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HomeMy WebLinkAboutItem VI (B)1,2 Master Drainage Plan (Spring Lake/Lake Johio Drainage Basin Study) 1. Status Report-David Hamstra, Professional Engineering Consultants 2. Approval of Work Order No 5 I AGENDA 4-20-93 I Item VI B 1 & 2 .Orv44o ©n�yrf* OF 0000� JAMES W.SHIRA,P.E. CITY ENGINEER/UTILITIES DIRECTOR 150 N.LAKESHORE DRIVE•OCOEE,FLORIDA 34761 (407)656-2322 MEMORANDUM DATE: April 13, 1993 TO: Honorable Mayor and Board of City Commissioners FROM: James W. Shira, P.E. City Engineer/Utiliti Director SUBJECT: Professional Engineering Consultants, Inc. - Work Order No. 5, Master Drainage Plan (Spring Lake/Lake Johio Drainage Basin Study) Work Order No. 5 is a request for compensation for the Spring Lake/Lake Johio Drainage Basin Study portion of the Master Drainage Plan. Work as outlined in Attachment "A" is to be accomplished by October 4, 1993. The cost for the work products is $48,640.00 with an additional amount of $1,250. 00 for reimbursable charges, for a total not-to-exceed amount of $49,890. 00. Staff recommends that the City Commission (1) approve Work Order No. 5 for a not-to-exceed amount of $49,890.00 and (2) authorize the Mayor and City Clerk to execute Work Order No. 5. Ow THE PRIDE OF WEST ORANGE WORK ORDER FOR ENGINEER'S SERVICES AGREEMENT WORK ORDER NO. 5 PROJECT: Master Drainage Plan (Spring Lake/Lake Johio Drainage Basin Study) ENGINEER: Professional Engineering Consultants, Inc. Execution of the Work Order No. 5 shall serve as authorization of ENGINEER to provide professional engineering services as described in Attachment "A" which is attached hereto and made a part hereof. ENGINEER shall provide said service pursuant to Work Order No. 5, its attachment and that certain Agreement of May 4, 1993 between CITY and ENGINEER which is incorporated herein by reference as if it had been set out in its entirety. Whenever the Work Order conflicts with said Agreement, the Agreement shall prevail. TIME FOR COMPLETION: The work authorized by this Work Order shall be completed by Monday, October 4, 1993. COMPENSATION: The CITY shall compensate the ENGINEER on an hourly basis with a not-to-exceed amount of Forty-Eight Thousand Six Hundred Forty Dollars ($48,640.00) for the professional services required under this Work Order. An additional amount, not to exceed One Thousand Two Hundred Fifty Dollars ($1,250.00) shall be paid as direct reimbursable charges for copying and reproduction expenses. Engineer shall perform all work required by this Work Order; but, in no event shall ENGINEER be paid more than the fixed fee set forth above without authorization of the CITY. i IN WITNESS WHEREOF, the parties hereto have made and executed this Work Order on this 4th day of May, 1993 for the purpose stated herein. ATTEST: PROFESSIONAL ENGINEERING CONSULTANTS, INC. By: R. Craig Batterson, President Date: ATTEST: BOARD OF CITY COMMISSIONERS CITY OF OCOEE, FLORIDA By: S. Scott Vandergrift, Mayor Date: For the use and reliance of City of Ocoee only. Approved as to form and legality this day of , 1993. City Attorney ii • ATTACHMENT "A" SCOPE OF SERVICES WORK ORDER NO. 5 SPRING LAKE/LAKE JOHIO DRAINAGE BASIN STUDY INTRODUCTION The City of Ocoee, as part of their continuing effort to provide improved services for their residents, is undertaking the creation of a Master Drainage Plan. The plan will identify the needs of the Stormwater Management System and establish a Capital Improvements Program. Professional Engineering Consultants, Inc. (PEC) has been selected by the City to assist them in the undertaking of the tasks required for a successful implementation of a Comprehensive Master Drainage Plan. As part of the Master Plan, PEC will evaluate the Spring Lake and Lake Johio Drainage Basins and address the following objectives: 1. To develop an inventory of the existing stormwater drainage facilities, the watershed drainage basin, and other related hydrologic parameters; 2. To evaluate existing and proposed stormwater drainage systems and identify problem areas and deficiencies; 3. To establish a level of service criteria for the various components of the stormwater drainage system; 4. To develop and apply a stormwater management computer model capable of simulating storm runoff under existing and future planned land use conditions within the drainage basin; 5. To evaluate alternative management plans to meet the established service levels based on any deficiencies identified through data collection and modeling; 6. To generate a Master Drainage Plan with established improvement priorities and engineering and construction cost estimates; and 7. To develop a Capital Improvement Plan based on system requirements identified in the Master Drainage Plan. The Master Drainage Plan has occurred in phases and/or work orders. The following is a list of ongoing and/or completed work orders to date: • Work Order No. 1 - NPDES Part 1 MS4 Permit Application (100% complete as of June 1992). 