Loading...
HomeMy WebLinkAboutCT 88-03; Encinitas Creek Master Drainage Plan Zn 11,12,23; Encinitas Creek Master Drainage Plan Zn 11,12,23; 1988-07-28«l m m m m cr 85-03-( ENCINITAS CREEK MASTER DRAINAGE PLAN CITY OP CARLSBAD ZONES 11, 12, AND 23 VOLUME "A»« July 28, 1988 Job Number 10554A m m •I 4rt Of Cl J Oeimis C. Bowliiigs^M, RCE 32838; EXP. 6, RICK ENGINEERING COUPANY WATER RESOURCES DIVISION 5620 FRIARS ROAD SAN DIEGO, CA 92110 (619) 291-0707 TABLE OF CONTENTS VOLUME A M PAGE INTRODUCTION 1 BACKGROUND "* LOCATION BASIN DESCRIPTION " SCOPE OF WORK m MASTER PLAN DATA BASE 4 HYDROLOGIC METHODOLOGY AND DESCRIPTION 5 INTRODUCTION ^ RATIONAL METHOD CALCULATIONS RATIONAL METHOD RUNOFF COEFFICIENTS ^ HEC-1 MODEL HYDROLOGY REPORT HEC-2 HYDRAULIC ANALYSIS- ENCINITAS CREEK 9 * PREVIOUS COUNTY STUDY DATA BASE SUMMARY OF RESULTS- EXISTING CONDITIONS « RECOMMENDATIONS HEC-2 COMPARISON TABLE EXISTING DRAINAGE CONDITIONS 12 ADEQUACY OF EXISTING STORM DRAIN FACILITIES * RECOMMENDED DRAINAGE INFRASTRUCTURE IMPROVEMENTS 14 INTRODUCTION " DESIGN CRITERIA mm EL CAMINO REAL CULVERTS PRIORITY OF IMPROVEMENTS DRAINAGE FACILITY TABLES DESCRIPTION SUMMARY OF PRELIMINARY FACILITIES COST ESTIMATES BY * PRIORITY 17 DRAINAGE FACILITY TABLES INDEX 18 PRELIMINARY COST ESTIMATES 27 - INTRODUCTION SUMMARY OF UNIT PRICES USED 28 - PRELIMINARY COST ESTIMATE TABLES INDEX 2 9 ^ REFERENCES 42 - VOLUME B APPENDICES mm APPENDIX 1- RATIONAL METHOD CALCULATIONS mm m APPENDIX 2- HEC-2 MODEL COMPUTER OUTPUT- EXISTING CONDITIONS - APPENDIX 3- HEC-2 MODEL COMPUTER OUTPUT- PROPOSED CONDITIONS m f^^-^. f^.. f INTRODUCTION BACKGROUND This report describes the Drainage Master Plan for the Encinitas Creek watershed within the City of Carlsbad, San Diego County, California. The report identifies the hydrologic criteria used for analysis and design of the drainage infrastructure of the watershed, the data base used in the analysis, the effects of the development in the watershed on flood peaks, and the drainage network to be used to convey the predicted flood peaks within the watershed. The Drainage Master Plan is developed to provide preliminary design information on the drainage conveyance network of the Encinitas Creek watershed. It is engineered following the guidelines and regulations within the City of Carlsbad Standard Design Criteria Manual, Section 5.7 of the San Diego County Standards, and the San Diego County Flood Control District Design and Procedure Manual and Hydrology Manual. It is prepared to fulfill the requirements by the City of Carlsbad for a Drainage Master Plan for the Encinitas Creek watershed area affecting planning Zones 11, 12, and 23. The Drainage Master Plan is intended to provide a guideline for design of storm drainage improvements for the area. The Plan addresses storm drains greater than or equal to thirty (30") inch diameter pipe size. Storm drain collection systems including inlets, and storm drains less than thirty (30") inches in size will be provided as part of the individual developments and projects within the watershed. Capacities of existing systems and sizing of proposed improvements where needed to convey the design flows are based upon approximate methods and engineering judgment. Final design of any storm drain or open channel system should be performed by a qualified engineer. LOCATION The Encinitas Creek watershed area is located within the south portion of the city of Carlsbad, in north San Diego County, California (Vicinity Map). The watershed area studied is bounded by Olivenhain Road on the south. The watershed is traversed by El Camino Real in its western portion, and Rancho Santa Fe Road in its eastern portion. La Costa Avenue and the Batiquitos Lagoon lie at the north discharge point of the basin. BASIN DESCRIPTION The Encinitas Creek watershed is approximately 5 miles long and approximately 7.3 square miles in size at its discharge point to Batiquitos Lagoon. This study covers the northerly portion of the watershed which is within the City of Carlsbad. The study area is approximately 4.4 square miles in size. tl II II ki II li li il il lit 11 IJ fci fel fti tl ti il ij ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD: JULY, 1988 VICINITY MAP RICK ENGINEERING COMMNY CIVIL ENGINEERS : PLANNING CONSULTANTS : SURVEYORS 5620 FRIARS ROAD SAN DIEQO. CALIFORNIA 92110 C619) 291 0707 3088 PIO PICO DRIVE CARLSBAD. CALIFORNIA 92008 t619] 729-4987 365 S. RANCHO SANTA FE RD. SAN MARCOS. CA. 92069 (619) 744-4600 m m The upper portion of the study area consists of two tributaries which join at the intersection of Rancho Santa Fe Road and Olivenhain Road. Encinitas Creek flows westerly from this confluence on the south side of Olivenhain Road within the City of Encinitas to El Camino Real. The creek flows northerly from Olivenhain Road within the City of Carlsbad along the west side of El Camino Real to La Costa Avenue and Baticjuitos Lagoon. The lower portion of the study area drains to Encinitas Creek through natural swales or road culverts. Current land use in the study area includes single and multiple family residential, parks, and undeveloped land. Future land use plans in the study area include low and medium density single family residential, multiple family residential, commercial developments, industrial developments, schools, open space and a golf course. Soils in the study area are predominately Hydrologic Soil Group "D" but also include areas of Groups "A", "B", and "C". m Vegetation on the undeveloped areas east of El Camino Real in the study area is mostly native grasses which has been used for range * land. Ground cover on the hillsides is typically broadleaf chaparral. A portion of the area west of El Camino Real is currently used for farm land. The Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (FIRM) Panel Number 060284 1050C for the County of San Diego (June 15, 1984) and FIRM Panel Number 060285 0015C for the City of Carlsbad (August 15, 1983) show areas of Zone "A" floodplain in the study area. The Zone "A" areas are shown for Encinitas Creek, the easterly tributary of the creek along the east side of Rancho Santa Fe Road and the tributary east of El Camino Real between Levante Street and Olivenhain Road. SCOPE OF WORK This study addresses the following major topics related to the drainage infrastructure: 1. Calculate lOO-year design discharges for developed land use conditions. 