as renovating buildings or constructing sewers and access roads for industrial parks. Assistance is also available for downtown revitalization projects, including the construction of pedestrian malls, and for port and cargo handling facilities and skill training centers. VI-12 Title I funding will pay up to 50 percent of the cost of a project, although severely distressed areas may receive an additional 30 percent in supplementary grants. (Local matching funds may be waived com- pletely if the locality proves it cannot supply its share.)( Local bond or budget authority, cash on hand, regional commission funds or Community Development Block Grant (CDGB) funds may be used to provide the 1 oca! match. ) Title IX Economic Development and Adjustment Assistance EDA's Special Economic Development and Adjustment Assistance (Title IX) program is designed to create jobs in areas o.f very high unemployment. The Title IX program is divided into two parts; one funds projects combating long-term economic deterioration, while the other supports activities countering sudden and severe economic dislocation (sudden changes in the economy, such as those caused by the closing of a major employer). The Title IX program allows EDA to fund a wide range of economic development activities under a single grant. Title IX grants may be used to improve public facilities by providing money to acquire, develop or improve land, buildings or related equip- ment. Localities have used grants to restore and enlarge water sys- tems, develop industrial parks, rejuvenate industrial areas, and renovate buildings for attractive retail and residential space- VI-13 Community DeveTjopmen^t Block ^ The largest source of funding for publicly financed physical development is the Community Development Block Grant (CDBG) program, administered by the Department of Housing and Urban Development (HUD). Communities with a population of 50,000 or more and central cities of Standard Metropolitan Statistical Areas (SMSAs) are entitled to CDBG assistance upon application to HUD, although smaller communities may receive block grant funds at the agency's discretion. The amount of assistance is determined by a formula. CDBG funds may be used to buy and improve real property; to acquire or rehabilitate certain public facilities (including those needed to implement neighborhood or economic development strategies) ; to clear away unwanted buildings; and to acquire or rehabilitate commercial or industrial buildings and equipment. CDBG funds may also be used for the local matching share of any federal program which will fund activi- ties otherwise eligible for CDBG assistance. It is our understanding that Carlsbad is receiving CDBG funding through the County and that a portion of this money is being used for funding activities in the Downtown Redevelopment Project. In this instance the funds could be appropriately used for the storm drain construction in the downtown area. 302(a) State Technical Assistance These are EDA funds administered through the State of California's Office of Local Economic Development. They can be used for the VM4 construction of public facilities and may be of benefit in those areas of Carlsbad which have industrial or commerical potential and currently have insufficient public facilities. Sjjmrnary^ Currently, because of the uncertainties created by the passage of Proposition 4, all the financing alternative, with the exceptions of Corps of Engineers and EDA/HUD funding, have some unresolved questions to the extent of their applicability. Once the state legislature acts to define how Proposition 4 will be implemented multi-purpose assess- ment districts* development impact fees, and user fees may still be realistic methods for financing capital improvements. Corps of Engineers funding is not likely since no flood hazard exists to development on the scale that the Corps is involved in. The expansion of the Flood Control District into more of Carlsbad may provide means of financing improvements. This expansion would increase the District's Population Service Area and would allow the District to increase its appropriations beyond limitations of inflation indexes imposed by Proposition 4. Finally, General Obligation Bonds as a financing method are greatly restricted because of the Proposition 4 and 13 limitations. HEC OMM £ NDAT1 QNo VII-1 VII. RECOMMENDATIONS The following recommendations set forth in this Master Plan are intended to complete a storm drain system of adequate capacity by current stand- ardss to provide facilities and policies to mitigate the impact of future development on natural watercourses and the lagoons, and to establish the best means to implement the Plan and policies. VII-2' RECOMMENDATIONS (1) This report should be adopted as the Master Drainage Plan by the City Council of Carlsbad, replacing the 1971 Master Drainage Plan. DISCUSSION Adoption of this report as the Master Drainage Plan is required for the City to collect development impact fees from new development, under the Sub- division Map Acts to finance construction of the drainage facilities proposed in this plan. (2) The drainage and erosion control facilities tabulated in Table B and shown in Plates 1, 2S 3 and 4 should be constructed according to the Priority Matrix established in Table B. DISCUSSION This study has identified the facilities recommended herein to provide the necessary flood protections to existing and new development, eliminate nuisance drainage problems, and mitigate erosion and sedimentation impact on the lagoons. Priorities for implementation have been established reflecting the urgency of the drainage deficiency, the method of financing, and the growth management policies of the City. (3) The grading ordinance should be amended to include concepts put forth in the Model Erosion Control Ordinance found in the Appendix. DISCUSSION The primary causes of siltation of the lagoons are a) sediment generated by runoff of supstream developments under construction; and b) sediment generated by the erosive velocities in natural channels produced by concentrated and increas- ed runoff from urban development. An amended grading ordinance would provide for mandatory onsite containment of erosion and sedimentation of caused by grading. VII-3 (4) Drainage facilities required by new development should be financed by new development. As conditions of approval of a final Subdivision Map or building permits, the City should require the developer to construct all Master Plan facilities located on site at the developers expense, with possible partial reimbursement from fees collected previously from other developers in the watershed. In addition, the developer should fulfill one of the following alternatives to finance offsite drainage facilities: a) Pay development impact fees for planned local drainage facilities established by local ordinance under the Subdivision Map Act, and bond for construction of facilities to serve his project and connect to existing adequate facilities. The fees may be credited against assessments if an improvedment district is formed. The bonds may be released if an improvement district is formed. b) Participate in formation of an improvement district conforming to the recommendations of the Master Plan. c) The developer may construct, at his expense, all those facilities required to serve his project and connect to any existing adequate facilities. Portions of these expenses may be reimbursed later if an improvement district is formed. DISCUSSION To avoid an excessive financial burden on the City, the policy of requiring new development to pay for new public utilities and facilities it requires is endorsed by this report. The methods available are somewhat clouded by Propositions 13 and 4. However, these methods will probably continue to be the most attractive to developer and City Staff alike. Construction of onsite facilities where required, should be a condition of a grading permit final map approval. Where a major facility exists, the cost VII-4. might be shared by other tributary development through fees collected under the Subdivision Map Act, Offsite facilities required may be very expensive to construct for a specific development. If the development creates a major impact on the drainage basin, it should be required to construct major facilities offsite downstream to an adequate point of discharge. This would probably include any planned debris basins. The expense may be great enough to encourage the developer to join other property owners in the basin in forming an improvement district to construct such facilities. If a drainage basin will be significantly impacted by proposed develop- ments, within a short time span debris basins should be constructed prior to issuance of advance grading permits. The maintenance of such debris basins should also be paid for by the developers during construction of the development. This payment could be in the form of a bond or fees, or the contractors could be required to maintain the debris basins during construction. If the impact of a particular development is minor on a basin where there are Master Plan facilities, the City may then require the developer to pay fees under the Subdivision Map Act on a per acre basis for the developments contribu- tion to drainage into the facilities. The City policy maintain flexibility and consider developments case by case. The conditions of approval should reflect the magnitude of impact on a basin and its receiving water, the likelihood of imminent development elsewhere in the basin, the urgency of the need for drainage facilities, and the financial ability of the developer to implement the planned facilities through the recommended methods. The timing of the construction of the Master Plan facilities should reflect the need for the facilities as well as the growth management policies of the City. It is recommended that Master Plan debris basins be in place prior to commencement of major grading operations, and that Master Plan storm drains be constructed during grading. VII-5 (5) Fees collected from new development for Master Plan facilities should be charged on a cost per acre basis uniformly throughout a particular drainage zone. DISCUSSION Drainage zones are shown on Plates 1 through 4. The areas covered by the zones are tributary to Master Plan facilities required by new and/or existing development. The costs to construct proposed facilities have been estimated in this report and are to be contributed uniformly throughout each zone from tributary development. Table B summarizes the cost per acre for each zone. These costs may be interpreted as the fees to be charged developers under the Subdivision Map Act, or as preliminary assessments under a 1911 Act Improvement District. The fees would have to be adjusted for inflation at the time they are collected. (6) Storm drain lines AA, AA-1, AA-2, AA-3 and BA located in the downtown area of Carlsbad should be financed by Redevelopment funds allocated by the City Council. In lieu of this method of fundings a 1911 Act Drainage Improve- ment District or General Fund monies should be utilized to provide financing. DISCUSSION A source of financing drainage improvements unique to the downtown area is Redevelopment funding. Priorities for funding expenditures are set by the City Council. It is recommended that the storm drain improvements be allocated redevelopment monies to provide an adequate drainage system, free from nuisance flooding. Funds from a 1911 Act Improvement District and/or City General Funds are possible sources to augment redevelopment funds. (7) Where a developing basin is to be drained by natural watercourses, the developers should implement measures to mitigate erosion due to concentration VI1-6 [and increase of runoff caused by urbanization. j DISCUSSION The development engineers should determine the anticipated increase in erosion potential of the watercourse due to upstream development and provide improvements to the satisfaction of the City Engineer which will reduce the erosion impact to acceptable levels. The mitigating measures may include runoff detention facilities, hydraulic drop structures, energy dissipators, or other means in addition to Master Plan facilities, debris basinss and onsite erosion control. Table B summarizes the costs for proposed drainage facilities de- tailed in Chapter VIII. A distribution of the costs is tabulated for two cases. Facilities are grouped into "Districts" generally delineated with major watersheds. Columns 1 through 5 tabulate the gross areas of the District, the developable area based on gross area minus existing develop- ment and proposed open space, total cost of facilities within the district, and an average fee per developable acre within the district. Columns 6 through 10 detail each storm drain line priority, cost, net drainage area minus open space based on an average fraction of 16% open space, and a fee per acre assuming costs born only by the areas tributary to a storm drain facilities, that is, a subzone. Areas within Zone 1 of the San Diego County Flood Control District are shown with the detailed subzone fees only. Since a Comprehensive Plan (ref. 6) already exists for this area, the City and District staff should resolve differences in the Plans and fee assessments on new development. (1)(2)(3)(4)(5)-(4)5(3) (6)(7)(8) DISTRICT A B BN GROSS AREA AC 2,474 7,596 1,370 DEVELOPABLE AREA AC 988 4S109 1,198 TOTAL ESTIMATED COST $2,451,706 $4,973,159 $3,725,376 AVERAGE FEE PER DEVELOPABLE ACRE $2,481 $ 1,210 $ 3,110 £ »— * o1 — 1a:a. 1 1 1 1 1 2 3 4a 2 1 2 4b 4a 4a 4b 4a 4a 4b 4b 4b 4c 4a 4a 4a 4c 4c 4a 4a FACILITY NO. AA AA-1 AA-2 AA-3 AB AC AD AE BA BB BC BD BE BF BG BH BH-1 BI BJ BK BM BL BL-1 BN BN-1 BN-2 BN-3 BN-4 EST. COST $1,003,190 $ 96,186 $ 239,706 $ 85,560 $ 188,852 $ 375,222 $ 418,830 $ 44,160 $ 380,742 $ 714,702 $ 232,806 $ 170,706 $ 494,592 $ 771,696 $ 150,696 $1,235,444 $ 192,909 $ 309,948 $ 304,980 $ 134,136 $ 184,782 $ 631,556 $ 49,680 $2,152,316 $ 466,784 $ 171,672 $ 148,488 $ 104,880 NET SUBZONE DRAINAGE AREA 383 53 134 190 305 187 454 178 71 193 188 82 166 102 267 85 34 310 1,036 SUBZONE FEE PER ACRE $ 3,719 $ 3,563 $ 2,800 $ 2,204 $ 145 $ 2,036 $ 1,574 $ 1,308 $ 2,404 $ 2,563 $ 4,105 $ 1,838 $ 8,605 $ 3,039 $ 1,142 $ 1,578 $ 5,435 $ 2,198 $ 2,938 TABLE B PROPOSED FACILITIES - COSTS AND PRIORITIES (1) (2) (3) (4) (5)-(4H(3) (6) (7) (8) (9) (10)-(8)5(9 DISTRICT C San Diego Countv Flood" Control District GROSS AREA AC 2,484 DEVELOPABLE AREA AC 1,927 TOTAL ESTIMATED COST $2,988,522 $9,944,346 • TA AVERAGE FEE PER DEVELOPABLE ACRE 1,551 BLE B PROPOSED >-s—i—* D£. O»— iC£ 0. 