2. Evaluate the adequacy of existing drainage facilities to safely convey the design flows. 3. Describe the drainage improvements recommended in the watershed study area to correct existing system inadequacies and provide an adequate backbone drainage system for future development. 4. Provide preliminary construction costs for recommended improvements. 5. Analyze the hydraulic conditions in Encinitas Creek west of El Camino Real from Olivenhain Road north to La Costa Avenue. m The analysis uses current topographic information and design flows based on future land use. The following sub-basins tributary to Encinitas Creek are covered in this study (see Plate A) : •m * The Calle Barcelona Basin which drains westerly to an H existing Dual 5' X 6' Reinforced Concrete Box culvert under El Camino Real. M ^ * The Green Valley Basin which is west of El Camino Real and drains directly into Encinitas Creek within several natural ^ swales. * * The Olivenhain Road Basin which drains under Olivenhain Road towards Encinitas Creek through several road culverts. 4 * The Levante Street Basin which drains westerly to an existing sixty (60") inch CM.P. under El Camino Real. m * The Upper Encinitas Creek Tributary Basin which is mostly east of Rancho Santa Fe Road and drains into two existing detention basins constructed with the Vista Santa Fe development. An existing dual 4' X 9.3' Reinforced Concrete « Box culvert under Rancho Santa Fe Road is the watershed discharge point. m ^ * The Upper Encinitas Creek Basin which drains to an existing dual 4' X 10' Concrete Box Culvert under Rancho ^ Santa Fe Road. *• The lower portion of the Encinitas Creek watershed which is within the City of Encinitas is not addressed in detail by this study. The design flows for the major drainage courses which ^ were calculated using the HEC-1 hydrologic model account for the entire watershed. The HEC-1 analysis is described in a separate — HEC-1 report (Rick Engineering Company, July 1988) submitted to the City of Carlsbad. [ Lagoon \ \ \ \ - • \ \ IT \ _>»-•. •. '\ -•.\:.-\ pL WER ENCINITAS CREE 3NB\H wiTHtf^ Grrr-OF llHIS -7 / o CO o CO o CJ UJ -J II Ul < o < CO o -Ui< >- z o PA 1-07 s 1-07 o a> CM o 0> o z S Q g Ul < CM Ul O z cr < NGI ARS o m. o Ui cc U-UJ Q o o CJ (£> z MM o CJ (£> < to to PLATE HASTER PLAN DATA BASE Topographic information for development of the Encinitas Creek Drainage Master Plan was derived from the current County of San Diego 2 00 scale Orthophoto Topographic Survey maps for the area. These maps were supplemented by the USGS Quadrangle maps and a detailed field investigation. Existing drainage facilities in the watershed area were identified using as-built storm drain plans obtained from the City of Carlsbad's files and engineering consultants. Existing facility discharge points and sizes were verified by field reconnaissance. Existing flow characteristics and problem areas were also noted by field investigation. Developed land use for the Encinitas Creek watershed area in the City of Carlsbad was obtained from the latest General Plan Map (April 1987). Soil characteristics were identified using the Soil Conservation Service's Soil Survey for the San Diego Area, California (1973). Rainfall information for use in this study was obtained from the San Diego County Hydrology Manual. The 100-year frequency, 6-hour duration design storm was used. The San Diego County "Hydrology Report for Encinitas Creek" was used to identify major drainage basins and discharge points. The County flood plain mapping and accompanying HEC-2 computer runs for Encinitas Creek were used as a baseline for hydraulic analysis. The U.S. Army Corps of Engineers report "Floodplain Information report for San Marcos Creek" (1971) was used for downstream hydraulic control in the lOO-year storm event. m m HYDROLOGIC METHODOLOGY AND DESCRIPTION INTRODUCTION Hydrologic calculations for the major design points within the watershed were completed using the HEC-1 Model computer program. The results of the HEC-1 analysis for the Encinitas Creek watershed are used for design of the major drainage facilities. The HEC-1 Model analysis prepared for this study is discussed in a separate report submitted to the City of Carlsbad (Rick Engineering Company, July 1988). Hydrologic calculations for design of minor drainage facilities with tributary areas of less than approximately 0.5 square mile were completed using the Rational Method. m RATIONAL METHOD CALCULATIONS Rational Method calculations performed for this report are shown in Appendix 1 of Master Plan, Volume "B". The Rational Methcxi runoff coefficients used assume developed conditions based upon the City of Carlsbad General Plan and previously submitted planning studies for the area. The Rational Method runoff coefficients from the County "of San Diego Hydrology Manual are shown on page 7 of this report. The lOO-year design storm was used in the calculations. The County of San Diego Intensity Duration design chart is shown following page 7 of this report. The results of the Rational Method analysis were used for preliminary design of the recommended drainage facilities with a tributary area of less than approximately 0,5 square mile. The Rational Method calculations for the lOO-year storm were performed using a Rational Method program. This program is a computer aided design program where the user develops a node-link model of the