4c- 4c 4c 4c 4c 4c 4c 4c 4c 4a 4a 3 3 3 4c 4c 4c 4c 4c 4a 4c 4c 4c 4c 4c 4c 4c 4c 4c 4a 4a 4a 4c 4a FACILITY NO. CB CC CD CE CF CG CH CI CJ CK CL CM DA DB DC DC-1 DD DE DF DG DH DI , DJ DK DL DM DN DO • DP DQ DR DS DT DU EST. COST $ 477,686 $ 413,172 $ 119,576 $ 112,608 $ 411,446 $ 72,864 $ 241,224 $ 214,796 $ 135,446 $ 274,274 $ 80,592 $ 434,838 $ 823,584 $ 171,810 $1,180,866 $ 85,284 $ 247,986 $1,115,730 $ 825,722 $ 327,198 $ 516,120 $ 178,986 $ 795,018 $ 102,188 $ 586,086 $1,095,306 $ 239,706 $ 146,832 $ 122,130 $ 104,880 $ 830,414 $ 200,100 $ 124,200 $ 124,200 NET SUBZONE DRAINAGE AREA 136 125 69 81 208 26 76 77 75 105 22 219 219 219 383 99 388 293 188 321 100 407 63 291 1,642 150 86 186 2,370 434 904 498 358 SUBZONE FEE PER ACRE $ 3,512 $ 3,305 $ 1,733 $ 1,390 $ 1,978 $ 2,802 $ 3,174 $ 2,790 $ 1,806 $ 2,612 $ 3,663 $ 1,986 $ 3,761 $ 785 $ 3,306 $ 2,505 $ 2,876 $ 2,818 $ 18740 $ 1,608 $ 1,790 $ 1,953 $ 1,622 $ 2,014 $ 667 $ 1,598 $ 1,707 $ 657 $ 44 $ 1,913 $ 221 $ 249 $ 347 1 FACILITIES - COSTS AND PRIORITIES VII-9 Following is a proposed ordinance for City Council adoption implementing Master Plan proposed policies to require new development to pay for storm drain facilities required by new development as is allowed by the Subdivision Map Act: SECTION 1: Potential storm drain improvement districts may be established by resolution of the City Council after a recommendation therefor is made by the City Engineer. Storm drain system improvement fees based upon the City Engineer's estimated cost shall be established in said resolution for each area and may be adjusted as necessary to reflect changing costs. Each potential district shall be established by separate resolution of the City Council which shall accurately designate by title and accompanying map the district boundary and principal major facilities to be constructed. SECTION 2: When the owner of property lying within an area design- ated by the City as a potential storm drain improvement district proposes to develop, improve, change or revise the existing use of all or a portion of the property in such a manner as to require downstream storm drain facilities, the owner shall deposit the storm drain improvement fee established by the City for the affected property prior to: (a) Filing a final subdivision or parcel map. (b) Obtaining a development plan or conditional use permit. (c) Obtaining a permit for construction of residential, commercial or industrial buildings or other sturctures. Said storm drain improvement fee shall not be required for the construc- tion of a single family residence and/or appurtenant structures on an existing parcel unless one or more of the other above conditions are also applicable. SECTION 3: Storm drain facilities of district-wide benefit previously constructed by developers or property owners shall be credited toward the fee on VII-10 the basis of verified original costs. SECTION Jl: Fees collected shall be used only for the design, construction or purchase of storm drains specifically of benefit to the particular district. SECTIONS: The City shall designate a separate account for each potential storm drain improvement district created hereby into which all fees collected shall be deposited. Expenditures from each account shall be made only upon authorization of the City Council in accordance with the provision set forth herein. The City Manager shall be responsible for properly administering the provisions of this ordinance and making reports and recommendations to the City Council relative thereto, including an annual report for each fiscal year for each district. SECTION 6: Upon formation of a 1911 Act or 1913 Act Improvement District for the construction of all of the remaining major storm drain system improvements of specific benefit to a district hereby designated and defined, the balance of funds remaining in the particular potential improvement district account shall be credited to the newly formed improvement district account to be used for construction, administration, and engineering costs of said storm drain facilities. CO c" crLC^ S hVJAT VIII-1 VIII COST ESTIMATES A. GENERAL Preliminary cost estimates have been made for storm drain facilities recommended in Chapter VIII. These estimates are intended to be used for planning purposes to establish drainage acreage fees for drainage areas. These fees can be applied as assessments in proposed improvement districts or development impact fees. B. UNIT PRICES • Unit prices for pipe conduit, catch basins, cleanouts, headwalls, concrete channels, and junction structures reflect January 1930 prices as determined by comparison of bonding unit price estimates of various localities and other studies. Included in prices for pipe conduit are excavation, sharing and replacement of overlying pavement, if necessary. Unit prices for catch basins assume 14 foot curb inlet openings and include laterals to main lines. Box culverts are estimated based on concrete volume and typical unit prices for structural concrete work at $350 per cubic yard. Concrete channels are estimated based on required excavation at $10 per cubic yard, 4 inch concrete lining at $200 per cubic yard, chain link fence each side and decomposed granite-surfaced acess road at, an additional $22 per lineal foot. Unit prices are given in Table 5. VIII-2 C. COST ESTIMATES Table 6 provides a listing of required storm drains and appurtenances for each facility. Quantities and unit prices are listed and totaled. Construction contingencies of 15% of construction cost are added to provide for utility relocations and miscellaneous items not considered in estimated unit prices. Inflation is no£ included in the contingencies. It is recommended that prior to formation of assessment districts, these cost estimates should be updated to current prices from this study's January 1980 datum. The Engineering News Record Construction Cost Index may be utilized for this purpose. Engineering, administration, inspection and materials testing are included at 20% above the subtotal of construction cost. Right-of-Way costs for acquisition, damages, legal and administrative expenses are included for recommended facilities in existing developed areas. It is assumed that right-of-way dedications will be obtained as conditions of approval for development. Right-of-Way not obtainable by dedication must be purchased prior to construction. Right-of-Way area requirements can be estimated at this time, however, the final designs will determine exact right-of-way needs. Cost estimates for right-of-way depend on land values, zoning, value of remainder land, which, along with final alignments, are not included in the scope of this study. Table 7 provides a summary of costs grouped by major facility drainage area. Several areas are grouped together into proposed improvement districts and drainage acreage fees computed and listed in Table B, Chapter VII. TABLE 5 UNIT PRICES CITY OF CARLSBAD MASTER PLAN OF DRAINAGE ITEM VIII-3 ITEM 17 27 30 33 36 42 43 48 S3 54 60 66 72 78 n u.n H 96 100 130 133 136 142 148 154 C u \\t i ---- D DEBRIS 1700 C. DEBRIS 2700 C, 30" RCP 33" RCP 36" RCP 42" RCP DEBRIS 4300 C. 4 b " RCP DEBRIS 5300 C. 54" RCP b 0 " RCP 66" RCP 7i" RCP 7fc" RCP , /i K '~> r* Di M < u r 96" RCP L'EBRiS luoooc. 30 "RCP 33 "RCP 36"RCP 42"RCP 4£"RCP 54"RCP L iM 1 b 0 F t s C H I P T BAslN Y, SED. VOLUME BASIN Y, SED. VOLUME BASiN Y. SLD. VOLUME » 3 /' S I N Y, SED. VOLUME BAolri Y. SED, VOLUME */4C PVMT A'/AC PVMT ^/AC PVMT w/AC PVMT rt/AC PVMT rt/AC PVMT PAGE 1 DATE 04/U3/80 FILE --------UNIT --PRICE EA 200UO,00 EA 32000,00 LF LF LF LF EA LF LF LF LF LF LF LF EA LF LF LF LF UF LF 52,00 56,00 59,00 64.00 360UO.OO LF 75,00 EA 50000,00 88,00 93»00 102,00 112,00 130,00 147,00 193,00 550UU,00 62,00 b&.OO 69.00 7%, 00 85,00 CITY nF CARLSBAD RASTER PLAN UF DRAINAGE VIII-4 2B1H PAGE 2 DATE 04/03/80 ------ LUIM ' L !\1 I O U r 1 I L n ITEM ---- DESCRIPTION ---- 160 60»RCP *i/AC PVMT 166 66"RCP d/AC PVMT 172 72"RCP hl/AC PVMT 178 70"RCP *!//\C PVMT 184 64"RCP w/AC PV/MT 196 yb'^CP */AC PV!VIT 210 JL&KJS dASli'J 21 OOaOC.Y.SL'D. VOLUME 451 CLEA'JQUTS (6bH-66") 460 CLEA^OUTS ibS>"-93") 4^0 jLj|\,CTICiv ,TKl*CTuRES ( 2b"-D4" ) 490 ju'viCriO,^ oT^uCTuRES (t>7"-yfc" > 530 LATC;! BAsihb (14 FT) (irJCLUDr:o LATERALS b4n itLAJ,vALi_S (15"-D'4") 650 nEAD^ALuS (L)7"-144") 2312 t-.APT i TKAp. CHANNEL i- J. U t UNIT LF LF LF LF LF LF EA EACH EACH EACH EACH EACH EACH EACH LF --PRICE 103,00 112.00 122.00 140,00 157,00 203.00 76000.00 2000,00 2500.00 2500,00 3500.00 30UO.OO 3000,00 3500,00 155.00 CAKlM Tr-cAP, ChAf-jiMEL P, = 1 4 D + F R = L 1-2 8012 FAK1H 8014 cART'. ChANMEL 8018 EAHTH TRA->. CHANNEL 8020 EARTH TKAP. CHANiMEL = b 2 = 2 8120 CONC. TRAp. CHANNEL B=20, LF IfeO.OO LF 140,00 LF 145.00 LF 150.00 LF 115900 LF 185.00 VIII-5CITY nF CARLSBAD CASTER PLAN OF DRAINAGE PAGE 3 DATE 04/03/80CONTENTS OF ITEM FILE ------ ITEM ---- UL-NCRIPTION ---- UNIT --PRICE 9000 RIGHT OF *AY REQUIRED .1AC 30UO.OO TABLE 6 COST ESTIMATES DRAINAGE AREA AA STORM QRAII\ LINE AA VIII-6 ITEM N0« 1 2 3 4 5 6 7 8 9 10 11 12 ITEM DESCRIPTION 42»RCP W/AC PVMT 48"RCP W/AC PVMT 54"RCP H/AC PVMT 72" tCP */AC PVMT 84"KCP W/AC PVMT CLEA.MOUTS (36"-fa648) CLEAMOUTS <S9"-93") JUNCTION STRUCTURES JUNCTION STRUCTURES CATCH BASINS d4 FTJ (INCLUDING LATERALS RIGHT UF MY REQUIRE STORM DRAINAGE AREA AA ITEM 11 Ei NO* DESCRIPTION 1 2 3 4 3fa"KCP W/AC PVMT GI EANUUTS ( 3fa"-66" >JUNCTION STRUCTURES CATCH BASINS (14 FT) (INCLUDING LATERALS ESTIMATED QUANTITY UNIT UNIT PRICE 800 LF 74.00 750 LF 8b.OO 450 LF 98.00 500 LF 122.00 2,200 LF 1&7.00 8 EACH 2,000.00 9 EACH 2,500.00 1 EACH 2,500.00 2 EACH 3 23 EACH 3 1 EACH 3 11 .1AC 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL E^GR. AND ADMIN +20 TOTAL CONSTRUCTION QRAIfo LINE AA 1 ESTIMATED QUANTITY UNIT 800 LF 3 EACH 2 1 EACH 2 2 EACH 3 SUBTOTAL ,500.00 ,000.00 ,500.00 ,000.00 % St. COST UNIT PRICE ,000.00 ,500.00 ,000.00 CONTINGENCIES -t-isss SUBTOTAL ENGR. AMD ADMIN -f-20 TOTAL CONSTRUCTION % COST TOTAL COST 59«200 63, 750 44, 100 61tOOO 345,400 16,000 22,500 2.500 7,000 69,000 3,500 33,000 726,950 109,042 835,992 167,193 1 ,003« 190 TOTAL COST 55,200 6,000 2,500 6,000 69, 700 10,455 80*155 16,031 96*186 DRAIiMAGL, AREA AA ITEM ITE>; NO. DESCRIPTION STORM DRAIN LIME AA 2 VIII-7 1 30»RCP W/AC PVMT 2 46"RCP W/AC PVMF 3 CLE;\MOUTS (3b"-b6") 4- JUNCTION STRUCTURES <3&"-5<4") 5 CATCH BASI.MS (14 FT) (IfJCLUDING LATERALS STORf. DRAINAGE A.-vEA AA ITEM ITF"' NO. DLSc-UPl IO.J CLL^MUUTS <3&"-bb") JUrJC 1 ION S CAICH BASINS (14 FT) (rNCLUUIMO LATERALS ESTIMATED UNIT 3UAMFITY UNIT PRICE 850 LF 62.00 900 LF 65.00 fe EACH 2.000.00 1 EACH 2,500.00 10 EACH 3, QUO .00 SUBTOTAL CONTINGENCIES +15% SUBTOTAL EhGR. AND AOMIN + 20* TOTAL CONSTRUCTION COST ORAIIV LINE AA 3 ESTIMATED UCJIT QUANTITY UNIT PRICE 750 LF 62,00 2 EACH 2»00(J«QO 1 EACH 2i5UO.,00 3 EACH 3,000.00 SUBTOTAL CONTINGENCIES + 1555 SUBTOTAL ENGRe AND ADMIN +205^ TOTAL CONSTRUCTION COST TOTAL COST 52.700 76,500 12.000 2.500 30,000 173.700 26.05b 199.755 39,951 239.706 V TOTAL COST 1*6,500 4, 000 2.50C 9.000 62.000 9.300 71.300 It. 260 85.560 DRAINAGE AKEA AB ITEM ITEM NO* DESCRIPTION 1 36" RCP 2 SV'KCP W/AC pvnr 3 3t>''RCP w/AC PVMT t CLFANOUTS <36"-b6") 5 JUWrTlOiNi STRUCTURES (36"-54") fe CATCH BASINS d<+ FT> (INCLUDING LATERALS 7 HLA'JwALLS (15"->o4>') STORM DRAIfv LINE VIII-8 D R A I M A G E A I- c. A AC ITEM ICES I\i0« DESCRIPTION 1 2 3 "4 5 6 30" RCP "t2" ~(CH CLEA..JOUTS <36"-6&") Jj'-JCTlON STKllCTuRES (j&»-54") CATCH ;>ASiivJs d-+ FT; 1Mb LATERALS ESTIMATED QUANTITY UNIT 500 LF 3bO LF 750 LF 6 EACH 2, 1 EACH 2, 5 EACH 3, 1 EACH 3, SUBTOTAL CONTINGENCIES +15°; SUBTOTAL E!\6R. Af.0 AOilI-i +20^ TOTAL CONSTRUCT I Oh c. i^ OR A IK LlrtE AC £SUiv.Al£:u QUANTITY UNIT 1,500 LF 2,100 LF 12 EACH ?, 1 EACH 2, 9 EACH 3, 2 EACH 3, SUBTOTAL CONTINGENCIES 4-15=?. SUBTOTAL EKGR. AND AOMIN +20& UiMIT PKICE t>9.00 bfa.OO 6^.00 000.00 500.00 QUO. 00 000.00 OS1 UNIT PH1C£ bi; . oo 61.00o o o . o n 500. 00 000.00 OUO .00 TOTAL CONSTRUCTION COST TOTAL COST 29,500 23,100 51,750 12,000 2,500 15,000 3,000 136, 650 20,5ii7 157,377 31«<+7S I88«8b2 TOTviL COST 78,000 13M-»'+GO 24,000 2,500 27,000 6,000 271«900 <4-0,7b5 312,685 62«537 375,222 DRAINAGE AREA AD ITEM ITE"! NO. DESCRIPTION 1 36" RCP 2 42" RCP 3 66" RCP 4 CLEAMOuTS (3&"-bfr") 5 JUNCTION STRUCTURES <57''-9b" ) b CATCH BASINS (14- FT) (IMCLUCUNG LATERALS 7 HEAD'*ALLS <15"-54") 8 HEAOwALLS <57"-144") STORM DRAIIV LINE AO VIII-9 ESTIMATED QUANTITY 600 1,050 1,200 10 2 li> 1 1 UNIT LF LF LF EACH EACH EACH EACH EACH UNIT PRICE 59.00 feH.OO 102.00 ?,000.00 3,500.00 3,000.00 3,000.00 3,500.00 TOTAL COST 35,400 67,200 122,400 20,000 7,000 M-5,000 3,000 3,500 SUBTOTAL CONTINGENCIES SUBTOTAL £i\GR« AND AuMIN +20£ TCTAL CONSTRUCTION COSI 303,500 319,025 69,80S ma,P3o DRAINAGE. AKfcltt At ITF , STQRM LUML At 1 Dc>rUS BAbLM 270i- C.Y. SED.VOLUM UNIT QUANTITY UNIT PRICE 1 EA 32,OUU.OO SUBTOTAL CCNTIIMCiENCItS +155,; SUBTOTAL ENGh. A^n AOMIN +20fc TCTAL CONSTRUCTION COST TOTAL COST 32,000 32,000 36»800 7,360 44,160 STORM ORAIIV LXNE BA VIII-10 DRAINAGE ANEA BA ITEM N0« 1 2 3 1 5 6 I TEN DESCRIPTION 60" RCP CLEANOuIS <3b"-fa6") JUNCTION STRUCTURES CATCH BASINS (It FT) (IfJCLUOIMG LATERALS HEAOkJALLS (57"-111"> RIGHT OF WAY REQUIRE STORM ESTIMATEDQUANTITY UNIT 2,300 LF 8 EACH 2. 1 EACH 3 b EACH 3 1 EACH 3 7 C1AC 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL ENGRc AND ADM IN +20 TOTAL CONSTRUCTION DRAH\ LINE F)B UNIT PRICE 9.5.00 ,000.00 ,500.110 ,000.00 , sou. oo ,000.00 fc °« COST • TOTAL COST 213,900 16.000 3,500 18,000 3,500 21,000 275.900 <4l»3o5 317,285 63,457 380,742 DRAINASt Ai?EA 68 ITEM NO. 1 2 3 4 5 6 7 6 9 10 il ITF'l DESCRIPTION 42" SCP 4 0 " R C P 48'VCP W/AC PVMT 51'V.CP W/AC PVMT &o"p.CP ft/AC PVMT CLF.AMOJTS (3b"-fafa») CLE, '\r\iOUTS (69"-:*3") JUNCTION STRUCTURES (36"-bi+") CATCH RASINS (It FT) ( ir.:cLUl'ING LATEKALS HEAOXALLS (57"-114") RiG-HT OF i«AY KEQU1RE ESTIMATED QUANTITY UNIT 950 LK 2,550 LF 250 LF 700 LF 250 LF 16 EACH 2 1 EACH 2 2 EACH . 2 22 EACH 3 1 EACH 3 13 .1AC 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL EMGR. AND AOMIN +20 TOTAL CONSTRUCTION UNIT PRICE fot.oo /5.00 15.00 98.001 1 a . o o ,000. on ,500. 00 ,500.00 ,000.00 ,500.00 ,000.00 % a, COST TOTAL CO.ST faO ,600 191, 250 21,250 68,bOO 28, 000 32,000 2,500 5,000 b6,000 3,500 39,000 517,900 77,665 595,565 119,117 711,702 DRAINAGE. AREA BC STORM DRAH\! LINE 8C VIII- ITEM N0« 1 2 3 4 5 I TEN DESCRIPTION 3b"RCP l«i/AC PVMT CLEANUUTS (36"-66"J JUNCTION STRUCTURES ( 36" -=54" ) CATrH BASINS (14 FT) (INCLUDING LATERALS HEADrtALLS <l5"-b<4") ESTIMATED QUANTITY UNIT 1,800 LF 6 EACH 2 1 EACH 2 8 EACH 3 2 EACH 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL UNIT PRICE 69.00 , QUO. 00 ,500.00 ,000.00 , QUO. 00 % ENGR. AMD At) 11 IN +20IK DRAI IT Eh NOc 1 2 3 4 5 STORMMAGE ARE« BD ITEM DEScR IHTION 3b" «CP 4 a " 3 C PCI_E-»I\OUTS (36"-b&") CATrh 6AS1NS (14 FT) < i r 1 1 • i t ) i 1 1 ; j u i /A T r ri A i ^% A ! i \_ L. U tj A : » xj L. -•*'[— '' M L. o Ht-AjAALLS (15"-b4") TOTAL CONSTRUCTION DRAII\ LINE 30 ESTIP ATEJQUANTITY OMIT 500 LF 1,050 LH 6 EACH ? i EACH 3 2 EACH 3 COST UNIT PRICE by. 1)0 bf .00 , 0 U 0 . J 0 , 0 U 0 . J 0 ,000.00 TOTAL COST 124,200 12,000 2,500 24,000 6,000 168,700 25,305 194,005 38,601 232,806 TOTAL LOST 29« 500 67,200 12, 000 °,000 6,000 SUBTOTAL CONTINGENCIES +I5?n SUBTOTAL EMGK. AIYQ AOMIN +20?6 TOTAL CONSTKUCTION COSI 123,700 112,2-35 170,706 STORM QRAII\ LINE vrn-12 ORAI ITEM NQe 1 2 3 4 5 6 7 CRAI I TEN NO. 1 2 6 4 5 6 7 8 9 10 11 NAGE AREA BE ITE< DESCK1PTION 42" RCP 46" RCP DEBRIS BASIN 530;) C.Y. SED. VOLUME CLEANOUTS (3&"-fa6") CATCH BASINS 114 FT> ( INCLUDING LATERALS HEAj«ALLS (15"-b4") RIGHT OF WAY REQUIRE STORM NA5E «KEA BF ITf-i DLScRU'TICM DEBKiS BASI'j 2700 C.Y. SEin, VOLUME 3u" RCP 3b" RCP 54" RCP 7 d. " RCP C, E ,>JOUTS <3fo"-b6") JUNCTION STRUCTURES CATCH BASINS (14 FT) (INCLUDING LATERALS HrAOWALLS (15"-S4") HLAijWALLS (57"-144") RiG,-iT OF UAY REQUIRE ESTIMATED QUANTITY UNIT 2*350 LF 600 LF 1 EA 50 10 EACH 2 7 EACH 3 2 EACH 3 22 .1AC 3 SUBTOTAL CONTINGENCIES *15 SUBTOTAL D\SR. ANO AOI1IN +20 TOTAL CONSTRUCTION GRATIS LINE BF ESTIMATED QUANTITY UNIT 1 EA 32 1.000 LH 1,200 \_f 1,500 uF it 200 LF 16 EACH 2 1 EACH 3 16 EACH 3 2 EACH 3 i EACH 3 15 .1AC 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL ENGR. AND AOMIN +20 TOTAL CONSTRUCTION UNIT PKICE G4.00 7b.OO , QUO. 00 , 000. 00 ,000.00 ,000.00 ,000.00 fi ~ COS! UN 11 i'KlCL , QUO. 30 02.00 a9. JO dfi. 30 112.00 , 0 U 0 . 0 0 ,500.00 ,000.00 ,000.00 ,500.00 ,000.00 .% & COST TOTAL COST 150,400 45,000 50,000 20,000 21,000 6.000 66. 000 358.400 53« 760 412«lt>0 82,432 494,592 TUTAL COST 32, 000 52,000 70,300 132,000 134,400 32,000 3,500 43,000 fa, QOu 3,500 45,000 559,200 83.830 643.030 128.616 771«o9& DRAINAGL AREA BG ITEM ITE-S NOc DESCRIPTION STORM DRAXiV LINE BG VIII-13 1 f2» RCP 2 CLEAMOUTS (3b»-66") 3 CATCH BASINS (1<+ FT) (INCLUDING LATERALS <* HEAQwALLS <15''-5V) DRAINAGE Ai<EA BH ITEM I IE1: N0« DESCRIPTION 5 b 7 8 3o» RCP BASIN CL£/\,MOuTS JJi'lCTlC-'i'J STRt.it 1 URLS ( ^6"-j4" ) CATfri BASINS (14- FT (INCLUnirJ Htlfl"i«ALLS COI'Jr. TKAP. CHAi\iMtL 3 = 20 * i) + FD = ^ RiGhT OF */AY .") FT) I SL> O ") STORM i i Mr. u IL.,"> :LS FT) I Q> L o• " i ILL IIRE ESTIMATED QUANTITY UNIT 1,300 LF 4 EACH 2 ^ EACH 3 2 EACH 3 SUBTOTAL, CONTINGENCIES +15 SUBTOTAL ENGRo AND ADMIN +20 TOTAL CONSTRUCTION DRAIN LINE BH ESllMATFU QUANTITY UNIT 1,000 LF 1,250 LF 1 EA 55 8 EACH 2 1 EACH 2 7 EACH 3 1 EACH 3 .5,000 LF 30 dAC 3 SUBTOTAL CCNT1NGENCILS +15 SUBTOTAL EiNiSRe AND ADMIN -t-20 UNIT PRICE 64.00 ,000.00 ,000.00 ,000.00 ?0 X COST UNIT PRICE 'J9.00 '5.00 , 0 U 0 . J 0 ,0110.00 , "-jUO. :10 ,000.00 ,000.00 IBb.OO ,000. 00 £ 58 TOTAL COST 83,200 8,000 12«000 6,000 109«200 16*330 125*560 25 « 116 150.696 TOTAL COST 59«000 93,750 55, ODD 16,000 2,500 21«000 3,000 555,000 90, 000 895,250 134,2cJ7 1,029«537 205,90? TOTAL CONSTRUCTION COST .J O Cx DRAINAGE AKEA BM ITEM ITE." N0« DESCRIPTION STORM DRAII\ LINE BH 1 1 3t" RCP 2 CuEAMUUTS (3fa"-bb") 3 CATCH BASINS d1*- FT; (INCLUDING LATERALS H HEADwIAL.LS 1 EACH SUBTOTAL CONTINGENCIES SUBTOTAL ENGR. AND AOMIN VIII-14 ESTIMATED QUANTITY 1,810 6 6 UNIT LF EACH EACH UNIT PRICE 59.00 2,000.00 3,000.00 TOTAL COST 106*790 12.000 18. 000 3,000. no 205? TOTAL CONSTKUcTlOiM CU6T 3«000 160.758 192«9D9 STORM ORAH\ LINE BI DRAINAGE ARL.t 51 ITEM ITE'l 6 7 3u" RCP 3b» qct1 Dt.BRlS tfAblM 5500 C.r. SEn.VOLUv1f CLE/.^UUIS (3fa"-bb") CATCH fASiMS (m t-T) (ir!CLUC;INt LATERALS HEAjftALLS (lb"-bt") RIGHT OF I«AY REQUIRE: ESTIWATEO UNIT QUANTITY 9bu 800 1 6 5 2 15 uiMir LF LI-LA EACH EACH EACH .1AC 50, 2, 3. 3, 3, PR t>2 t»9 000 000 00 11 ouc 000 ICE .DO .00 .'10 .no .'10 ,nc .00 TOTAL 49 H7 50 1?- 15 6 4^ CObT ,^00 » 2.0 C ,000 . noo « nuo .000 . 000 SUBTOTAL CONTINGENCIES SUBTOTAL EtvGRe AMD ADMIN +2086 TOTAL CONSTRUCTION COST 258.290 309.948 STORM DRAIf\> LINE B>J vni-15 DRAINAGE AREA BJ ITEM IT £••-•; NOo DESCRIPTION 1 48" RCP 2 CLECNOUTS n6»-b6 3 CATCH BASINS <!<+ (INCLUDING LATERALS 4 HEADwALLS (15"-b4 5 RTGHT OF WAY REuU DRAINAGE AREA BK ITEM I IE'" NOe OrSrRirTIGf\i 1 5t" RCP 2 CLEAWOuTS (3fa" 3 CATCH BASINS dt f-n Ht,AuwALLS 11 ) FT) 1 C Lr, O ") IRE STORM >" ) f-T) \ , C•* L o p') ESTlfiATtO 8UANTITY UNIT 1«600 LF 7 EACH 2 7 EACH 3 2 EACH 3 IS dAC 3 SUBTOTAL CONTilMGENCItS *15 SUBTOTAL ENGR. AND Auniw +20 TOTAL CONSTRUCTION DRAIN LINE HK ESTIMATED QUANTITY UNIT 900 Lf 3 EACH •? 2 EACH 3 2 EACH 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL UNIT PRICE 7b.OO ,000.00 ,000. UO ,000.00.ouo.oo fc fc COST UNIT PRICE H8.DO , 000. .)0 ,000,, 10 ,OUO.OO l?0 ENGR. AND AOMIN +202 TOTAL CONSTRUCTION COST TOTAL COST 135.000 14.000 21.000 6.000 45. 000 221.000 33«lbO 254.150 50.830 304.960 TOTAL COST 7^i?UO 6.000 6.000 6.000 97*200 14.500 111«7<JG 22.356 134*136 DRAINAGE AREA BL STORM DRAIN LINE BL VIII-16 ITEM M0« 1 2 3 4 5 6 7 8 9 10 11 ITEM DESCRIPTION DEBRIS BASIN 2700 C.Y. SEO. VOLUME 30" RCP 42" RCP 6 u " RCP 66" RCP CLEANOUTS <36"-b6"> CLEANOUTS (&9"-93") JUNCTION STRUCTURES (36»-54"> CATCH BASINS (14 FT> ( INCLUf ING LATERALS H£Al,jALLS (15"-b4") H£AJwALt,S (57"-144") STORM ESTIMATED QUANTITY UNIT 1 EA 32 650 LF 650 LF 1,050 LF 1*300 LF 7 EACH 2 4 EACH 2 1 EACH 2 29 EACH 3 1 EACH 3 1 EACH 3 SUBTOTAL CONTINGENCIES -t-is SUBTOTAL ENGR. AND AuniN +20 TOTAL CONSTRUCTION ORA1K LINE 3L 1 UNIT PKICE ,000.00 t>2.00 64.00 93.00 102,00 ,000.00 ,5UO,i)0 ,500.00 ,000.00 ,000.00 ,500.00 °r a COST TOTAL COST 32.000 33.600 41 .600 37.650 132,600 14.000 1 0 . 0 0 0 2.500 87.000 3.000 3.500 457,6'JO 68.647 526.297 105.259 631.556 DRAINAGE AKEA dL ITEM NG« 1 2 3 ** ITEM DESCRIPTION 33" RCp CLfANOUTS (56"-66") CATCH BASINS (14 FT) (INCLUDING LATERALS HEADWALLS <i5"-54») ESTIMATED QUANTITY UNIT 500 LF 1 EACH 2 1 EACH1 3 i EACH 3 SUBTOTAL CCNTIfJGENCILS +15 SUBTOTAL ENGRc AND AUMIM +20 TOTAL CONSTRUCTION UNIT PRICE t)6. 00 ,uuo. no ,000.00 ,000.110 % % COST TOTAL LOST 28.000 2.000 3,000 3.000 36.000 5,400 4l«'H)0 8,2ao q.9«6BO STORM DRAIfo LINE BM VIII-17 DRAINAGE AwEA BM ITEM ITEM NOc DESCRIPTION 1 36" RCT 2 3fa"RCP nVAC PVMT 3 CLE/vMOUTS <3fa"-bfe") 4 CATCH BASINS (14 FT) (INCLUDING LATERALS 5 HEADtrJALLS U5"~54") STORM DRAINAGE AH LA 8N ITEM ITEf-i NO. DESCRIPTION 1 3r," RCP 2 <*2" RCP 3 60" RCP 4 72" RCP 5 DEBRIS BASIN 10000C.Y. SED. VOLUME 6 CuCA^OUTS (3fa"-bb") 7 CLEAiMCUTS (69"-93"> 8 JUNCTION STRUCTURES (7 /" I. t » H 1ob "-OH ; 9 JUNCTION STRUCTURES ( 57"-96" ) 10 CATCH BASINS (14 FT) (INCLUDING LATERALS 11 HeAnnALLS (l5"-54") 12 EARrH TRAP. CHANNEL B=12, D+FB=7,Z=2 13 EARTH TRAP. CHANNEL B— 1/i i"^j.P^~"7.7Z!:P•"iH* U'~3~"' tit-C 14 EARTH TRAP. CHANNEL B-18, D+FB=7,Z=2 ESTIMATED UNITQUANTITY UNIT PRICE 750 LF S9.IJO 850 LF b9.00 b EACH 2,000.00 5 EACH 3,000.00 2 EACH 3,000.00 SUBTOTAL CONTINGENCIES +15 ft, SUBTOTAL EfcGR. AND AOMIN +2 OS, TOTAL CONSTRUCTION Cf>S7 DRA^ LII^IE BN ESTIMATEU CIN;T QUANTITY UNIT PRICE 1,000 LF 52.00 800 LF b4.00 450 LF 93.00 5,550 LF 112.00 1 EA 55,01)0.00 8 EACH 2,000.00 16 EACH 2,500.00 1 EACH 2,500.00 2 EACH 3,500.00 49 EACH 3,000.00 1 EACH 3,000.00 1,600 LF 14CI.DO 1,300 LF 145.00 700 LK IbO.OO SUBTOTAL CONTINGENCIES +15SS SUBTOTAL EI\iGRc AMD ADMIN *20S TOTAL CONSTRUCTION COST TOTAL COST 44,250 58,650 10,000 15,000 6,000 133*900 20*085 153,985 30*737 184,782 TOTAL COST 52« 000 51«200 41,850 621 «feOO 55*000 16,000 45,000 2,500 7,000 147,000 3,000 224, 000 iafl*5oo 105*000 1,559*650 233*947 3 ,793*597 358*719 2,152*316 ! n STORM DRAII\ LINE VIII-18 [TEM ITEM ESTIMATED UNIT ylCU DESCRIPTION QUANTITY UNIT PRICE i 30" RCP 2 33" RCP 3 36" RCP «i 54" RCP 5 CLEANOUTS (36»-66»)6 JUNCTION STRUCTURES (36»-5t"> 7 CATCH BASINS (it FT> (INCLUDING LATERALS 6 HEADkALLS (15"-bt") STORM DRAINAGE AREA 6M ITEM ITE-; NO- DESCRIPTION 1 3fa" RCP2 CLEANOUTS <36»-fa6") 3 CATCH BASINS (It FT) (INCLUDING LATERALS t H_AOwALLS (l5"-5t") 500 LF b2«()0 650 LK bfe.DO 1,250 LF t)9,00 1.H50 LF W8.DO 12 EACH asOUOo'lO 1 EACH 2.500,1)0 Ib EACH 3,01)0.00 1 EACH 3, OUO.DO SUBTOTAL CONTINGENCIES +15fi SUBTOTAL ENGR. AND ADMIN +20Si TOTAL CONSTRUCTION COST OR A I IS LINE BN 2 ESTIMATED uNiT QUANTITY UNIT PRICE 1,600 LF b9.UO 6 EACH 2,OUO.OO 5 EACH 3,000.00 1 EACH 3,000.00 SUBTOTAL CCNTINGENCILS +1585 SUBTOTAL ENGR. AND AOMIN +20% TOTAL CONSTRUCTION COST TOTAL COST 26«OUO 36, M-00 73*750 127.600 2t,000 2.500 45.000 3.000 338t2!5C 50.737 388.9«7 77,7^7 t66.7B4 TOTAL COST gt.too 12.000 15.000 3,000 12t«tOO 18.660 143,060 28.612 171.672 VIII-19 DRAIMA6E A«EA 8N STORM DRAIIV LINE ITEM ITEM NO* DESCRIPTION 1 30" RCP 2 t2" RCP3 CLEANOUTS <36"-66») M. CATCH BASINS (It FT) (INCLUDING LATERALS 5 HEAOwALLS <15"-bt"> ESTIMATED QUANTITY UNIT 900 LF t50 LF t EACH 7 EACH 1 EACH SUBTOTAL CONTINGENCIES SUBTOTAL ENGR. AND ADMIN UNIT PRICE 52.00 fet.OO 2,000.00 3,000.00 3,000.00 + 1555 + 20?o TOTAL COST 46,800 28*800 8,000 21.000 3,000 107.600 16.140 123«7tO 2t«7t8 TOTAL CONSTKUCTION COST 1^8.488 STORM DRAINAGE AKEA 3N ITEM IT£M N0« DESCRIPTION 1 3." RCP 2 CLEnNOUTS (36"-66") 3 CATCH BASINS (It FT) (INCLUDING LATL'KALS H HLADWALLS (l5"-3t") DRAIfV LINE BN 4 ESTlf.ATEU QUANTITY UNIT 1,000 LF H EACH 3 LACH 1 EACH SUBTOTAL CONTINGENCILS SUBTOTAL UNIT PRICE h6.no 2,01)0 .00 3 , 0 U 0 . 0 0 3,OUO.uO + 15?o TUTAL COST 56. 000 0.000 9.000 3.000 76.000 11» too 87,400 ENGRC AND AOMIN +20% TCTAL CONSTKUCTION t< STORM DRAIN LINE CB VIII-20 DRAINAGE AREA CB ITEM ITEM NO. DESCRIPTION 1 4ij" KCP 2 4o" RCP 3 CLEAMUUTS <3&"-&4 CATCH BASINS (14 (INCLUDING LATERALS 5 HLADWALLS (15"-D4' CCDRAINAGE ITEM- ITE-i NO. 1 42" 3CP 2 Ci_EA\'OjTS <36» 3 CATCH 3ASIN3 (11 FT) (INCLUDING LO 4 HLAj-ALLS (l5"-5'(-" ESTIMATED UNIT QUANTITY UNIT PRICE 1,100 LF b«f,nO 2,650 LF 75. '10 «> 13 EACH 2*OUO..JO rT) 15 EACH 3, QUO. no .S ») 2 EACH 3,000.00 SUBTOTAL CONTINGENCIES + 15K SUBTOIAL F.N6R. AND AO'IIN +20?c TOTAL CONSiKJv-TlON CObl STORK DRAI^ LXiJE- CC EsTTl"ATLD UNCT QUANTITY UNIT PKICE d,6UO L'f 'jt*' JO ,», 12 uACM 2,0'.iO.)0 FT) 14 EACH 3.0i'0.;Hl ^LS f") 2 CAC1-1 3,0'.'0.')Q SUBTOTAL CONTINGENCIES +15K SUBTOTAL EIVGR» AND ADPItN +205o TOTAL CONSTRUCTION COST TOTAL COST 70,400 19fl«750 26,000 (+5,000 6,000 346, IbO 51 '9^2 398,072 79,6i4 477, 6ab TOTAL COST 230 » 4 CO ?4 »0 JO 39, 0 JC 6 .090 299,400 "+4,910 344,310 68,862 413,172 VIII-21 STORM DRAIN LINE CD DRAINAGE AREA CD ITEM ITEM NO. DESCRIPTION 1 30" RCP 2 H8" RCP 3 CLEANOUTS <36"-fa6 4 CATCH &ASINS (1"+ (INCLUDING LATERALS5 HFAOWALLS CE DESCRIPTION DRAINAGE A ITEM. HE N0« 1 33" 2 CLEANOUTS (3fa"-fab" 3 CATrH «ASIIMS (INCLUDING LATERALS 4 HEAOWALLS ESTIMATEDQUANTITY UNIT 700 LF 150 LF 11 ) 3 EACH 2. FT) 9 EACH 3. I Q UNIT HRIUE 52.00 75.00 0 U 0 . 0 0 000.00 ") 2 EACH 3, 000,00 SUBTOTAL TOTAL COST 36.400 11.250 6.000 27.000 6.000 86.650 CONTINGENCIES +I5fc 12.997 SUBTOTAL ETN6R. AMD AUMIN +20?6 TOTAL CONSTRUCTION C STORM DRAIN LINE CE ESTIMATED QUANTITY UNIT 1.100 LF i>") 4 EACH 2 FT) 2 EACH 3 n 1 CA u. .-> +") 2 EACH 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL ENGR. AND ADMIN +20 TOTAL CONSTRUCTION ;DST UNiT PRICE bfe.no ,000.00 ,000.00 ,000.00 ft) % COSI 99.647 19,929 119.57& TOTAL COST 61.600 ft. 000 6.000 6.000 81.600 12.240 93.8HO 1,8,768 112.608 VI11-22 STORM DRAIN. LINE CF DRAINAGE AREA CF ITEM ITE1 N0» DESCRIPTION 1 30" RCP 2 3b" RCP 3 42" KCP 4 46" RCP 5 CiEAMOUTS <3&»-b6" 6 CATCH BASINS c (INCLUDING LATERALS 7 HEAOriALLS (l5"-34" DRAINAGE A^EA CG ITEM ITE:") NO* DESCRIPTION 1 30" KCP 2 CLEflAlUUTS (.?fa"-b 3 CATCH BASINS (it (INCLUDING LATERALS 4 HEAUWALLS <15"-5t»> ") FT) i CL o ") STORM 3"> FT) i\ j o*LS 4.") ESTIMATED QUANTITY UNIT 650 LF 8bO LF 1,050 LF 1,000 LF 12 EACH 2, 14 EACH 3, 2 EACH 3, SUBTOTAL CONTINGENCIES +15J SUBTOTAL ENGRe AMD AUriiN +205 TOTAL CONSTRUCTION C DRAIN LINE CG ESTIMATED QUANTITY UNIT 6bO LF 2 EACH 2 3 EACH 3 2 EACH 3 SUBTOTAL UNIT PRICE b2,DO b9.UO to4-.i)0 75,i)0 OOO.DO 0 U 0 , 0 0 ouo.no t, ;OST UNIT PRICE b2, no ,0110. ')0 ,0(10 .DO ,000.00 CONTINGENCIES +15»; SUBTOTAL EWGR. AND AOMIN +20fc TOTAL COST 33,ROO 50,130 67,200 75,000 2t, 000 4-2>000 6, 000 298*130 44,722 342,872 6ft, 574 411,446 TOTAL COST 33,800 4, 000 9,000 6,000 52,800 7,920 60,720 12,144 TOTAL CONSTRUCTJOM COST STORP! QRAIM LINE CH VIII-23 DRAINAGE AREA CH ITEM ITE-1 NO. DESCRIPTION 1 30" RCP 2 42" RCP3 CLEANOUTS (36"~66") it CATCH BASICS (If FT) (INrLUDING LATERALS 5 HEADwALLS (l5"-5f") ESHPATEU QUANTITY UNIT 1,000 LF 1,200 LF 8 EACH 8 EACH 2 EACH SUBTOTAL CONTINGENCIES SUBTOTAL EMSH, AMD AOMIN UNIT PRICE 52.00 b<4.00 2 , 0 U 0 . 1) 0 3,000.00 3,000,00 + 15Sn + 20?; TOTAL COST 52.000 76.800 16,000 24 « 000 6.000 174,800 26.220 201.H20 40,204 TOTAL CONSTKUCTIOIM COST DRAI^ LINE DRAINAGE AREA CI ITEM ITE--1 N0» DESCRIPTION 1 3b« RCP 2 42" Rd->3 CLEAMGUTS (3fe"-fa6") «t CATCH BASINS (14 FT) NG LATEKALS ESHPATEU UNtT QUANTITY UNIT HKiuE 750 LF b9.no 1,100 LH 64. UO 7 EACH ?, 01)0. HO 7 EACH 3,0i>u.:)0 2 EACH 3, QUO. 00 SUBTOTAL CONTINGENCIES +155: TOTAL COoT 44,2!->0 7 0 , U Q 0 14.000 21 « 000 6,000 155. 6bo 23.347 SUBTOTAL EMGR. AND. AUllIN +20it TOTAL CONSTRUCTION COST 35.799 STORM DRAXK LINE VI11-24 DRAINAGE AREA CJ ITEM ITE.-i NO ITEM NOe " 1 2 3 4 5 6 7 DEScKIPTIOM 30" RCP 3," RCP CLEAMO'ITS <36"-bfo") CATCH BASINS (14- FT) (INCLUOIMG LATERALS H_ADWALLS (15" AixEA CK JTE> DESCRIPTION 3u" RCi1 I?" RCP (36"-b JU'JCTION STK'JCTJRILS CATCH BASINS ( (INCLUDING LAI HLAfjdALLS <15"-b1") 11 ) FT) LS 11 ) STORM *") «ILS FT) ttL? 14") ESTI^ATEU UNIT QUANTITY UNIT PRICE 250 LF S2.HO 850 LF S9.nO t EACH 2,000.00 7 EACH 3, QUO. 00 2 EACH 3»QUO»'JO SUBTOTAL CONTINGENCIES +15?b SUBTOTAL EIMGK* AMD ADMIN *20?o TOTAL CONSTRUCTION C'JST ORAH\ LINfc, CK ESTT^.ATEU UiMiT QUANTITY UNIT PRICE 650 LF S2.00 600 LF b't.'lO 750 LF ^b.'JO 8 EACH p, OHO. 00 1 EACH 2.5UU.OO 11 EACH 5,OUO.i)0 2 EACH 3, 000. JO SUBTOTAL CONTINGENCIES +15=6 SUBTOTAL E(MGR« AND ADMIfJ +20?.. TOTAL CONSTRUCTION CDST TOTAL COST 13»OGO 50»lbO 8«000 21 « 000 6^000 9ft« 150 11.722 112.872 22«57H 135.4^6 TUTaL COST 33«80Q S1.200 5ti.2bO If,' 000 ?. t 5 U 0 33.000 6,000 198. 7SO 29.B12 22fi.S»i2 15.712 271.2/1 STORM LINE CL VIII-25 ITEM ITE-i NO- DESCRIPTION 1 30" RCP 2 CLEAiviOUTS (36"-fc>6") 3 CATCH BASINS (14 FT) (INCLUDING LATERALS 4 HE-AC/n/ALLS (l5"-54") ESTI^ATEU QUANTITY UNIT 700 LF 2 EACH 2. 4 EACH 3, 2 EACH 3, SUBTOTAL CONTINGENCIES +15$ SUBTOTAL ENGRc AND ADMIN -*-20Si UNIT PRICE t>2.00 000.00 000.00 000.00 ) TOTAL CONSTRUCTION COST STORM DKAINASL AHEA C'"! ITEM ITE ; NO- DESCRIPTION 1 3b" W 2 b4" RCP 3 61" KtP 4 CLE /-.MOijTS (3fa"-66") 5 JUNCTION STRUCTURES ( 36,,. 