watershed. The program can estimate the conduit and channel sizes needed to accommodate the design storm discharge. The node-link model is developed by creating independent node-link models of each interior sub-basin and linking these sub-models together at confluence points. The program allows up to five streams to be confluenced at each node. The program has capability to perform calculations for eight hydrologic processes. These processes are assigned code numbers which appear in the printed results. The code numbers and their significance are as follows: CODE 1: Confluence analysis at a node CODE 2; Initial sub-area analysis CODE 3: Pipeflow travel time (computer estimated pipe size) CODE 4: Pipeflow travel time (user specified pipe size) CODE 5: Trapezoidal channel travel time CODE 6: Street flow analysis through a sub-area CODE 7: User specified information at a node CODE 8: Addition of sub-area runoff to main line m RATIONAL METHOD RUNOFF COEFFICIENTS LAND USE COEFFICIENT. C Soil Group mm m Residential: A B C D mm Single Family .40 .45 .50 .55 mm Multi-units ,45 .50 .60 .70 mm Mobile homes .45 .50 .55 .65 m Rural (lots greater than 1/2 acre) .30 . 35 .40 .45 mm mt Commercial 80% impervious .70 .75 .80 .85 m Industrial ,80 .85 .90 .95 90% impervious Source: San Diego County Hydrology Manual RATIONAL METHOD RAINFALL INTENSITY DURATION CURVE QC O X CO UJ X u CO z UJ <0 UJ X o I- o UJ Q: CL oc O iO 15 20 MINUTES DURATION HEC-1 MODEL HYDROLOGY REPORT The U.S. Army Corps of Engineers HEC-1 flood hydrograph program was used for the hydrologic analysis at the major design points in the Encinitas Creek watershed. The development of the HEC-1 Model and a summary of the results of the analysis are discussed the previously mentioned report submitted to the City of Carlsbad (Rick Engineering Company, 1988). The recommended values from the HEC-1 report account for the effects of the existing detention basins in the Vista Santa Fe development on the 100-year flood hydrograph. The recommended HEC-1 Model peak flows are used in the hydraulic analysis of Encinitas Creek. The HEC-1 design flows are also used for evaluation of existing major drainage facilities at the design points in the model and preliminary sizing of any facilities found to be inadequate. Ml m HEC-2 HYDRAULIC ANALYSIS- ENCINITAS CREEK PREVIOUS COUNTY STUDY The previous County of San Diego HEC-2 computer analysis for Encinitas Creek was completed in 1981, The study was completed for several reaches of the creek and tributaries. The County study includes the reach west of El Camino Real which is of interest in this study. The County HEC-2 study uses the design flows from the County of San Diego Hydrology Report for Encinitas Creek (1980), A field topography check completed in June 1988 as part of this study showed substantial variations in the Encinitas Creek geometry and invert elevation between the County HEC-2 study and existing conditions. The invert of the creek has been filled with a substantial amount of silt which causes concern about the 100-year water surface in the creek relative to the El Camino Real roadway. The lOO-year water surface in the creek must also be considered in the analysis of the capacity of the existing crossings under El Camino Real, A revised HEC-2 analysis was completed for this study to evaluate the effects of the changes in the creek's geometry and invert on the lOO-year water surface elevation. The HEC-2 study reach is the 1,5-mile reach of Encinitas Creek in the City of Carlsbad which is on the west side of El Camino Real and flows northerly from Olivenhain Road to the Batiquitos Lagoon at La Costa Avenue, DATA BASE The input data for the revised HEC-2 analysis of the creek is based on current topography and developed land use design flows. The cross section locations used in the HEC-2 analysis are the same as in the San Diego County analysis. The Manning "n" roughness values used for the creek are also from the County analysis. Additional cross sections were added between the County sections when additional detail was needed. The starting water surface for the HEC-2 analysis downstream of La Costa Avenue in the Batiquitos Lagoon was derived from the U.S. Army Corps of Engineers report "Flood Plain Information San Marcos Creek" (USACOE, 1971). This report shows the lOO-year water surface in the lagoon from the ocean upstream to the discharge point of San Marcos Creek. The water surface in Batiquitos Lagoon downstream of San Marcos Creek is the downstream control of Encinitas Creek at its discharge point into the lagoon. The cross sections used in the analysis are derived photogrammetrically from aerial photography dated May 3, 1988. The accuracy of the digitized cross sections exceeds FEMA standards. The cross section end point coordinates were ^ digitized from the County Floodplain Maps for Encinitas Creek to accurately reproduce the section locations. The cross section of m the bridge at La Costa Avenue was measured in the field. The lOO-year design flows were taken from the HEC-1 Model ^ hydrologic analysis described in a separate report (Rick Engineering Company, 1988). ** SUMMARY OF RESULTS- EXISTING CONDITIONS m The HEC-2 computer model output for Encinitas Creek for the lOO-year storm under existing conditions is shown in Appendix 2 m of Master Plan, Volume "B". « The analysis of the existing creek shows that the existing triple 8' X 12' R.C.B. crossing at La Costa Avenue is inadequate for the * design flows given the existing headwater available on the La ^ Costa Avenue and El Camino Real roadways near the culvert, m The HEC-2 analysis of the existing conditions also shows that the lOO-year water surface in Encinitas Creek is below the El Camino Ml Real roadway for the study reach except near the Olivenhain Road intersection. The backwater caused by the silt downstream of the El Camino Real culvert near Olivenhain Road