54" ) 6 CwTrH BASIMS (14 FT) (iflrlUUIiJb LATERALS 7 HrAnWALLS (!5"-b4") 8 HEATi^ALLS (57"-144") ORAIIV LINE CM ESTIMATED QUANTITY UNIT 1,200 LF 6bO LF 1,050 LF 10 EACH 2 1 EACH 2 17 EACH 3 1 EACH 3 1 EACH 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL EINiGRe AND AD1IN +20 TOTAL CONSTRUCTS, UIMU PRICE b9.00 US. JO 102. JO ,000.i)0 ,500 . 10 ,000.00 ,000.00 ,500. JO a, 5n COST TOTAL COST 36.400 4.000 12.000 6.000 58.400 fl, 760 67.1c.O 13.432 80.592 TOTAL COST 70,300 57.200 107,100 20,000 ?. 500 5 1 i 0 0 0 3.000 3.500 315,100 47.265 362.365 72.473 434.838 STORM DRAIIN. LINE DA VIII-26 DRAINS ITEM N0» 1 2 3 14 5 6 7 8 ,GL ARtA UA IrEfl DESCRIPTION 30" RCP ^2" RCP tb" RCP 5<+" ^CP CLFANOUTS <36"-b6») JUNCTION STRUCTURES (36" -54") CATCH BASINS (it FT) (INCLUDING LATERALS HtlATi/jALLS !15"-'J<+") ESTIMATED QUANTITY 750 700 700 •4,250 21 1 13 1 SUBTOTAL C.QNTINGE SUBTOTAL FNSK. AM UNIT LF LH LF LF EACH EACH EACH EACH NCIES D ADMIN UNIT PRICE 52.00 b4 . 0 0 /5.00 SB. 00 2,000.00 2,500.00 3,000. 00 3,000.00 + 15Sf. + 2,0?. TUTAL COST 39,000 1+4 , aoo 52,500 37^'OOD J+2vOOO 2,500 39,000 3,000 596,800 89,520 686' 320 137,264 TOTAL CONSTRUCTION COST 32-3,564- STORM LINE DO DRAIWAGL A:'.E.A J<3 ITEM ITF -; NO. DLSCHiPTIOM 6 7 1700 C.Y. SED.VOLUME 3b" RCP CLEAMOUTS (S6"-bb») JuneTION STRUCTURES Cj7"~y^" ) C,TCH RASHMS <!<+ FT) LATERALS RIGHT OF WAY REQUIRE ESTIfATEU 9UA.NJ1 ITY 1 1,000 3 1 2 1 9 SUBTO! uiJir EA 20 LF EACH 2 EACH 3 EACH 3 EACH 3 «1AC 3 AL UiJtT PRICE , ! ) 0 0 . 3 0 r>y. jo ,000.00 , 5UO. ,1U ,OUO. JO ,000. JO ,000.00 CONTINGENCIES +15fc SUBTOTAL ENGR. TOTAL AND ADMIN +20S6 CONSTRUCTION COST TUTAL COST 20,000 59,000 6, 000 3,500 6,000 3,000 27,000 12<*'500 18,675 113,175 28,635 17l«810 VIII-27 STORM DRAIN LINE DC DRAINAGE AREA OC ITEM ITE'\ NO. DESCRIPTION 1 2 3 4 5 6 7 & <3 10 11 12 33" RCP 42" RCP DEBRIS BASIN 430n C.Y. SEO. VOLUME 54" RCP 60" RCP 6b» RCP CLFANjOuTS (36"-b6") JUNCTION STRUCTURES (~f f_ ,, t i It \36 "-54" ) CATCH BASINS di FTJ (INCLUDING LATERALS HtAOwALLS ( 15"-b4" ) HLAOw'ALLS <57"-144") RIGHT OF WAY REJU1RE ESTIMATED QUANTITY UNIT 1,100 LF 1,450 LF 1 EA 36, 850 LF 1,000 LF 3,250 LF 26 EACH 2, 1 EACH 2, 17 EACH 3, 1 EACH 3, 1 EACH 3, 18 .IrtC 3, SUBTOTAL CONTINGENCIES +155, SUBTOTAL UNIT PRICE S6.JO 64.00 000.00 08.00 93.00 1U2.00 QUO. 00 500.00 000. JO 0 U 0 . 0 0 5110. 00 0 U 0 . J 0 ENPR. AMO AO.'UtJ +-20?,, TOTAL CONSTRUCTION COST DRAIN- ITEM NO. 1 2 3 U STORM !\GE A ;EA OC 1TFJ" DESCRIPTION 30" RCr CLCAMOLiTS (3fa"-66"i CATCH iJASINS (14 FT) ( INCLUDING LATERALS HtAu,jALLS (15""b4") ORAHN LINE DC 1 ESTIMATED QUANTITY UNIT 900 LF 3 EACH 2 2 EACH 3 1 EACH 3 SUBTOTAL CONTINGENCIES +15 SUBTOTAL ENGR. AMD ADMIN +20 TOTAL CONSTRUCTION UNIT PRICE u)2.')0 , 0 U 0 . ') 0 , 0 U 0 . 0 0 ,000.00 fc % COST TOTAL COST 61'600 92,800 36,000 74,300 93, 000 331,500 52,000 2,500 Sl'OOO 3,000 3, 500 54,000 855*700 12a«3cj5 984, Ob5 196,811 1 , ISO'Pbh TOTAL COST 46, 8 JO 6,000 6 , 0 0 0 3,000 6l»80C 9,270 71,0^0 14,214 85,264 , T ^^ VIII-28 STORM DRAIN LINE DO DRAINAGE A:;EA DO ITEF< NOe 1 2 3u 5 I 1 E ': DESCRIPTION 33"' RCP 3b" RCP CLEANOUTS <3fe"-fefo") C(»TCH 3AS1NS (It FT) ( 'MrLUDING LATERALS HEAOWALLS <i5"-bV) ESTIMATED QUANTITY 2,250 300 9 4 2 SUBTOTAL. UNIT LF LF EACH EACH EACH UNIT PRICE b6. (10 S9.00 2,000.00 3.0UU.OO 3,000.00 CONTINGENCIES +15?; TOTAL COST 126,000 17.700 16,000 12.000 6?0 JO 179,700 26,955 SUBTOTAL EI\iGR. AMD ADMIN -s-20?o TOTAL. CONSTRUCTION LOST STORM ORAIK LINE DE DRAINAGE A:\tA DE ITEM irr-i NO. DESCRIPTION 1 3:-" RCP 2 t2" HCP3 DEBRIS BASIN 4300 C.Y. SCO.VOLUME M- 4d" RCP 5 5^" RC( 6 60" RCP 7 CLEAMOuTS (?l6''-66») 8 CATCH BASINS (It f-T) (INCLUlUNli LATERALS 9 HEAJWALLS d5"-bf") 10 H^AOw'ALLS (57»-lift») 11 RIGHT OF wAY REQUIRE ESTIMATED QUANTITY 1,600 1,150 1 2,000 2,700 400 2b 24 1 1 18 SUBTOTAL UNI r LF LF EA 36 LF LF LF EACH 2 EACH 3 EACH 3 EACH 3 ,1AC 3 CONTINGENCIES -f-15 SUBTOTAL UNIT PRICE bfa.OO b 4 . 0 0 5 0 U 0 . 0 0 fb.GO 66.00 93.00 ,000.00 ,000.00 ,000.00 ,500.00 ,000.00 D1 ENGR, AND AUMlfl 4-20& TOTAL CONSTRUCTION COST TOTAL COST 89. 600 73.600 36.000 150,000 237,600 37,200 52.000 72*000 3.000 3,500 54.000 808.500 121.275 929,775 185.955 1,115«730 STORM LINE. DF VI11-29 DRAINAGE. Ai\EA DF ITEM IVErl NO- DESCRIPTION 1 2 3 4 5 6 7 6 9 10 11 12 DLUrUS BASIM 2700 C.Yc SED. VOLUME RCP30' 3o' 42' RCP 48' RCP 54' RCP 6b» RCP CLEP MGJ1S (36"~fa6") CATCH RASINS (14 FT) (INCLUDING LATtRALS HEAPWALLS <15"-b<+") HEAUdALLS (57"-144») RIGHT OF wAY HEUU1RE ESTIMATEDQUANTITY i ii i ?000 700 500 ,650 ,050 700 18 22 1 1 15 UNIT EA LF LF LF LF LF LF EACH EACH EACH EACH .1AC UNIT PRICE 32 2 3 3 3 3 ,000 52 59 64 75 M8 102 ,000 ,000 ,000 ,500 ,OUO ,,00 ,. no ,00 .00 .00 .00 . 00 .00 .00 .00 .00 .00 TOTAL COST 3? 52 41 32 123 92 71 36 66 3 3 45 .000 ,000 .300 . 000 ,750 .400 .400 .000 .000 .000 .500 .000 SUBTOTAL. CCNTINGENCILS +15?r, sut'Toi AL K. AND +205,, TOTAL CONSTKULTION COST 593.350 89»7b2 02 STORM DRAIN LINE DKAII\!AGE At\E.A DG ITEM ITE'. NO. [)c-ScMPTIOIM 1 DLo'^lS bAST'.l 170'j C.Y. SCO. VOLUME 2 30" uCP 3 6b" RCP 4 CuEAfjOUlS <*6»-bfa'') 5 CATL>H -iwSINS (14 FT) (INCLUuI'vlG LATE.KALS 6 HLA'jwALLS (l5"-b4») 7 H,.Aji\.ALLS (57""i44") 8 RIG IT OF WAY REQUIRE ESTIMATE. UQUANTITY i 500 1,300 b 5 1 1 9 UNIT tA 20 LF LF EACH 2 EACH 3 EACH 3 EACH 3 .1AC 3 U N I T PKIC.E , 0 U L . b2. 102. ,000. ,000. ,000. ,500. ,000. CO 00 00 10 no 00 00 00 SUBTOTAL CONTINGENCIES + 15?e SUBTOTAL ENGH. TOTAL AND ADMIN +20 CONSTRUCTION % COST TOTAL COST 20,000 26. 000 132.600 10 . 000 15.000 3.000 3.500 27. 000 237.10C 35.565 272«6t>5 54*533 327cl96 ^ C "?T VIII-30 DRAINAGE A?EA OH STORM DRAIN LINE OH ITEM MO. 1 2 3 4 5 6 . 7 8 ITE^' DESCRIPTION t:<» RCP tb» RCP 60" RCP 6fe" 9CF' CLE.iNOUTS (36"-b6") JUNCTION STRUCTURES ( "4£lt .."SU" 11 Q O * -J ~ / J,,NCTION STRUCTURES <b7"-5b") CATrH BASINS (It FT) (INCLUDING LATERALS STORM DRAINAGE A.-EA DI ITEf HE.1. N0« DcS'j-ilHTIGN 1 2 3 4 5 t2" *<CF CLE^'jOiJTS (3fa"-t.6") Uj IrTiOfj STRUCTURES (3fa''-jH") CATCrt BASINS (It FT) ( , NCLUCIUG LATEKALS HE A.ji-jwLLS ( 1 5"-bV ) ESTICATEU QUANTITY UNIT 650 LF 2,200 LH- 300 LF 750 LF 12 EACH 1 EACH 1 EACH 11 EACH SUBTOTAL CONTINGENCIES SUBTOTAL ENGR. AND ADMN TOTAL CONSTRUCT] DRAIK LINE DI ESTIMATEDQUANTITY UMIT 1,550 LP b EACH 1 EACH b EACH 1 EACH SUBTOTAL CONTINGENCIES SUBTOTAL E'^GR. AND ADMIN UNIT PRICE 6<+.00 /b.OO 93.00 102.00 2,000.00 2,5"U.OO 3,5UO.OO 3, QUO. 00 + 15 Si + 209r :ON cosi UNIT HR1CE 64.00 2,000.00 2,500.00 3,000.00 3,000.00 + 15St + 2 OK TOTAL CONSTRUCTION COST TOTAL COST 41,600 165,000 27,900 76,500 2t,000 2,500 3,500 33,000 37t,000 56*100 S430,130 66«020 516*120 TOTAL COST 99,2uO 10,000 2,500 15,000 3,000 129,700 19,455 149,155 29,831 17B*96& VIII-31 DRA1MAGE AHEA DJ ITE N0« STORM DRAII\ LINE EM e 1 2 3 4 5 6 7 8 9 10 11 ITEM DESCRIPTION 36" RCP 54" RCP 60" r<CP 6b" RCP 72" RCPCLE,\MOUTS <36"-b6">CLE.ANOUTS <f,9"-93") JUNCTION STRUCTURES (-> £. M V4 1 1 11 \3r> " -= D*4 ; CATCH bASiMS (14 FT) (INCLUDING LATERALS HEAD* ALLS (15"- 34") HC.A ujALLS (57"-144") ESTIMATED QUANTITY 1.800 700 800 1,300 900 15 3 1 18 1 1 SUBTOTAL UNIT LF LF LF LF LF EACH EACH EACH EACH EACH EACH CONTINGENCIES SUBTOTAL ENGR. AMD AOMIN UNIT PKICE D9.00 88.00 93.00 102.00 112.00 2,000.00 2,500.00 2,500.00 3,000.00 3,000.00 3,500. 0 J + 15S, + 20?c, TOTAL COST 106,200 6l«600 74,4UO 132,600 100,800 30 ,000 7,500 2,500 54.000 3,000 3,500 576,100 86,415 66?, 515 132,503 TOTAL CONSTRUCTION COS I 795,018 STORK OK DRAl ITEM 1 2 3 AiiEA ITE^i 3b" RCP CATCr, ^: AS I IMS (1"+ FT) (iNcLUOINb LATERALS QUANflTY T£L) UNIT TY UNIT PKICE 950 LF 5S.OO 3 EACH 2,OutJ.J':' 2 EACH 3,OOU.OO 2 EACH 3,000.00 .TOTAL ITIUGEMCIES +15?^ ITOTAL iR. AMD AUMIM +2056 'AL CONSTRUCTION COST TUTAL. COST 56«ObO 6,000 6,000 6,000 74 ,050 11.107 85,157 17.031 102,188 •7 T- __ 0 f C w -,,•• STORM DRAIN UNE DL VIII-32 DRAINAGE AREA UL ITEM ITr-i N0» DESCRIPTION 1 2 3 4 5 6 7 8 10 30 RCP RCP RCP RCP RCP RCPCLEANOUTS !36»«.6fa») CATCH BASINS '(14 FT» (INCLUDING LATERALS HLADWALLS <15"-b4"> HEAjvjALLS <57"-144») 54" 60" 60" DRAINAGE AREA ON ITEM ITF> NO. DESCRIPTION 1 2 3 4 5 30" RCP 42" RCP 4o" RCP CLE/iv'OUTS (36"-bb") CATCH F.ASiNS (14 FT 1Mb LATERALS EARTH TKAP. CHA.MIMLL7 8 EARTH TRAP. CHANMLL 8 = m D + Ffl = 3 T.-2 y EARTH TRAP. CHANEL ESTIMATED 3UANT1TY UNIT 1,050 LF 600 LF 400 LF 2SO LF 1«400 LF 600 LF 15 EACH 13 EACH 1 EACH 1 EACH SUBTOTAL CONTINGENCIES SUBTOTAL EN6R, AND AOMIN TOTAL CONSTRUCri DRAIfv LINE 0>i ESUi*ATEUQUANTITY UNIT 650 LF 650 LF 500 LF fa EACH 7 EACH 2 EACH 1,000 LF 2,000 LF 1,100 LH SUBTOTAL COT'TlNGENCltS SUBTOTAL ENGR. AND ADMIN UNIT PRICE 52.00 64.00 75,00 8tJ«00 9.S.OO 102.00 2,000.00 3,000.00 3,000.00 3 , 5 U 0 . 0 0 + 15 iS + 20R ON COST UJMITPRICI; 62.00 t4.00 7 b . 0 0 2,000.00 3,000.03 3,000.00 lbb.00 160.00 140.00 + 15% + 20% TOTAL CONSTRUCTION COST TOTAL COST 54,600 51*200 30,000 22,000 130,200 6l«200 30,000 39,000 3 ' 0 0 0 3,500 424,700 63,705 488,405 97,681 536,066 TOTAL COST 33,800 54 ,400 37,5UO 12,000 21,000 6 t 000 i55«oon 320 « 000 154,000 793,700 119,055 912,755 182,551 1 ,095,306 DRAINAGE, AREA ON ITEM ITEM NO. DESCRIPTK STORM DRAIN LINE ON VIII-33 (INCLUDING LATERALS DRAINAGE Ai<EA DO ITEK IFFNO. ots:-fir>Tii. 3o" RCP CLEAMOUTS O6"-fafa") CATCH BASINS (14 KT) l."lrLUUIrJb LATLKALS HETAOwALLS (15"-bt"J "» FT, 1 QL. Jit, STORM >"} FT),|_S ") ESTIMATED UNIT QUANTITY UNIT PRICC 900 LF b9.QO 1.150 LF 64.00 7 EACH 2. QUO. 00 9 EACH 3, QUO. 00 2 EACH 3,000.00 SUBTOTAL CONTINGENCIES +15°, SUBTOTAL EINiGR. AMD ADMIN +-20& TOTAL CCNSTKUCTION cosr ORAHN LINE DO ESTIMATED UNIT QUANTITY UNIT PKICt l,4bO LF 52.00 3 EACH 2.0UO.OO S> EACH 3, QUO. 00 2 EACH 3,000.00 SUBTOTAL CONTINGENCIES -t-15?;, SUBTOTAL ENGR. AMD AQilIM +20S, TOTAL CONSTRUCTION COST TOTAL COST 53,100 73.600 14.000 27,000 6,000 173.700 2,6.0b5 199«7b5 39.9bl 239.706 TOTAL COST 75,400 10,000 15,000 6, 000 106, 400 15,960 122,360 24.472 146.832 DRAINAGE A3EA DP ITEM ITErt NOc DESCRIPTION 1 46" RCP 2 CLEANOUTS <3fe"-=fek") 3 CATcH BASINS U<+ f- T) (ifJCLUDIiMG LATERALS 4 HEAOI/JALLS <15"-bV) STORM ORAIK LINE DP VIII-34 ESTIFATEU QUANTITY 900 3 3 UNIT LF EACH EACH UNIT PKICE 75.no 2,OUQ.OO 3, QUO. 00 TOTAL COST 67«500 6*000 9* 000 2 EACH 3*000,00 SUBTOTAL CONTINGENCIES + 15^ SUBTOTAL EfvGR. AND ADMIN +2OS. TOTAL CONSTuUCTlOr, COST 88*500 101*775 20*355 D8AIMAGE ITEM IT I\i0« DO STORM DRAII\ LlNt 1^ 3ASI") 2inoC'OC .Y.SEH.VOLUME ESTIMATEDQUANTITY UNIT 1 EA SUBTOTAL UNIT 76, DUG. 00 SUBTOTAL ENGRo AND AUP'IN TOTAL CONSTKUCTIOM COST TOTAL COST 76« OUO 76* 000 11 . H U 0 87.400 DRAINAGE. AREA OR ITE.P ITEM NO. DESCRIPTION STORM 1 2 3 DEBRIS BASIM 4jOo C.Y. SED.VOLUME EARIH TRAP. CHANNEL RIGHT OF I«AY REQUIRE ESTIMATED QUANTITY LINE DR UNIT VIII-35 PRICE 36? QUO ,,00 11 b ., 0 0 3,000.00 LF 18 .1AC SUBTOTAL COMTIN6ENCILS SUBTOTAL EMGRe AND ADMIN +20?,' TGTAL CONSTRUCTION COST TOTAL COST 36t000 511,750 54,000 601«750 692.012 830 DRAIMAGE A-<EA OS HEN UK:-NO. DESCRIPTION U'lU'OC.Y. RiGHT OF i.AY STORM DRAIfti L-INL OS ESTIMATED QUAMITY UNIT 1 EA 30 .1AC SUBTOTAL CONTINGENCIES SUBTOTAL EI^GR. UIJI T PKiCE b5,000 .00 3 , 0 0 0 . u 0 + 15?o + 20fc ON COST T'JTAL LOST 55,000 90,000 145,000 21«750 166,750 33,350 200, 100 r c "7" DRAINAGE A,?£A DT ITEM ITT.i N0« DESCRIPTION 1 2. STORM DRAIN* LINE VIII-36 S BASIN 4300 C.Y. SEO.VOLUME RIGHT OF WAY REQUIRE QUANTITY UNIT 1 EA 16 .1AC SUBTOTAL UNIT PRICE 36«OUO.OO 3tOUO.OO SUBTOTAL EfoGRe A|\;0 AOMIN + 2Q& TOTAL CONSTRUCTION COST TOTAL UOST 36f000 54»000 90*000 13.500 J. 0 3 « 5 0 0 20^700 12^*200 STORM DRAIf>, LiNE QU DRAINAGE AutA DU ITEM ITE"< MO- OLSCKIPTION 10 C.Y. SEO.VULUME 2 RIGHT OF lA-AY RtvJlURF, QUANIITY UNIT 1 EA SUBTOTAL. PR 36iOUU ?> , o i; o ICE .00 .00 TOTAL LOST 36 t QUO 54. noo 90« 000 ** n SUBTOTAL EwGR, AMD ADMIN TOTAL CONSTRUCTION COST 20.700 124*200 DRAINAGE AREA NUMBER AA AA AA 1 AA 2 AA 3 LINE VIII-37 ESTIMATED CONSTRUCT ION COST 1,Q03»190 9fa,l86 249,70ft TOTAL COST NUMBER AB AB 1H8,852 TOTAL COST ****************************** NUMBER AC AC 3^'22? TOTAL COST 37b,22? **********i**********************************************'"****** TOTAL COST <+O.H,fl30 4. + ***************' .? At AE. BA TOTAL COST ,************** ******** "+4,160 "+H,lbO * ****** NUMBER eti **********<*******************' NUMBE.K a BC TOTAL COST TOTAL COST TOTAL COST ********** NUMBER BE BE 3tiO, 3HO,7"+2 714, 70? 714, 702 232,806 ******* TOTAL COST ********** DRAINAGE AREA NUMBER dF STORM QRAJN LINE BF TOTAL COST VIII-38 ESTIMATED CONSTRUCTION COST 7/1,696 771,696 NUMBER BG **********+ ; NUMBER an Bfe BH BH 1 TOTAL COST TOTAL COST ISO,696 150,696 192,909 1,428,353 NUMBER BI 81 TOTAL COST 309,946 309,948 NUMBER BJ BJ TOTAL COST 304,960 304,980 NUMBER BI\BK **********.» **+***********: NUMBER BL NUMBER B ******* ' NUMBER a,\i **********, NUMBER CB 8LBL i BM BN BN 1 BN 2 BN 3 BN 4 CB TOTAL COST TOTAL COST TOTAL COST TOTAL COST TOTAL COST 134,136 144,136 631,556 49,680 681,236 i ************* 1M4.7Q2 ia4,782 = ****** *** 2,152,316 466,784 1^1,672 14tt,488 104,860 3,0*4,140 477,686 477,686 ******************* DKAINAGt AhEA NUMBER CC CU VIII-39 ESTIMATED STORM DRAIN L1NL CONSTRUCTION COST CC 4131172 TOTAL COST 414,172 *#*****>M. ******************************* CU TOTAL' COST 119, 576 liy.,576 NUMBER CF ^ CG ; tt A * +:**«. Crl CL TOTAL COST ii2,6oe 112,60ft CF TOTAL CObl 411,446 *******+***=»******* CG TOTAL COS! /2, : i************ .«.*** ***** * * .* * * 4 CH 241,224 241,324TOTAL COST ***** + ****>.**** *t*t: ********************** ***+»****************** CI ***************************** NUMBER Co cu 214,796 214,796 *******:**** * ********** *** BEPv CA CK TOTAL COtsT TOTAL COSI lib, 446 ***** ************************** 2/4,274 2/^,274TOTAL COST ****************#************************************ NUMBER CL ********** NUMBER CM CL TOTAL COST ********************** CM TOTAL COST 80,59? 80,592 ******* 454,338 434,83fl ***********: DRAINAGE AREA NUMBER DA NUMBER D;, *****! NUMBER DC STORM DRAIN LINE DA k * * * * • TOTAL COST TOTAL COST VIII-40 ESTIMATED CDNSTRUC1ION COST 824,584 824,' > ******* DC DC 1 ********** ,.******************; NUMBER DJ DO #*** *********> R OL TOTAL COST TOTAL COST TOTAL COST **********«**+*************** NUMBER DF of TOTAL COST *********** *********•***.*********************************• 171,810 171,810 1,180,866 85,264 l,26fa,150 2f7,966 2M-7,986 r****** 1,lib,730 1,lib,730 ***** *** ^* + NUMBER UG NUMBER OH **********; NUMBER DI *********- NUMBER oj ********** ***: NUMBER D., 32/.19P TOTAL COST 327,198 •****.***.********:******, DH DI DJ DK TOTAL COST bib, 120 516,120 * ******* 178,986 178,986 TOTAL COST TOTAL COST 102,188 102,188 **********+******• DRAINAGE AREA NUMBER DL STORM DL •-VI 1 1 -41 ESTIMATED CONSTRUCI ION COST TOTAL COST 5tib,Q66 ***************** NUMBER ON **********,******#( NUMBER DO * * * * * * «. * NUMBER DP DM ON DO OP TOTAL COST t***** ***** TOTAL, COST I**********: TOTAL. COST ,*******************> 1.09b,306 l»09b,30fe 239,706 >*** !**»** 122,130 122,130TOTAL COSH .****+***************************»****#***+********** DQ TOTAL COST ** + •» + **************< OK TOTAL COST : t *********** ************************* OS TOTAL COST ,******************«***************** NUMBER Df ********* *, NUMBER OU ********* > 01 DU TOTAL COST TOTAL, COST i o"+, e B o 104,B80 ****** 2 0 U , 10 0 2UU,1QO 124,200 124,200 124,200 124,200 r**** ^PPENDiX A-l EROSION AND SEDIMENTATION Preservation of the lagoons is a prominent goal of the Land Use, Open Spaces Parks and Recreation» and Geologic and Seismic Safety Elements of the Carlsbad General Plan. Urbanization has already adversely impacted other lagoons in Southern Californias reducing habitat for flora and fauna and impairing their esthetic aspects. Siltation of lagoons by erosion of upstream grading sites has greatly accelerated the filling of the lagoons and threatens habitat for endangered species. As the City urbanizess construction of new development will expose large areas to erosion. If uncontrolled, the eroded material (debris) will be transported during storms along existing watercourses and storm drains until the transport capacity of the watercourse is reduced, such as at entrances to lagoons. A large portion of debris can be prevented from entering the drainage system by controlling it on the grading site. On-site erosion control can be achieved by means of appropriate grading techniques, on-site debris basins, sediment filters, drainage diversion, etc. A city policy should be established to enforce such erosion control with the grading ordinance amended to provide for specific measures. A model erosion control ordinance, developed by the California Division of Mines and Geologys will be provided in the Master Plan. A-2 Accelerated erosion of existing watercourses may occur due to increased and concentrated runoff from new development, which may be more impervious than natural terrain. This off-site erosion must be handled on a basin-wide approach. Check dams, detention and debris basins may be necessary to mitigate erosion from this source. Such facilities require right-of-ways construction funding, and maintenance. An alternative to construction of debris control facilities is periodic lagoon dredging. However, dredging would probably not be acceptable to California Fish and Game, U.S. Fish and Wildlife, and Coastal Commission authorities. At this time* the preferred approaches to erosion control are as follows: (1) Amend the grading ordinace to include provisions for controlling erosion and sedimentation on-and off-site. The amendment would require that erosion control plans, specifications be submitted by the developer, and would include provisions for enforcement of the ordinance; and (2) Prior to approval of grading plans for a specific develop- ment, Master Plan erosion control facilities should be constructed within that basin. These facilities may include channel stabilization, check dams, debris basins, or detention basins. A-3 To protect the Lagoons from siltation generated by new development, this Master Plan proposes construction of seventeen sedimentation basins located to intercept silt-laden runoff prior to draining into the lagoons. Ideallys, these basins should be in place and operative prior to grading operations within the drainage area. These basins have been sized for cost estimate purposes using the Flaxman Method to predict annual sediment yield. Soil types in Carlsbad fall into four general categories: (1) Marina - Chesterton Association: Loamy coarse sands and fine sandy loams with a subsoil of sandy clay over hardpun with 2 to 15% slopes ~ Coastal strip. (2) Diablo - Las Flores Association: Clays and loamy fine sands over a subsoil of sandy clays; 9 to 30% slopes - inland from Coast. (3) Cienaba -> Fallbrook Association: Very rockys coarse sandy loams with a sandy clay loam subsoil over decomposed granodiorite; 9 to 75% slopes - inland hills. (4) Salinas - Corralitos Association: Clayss clay loams, and loamy sands on alleviated fans; 0-9 percent slopes - Buena Vista Creek, San Marcos Creek and Encinitas Creek floodplains. Based on the soil characteristics of the above soil types, the topo- graphy, the experience of grading operations for typical developments, and the intensities of storms experienced in 1978, 1979 and 1980, an average sediment yield value of 3.5 acre-feet per year per square mile was derived. This value assumes the basins will be cleaned out annually. The City may elect to require the maintenance to be performed by the developer's con- struction contractors during construction or have the maintenance paid for by the developers, as needed. Otherwises it would be the City's responsibility to maintain the basins. Criteria for sizing debris basins has been established by the City Los Angeless based on street slopes and graded areas* These values, shown in Table 4 apply to smaller areas ranging from less than 10 acres up to 200 acres. The sediment yields range from 10.7 to 19.8 AF/S.M. These higher values reflect smaller tributary areas and the fact that a smaller graded area will produce a higher yield per acre than a large basin with some areas graded and other areas imperviouss landscaped, or with original vegetation intact. These values should be used as guides for controlling silt generated by developments in the grading phase. Actual basin si zings will depend on sites available, frequency of anti- cipated maintenance, whether the structure is temporary or permanent in nature, and the duration of the construction upstream of the basin. Outlet works and emergency spillway should be designed to convey 100-year flows with no reduction due to retention, and with adequate freeboard. in DESILTING BASIN CAPACITY TABLE ESTIMATED QUANTITIES OF SILT AND DEBRIS 3. 3 i TtACT ARIA. IAc«e*J 100 ISO 200 SOIL Loose G*amula* . 270 1©,®' Loose Gnanukaw 40.0*ISO Loose GfafflwjJSa* 540 Coropaiclted — 200 Loose Gcamwlar * Compacted * Granular 2160 Loose Granular , ^...2700 Compacted - 1000 Loose Granuta* Cocinf)acted Loose Granular -5400 Compacted - 2000 AVERAGE STREET SI OPE 5%, 350 17© 420 340 1.400 5360 3500 1700 4200 2S50 7Q.Q& 3400 200 11%. 450 270 15% 750 450) 1TOJO S40 UBO 1200 4HM},0 2400 30ADO 740© 2400 €>G€© 360Q 4800 450)0 2700 95KK) 5400 7500 ' 4500 10000 6CKH) Note: Aiways use «he vaiue ior granular material unless the project is finished and the utility trenches are filled with soil which has been compacted to 90% relative compaction.- The capacity required by the above table shall be in a pit or basin. At the lower end of the basin there shall be constructed an outlet dike with dimensions as per instructions. The size of the desilting basin may be reduced by constructing tnorfi than one basin. However, the total volume of basins constructed shall be equal to the estimated volume of runoff solids. TABLE A-6 MODEL EROSION CONTROL ORDINANCE ARTICLE I TITLE, PURPOSE, AND GENERAL PROVISIONS 101.00 Title. This ordinance shall be known as the "(City/County) Erosion Control Ordi- nance." 101.01 Purpose. The purpose of this ordinance is to control erosion and production of sedi- ment, and related environmental damage by establishing minimum standards and pro- viding regulations for the construction and maintenance of land fills, excavations, cut and clearing of vegetation, revegetation of cleared areas, drainage control, as well as for the protection of exposed soil surfaces in order to promote the safety, public health, convenience, and general welfare of the community. 101.02 Rules Applying to Text. For the purpose of this ordinance, certain rules of word us- age apply to the text as follows: 1. Words used in the present tense include the future tense, and the singular in- cludes the plural unless the context dearly indicates the contrary. 2. The term "shall" is always mandatory and not discretionary; the word "may" is permissive. 3. The word or term not interpreted or defined by this article shall be used with a meaning of common or standard utilization. 10L03 Definitions. The definitions as stated in the "GLOSSARY" of the EROSION AND SEDIMENT CONTROL HANDBOOK maintained by the permit-issuing authority shall apply to the interpretation and en- forcement of this ordinance. : '- '%".,''.,; 101.04 Appeals. Appeals'^froih decisions under this ordinance may be made to the permit- issuing authority in writing within ten days from the date of such decision. The appel- lant shall be entitled to a hearing before the permit-issuing authority within thirty days from the date of appeal. 101.05 Validity and Severability. If any part of this ordinance is found not valid, the re- mainder of this ordinance shall remain in effect 101.06 Fees. A schedule of reasonable fees shall be established that will reimburse the per- mit-issuing authority for costs incurred in the review and approval of the application. 101.07 Review and Approval. Applications for grading permits shall be reviewed by the permit-issuing authority and approved when in conformance with this ordinance. •References used: [10][22][44][47][57] Bibliography of Erosion and Sediment Control Handbook. : A-7 ARTICLE II , !. PROCEDURi 102.01 102.011 102.02 Grading Permit Except as indicated be- low, no person shall commence or perform any grading or filling or clearing of vegeta- tion without having first obtained a grad- ing permit from the permit-issuing authority. Exceptions. A permit shall not be re- quired if the work meets any of the follow- ing conditions: L The excavation does not exceed four (4) feet in vertical depth at its deepest point, measured from the original sur- face, and does not exceed 200 square feet in area. 2. The fill does not exceed three feet in vertical height at its highest point, measured from the natural ground surface, and does not cover more than 200 square feet. 3. Exploratory excavations do not ex- ceed an aggregate area of 200 square feet 4. An excavation below finished grade for basements and footings of a build- ing if authorized by a valid building permit. This exception does not affect the requirement of a grading permit for any fill made with the material from such excavation. 5. Clearing of vegetation does not exceed 1,000 square feet in area. 6. Use of land is for gardening primarily for home consumption. 7. Agricultural use of land that is oper- ated in accordance with a farm con- servation plan approved by the Resource Conservation District or when it is determined by the Resource . Conservation District that such use will not cause excessive erosion or sediment losses. ii ' . ^i \ i Application for a Grading Permit. The ap- plication for a grading permit shall in- clude: i. a site map. 2. & grading plan. 3. an assessment of the site. 4. an erosion and sediment control plan except where an assessment of the site shows that a plan is not necessary. 102.021 Site Map. following: The site map shall include the 1. The exterior boundaries of the prop- erty on which the grading is to be per- formed. 2. Contour line which shall conform to minimum intervals as follows: a. 2-foot contours for slopes less than 16%. b. 5-foot contours for slopes over 16%. c. 15-foot contours for topography of adjacent areas. 3. Soil description including: a. soil type b. soil depth c. credibility d. capability for establishing vegeta- tion. e. coefficient of runoff. (Appendix 11C, Determining Rate of Rain- fall runoff.)* 4. Evaluation of subsurface information (as described in part 5 below) where the stability will be lessened by proposed grading or filling, or where any of the following conditions are discovered or proposed: a.At locations where a fill slope is to be placed above a cut slope. • References are to permit-issuing authority's Erosion and Sedi- ment Control Handbook 402.022 b. At proposed cuts exceeding twenty feet in height unless in competent rock as determined by ~~ -an engineering geologist, & Locations of proposed fills ex- ceeding twenty feet in height d. Where side hill fills are to be placed on existing slopes steeper than 16%. e. Wherever groundwater from ei- ther the grading project or adjoin- •••-----• ing properties is likely to reduce the stability. £ At zones of trapped water or high water table. g. Where the topography is indica- tive of landslides, as determined 2_z: .by engineering geologist 5. Where any of the particular condi- tions listed above or other weaknesses are found, subsurface investigations ^ shall consist of drilling, excavations, _ or observations of naturally exposed soil and bedrock exposures at suffi- cient intervals and depths to indicate . the type of material or condition to be encountered at final grading. The per- - son or firm making the investigation - shall submit a written report of their findings and recommendations. Grading Plan. The grading plan shall in- clude the following information which may be shown on the site map: 1-. Elevations, dimensions, including quantity, location, and extent of ----- proposed grading. _;2. -_A.report showing extent and manner of tree cutting and vegetation clearing, ^—including.a plan for disposing of cut trees and vegetation. 3. Provision for stockpiling topsoil and using it to topdress exposed areas to be revegetated or a statement that this provision is not applicable. 102.023 Assessment of the Site. The assessment of the site shall determine the need for an erosion and sediment control plan by con- sidering the detrimental effects of con- struction of the site as it pertains to: 1 erosion and loss of sediments 2. slope stability 3. water quality 4. plant communities 5. aquatic life 102o024 Erosion and Sediment Control Plans 1. The plan shall be prepared by a person or firm qualified by training and expe- rience to have expert knowledge of erosion and sediment control meth- ods, 2. .The permit-issuing authority shall de- termine the adequacy of the plan and may require the submission of further information when necessary to judge the adequacy of the planned erosion and sediment control measures. 3. Formulation of the implementation of the proposed measures may be adopt- ed from recommendations contained in the permit-issuing authority's Ero- sion and Sediment Control Hand- book. The plan shall contain a description of the following: a. Vegetative measures b. Drainage protection and control measures ,- : . 