results in the flooding of the roadway in this area. The capacity of the El Camino Real culvert also is impacted by the creek backwater. The results of the HEC-2 hydraulic analysis of Encinitas Creek under existing conditions are summarized in the HEC-2 Comparison Table on page 11 of this report. RECOMMENDATIONS The following improvements are recommended to mitigate the existing inadequacies in Encinitas Creek from La Costa Avenue to Olivenhain Road: * Improve the existing triple 8' X 12' Reinforced Concrete Box (R,C.B,) under La Costa Avenue. We recommend adding an additional dual 8' X 12' R.C.B. and adding a berm along La Costa Avenue and El Camino Real to increase the available headwater at the culvert. The top of berm is proposed to elevation 19.7 (the top of the bridge above the culverts is at elevation 20.8) to provide 0,5 foot of freeboard. * Improve the existing Encinitas Creek channel immediately downstream of the El Camino Real culvert near Olivenhain Road. The proposed improvements consist of an 1100-foot long trapezoidal channel which is 100 feet wide on the main part of the creek and 50 feet wide on the creek directly downstream of the culvert. The trapezoidal channel depth is proposed to vary from approximately 3 feet to 5 feet. The HEC-2 computer model output for the lOO-year storm with the proposed improvements in place is shown in Appendix 3 of Master Plan Volume B. The results of the HEC-2 analysis considering the 10 recommended improvements are shown in the HEC-2 Comparison Table below. The results of the recommended improvements analysis are also compared to the edge of pavement elevation on the El Camino Real roadway and the available freeboard height is shown. HEC-2 COMPARISON TABLE Comparison of lOO-year Water Surface in Encinitas Creek between San Diego County (1981) and Rick Engineering Company (1988) HEC-2 Runs (values in feet) m Section 100-yr, 100-year 100-year Approx, Freeboard No. WSEL WSEL (REC) WSEL (REC) Rd, edge To Road- m County Existing Proposed Elev, Prop . run mm m 0.098 18,2 19.6 19.2 20.1 dri . 1. 2 0.129 18. 0 19,8 19.5 25.3 - . '5,9 -mi 0.202 27.2 28,7 28.8 42,4 r3T6 0. 310 36.5 38,7 38.7 50.1 11.4 -Hi 0.451 44 ,7 45.4 45.4 58.3 12.9 0,522 46.4 48.2 48,2 56.3 8.1 0.615 50.5 51.9 51,9 69.1 17.2 m 0.678 55, 5 55.2 55,2 78.6 23.4 0.780 59.8 60.1 60,1 80.0 19,9 mm 0.834 62, 0 62.3 62. 3 74 ,4 12.1 m 0.918 63.4 65,2 65.2 66,6 1,4 0.998 64.9 66. 6 66.6 69, 6 3.0 mm 1.096 67.5 67.6 67,6 79.2 11.6 1.164 69.3 69.4 69,4 85.7 16.3 m 1.236 72.0 76.5 72.4 89.6 17.2 1. 313 74 ,0 78,4 74.9 83.6 8.7 1. 365 — 81.4 76.9 80.2 3 , 3 11 EXISTING DRAINAGE CONDITIONS - ADEQUACY OF EXISTING STORM DRAIN FACILITIES The existing storm drain and culvert facilities were evaluated ^ for their adequacy for the lOO-year design flows. The capacity of the facilities was based upon approximate methods and ^ engineering judgment. The existing culvert capacities were based upon inlet control unless specific downstream control was known. * The only instance where downstream control is known to be significant is west of El Camino Real in Encinitas Creek. Ml m The existing storm drain facilities within the watershed study area are, in general, adequate to convey the lOO-year design -m storm. Most of the development in the basin has occurred recently and the drainage facilities associated with the '* developments were adequately designed. *" Some of the existing road culverts constructed with the major « roadways were found to be inadequate for the lOO-year design flows. Some of these culverts may have been sized for historic « flows rather than developed flows. * The following existing road crossings were found to be inadequate ^ for the lOO-year design flows: * 1. The bridge crossing of Encinitas Creek at El Camino Real is silted and will not pass the design flow without over-topping the roadway. m 2. The existing 60" CM.P. under El Camino Real north of Levante — Street is inadequate for the lOO-year design flow. •** 3. The existing 24" R, C P. under El Camino Real north of ^ Olivenhain is inadequate for future developed flows. « 4. The existing dual 24" C.M.P under Olivenhain Road is inadequate for the lOO-year design flow, •ivta 5. The existing dual 4' X 10' Concrete Box Culvert crossing of Encinitas Creek under Rancho Santa Fe Road is inadequate for the ^ lOO-year design flow. * 6. The existing triple 8' X 12' R.C.B. culvert under La Costa Avenue is inadequate for the design flow due to the limited available headwater on the roadways. m Several of the existing road culverts have collected silt which m reduces their capacity. The existing silt volume in the majority of the culverts will be flushed out during any major storm. As * the remainder of the watershed is developed, smaller volumes of silt will be delivered to the culverts and the future problems should be minimized. 12 Two of the existing major crossings which are presently silted will require special attention during final design to minimize the effects of the existing silt on the facility capacity. The crossings affected are: 1. The Encinitas Creek crossing of El Camino Real south of •M Olivenhain Road which is almost entirely filled with silt. The downstream creek bed has also collected silt. Ml 2, The dual 5' X 6' Concrete Box Culvert under El Camino Real near the proposed Calle Barcelona intersection (Facility Number ^ 11) is silted about 2'. Downstream silt conditions in Encinitas Creek cause the culvert to collect silt. MW The preliminary design for these crossings are discussed in the "Recommended Drainage Infrastructure Improvements" section of ^ this report. 