6. Erosion and sediment control d Cut and fill construction e. Disposal of spoil materials f. Stockpiling of materials g. Dust control measures h. A construction schedule ARTICLE III CONTENT OF EROSION AND SEDIMENT CONTROL PLANS A-9 103.01 Requirements. The erosion and sediment control plan shall contain appropriate in- formation according to this article. The plan shall also conform to the requirements in the sections on "Standards" and "Im- plementation" of Articles IV and V, respec- tively. 103.02 Protection of Native Vegetation. In order to protect native vegetation from construc- tion activities the following information shall be provided; 1. Location of native vegetation whose root zone will be affected by compac- tion, fills, trenches, and changes in the groundwater table. 2. Measures which will prevent condi- tions damaging to vegetation shall be specified. (Section 10 - Tree Protec- tion)*. 103.03 Removal of Native Vegetation. When na- tive vegetation is to be removed, the follow- ing information shall be provided: L Descriptions of the native vegetation. 2. A list of the vegetation to be removed and the criteria used to determine re- moval. (Section 10). 3. The methods for removing and dispos- ing of the vegetation. (Section 10). 103.04 Establishment of Vegetation. Where the establishment of vegetation is required on slopes of cut and fill, graded areas, and watercourses, the following information shall be provided on the: 1= Location and area to be vegetated. 2. An indication of whether vegetation is temporary or permanent. * References are to permit-issuing authority's Erosion and Sedi- ment Control Handbook 3. Type and quantity of seeds or plants. (Section 20 - Establishment of Protec- tive Vegetation), 4. Ground conditions: a. Surface condition of soil. b, Soil pH. e. Permeability. d. Soil size distribution. e. Slope angle, slope length, and as- pect f. Nutrients in soil * 5. Type and quantity of mulch. (Section 30 - Surface Protection with Mulches and Other Materials). 6. Type and quantity of fertilizer. (Sec- tion 20). 7. Method and schedule of seeding, mulching, planting, and fertilizing. (Section 20). 8. Schedule of irrigation. (Section 20). 103.05 Drainageway Protection and Control Measures. Where it is necessary to reduce the increased rate and volume of rainfall runoff due to the alteration of the runoff pattern, the following data shall be pro- vided: L The runoff to be expected during and after the proposed development. (Ap- pendix II - Climate, Runoff, Allowable Velocities). 2. The location of natural and man-made drainageways. 3. The size of drainage areas above cuts and slopes. A-10 4. The methods to be used to reduce ero- sion of drainageways. (Section 60 - Channel Protection; Section 70 - Grade Control and Realignment of Channels). 5. The procedures used to trap sediment in order to protect drainage control measures. (Section 90 - Sediment Traps and Detention Basins). 6. The methods to control the rate and direction of runoff on roadways during and after development. (Section 50 - Roadway Protection). 7. The methods used to control runoff across the slopes of cuts and fills and graded areas during and after construc- tion. (Section 40 - Protection of Slopes and other Graded Areas from Runoff). 8. The construction schedule for drainage protection and control measures. (Ar- ticle HI, 103.12 Construction Sched- ule). 9. The method and schedule of construc- tion of waterway crossings. (Section 80 - Installation of Culverts, Paved Fords, Bridges). 103.06 Sediment Detention Measures. Informa- tion on the design criteria of sediment ba- sins shall include the following: 1. The location and dimensions of the sediment basins. (Section 90). 2. The hydrologic and sediment transport. data used to determine the proper capacity of the needed basin. (Appen- dix I, Estimating Erosion and Sediment Losses; Appendix II, Climate, Runoff, Allowable Velocities). 3. The construction procedure and sched- ule. (Section 90). 4. The source of borrow material. 5. The maintenance schedule. <S. The type and manner of vegetating the credible slopes as described in item 103.04, Establishment of Vegetation. 103.07 Fill Slopes. Where fill slopes are to be constructed, the following information shall be included: 1. Location of fill area. 2. Slope and height of fill. 3. Slope and condition of original ground. 4. The number and dimensions of benches. 5. Source of fill material. 6. Ability of fill to support vegetation. 7. Percent organic content of fill. 8. Maximum size of rock in fill. 9. Maximum thickness of layers of fill to be compacted. 10. Percent Compaction. 11. Methods of protecting the slope sur- face of the fill. : 12. Number and width of drainage ter- races to be installed. 103.08 Cut Slopes. Where slopes are to be formed from cuts, the following information shall be included: 1. Location of cuts. 2. Slope and height of cuts. 3. Identification of cuts to be vegetated or not subject to erosion. 4. Number and width of drainage terraces provided. 5. The ability of the ground to support vegetation. (Section 20). 103.09 Disposal of Spoil Material. The informa- tion concerning the disposal of spoil materi- al shall include the following: L Type of spoil material. 2. Location of disposal area. A-ll 3= Method of processing and disposing of spoil material 4. Procedures to prevent soil loss to adja- cent watercourses. 5. Burning procedure for flammable spoil material and its schedule, 103.10 Stockpile. Stockpiled material shall be identified according to: 1. Source of material. 2. Location, slope, and height of stock- pile. 3. Duration that the material is to be stockpiled. 4. Provisions to prevent erosion and sedi- ment loss from rain and wind action. 103.11 Dost Control. The following provisions for dust control shall be included: 1. Measures to keep dust to a minimum during equipment operation. 2. Measures to prevent wind erosion of exposed soil. (Sections 20 and 30). 103.12 Construction Schedule. A construction schedule shall be provided by the contrac- tor. No work shall be permitted on the site until the schedule has been approved in writing by the permit-issuing authority. The permit-issuing authority shall check the adequacy of the schedule with respect to the factors that could contribute to both short-term and long-term erosion on the project site. The construction schedule shall be checked for prompt establishment of protective vegetation with full recognition of climatic and other factors that influence its estab- lishment A-12 ARTICLE IV STANDARDS 104.01 General. The grading plans and erosion control plans shall conform to the standards set forth hi this Article. 104.02 Sediment Control. 1. Sediment shall be retained on the site. (Section 90 - Sediment Traps and De- tention Basins).* 2. Sediment basins, sediment traps, or similar sediment control measures shall be installed before extensive clearing and grading operations begin. 104.03 Native Vegetation. 1. 3. Native vegetation shall be retained, protected, and supplemented wherever possible. (Section 10 -Tree Protection; Section 20 - Establishment of Protec- tive Vegetation). When vegetation must be removed, the method shall be one that will minimize the erosive effects from the removal. (Section 10; Section 30 - Surface Pro- tection with Mulches and Other Materials). Exposure of soil to erosion by removing vegetation shall be limited to the area required for immediate construction operations. 104.04 Grading Practices. ' : 1. Grading operations shall be conducted •_. so as to prevent damaging effects of sediment production and dust on the site and on adjoining properties. • » • 2. In no event shall the native vegetative ground cover be destroyed, removed, . ' or disturbed more than 1 5 days prior to grading unless otherwise approved by the engineer representing the permit- issuing authority. * References are to permit-issuing authority's Erosion and Sedi- ment Control Handbook 104.05 Control of Runoff 1. Provisions shall be made to control the increased runoff caused by changed soil and surface conditions during and after development. (Sections 40 through 100). 2. To prevent excess runoff the'"rate of sur- face water runoff shall be structurally retarded. (Sections 90 and 100). 3. Each applicant requesting permission , to make any surface changes shall be , „ required to: a. Collect on-site surface runoff and dispose of it at nonerosive velocities to the pouit of discharge into the common natural watercourse of the drainage area. b. Handle existing and potential off- site runoff through his develop- ment by designing to handle ade- quately stonn runoff from a fully developed area upstream. c. Pay his proportionate share of the total cost of off-site erosion and sediment control improvements to the common natural watercourse, based on a fully developed drainage area. •-•''••• d. 'Provide and install, at his expense, • rv" •• • all drainage, erosion, and sediment '• • - ' control practices (temporary and -•-.'-'"- permanent) required by the Ero- sion and Sediment Control Hand- book. -*-',••' -C. Retain sediment being transported ' - by runoff water on-site through the '- ' use of sediment basins, silt traps, or similar measures. 4. Concentration of surface water runoff shall only be permitted in swales or watercourses. A-13 5. In order to prevent polluting discharges from occurring, approved erosion and sediment control devices shall be re- quired for all grading and filling. Con- trol devices and measures which may be required include, but are not limited to, the following: a. Energy absorbing devices to reduce the velocity of runoff water. (Sec- tion 100 - Dissipating the Energy -of Runoff Water). & Sedimentation controls such as sediment debris basins and sedi- ment traps. Any trapped sediment shall be removed to a disposal site approved by the permit-issuing au- thority. (Section 90). c» Dispersal of water runoff from de- veloped areas over large undis- turbed areas. d. Multiple discharge points to reduce the volume of runoff over localized areas. 104.06 Slope Construction 1. Slopes, both cut and fill, shall not be steeper than 2:1 unless a thorough geo- logical and engineering analysis indi- cates that steeper slopes are safe and erosion control measures are specified. 2. Slopes shall not be constructed so as to endanger or disturb adjoining property. 104.07 Slope Surface Stabilization. 1. Temporary mulching, seeding, or other suitable stabilization measures shall be used to protect exposed critical areas during construction or other land dis- turbance. (Sections 20 and 30). 2. : Earth or paved interceptors and diver- sions shall be installed at the top of cut or fill slopes where there is a potential for surface runoff. (Section 40 - Pro- tection of Slopes and Other Graded Areas from Runoff)- 104.08 Grading. L All land within a development shall be graded to drain and dispose of surface water without ponding, except where approved by the permit-issuing author- ity. 2. Where drainage swales are used to di- vert surface waters, they shall be vege- tated or protected as required. (Section 60 - Channel Protection) 104.09 Protection of Watercourses. 1. Fills shall not encroach on natural watercourses or constructed channels. 2. Fills placed against watercourses shall have suitable protection against erosion during flooding. 3. Grading equipment shall not cross or disturb live stream channels. 4. Excavated materials shall not be depos- ited or stored in or alongside the river or watercourses where the materials can be washed away by high water or storm runoff. 104.10 Disposal of Cleared Vegetation. Vegetation removed during clearing opera- tions shall be disposed of as follows: L Chipping all or some of the cleared vegetation for use as mulch or compost on the site. (Section 30). 2. Burning all or some of the cleared vege- tation. Material to be burned shall be piled in a manner and in such locations as will cause the least fire risk and least damage to adjacent trees by insect in- festation. 3. Burning so thorough that the materials are reduced to ashes. No logs, branches, or charred pieces shall be permitted to remain. Burning shall comply with local air pollution regula- tions. A-14 4. Disposing the balance of the material in & manner and at a location approved by the permit-issuing authority. 104.11 Disposal of Excavated Materials. Ex- cavated materials removed during grading operations shall be disposed of as follows: L Stockpiling all or some of the topsoil on the site for use on areas to be revegetat- ed 2. Locating stockpiled soil so that if ero- sion occurs, it would not become a source for off-site sediment damage. 3. Stockpiling soil far enough from streams or drainageways that surface runoff cannot carry sediment down- stream. 4. _ Stockpiling material from trenches and pits on the upslope side of the excava- tions. 5. Promptly backfilling and compacting stockpiled soil into trenches and pits to reduce the risk of erosion. 6. Applying mulch or other protective coverings on stockpiled material which will be exposed through the winter sea- son or which faces a high risk of inten- sive summer rains. (Section 30). 7. Excavated material not to be used at ... the site to a location approved by the permit-issuing authority. A-15 ARTICLE V IMPLEMENTATION 105.01 Enforcement and Inspection. The provi- sions of this ordinance shall be enforced by the permit-issuing authority who shall re- view project plans and approve them if found to be in compliance with the ordi- nance, and by the engineer who shall in- spect work and require compliance with all the provisions of the ordinance. 105.02 Authority and Responsibilities. The con- tractor shall install all soil erosion and sedi- ment control measures in strict compliance with the ordinance and in accordance with the approved erosion control plan. All soil erosion and sediment control meas- ures shall be adequately maintained by the contractor for a period of three years or until such measures are stabilized as deter- mined by the engineer. Upon application by the contractor, the en- gineer shall give the contractor a certificate of completion indicating the date on which the measures in the approved plan were completed. The engineer shall prohibit further work to be done if it is determined by him that the work does not comply with the provisions of the approved erosion control plan or with the provisions of the ordinance until such time as compliance with the ordinance is assured. The engineer may allow a new or modified erosion and sediment control technique to be used provided there is mutual agreement between the engineer and contractor that the technique meets the intent of the erosion control plan. The engineer may cause remedial work to be done if he determines that it is necessary to protect completed work or to prevent damage. The cost of such remedial work shall be deducted from the amount due the contractor under the terms of his contract 105.03 Performance Bond. A performance bond shall be posted by the contractor. The amount of bond shall be the full cost of the installed erosion and sediment control measures. The bond shall not be released until the erosion and sediment control measures have performed satisfactorily as determined by the engineer for a period oi three years. The bond may be used to pro- vide for the installation of the control meas- ures if not done by the contractor and sediment runoff is occurring as a result. 