13 RECOMMENDED DRAINAGE INFRASTRUCTURE IMPROVEMENTS INTRODUCTION The recommended facility improvements for the Encinitas Creek watershed area in the City of Carlsbad is intended to provide a guideline for design of the storm drainage infrastructure for the area. The analysis addresses storm drains greater than or equal to thirty (30") inch diameter pipe size. Storm drain collection systems including inlets, and storm drains less than thirty (30") inches in size will be provided as part of the individual developments and projects within the watershed. Sizing of the recommended facilities are based upon approximate methods and engineering judgment. Final design of any storm drain or open channel should be performed by a qualified engineer. The existing and recommended drainage facilities are tabulated in the Drainage Facility Tables beginning on page 18 of this report. The location of the drainage facilities referenced in the tables are shown on Plates B and C following the tables. DESIGN CRITERIA The lOO-year frequency storm was used as the basis for design of the recommended improvements in the watershed, Hydrologic methodology is discussed in the "Hydrologic Methodology and Description" section of this report. Closed conduits are recommended in most cases for systems fourty-eight (48") inches or less. Closed conduits larger than 48-inch are used if a channel is impractical in the reach. Storm drains are designed to connect into existing systems found adequate for the ultimate capacity as defined by this study. Reinforced concrete pipe (R,CP.) is assumed for closed conduit design. For road crossings, either R.C.P. or reinforced concrete box culverts are used, R.C.P. sizes from 3 0-inch to 78-inch diameter in increments of 6-inches are used in the study. A Manning's roughness coefficient (n value) of 0.012 is used for R.C.P. storm drain design. Pipe slopes are based on the existing ground slope where applicable with a minimum gradient of 0,5 percent. Box culvert sizing is based on a minimum 3 foot height for ease of maintenance. Height sizing is based on one foot vertical increments and width on two foot horizontal increments. A Manning's roughness coefficient of 0.014 is used for design. Where existing pipes were found to be inadequate, they were assumed removed if metal and removed or paralleled depending on the situation for concrete pipes. 14 mt Floodplain management including natural channels and vegetation lined graded channels is used for open channel reaches of the drainage system in lieu of lined channels. Natural channels which are narrowed to accommodate development and graded channels will be designed to meet allowable velocity criteria. The finished floor of structures shall be built a minimum of one foot above the lOO-year water surface in the channel. All channels shall be in compliance with current flood plain criteria. EL CAMINO REAL CULVERTS ^ Desilting basins are recommended at the upstream side of the two culverts under El Camino Real draining towards Encinitas Creek ^ These culverts have collected a significant amount of silt. We also recommend that the culverts be cleaned out and the creek downstream of the culverts be dredged to provide positive outflow for the culverts under all flow conditions. Ml M We propose to clean out the dual 5' X 6' R.C.B, under El Camino Real near the proposed Calle Barcelona Intersection to its « invert. It is also recommended that a 15-foot wide trapezoidal channel be constructed from the culvert invert draining to the * creek flowline to provide an outfall. The depth of excavation needed to implement this recommended solution is approximately 2 feet to 3 feet. m We propose to lower the invert of the existing bridge under El Camino Real south of Olivenhain Road to provide adequate capacity and positive drainage. The invert is proposed to be lowered to elevation 72 at the downstream side of the bridge from the _ existing invert elevation of approximately 75. The..proposed channel improvement downstream of the bridge is discussed in the -* "HEC-2 Hydraulic Analysis - Encinitas Creek" section of this report. „ The land for the desilting basin at the dual 5' X 6' R.C.B. is a part of the development upstream and is zoned as open space. The — land upstream of the bridge crossing south of Olivenhain Road is within the City of Encinitas and will need to be coordinated with Encinitas. The land acquisition cost is not included in the ^ preliminary cost estimates. m The proposed desilting basins and channel dredging should solve the problem since the upstream drainage areas are being developed •m and silt volumes delivered to the culverts will be reduced in the future under developed conditions. The proposed solutions to the silt problem in the culverts will, however, need to monitored periodically after completion to insure that the design is maintained. m 15 m Ml PRIORITY OF IMPROVEMENTS The recommended improvements as outlined in this Plan have been given a priority rating in the Drainage Facilities Tables. The ratings vary from 1 as the highest priority to 3 as the lowest priority. Criteria for determining the ratings are: 1. Improvement is needed due to an endangerment to life or public health and safety. 2. Improvement is needed to mitigate potential damage to existing property or structures. 3. Improvements will be needed to protect future development. A summary of the total cost of improvements broken out by priority rating is shown on page 17. Refer to the cost estimate portion of this study for total cost of improvements in each study sub-basin, DRAINAGE FACILITY TABLE DESCRIPTION The existing and recommended drainage facilities in the Encinitas Creek watershed study area are shown on the Drainage Facility Tables. These tables iist preliminary facility location, tributary drainage area, size, length, capacity, lOO-year design flow and recommended improvements (where applicable), The location of the drainage facilities are shown on Plates B and C included with the tables. Confluence points of storm drains shown on the plates are approximate. Location and size of inlets and lateral storm drains smaller than 30 inch diameter pipe size will be designed and provided as part of the individual developments within the watershed. Conveyance of flow in streets was neglected for preliminary design of storm drains. In final design, street conveyance capacity should be considered in the analysis. 