105.04 Penalties for Violations. Penalties for viola- tions of the ordinance may be assessed by proper authority on recommendation of the engineer. The kind of penalty and severity of penalty shall be specified and may consist of: L Fines 2. Stop orders 3. Corrective action order END- A-16 - / v\v,v- CITAIN FOt SIMM WATU OETINT10N Figur* 2. Pictorid Map of Development Plan Showing Erosion and Sediment Control Measures. [48] Side Swale or Channel- Rear Drainage Swale; -Protectiv "Front Drainage Swale Drainage Divide ossible locations of rear drainageeasements to proper outfall Drainage Divides- Rear Slopes to Drainage Easement7' Rear Drainage Easement to proper outfall -Protective Stapes-7 side Swale or Channel- • Rear Drainage S wales- Hgur* 3. Examples of Providing Proper Drainage Location. [30] A-17 Storm sewer structure L ' ftir-C?. -^g —-——— — - — — ^ <._„ ... — «,-.._.„. ,_„ — ,J L*L*hi ©utter Anchor with two stakes driven into the ground Temporary barrier of hay bales to prevent sediment-laden water from entering incomplete storm sewer system. Flow Top View Bales of straw staked down ~zi—A*-£s^er*»t'r-~v1 Provide sand and gravel filter out'*1 at lower area along with" straw r*V/.-*•.nrr » a • Front view Semi"pervious barrier of hay bales with more pervious embankment of sand and gravel for spillway. Figure 34. Temporary tarrter of Straw Bales to Prevent Sediment-Laden Water from Entering Incomplete Storm Sewer. [57] A-18 Plywood top Building block laid in throat- web horizontal Sand & gravel filter Building block •Gutter section Figure 35. Sand and Gravel Filter Protecting Intake Area of Incomplete Storm Sewer System. [56] Sandbag or compacted tarth btrm • TYPICAL DESILTING BASIN ~2f *A.C. of gunlte Unimproved Street Driveover Paved Berm — see detail PAVED BERM DETAIL TYPICAL LAYOUT DETAIL OF SEEP RINGInlet apron at street elevation and sloping steeper than street grade Paved Inlet with Wingwalls- 3" A.C. or g unite See Figure GI548 for desilting basin capacity required Standpipt — weld *4 bars 96* across top of pipt 3 AC. or Gunile Weir or Spillway Basin Outlet Step Ring — set detail 18 C.M.Ror equiv. - all jointswatertight PLAN —BASIN OUTLET Weir and Spillway — $e» Figure GI54A Apron or channel paved to paved street, storm drain, or water- course. See Figure GI54A/, NOTE: With tandem basins, apron or channel shall bt 20'minimum length. Ust cutoff wall at end of spillway. 18" C.M.P or equi*. Seep Ring - not required with gunita spillway SECTION A-A 2% mm. LJ Note: Desilting basins built on lots adjacent to dwellings shall bet completely fined with 3"A.C. or gunite. 3 AC. Of Gunitt apron or channel P.JM ?-W A-20 51.00 INTERCEPTOR DIKE [41] An interceptor dike is a temporary ridge of compacted soil constructed normal to the slope or graded right-of-way and is used to intercept and convey surface water at nonerosive velocities to an adequate and sta- ble outlet (Figure 21). It is a temporary structure which may be designed for construction traffic to cross. It should be inspected after each rain and re- paired before the next storm. 51.10 DESIGN CONSIDERATIONS L Minimum ridge height: 1.5 feet 2. Minimum top width: 2 feet. 3. Maximum side slopes: 2.1 (Horizontal:- Vertical), 4. Maximum allowable spacing between dikes ranges from 200 to 300 feet. Spac- ings may also be determined by Tables 21 and 22 on cross drain spacings. 5. Dike material shall consist of compacted soil. 6. Interceptor dikes should have a positive grade draining to a stabilized outlet. 7. Diverted runoff shall outlet to a stabil- ized undisturbed area, a prepared level spreader, or into a slope protection structure (culvert, down drain, etc.) 8. Interceptor dikes can be installed by a road grader or angle blade dozer. Figure 21. Interceptor Dike. [41] A-21 ?I.OO CHANNEL GRADE CONTROL Grade control measures are structures which reduce and maintain the channel gradients. By reducing the channel gradient, the runoff velocities decrease, thus preventing erosion . at higher flows. Such structures include check dams, drop structures, and erosion stops (erosion checks). 7UO CHECK DAMS [57] L General a. Check dams are structures used to stabilize the grade and control head cutting in natural or artificial chan- nels (Photos 38 and 39). b. Check dams prevent excessive ero- sion by reducing flow velocities in watercourses and by providing par- tial lined channel sections or struc- tures that can withstand high flow velocities. c, Formal design is generally required. Specification & Overfall structures of concrete, met- al, rock, gabions, wood, etc., may be used in the construction of check dams, b. Site should be in a reasonable straight channel section. c. Site and foundation conditions and aesthetic considerations are impor- tant factors in material selection. d. Channel grade above and below the structure should be evaluated to de- termine if erosion, sediment deposi- tion or flooding will be a problem. A-22 a SEDIMENT TRAPS1 *** Sediment traps are vegetative or structural measures which trap sediment at cm-site construction areas to prevent clogging of drainage control structures and reduce sedi- ment runoff. Types of sediment traps include filter berms, sandbag or straw-bale barriers, filter inlet, vegetative filter strip, culvert ris- er. Photo 44 shows the need for sediment traps, 10 FILTER BERM [57] I- General s. The filter benn is a temporary sedi- ment trap and consists of a ridge of gravel or crushed rock constructed across a graded right-of-way. See Figure 33. b. Filter berms retain sediment on-site / by retarding and filtering runoff while at the same time allowing con- struction traffic to proceed along the right-of-way. j & Filter berms are also applicable for use in drainage ditches prior to road- way paving and establishment of permanent ground cover. d. After each storm remove trapped sediment and clean out or replace < clogged filter material. \ 2. Specifications &. Height 1.5 to 2.0 feet (uniform top elevation) b. Top Width: 3 to 5 feet e. Side Slopes: 3:1 or flatter. <L Spacing: 200 to 300 feet (steeper "lopes require closer spacing.) e. Material: Coarse (3/4* to 3*), well graded gravel or crushed rock. Fines less than 5 percent. 91.20 SANDBAG OR STRAW BALE BARRI- ERS [57] L General a. Sandbag or straw bale barriers are temporary sediment traps which re- tain sediment on-site by retarding and filtering storm runoff and are used at storm drain inlets, drainage- ways, and across rights-of-way. See Figure 34. •-••«- b. Dikes of sandbags or straw bales constructed across a right-of-way or immediately below the site of con- struction activities should have a low spillway-embankment section of sand and gravel filter that serves as a filter outlet. G. The barriers must be installed so that runoff cannot escape freely un- der the straw bales or sandbags. 2. Specifications a. Straw bales bound with nylon or wire are more durable than twine- bound bales. b. Straw bales should be anchored to the ground with steel rods, fence posts, rebars, wood pickets, etc. Two ....... . . anchors per bale are required. l.§'-2f Graded R.O.W. Slopes Figure 33. Filter Benn. [S7\ A-23 e, Sandbags exceeding two bags in height may require anchoring with steel rods, rebars, etc. 9L30 FILTER INLET [57] L Genera! &. A filter inlet is a temporary sediment trap consisting of gravel or crushed rock placed at storm sewer curb in- let structures. See Figure 35. b. Filter inlets retain sediment on-site by retarding and filtering storm run- off before it enters the storm or sew- er system. c. Trapped sediment should be removed and the clogged filter material cleaned out or replaced af- ter each storm. 2. Specifications ; 8. Concrete building blocks placed in throat of inlet. Filter material placed between blocks and street in the gut- ter section. See Figure 35. b. All filter material should be coarse (3/4* to 3*), well graded gravel or crushed rock. Fines less than five percent. 91.40 VEGETATIVE FILTER STRIP 1. General &. A vegetative filu.r strip is a tempo- rary or permanent sediment trap which consists of an area of vegeta- tive cover through which storm wa- ter must flow before it enters streams, storm sewers, conduits, etc. b. As the water containing suspended solids flows through the vegetative filter strip, some of the sediment is removed by "filtering" and by depo- sition as the flow velocity is reduced. c. Vegetative filter strips are naturally occurring or man-made. d. Tall, dense stands of grasses form the best sediment traps. 2. Specifications a. Naturally occurring vegetation may suffice. Light fertilizing may en- hance the growth. b. Man-made grasses may be provided by sod or by planting. c. Minimum width of vegetative filter strics: Above Diversions: 15' plus 1/2 of channel width. [21] Along Live Streams: 100' minimum (Recommended by California De- partment of Fish and Game in log- ging areas.) 91.50 CULVERT RISER V 1. The culvert riser is described in the chapter on culverts. 2. The chapter on sediment detention ba- sins should help in the safe storage de- sign of culvert risers. 92.00 SEDIMENT DETENTION BASIN A sediment detention basin is a reservoir which retains high flows sufficiently to cause deposition of transported sediment. Sedi- ment basins may be either temporary or per- manent structures which prevent off-site transportation of sediment generated from construction activities. See Photos 45,46 and Figure 36. 92.10 DESIGN CONSIDERATIONS 1. The design of the sediment basin shall be based on the total drainage area lying upstream and on the future use of such lands. 2. The spillway overflow from a debris ba- sin should not increase the down stream sediment loads. 3. Vegetation should be planted on slopes of embankments composed of credible soil. A-24 4. Beyond certain limitations on the height of the dam and the storage capacity of the reservoir, the design of the sediment basin will come under the jurisdiction of the California Division of Safety of Dams (See Table 23). 3. For basins which also serve as perma- nent water storage consideration should be given to the prevention of "algae bloom" which is aesthetically unsightly* 92.11 STORAGE [57] 1. The site should be selected to provide adequate storage. 2. Storage capacity shall be the volume be- low the pipe spillway crest or emergency spillway crest. 3. Consideration should be given to plan for periodic cleanout in order to main- tain the capacity requirements. 4. The maximum allowable level of depos- ited sediment before cleanout shall be determined and given in the design data as a distance below the top of the riser. 92.12 PIPE SPILLWAY [20] [57] 1. The combined capacity of the pipe and emergency spillways will be designed to handle the design flood. 2. Runoff will be figured by an acceptable • hydrologic procedure, and should be based on drainage area conditions ex- pected to prevail during the anticipated ' effective life of the structure. 3. The pipe spillway will consist of a per- forated vertical pipe or box-type riser joined to a horizontal pipe conduit (barrel) which will extend beyond the downstream toe of the embankment. 4. The horizontal pipe conduit (barrel) will bd a minimum of 12 inches in di- ameter. 5. The riser is a minimum of 30 inches in diameter and has a cross-sectional area of at least 1.5 times the cross-sectional area of the horizontal pipe conduit. 6, The crest elevation of the riser shall be such that full flow will be generated before there is discharge through emer- gency spillway and at least one foot be- low crest of emergency spillway. ?, If no emergency spillway is provided, the crest elevation of riser must be at least three feet below crest of emer- gency spillway. 8, The upper 1/2 to 2/3 of the riser shall be perforated with 1-1/2 to 4 inch holes, 10 to 12 inches on center and staggered. 9. The antivortex device can increase vol- ume of discharge by as much as 50 per- cent 10. An approved antivortex device is a thin, vertical plate normal to the cen- terline of the dam and firmly attached to the top of the riser. The plate dimen- sions are: Height = diameter of barrel Length — diameter of riser plus 12 inches 11. The riser shall have a base attached with a watertight connection and shall have sufficient weight to prevent flota- tion of the riser. Three recommended methods are: a. A square concrete base 18 inches thick with the riser embedded six inches in the base. Each side of base will be diameter of standpipe plus 24 inches. b. A 1/4 inch minimum thickness steel plate welded all around the base of the riser to form a water- tight connection. The plate shall be square with each side equal to two times the riser diameter. The plate shall have two feet of stone, gravel, or tamped earth placed on it to pre- vent flotation. c. Properly anchored guy wires may be substituted for the anchor block. A-25 12. The trash rack consisting of #4 bars, 6 inches on center shall be welded across the top Of riser. 13. At least one seepage ring is required and each ring shall be rectangular with each side a minimum of barrel diameter plus 24 inches. 92.13 EMERGENCY SPILLWAY [20] [57] L The emergency spillway should be de- signed for 1.5 maximum design flow. Two recommended designs are: &. Discharge over top of dam or em- bankment. Spillway must be lined with 3 inch thick gunite or 4 inch concrete reinforced with 6x6- 10/10 wire mesh, extending to a minimum of 3 feet down the up- stream face of embankment. Spill- way will be minimum of 18 inches deep with 1 1/2:1 side slopes. b. Earth spillways must be installed on undisturbed soil (not on fill) by grading. Side slopes will not be steeper than 2:1. Embankment and spillway channel must be protected by vegetation, rock riprap, etc. The maximum allowable velocity in exit channel shall be 6 feet per second. 92.14 FREEBOARD [49] 1. Freeboard is the vertical distance between the elevation of the water sur- face in the pond when spillway is dis- charging at designed depth and the elevation of the top of the dam after all settlement has taken place. 2. Minimum freeboard shall be 1.0 foot for sediment basins where the maximum length of pond is less than 660 feet. 92.15 EMBANKMENT [49] 1. The embankment shall have top widths based on the following: Height Top of dams width under 10' 8' 2. Side slopes shall be no steeper than 2:1. 92.20 CONSTRUCTION [23] [20] 92.21 SITE PREPARATION L The foundation area reservoir area shall be cleared of all trees, stumps, roots, brush, boulders, sod, and debris. 2. All topsoil containing excessive amounts of organic matter shall be removed. 92.22 BORROW AREAS L All borrow areas outside the pool shall be graded, seeded, and left in such a manner that they are well drained and protected from erosion. 92.23 EMBANKMENT 1 . The embankment material shall be taken from borrow areas as stated on plans. 2. The material shall be free of all sod, roots, woody vegetation, large rock (ex- ceeding 6 inches in diameter,) and other debris. 3. The embankment should be constructed to an elevation which provides for an- ticipated settlement to design elevation (allow 10% for settlement). 4. The foundations for embankment shall be scarified prior to placement of fill. 5. Placement of fill material shall be started at the lowest point of the foundation and shall be placed in 6 inch maximum lifts which are to be continuous over entire length of fill and approximately horizon- tal. 6. The satisfactory compaction is usually achieved when the entire surface of the fill is traversed by at least one pass of the loaded hauling equipment or through use of a roller. 92.24 PIPE SPILLWAY 15'~20' 2(y-25' 12' 14' 1. The barrel shall be placed on a foundation to the lines and grades sho* n on the plans. 2. Backfill material shall be placed around the barrel in 4 inch layers and each layer shall be thoroughly compacted with suit- able hand-operated equipment to at least 1 feet above the top of the pipe and seepage rings before heavy equipment is operated over it. 92.25 VEGETATIVE PROTECTION 1. A protective vegetative cover shall be es- tablished on all exposed surfaces of the embankment, spillway, and borrow area to the extent practical. 92.26 PROTECTION OF SPILLWAY DIS- CHARGE AREA 1. All areas subject to discharges from pipe spillway and emergency spillway must A-26 be protected with vegetation, rock, rip- rap, etc. 92.30 SEDIMENT CLEANOUT AND DIS- POSAL 1. The sediment should be removed when- ever the storage capacity has been re- duced to unsafe, improperly functioning levels. 2. The sediment must be disposed of in such a manner that will prevent its re- turn to the sediment basin or movement into downstream areas during subse- quent runoff. USDA Soil Conservation Service r r |li^fp^-•-• *£E4i^£a - il<Hi5»K= ^-•Jili.x'Sh-.-V' ]'^-*v - .*'* 2.7-%! • £7^4 i<:.?-!';• :- - -^'-'• ••• : •%*&• •'WWtlti i/^'J •; -r^^r^l.. 2 --^^^6>^^<^^!^^^^.^^ 1" ^-J^^S^^TT^^ ^^S^f^5^igp??^S^! :?^sri-i ^r^r^v^^*^^ ^.-:: ;~^i*^'i:'a^SaQ«zO; y.^^^r1^.^^"^?.'^ >*aM«™w,-• j -5^*«fe?»-^^^^Lii-; - _^t->rc<^r"v- - jri*tei-:, Photo 44. A S«dim«nt Trap Would Have Allowed This Storm Sewer System to Collect Runoff Without Excessive Sediment Load. f«hl* 1. Gh*ekli»t for Site Evaluation. A-27 [ POTENTIAL DETRIMENTAL EFFECTS1 DETRIMENTAL EFFECTSo 83Men§ DEVELOPMENT SITE CONDITIONS 1. Are there areas where soil conditions indicate that erosion is a possibility? 2. Will erosion occur as a result of any or all proposed alternatives'? 3. Will adjacent and nearby streams, ponds, and lakes be affected by project construction? 4. Is there the potential for flooding in natural and mamtiade waterways and' channels from the increased runoff caused by changed soil and surface conditions? 5. Will the development disturb areas in or near stream channels? 6. Do the proposed roads have long stretches of excessive grade? 7. Will the drainage to streets and from streets to storm sewers or other runoff disposal systems cause water to erode the land or flood property further down gradient? 1. Can areas of exposed soil be protected from erosion by the establishment of vegetative cover and by the diversion of runoff? 2. Can sediment from construction activities be contained on or near the project? 3. Will special erosion control and sediment collection measures be required to protect adjacent properties? 4. Will construction sequence, method of operations or season of work have an effect on control measures? 5. Does the adjoining property require special erosion control or sediment collection methods? 6. Can lots be graded without mass grading techniques? 7. Are underground utilities provided for? 8. Can trees and other vegetation be protected? 9« Are paved and other impervious areas held to the minimum? 10. Are onsite temporary storage of rainfall included? 11. Is fire protection included with sufficient and proper ingress and egress? 12. Can the maintenance of all erosion control practices be adequately provided? 13. Is the design storm frequency adequate? 14. Can vegetation be allowed to remain in some areas? YES * NO - A-28 Tcbte 2. Factor* in th« As>*»m«nt of a Sit*. List of Factors Assessment of Impact .of Factors on the Site (Statement Needed) Character-istics Soil and Geology • Soil - Physical & Chemical • Geologic Conditions • Groundwater Occurrence & Movement • Slope stability • Seismic Factor Climate and Precipitation Start and End of Rainy Season Intensity and Duration of Storms Occurrence of Summer Storms Seasonal Temperature Frost-Free Period Wind Erosion Snow Melt Runoff Rainfall Runoff Before and After Development Topography Slope Angle Slope Aspect -- - Slope Length Density and Capacity of Drainageways Suitability of Sites for SedimentBasins Vegetative Cover • Type and Location of Native Plants • Fire Hazard • Establishing Vegetative Cover • Adequacy of Existing Erosion ControlFeatures Type of Development • Cluster or High Density Structures « Single Family or Low Density Structures • Percent Open Space and Impervious Surfaces Manner of Development Percent Grade and Layout of Roads Density of Roads Distribution of Open Space Structures Affecting Erodible Areas Number of Culverts, Stream Crossings Size of areas, duration and time of year that are left bare L =29 Table 3. Relating Sources of Sediment or Cause* of Accelerated Erosion to Erosion Control Practice*. Section 10 20 30 40 50 60 70 80 90 100 'x^Sources of Sediment or ^^•xQauses of Accelerated ^***<»»%l.^ Erosion Erosion ^N**XX||^ and Sediment ^""""s^^ Control Practices ^"^"^v^ Protection of Trees Vegetative Measure Protective Covering of Mulch and Other Materials Temporary Diversion Dike Permanent Diversion Dike Interceptor Ditch Slope Drain Diversion Interceptor Dike Drainage Dip Side Ditch Open-Top Culvert Vegetative Lining Flexible Lining Rigid Lining Grade Control Structure Channel Realignment Culvert Paved Ford Bridge Sediment Trap Sediment Detention Basin Energy Dissipator Loss of Trees P BareCut and Fill Slopes and Graded Areas T,P T T P P T,P T,P Unpro- tected Road Surfaces T T T T T,P T,P Sensi- tive Water- courses T,P T P P P P P T,P P T,P T,P T,P T,P Hbte: 5?: temporary erosion control practices which would prevent erosion during construction or before construction is completed. 3?: permanent erosion control practices which would permanently stay on the project area for erosion control. A-30 fobl* 23. tocign UmHoHon* and Jurisdiction ef Dam* in California. [39] I*- Cond- ition 1 2 3 4 5 DESIGN HEIGHT (ft) <6 No limit S-5 >25 No limit STORAGE (acre-ft) No limit <15 No limit >15 >50 USE OP MM Impound or divert water . Impound or divert water. Underground per- colation. Impound or divert water. Impound or divert water. Jurisdiction by the California Division of Safety of Dams No (sec. 6003) No (sec. 6003) No (sec. 6004) Yes (sec. 6002a) Yes (sec. 6002b) A-31 It, » ' ' '• W . . •' 1 :• Ofr • 8 »f ' ; — 1 p C < 3 ' •» e3il t-" < 9 Ul j . §* t» E 1 E 22,1 H- 5 : 2n ' !ZO_ • A & T*\ 1Co. 90 -so :' « • 1 -70 ; - eo : ^•50 '. • ~ -40 ;• *" * 1 ™ oO * e „ 1-2Q'* ; v * Xio j I m < ro.o •% - O.I -0.2 /* « - 0.3 e • • f J-0.5 -0.6 '- 07 : 0.8 7 0.9 -1.0 -0 1 ' «an « * J • ' e ^*e « C e # * -* ™ * « EXAMPLE S Y*I.I4 ' « -5.0 • 4.0 r s.o N0 r 2.0 HO ** *B e • * * » e •*• 0.0 ......... ....... .... ^ *^i Ulo. X Ul lit Ca <9* HP - S 2 ^o EC u Ul 3CK Ce u < * 3 100 T90 : 80 -70 -60 - 50 -. 40 4 30 4 20 -1 .* ' c * «-10 ^ .-•"" -20 •:e « .•** -30 -_ '-40 •= • * * -50 ^ * -60 - 0 -T r • : 10 -_ ~ - '- .' '.•u •:«* 30- L 40 7 • : 50 - w • :. 70 - : 80 •; » « 90 -. ' 100 ^ ....... SEDIMENT PREDICTIVE YIELD EQ: log (Y + IOO) -6.63792-2.13712 log (X.-HOO) 4.0.06284log{X2l-IOO)-O.OI6l6 log(Xj-flOO) 4-0.04073 log(X44-IOO Equation by E. M. Floimon, US. DA. Soil Conservation Service 22/ fctAMVMnrnnk hu W Lit QiviUK 1 1 C Pt A CAI! P /*ne*runt inn C.Aruix<* t •»if i Figure 38. Sediment Predictive rwld. [8] Tab!* 25. Sodlmtjnt Y!«Id Computation thing tit* PSIAC M»fhod. [24] Sedtaent Yield 43 C B t B « itSTU STOfACt CF.Ol.OGY SOILS CtlMATE IIUNOrr TOPOGRAPHY GROUND COV»» ^Allp MW Sigh e* Moderate *e low (10). •lan«l 104 eilt- etonae. ,<s)..., ... a. fcocki of Md&uH kurdntAfi b. Hodentely v«*thtr*d c. Moderately frac- tured (0) A. Meael**, hard f«rMtiaae ho) eallne-elk«lin«; high •hrlnk-etfell cturacte{tetlc«. b. Sin(l« |r*ta lilts •nd tin* sende <S) • . Hediuei textured •oil b. Occeeionei rock fr*p»«nt« c- Caliche layere (0) A. High perceatttge of rack frA4»*ftt* •». Aggregated Clays c. ilgh IK »rgt«ie aietter (10) with ehort periods of intenie r*ln- Ull. b. Frequent intense convcctlve etonu c. ?rt«t*-th«w (5) «. Starve of «od«T- *t< duration and lnt«niity fa. InfrcquenS con- vcctlv* «tor*» - (0) 4. HimU clUut* with KAlaftll of lowUt «••!(? b. rr«cl«tt«tl«a U C«rm •( i»«w c. Arid cliMta, l« latMuLty ttenM 4. Art 4 tll**t«; »r« (10) p«r unit «r«i fc. Large volUM of(low |>*r unit ar«* (i) a. Had«r«t« p«*kflows b. Hod*rat* voituM of Clow per unit »!•*« (0)*. low peek flow* •«r unit arc* b. Lew volua* e{ ^ nMeff y«r tMit are* c. t*r* ruM><f wre»t* (20)a. fttaep up i end «lop*e{In ixcece of 301) High relief; littleor no Cloodpletn development (10i " ' e. Moderate uplandslopee (leee th*c • 202) b. Hod«rate fen or HoodpleJ.fi d*v*loB-IMtlt (0)a. Gentle upland•lop* a (l*e* thaft»» , k. (>t«MtM tlluvUl »Ulm UO) Ground covtr do«« noc CKCutd 20t •. V«t«catlon aptr««j llccla or no lltt«r b. No rock in «urf»c«coil. (i>y -" •" Cover not «ac«>d- • t»| MX a. Notic«*bl« litt«r b. 1C Kraft* prevent undcretory not v*ll developed (-10) ». Area completely •tetlott, roch Creaewata, Ittter Little orrortualt; f*l rainfall t* reach er*di»le •atettai (10) ». Mora than SOS cultivated b. Maoat all o« area intensively |ra«ed c. All ol area re- cently burned (0) a. Laie than 25S culttvet«d ta. SOX or leee r«- ceatly loued c. Leae then SOI .lo- Keneively grated 4. Ordinary road and 1-10} a. No cultivation t. H« recent loggia* c. Lo« Intaaalty «rail*« _, IffUmpOHCT ,(25) a. Mora than SOX a(the area char-acterized by r&ll and gully orlandalld« arooioc 1 hoi " a. Atone 251 at thearea character- ised Iby till a>4 |uUy or land-slide eroalon b. Hind aroalon ulth dapotAtioa in• treali chanaels (0) a. Ha afvarens ai^aa ol ftraalva. ciAwn. nosiM &ft^imm .Tuiiuan a. Erodlni banka coffl- tlnuoualy or atfrequent intervale vlth large depthe andlong flow duration b. Active headcuta e»4 degradation in trib-utary cKannale «. Itoderata ilov aeptka.•*dlu» fl» duratla* with occae loyallyending banka ar a«« (0) a. Vide afcalim clueMla •dth flat gradleaM. akort <U« doratiani b. CtkaalMlfl &« na*«4Mi rack. Ur«e in. men •« wit »«a)itae,ed e. ArtillctaUf a«a«mu<i*e«.ll» ii trtcinc mta micAtt *AUU to H A»ion Arrwnun aujuctuiificf.im nuii Ltrttts a. k. c, aiif* TO imcrcmat cmuucmuticj T* wici ruu. VALM NAT ai ir omiEKi 80 UBICATU. irrtxntATMM MTMTJI iw ) tosiaun neu Liratl Hat M NAM. !• newt laeuacaa ilgh Taluaa Cer tlw 4 Sbfough G iactan earnipo*d to high valuta (or th« • end/or 1 factare. FSUC la «• «bkr«viatto» (ar tlw facUlt Sauthuatt l«tetag«acy Coamittee. tulag R'S^JI, >100 75 - 100 50 - M 25-50 0-25 Tafcla Sadiemte Slald ftf/ee.ni. 3.01.0 - J.O 9.5 - 1.0 0.2 - 0.5 <0.2 All MAMTLg 01 THE USE Of 4 «ac«rah«d of IS *o,uara cttaracter&atlea aad cadi yaetora «, Surface gaoHagy» sou* C CllMta 9 tiataff C Topography P Ground c*ver G Land uaeH Upland •natac t Channel eroaioa mie total racing at tt THE iASUC OUU 18 A8 »OLLa«»i •lla« (• wntern E»l»t»l* kaa cka gnHntnyi naeit ylald lev«l»! S«dl^a*:t Ylald Levei Saflar HarijM ai»al«a ' U Caally 41an«r«<> "!»*> eAttak- awnli ckAract*fflatica M Infra^ienir ca«««ettv« sMnSo (m«4«-thtB« «cc«rtaae« 9High »*ak. flxM; le* ml«aaM S Moderate alop*a &B Sparae, little or i>« ilttas 1C lAtaoaiml; graced &A Nora t)>». 50 « till «*4 oily erMion 28Occaii»«iUy er.dlog baaka «M| bed bt»t ahatt How do ratio* 5_ ravld tnjlote that the eajlau* »1*14 t* h«tw«en 1.0 end 1.0 Af/ee,.«i. baaed on Utlng Table.OaBananiaiMaBaaEBn^n^an; •^P88 f\a> H1 oa IVSF' •»^i*^W;fl**tflf'^i»-^'*^fl;»i+.^.~*.^ i-^,^,,^,, pr^^.^. •ifcl<1 -".ft A-33 13,000 .04 .03 .02 J . .3 .3 A .9 .6 .7 4 .» I. 2 6CPTH OF FLOW (d) IN FEET k Meyer-Peter end Muller Equation: ij,-1.606 [|.306 n,, f,, 9. 6. 7. a. ft 10. COMPUTER ANALYSIS AND | 5 CHART BY PERRY Y. AMIMOTO rdS-Oj627D~l* DIVISION OF MINES AND GEOUJGT 20. Figure 43. Meyer-Peter end Muller Method. IHEfERENCES REFERENCES 1 • HYDROLOGY REPORT FOR AGUA _HEpIO_NDA CREEK, DECEMBER 1976, County of San Diego, Department of Sanitation and Flood Control. 2. HYDROLOGY REPORT FOR BUENA VISTA CREEK, DECEMBER 1976, County of San Diego, Department of Sanitation and Flood Control. 3. FLOODPLAIN INFORMATION, BUENA VISTA CREEK Department of the Army, Los Angeles District, Corps of Engineers, Los Angeless California, July 1973. 4. FLQQDPLAIN INFORMATION, SAN MARCOS CREEK Corps of Engineers, U.S. Army, Los Angeles District, California, April 1971 5. MASTER DRAINAGE PLAN, CITY OF CARLSBAD Shuirman and Simpson, Civil Engineers, Newport Beach, California, April 1971 6. COMPREHENSIVE PLAN FOR FLOOD CONTROL AND DRAINAGE - ZONE 1 SAN DIEGO COUNTY FLOOD CONTROL DISTRICT, Koebig, Inc., July 1976. 7. DESIGN AND PROCEDURE MANUAL. SAN DIEGO COUNTY FLOOD CONTROL DISTRICT, DECEMBER 1969, REVISED 1976 8. EROSION AND SEDIMENT CONTROL HANDBOOK DEPARTMENT OF CONSERVATION RESOURCES AGENCY, STATE OF CALIFORNIA, EPA 440/3-78003, MAY 1978. 9. SUBDIVISION MAP ACT, CALIFORNIA COUNCIL OF CIVIL ENGINEERS AND LAND SURVEYORS, JANUARY 1979 10. GENERAL PLAN OF THE CITY OF CARLSBAD, CALIFORNIA, 1977 11. BENEFIT CHARGE STUDY - SAN DIEGO COUNTY FLOOD CONTROL DISTRICT ZONES 1, 2, 3, 4S and 5, PREPARED BY STONE & YOUNGBERG MUNICIPAL FINANCING CONSULTANTS, INC. LOS ANGELES, 1976 p.ATES