16 SUMMARY OF PRELIMINARY FACILITIES COST ESTIMATES BY PRIORITY (Thousands of Dollars) Prioritv Sub-basin Total Calle Barcelona (Zone 12) Green Valley (Zone 23) Levante Street (Zone 12) Upper Tributary to Encinitas Creek (Zone 12) Olivenhain Road (Zone 12) Upper Tributary to Encinitas Creek (Zone 11) Upper Encinitas Creek (Zone 11) Totals 5,3 413,5 66.7 165,4 343.9 347.2 875.3 719.4 229.7 25.5 880.6 1,132.9 66,7 229.7 190.9 3,010,1 3,010,7 669.2 1,360.3 994.8 347.2 5,529.2 6,871.2 17 DRAINAGE FACILITY TABLES INDEX PAGE Calle Barcelona Basin - Zone 12 19 Green Valley Basin - Zone 23 20 Levante Street Basin - Zone 12 21 Upper Encinitas Creek Tributary Basin - Zone 12 21 Olivenhain Road Basin - Zone 12 22 Upper Encinitas Creek Tributary Basin - Zone 11 23 Upper Encinitas Creek Basin - Zone 11 25 m m 18 I 8 51 5 ° LU < a CD UJ < ^ 0£ OC \U < < Of Ui Q: LU I- < l-S < 3 < 3 V) < Of LU < 3 4i o o X UJ 8 ^ NO ... m < 3 19 £ S 51 - • U KJ •- CO CD (rt ^ S o < ^ < Qf UJ 3 -1 O O O Irt z O — oe < o o oe 8 S in in O CO to -» o O CO O CO %o » CO < 3 20 51 i o o 1 a o. oc •- (NJ a. a. oe u < < u Of oe oe LU Ot UJ e>e ~ LU 3 _l 3 o > " 1-«t 1— < ~ IO _l < 3 < (M 3 (rt 2 (rt >» (NJ U 3: O 8 O tM O •- 21 UJ UJ > QC o 51 (rt 'Ji z £ UJ I S o CO -I UJ iD oc oc i/) Q LU UJ LU LU S > o O _l H 00 O O < cc o t— CJ (K :3 < (rt (— o: O > > -1 3 -J ER EA EA o oc oc z LU 3 O (rt o O z z z 1— 3 .... oc X LU < «t > u t LU u —1 o LU 3 z oe _J U LU lU u UJ 22 o o o II *• Ul < 00 00 "3 m 51 8: m LU Z o _i O u. z (rt z z (rt O (rt (J lU *-< z. o •s CD >-z LU EK *— ta RE o u z u a. z »— CJ «t ^ o lU CJ Q: CJ X t— • LU >-».* X F-z UJ -J LJ Z Z u LU IE o < >— .—. u. o 1— t— z •—I >-LU a AR RY NO z < (J 1— z 3 CO X _) o LU oe oc t— QC 1-o. lu UJ oe < li. PPE «r UJ 3 ,GE oe < tr. OC UJ < 3 o 3 z O z oe u. Kl = ro i ° O I-M 0> O O (M CM o o (M N in > o o (M ro (M fM fM 1- fM (NJ fM fM (M (M O ro f\j Kl •-•I- (M (M fM 23 LU O (rt ^ Kl o (^ z X LU -(- >t X I tu fM 3 ^ i o U. UJ o > o < 3 -J ^ 3 Q. >-u oe oc LU > 3 ~l LU oe LU O < z z O t- O ne 3 < UJ (rt QC u. O 2 a (J < z o < o: >->->->-oe >-oe u < o: < oe LW oe < z < «t < u. u. < t— oe (J z (J t— (rt UJ t— O t— 3 LU (rt z 3 o z 3 oe o 3 3 < 3 CO > lrt < CD < CO lU u z CD »— 1— CD _• O 1— Ml a UJ •.^ (rt Z oe 3 oe (rt OC (rt oe z < > oe < < OC t— CJ (J UJ X UJ 3 J < (— UJ (rt »— i ° -o ro (M IM (M (0 >o (M ro fM (M ^ in ro Kl (M <M ^ (M Kl Kl ry fM ^ CM ro ro fM ^ -* (M (M m in (M ru 24 51 fM fM Ml (rt 1 -I (J CJ CO «t < Li. t— >- z Of » < t-> z z — LU z z ^ — LU s ^ ^ (rt o LU < 2 u t; ^ * Z ^ UJ " UJ _J (J lU ^ g u lu z oe (rt lu <J z z ^ lu o: u LU O z oe z UJ (J CO — o ^ in in in in Kl in in 25 LU UJ 5j Ml m < u. lU u-Z O < »— g O Z z < (rt LU (rt » UJ (J (J LU Z z oe < UJ CJ oe 8 O Ni in ^ in m 1^ r>-o -.a m m 26 PRELIMINARY COST ESTIMATES «• INTRODUCTION ** The preliminary cost estimates used in this study were derived ^ from the City of San Diego Unit Prices for Checking Subdivisions and Permits (March 1, 1985), These unit prices are also ^ currently used for cost estimates in the City of Carlsbad. Costs are broken out by sub-basin in the Preliminary Cost Estimate • Tables which begin on page 29. The costs are given as unit prices in terms of linear feet (I.f.) , cubic yards (cy.) , or ^ each (ea.). The preliminary cost estimates are based on anticipated -M construction costs including materials and installation. The estimates include 10 percent contingency for possible relocation * of utilities and 2 0 percent contingency for engineering, ^ administration and legal expenses. « Proposed facility improvements are assumed to be constructed within public rights-of-way or easements. No additional cost is included for land or easement acquisition in the preliminary cost ^ estimates, ^ It should be recognized that actual construction costs may vary from the preliminary costs shown in this report. Possible reasons for construction cost variations include changes during final design, unforeseen field or soil conditions, variable costs of labor and materials, costs of traffic control, costs of street ^ or curb and gutter cuts, costs of landscaping replacement and/ or excess costs of utility relocation. Ml 27 SUMMARY OF UNIT PRICES USED (REF. CITY OF SAN DIEGO) Mi ITEM Culvert Culvert Culvert Culvert Culvert Culvert Culvert Culvert Culvert DESCRIPTION 30" R.C.P. 36" R.C.P. 42" R.CP, 48" R.CP, 54" R.C.P, 60" R.CP. 66" R.C.P. 72" R.C.P. 78" R.C.P, UNIT I.f. I.f, I.f, l,f. I.f, I.f. I.f. I.f. I.f. PRICE $80 $100 $120 $130 $150 $180 $190 $200 $220 •Ml Box culvert Box culvert Box culvert Box culvert 2- 4'X9.3' 2- 6'XIO' 2- 5'X6' 2- 8'X12' I.f I.f l,f I.f, $1,500 $1,650 $800 $2,350 Inlet Type "B" Cleanout Type "A" Headwall w/ wingwall R.C.P. Headwall w/ wingwall R.C.B. River dredging Export Berm construction Import Riprap dissipator Culverts Riprap @ u/s side Culverts Desilting basin Structure ea. ea. ea. ea. cy, cy. ea. ea. ea. $3,000 $3,000 $3,500 $4,500 $4 $7.5 $3,000 $1,000 $10,000 28 PRELIMINARY COST ESTIMATE TABLES INDEX PAGE 30 i. Calle Barcelona Basin - Zone 12 M Green Valley Basin - Zone 23 32 Levante Street Basin - Zone 12 34 Upper Encinitas Creek Tributary Basin - Zone 12 3 5 Olivenhain Road Basin - Zone 12 36 Upper Encinitas Creek Tributary Basin - Zone 11 37 Upper Encinitas Creek Basin - Zone 11 40 29 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES CALLE BARCELONA BASIN (ZONE 12) Page 1 of 2 m Facility Estimated Unit Facility m im Number Description Ouantitv Unit Cost Cost •m m 1 30" R.CP. 320 I.f. $80 $25,600 m 1 Cleanout 2 ea. $3,000 $6,000 2 Extend 36" R.CP 330 I.f. $100 $33,000 2 Cleanout 2 ea. $3,000 $6,000 M> 3 42" R.CP. 1,220 I.f. $120 $146,400 m 3 Cleanout 4 ea. $3,000 $12,000 m 3 Riprap dissipator 1 ea. $3,000 $3,000 m 4 48" R.C.P. 120 I.f, $130 $15,600 m 4 Headwall w/ wingwall 1 ea. $3,500 $3,500 4 Riprap @ u/s side 1 ea. $1,000 $1,000 Ml 4 Riprap dissipator 1 ea, $3,000 $3,000 5 30" R.CP, 800 I.f. $80 $64,000 5 Cleanout 4 ea. $3,000 $12,000 6 36" R.C.P. 350 I.f, $100 $35,000 6 Cleanout 2 ea, $3,000 $6,000 mm 6 Riprap dissipator 1 ea. $3,000 $3,000 -~ 7 36" R.C.P. 600 I.f, $100 $60,000 mm 7 Cleanout 3 ea. $3,000 $9,000 7 Riprap dissipator 1 ea. $3,000 $3,000 mm 8 30" R.C.P. 350 I.f. $80 $28,000 8 Cleanout . 2 ea. $3,000 $6,000 mt 9 36" R.CP. 300 I.f. $100 $30,000 m 9 Cleanout 2 ea. $3,000 $6,000 9 Riprap dissipator 1 ea, $3,000 $3,000 m» 9A Desilt basin struct. 1 ea. $10,000 $10,000 M« 10 2- 5'X6' R,C,B, 150 I.f. $800 $120,000 m 10 Headwall w/ wingwall 2 ea, $4,500 $9,000 10 Riprap @ u/s side 1 ea. $1,000 $1,000 10 Riprap dissipator 1 ea. $3,000 $3,000 «• 11 River dredging 1, 000 cy. $4 $4,000 30 Ml m ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES CALLE BARCELONA BASIN (ZONE 12) Page 2 of 2 31 ^ TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $667,100 M Contingencies including possible relocation of utilities @ 10% 66,710 TOTAL ESTIMATED CONSTRUCTION COST $733,810 Engineering, administration and legal expenses @ 20% $146,762 TOTAL ESTIMATED INSTALLATION COST $880,572 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES GREEN VALLEY BASIN (ZONE 23) WEST OF EL CAMINO REAL Page 1 of 2 411 Facility Number Estimated Description Quantity Unit Unit Cost Facility Cost mi 12 36" R.CP. 1, 000 I.f. $100 $100,000 Mi 12 Cleanout 5 ea. $3,000 $15,000 12 Riprap dissipator 1 ea. $3,000 $3,000 m 13 30" R.CP. 1, 000 I.f. $80 $80,000 m 13 Cleanout 5 ea. $3,000 $15,000 m 14 36" R.CP. 700 I.f. $100 $70,000 M 14 Cleanout 4 ea. $3,000 $12,000 m 14 Riprap dissipator 1 ea. $3,000 $3,000 m 15 30" R.CP. 900 I.f. $80 $72,000 15 Cleanout 4 ea. $3,000 $12,000 m 15 Riprap dissipator 1 ea. $3,000 $3,000 Ml 16 30" R.CP. 200 I.f. $80 $16,000 Ml 16 Cleanout 1 ea. $3,000 $3,000 Ml 17 36" R.CP. 300 I.f, $100 $30,000 mm 17 Cleanout 2 ea. $3,000 $6,000 NM 18 42" R.C.P. 750 I.f, $120 $90,000 imim 18 Cleanout 4 ea. $3,000 $12,000 18 Riprap dissipator 1 ea. $3,000 $3,000 ISA 2- 8'X12' R.CB. 125 I.f, $2,350 $293,750 18A Headwall w/ wingwall 2 ea. $4,500 $9,000 mm ISA Berm construction 1,400 cy. $7.5 $10,500 TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $858,250 Contingencies including possible relocation of utilities @ 10% $85,825 32 m m ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES GREEN VALLEY BASIN (ZONE.23) WEST OF EL CAMINO REAL Page 2 of 2 33 TOTAL ESTIMATED CONSTRUCTION COST $944,075 Engineering, administration and legal expenses @ 20% $188,815 TOTAL ESTIMATED INSTALLATION COST $1,132,890 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES LEVANTE STREET BASIN (ZONE 12) Page 1 of 1 Ml Facility Estimated Unit Facility Ml Number Descriotion Quantity Unit Cost Cost 21 72" R.CP, 160 I.f, $200 $32,000 m 21 Cleanout 1 ea. $3,000 $3,000 21 TYPE "B" INLET 3 ea. $3,000 $9,000 "Ml 21 Headwall w/ wingwall 1 ea. $3,500 $3,500 21 Riprap dissipator 1 ea. $3,000 $3,000 34 TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $50,500 Contingencies including possible relocation of utilities @ 10% $5,050 TOTAL ESTIMATED CONSTRUCTION COST $55,550 Engineering, administration and legal expenses !§ 20% $11,110 TOTAL ESTIMATED INSTALLATION COST $66,660 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES UPPER TRIBUTARY TO ENCINITAS CREEK BASIN (ZONE 12) Page 1 of 1 M Facility Estimated Unit Facility m MM Number Descriotion Quantity Unit Cost Cost r^m •m 24 42" R.CP. 850 l,f, $120 $102,000 24 Cleanout 4 ea. $3,000 $12,000 Mk 25 48" R.CP. 300 l,f. $130 $39,000 Mk 25 Cleanout 2 ea. $3,000 $6,000 4il 26 Extend 42" R.CP. 100 l,f, $120 $12,000 m 26 Cleanout 1 ea. $3,000 $3,000 TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $174,000 Ml Contingencies including possible relocation of utilities @ 10% $17,400 TOTAL ESTIMATED CONSTRUCTION COST $191,400 Engineering, administration and legal expenses @ 20% $38,280 TOTAL ESTIMATED INSTALLATION COST $229,680 35 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES m OLIVENHAIN ROAD BASIN (ZONE 12) Page 1 i Of 1 ^* Facility Estimated Unit Facility mm M Number Description Quantity Unit Cost Cost m 34 48" R.CP, 160 I.f, $130 $20,800 m 34 Headwall w/ wingwall 1 ea. $3,500 $3,500 34 Riprap dissipator 1 ea. $3,000 $3,000 mt mm 35 30" R.C.P. 160 I.f. $80 $12,800 35 Headwall w/ wingwall 1 ea. $3,500 $3,500 •m 35 Riprap dissipator 1 ea. $3,000 $3,000 m [5 5 A River dredging 22,000 cy. $4 $88,000 m i35A Desilt basin struct. 1 ea. $10,000 $10,000 TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $144,600 Contingencies including possible relocation of utilities @ 10% $14,460 TOTAL ESTIMATED CONSTRUCTION COST $159,060 Engineering, administration and legal expenses @ 20% $31,812 TOTAL ESTIMATED INSTALLATION COST $190,872 36 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES UPPER TRIBUTARY TO ENCINITAS CREEK BASIN (ZONE 11) Page 1 of 3 Facility Estimated Unit Facility m Number Descriotion Quantity Unit Cost Cost Ml 36 36" R.C.P. 2,650 l,f. $100 $265,000 m 36 Headwall w/ wingwall 1 ea. $3,500 $3,500 MK 36 Riprap @ u/s side 1 ea. $1,000 $1,000 36 Cleanout 10 ea. $3,000 $30,000 36 Riprap dissipator 1 ea. $3,000 $3,000 37 30" R.C.P. 1,000 I.f. $80 $80,000 m 37 Cleanout 5 ea. $3,000 $15,000 38 36" R.C.P. 1,200 I.f. $100 $120,000 m 38 Cleanout 6 ea. $3,000 $18,000 39 36" R.C.P. 1,450 I.f. $100 $145,000 m 39 Headwall w/ wingwall 2 ea. $3,500 $7,000 39 Riprap @ u/s side 2 ea. $1,000 $2,000 mm 39 Cleanout 7 ea. $3,000 $21,000 39 Riprap dissipator 1 ea. $3,000 $3,000 mm 40 30" R.CP, 1, 500 I.f. $80 $120,000 40 Headwall w/ wingwall 1 ea. $3,500 $3,500 mm 40 Riprap @ u/s side 1 ea. $1,000 $1,000 mm 40 Cleanout 7 ea, $3,000 $21,000 mm 40 Riprap dissipator 1 ea. $3,000 $3,000 mm 41 42" R.C.P. 1,700 I.f. $120 $204,000 41 Headwall w/ wingwall 1 ea. $3,500 $3,500 m 41 Riprap @ u/s side 1 ea. $1,000 $1,000 m 41 Cleanout 8 ea. $3,000 $24,000 m 41 Riprap dissipator 1 ea. $3,000 $3,000 m 42 30" R.CP, 650 I.f, $80 $52,000 m 42 Headwall w/ wingwall 1 ea. $3,500 $3,500 m 42 Riprap @ u/s side 1 ea. $1,000 $1,000 m 42 Cleanout 2 ea. $3,000 $6,000 Ml 42 Riprap dissipator 1 ea. $3,000 $3,000 37 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES UPPER TRIBUTARY TO ENCINITAS CREEK BASIN (ZONE 11) Page 2 of 3 m Facility Estimated Unit Facility m m Number Descriotion Ouantitv Unit Cost Cost m 43 48" R.C.P, 400 I.f, $130 $52,000 43 Cleanout 2 ea. $3,000 $6,000 Ml 43A 60" R.CP. 600 I.f. $180 $108,000 m 43A Cleanout 3 ea. $3,000 $9,000 43B 72" R.CP. 950 I.f. $200 $190,000 mt 43B Cleanout 4 ea. $3,000 $12,000 M 43C 78" R.CP, 1, 050 I.f. $220 $231,000 mm 43C Cleanout 5 ea. $3,000 $15,000 m 44 30" R.C.P, 700 I.f. $80 $56,000 mm 44 Cleanout 3 ea. $3,000 $9,000 m 44 Riprap dissipator 1 ea. $3,000 $3,000 47 Extend 30" R.C.P 450 I.f. $80 $36,000 47 Cleanout 2 ea. $3,000 $6,000 47 Riprap dissipator 1 ea, $3,000 $3,000 mim 48 Extend 36" R.CP 720 I.f. $100 $72,000 mm 48 Cleanout 3 ea. $3,000 $9,000 -rm 49 42" R.C.P. 1, 020 I.f. $120 $122,400 mm 49 Cleanout 4 ea. $3,000 $12,000 m~ 49 Riprap dissipator 1 ea. $3,000 $3,000 Mf 51 Ext. 2- 4'X9.3' RCB 100 I.f. $1,500 $150,000 mm 51 Headwall w/ wingwall 2 ea. $4,500 $9,000 51 Riprap @ u/s side 1 ea. $1,000 $1,000 51 Riprap dissipator 1 ea. $3,000 $3,000 TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $2,280,400 Contingencies including possible relocation of utilities @ 10% $228,040 38 Ml ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES UPPER TRIBUTARY TO ENCINITAS CREEK BASIN (ZONE 11) Page 3 of 3 39 TOTAL ESTIMATED CONSTRUCTION COST $2,508,440 Engineering, administration and legal expenses @ 20% $501,688 TOTAL ESTIMATED INSTALLATION COST $3,010,128 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES UPPER ENCINITAS CREEK BASIN (ZONE 11) Page 1 of 2 Facility Estimated Unit Facility m m Number Description Ouantitv Unit Cost Cost m 52 48" R.CP. 200 I.f. $130 $26,000 m 52 Headwall w/ wingwall 1 ea. $3,500 $3,500 mm 52 Riprap @ u/s side 1 ea. $1,000 $1,000 m 52 Riprap dissipator 1 ea. $3,000 $3,000 mm 53 30" R,C,P. 600 I.f. $80 $48,000 53 Cleanout 3 ea. $3,000 $9,000 54 36" R.CP, 480 I.f. $100 $48,000 -Ml 54 Cleanout 2 ea. $3,000 $6,000 Ml 54 Riprap dissipator 1 ea. $3,000 $3,000 Ml 55 30" R.C.P. 300 I.f. $80 $24,000 Mi 55 Cleanout 2 ea. $3,000 $6,000 -mm 56 2- 72" R.C.P, 440 I.f. $200 $88,000 m 56 Headwall w/ wingwall 2 ea. $4,500 $9,000 56 Riprap @ u/s side 1 ea. $1,000 $1,000 56 Riprap dissipator 1 ea. $3,000 $3,000 •W 57 42" R.C.P. 250 I.f. $120 $30,000 nub 57 Headwall w/ wingwall 1 ea. $3,500 $3,500 •mm 57 Riprap @ u/s side 1 ea. $1,000 $1,000 mm 57 Riprap dissipator 1 ea. $3,000 $3,000 m 58 30" R.C.P. 400 I.f. $80 $32,000 mm 5S Cleanout 2 ea. $3,000 $6,000 58 Riprap dissipator 1 ea, $3,000 $3,000 59 30" R.C.P. 500 I.f. $80 $40,000 mm 59 Cleanout 2 ea. $3,000 $6,000 mi 59 Riprap dissipator 1 ea, $3,000 $3,000 Ml 60 30" R.C.P. 350 l,f. $80 $28,000 Ml 60 Cleanout 2 ea. $3,000 $6,000 -61 30" R.CP. 725 I.f, $80 $58,00 m 61 Cleanout 3 ea. $3,000 $9,000 m 62 48" R.C.P. 1, 400 I.f. $130 $182,000 40 ENCINITAS CREEK MASTER DRAINAGE PLAN IN THE CITY OF CARLSBAD RECOMMENDED FACILITIES PRELIMINARY COST ESTIMATE TABLES UPPER ENCINITAS CREEK BASIN (ZONE 11) Page 2 of 2 Facility Estimated Unit Facility •m -JMI Number Description Quantity Unit Cost Cost t^m mm 62 Cleanout 6 ea. $3,000 $18,000 m 62 Riprap dissipator 1 ea. $3,000 $3,000 63 30" R.C.P. 330 I.f, $80 $26,400 63 Cleanout 2 ea. $3,000 $6,000 Ml 64 30" R.C.P. 270 I.f. $80 $21,600 m 64 Cleanout 1 ea. $3,000 $3,000 m 64 Riprap dissipator 1 ea. $3,000 $3,000 m 65 2- 6' X 10' R.C.B. 150 I.f. $1,650 $247,500 m 65 Headwall w/ wingwall 2 ea. $4,500 $9,000 MB 65 Riprap @ u/s side 1 ea. $1,000 $1,000 mm 65 Riprap dissipator 1 ea. $3,000 $3,000 Ml TOTAL ESTIMATED ITEMIZED CONSTRUCTION COST $1,030,500 Contingencies including possible relocation of utilities @ 10% $103,050 Ml TOTAL ESTIMATED CONSTRUCTION COST Engineering, administration and legal expenses @ 20% $1,133,550 $226,710 TOTAL ESTIMATED INSTALLATION COST $1,360,260 41 Ml m REFERENCES 1. City of Carlsbad, 1984; Standard Design Criteria for the Design of Public Works Improvements in the City of Carlsbad, 2. San Diego County Department of Public Works, 1985; Public Road Standards, 3. San Diego County Design Policy Committee, 1985; Design Policy for Flood Control and Drainage, 4. County of San Diego Department of Public Works Flood Control Division, 1985; Hydrology Manual. 5. San Diego County Regional Standards Committee, 1986; Regional Standard Drawings. 6. Rick Engineering Company, 1988; Encinitas Creek Watershed HEC-1 Model Analysis Hydrology Report. 7. San Diego County Flood Plain Mapping, 1981; Encinitas Creek HEC-2 Computer Output. 8. San Diego County Department of Public Works, 1982; Encinitas Creek Floodplain Mapping. 9. San Diego County Engineer, (latest revision), 200 scale Orthophoto Topographic Survey maps. 10. City of Carlsbad Planning Department, 1987; General Plan Map. 11. Soil Conservation Service, 1974; Soil Survey of the San Diego Area, California. 12. City of Carlsbad Engineering Department; Storm Drain As-Built Plans (files) . 13. U,S. Army Corps of Engineers, 1971; Flood Plain Information, San Marcos Creek, 14. City of San Diego, 1985; Unit Prices for Checking Subdivisions and Permits. 15. Mission Aerial Photo, May 3, 1988; Aerial Photography for Mello Roos District. 16. San Diego County, 1980; Hydrology Report for Encinitas Creek. 17. CH2M Hill, 1988 (Draft); Batiquitos Lagoon Enhancement Project. 18. Koebig, Inc., 1976; Comprehensive Plan for Flood Control and Drainage Zone 1, San Diego County Flood Control District. 42