1 S • Work Order No. 2 - Data Collection and Digital Mapping (95% complete as of April 1993). • Work Order No. 3 - Northwest Ditch Drainage Basin Study (50% complete as of April 1993). • Work Order No. 4 - NPDES Part 2 MS4 Permit Application (ongoing, due May 1993). The following scope will outline the steps required to complete Work Order No. 5 (Spring Lake/ Lake Johio Drainage Basin Study) and meet the aforementioned objectives. I. DATA COLLECTION The Engineer shall review all pertinent data as it relates to the Spring Lake/Lake Johio Drainage Basins. The Engineer shall perform the following tasks: a. The Engineer will review the following information: • Construction Plans and Drainage Calculations for Spring Lake Subdivision, Silver Glen Subdivision, Candlewood Shores (aka Lakeside) Subdivision, and Clark Road - Section "C"; • Orange County Drainwell Studies for Spring Lake and Lake Johio; • FDOT and/or County roadway plans for Silver Star Road and A.D. Mims Road; and • St. Johns River Water Management District aerial topographic maps. At the conclusion of the data review, the Engineer shall perform sufficient site inspections to identify existing stormwater facilities (i.e. ditches, inlets, collection systems), existing land-use, drainage patterns and drainage subbasin boundaries. b. Based on existing and proposed developments, FDOT drainage basin maps, site inspections, and existing SJRWMD topographic maps, the Engineer shall delineate the drainage basin and subbasin boundaries. Based on further investigation of the Spring Lake/Lake Johio Drainage Basins, the overall basin boundary may change and will be incorporated in the AutoCAD layer created during Work Order No. 2. c. The Engineer shall establish existing and future land-use characteristics based on aerial maps, Ocoee's adopted current and future land use maps, FDOT land use classification, and site inspections. 2 t + d. The Engineer shall delineate the existing storm sewer collection systems from review of existing construction plans and site inspections. The PEC Survey Department shall survey the two (2) existing 12-inch drainage wells to verify to existing control water elevations and drainwell diameters. e. The Engineer shall delineate existing conservation areas, potential future conservation areas, and/or jurisdictional wetlands based on review of recent aerials, Fast Central Florida Regional Planning Council maps, existing soil classifications, and the adopted Land Use Maps. f. The Engineer shall review Flood Insurance Studies (FIS), Flood Insurance Rate Maps, and previous studies to establish current 100-year flood elevations and limits. g. The Engineer shall review the SCS soil layer, provided by Orange County, and created during the digital mapping phase and assign attributes describing the hydrologic soil groups (e.g., A, B, B/D) within the Spring Lake/Lake Johio Drainage Basins. h. The Engineer shall compile the above referenced information and create a Spring Lake/Lake Johio Drainage Basins map utilizing AutoCAD, Version 11.0. The file will be plotted on reproducible mylar in addition to an aerial base map. II. EXISTING CONDITIONS The Engineer shall analyze the Spring Lake/Lake Johio Drainage Basins under existing conditions and establish the existing level of service (LOS) with respect to current flood stages and flow rates. The Engineer shall perform the following tasks to complete this phase: a. The Engineer shall establish existing basin characteristics for each drainage subbasin which includes the following parameters: drainage subbasin area(acres), weighted runoff curve number (CN), time of concentration (Tc, minutes), and peak rate factor. b. The Engineer shall prepare a stormwater model of the existing stormwater facilities in order to perform a single event simulation (e.g., 25-year, 24-hour). A computer program entitled "Advanced Interconnected Channel and Pond Routing Model (adICPR, Version 1.40)" will be utilized to analyze the existing system. The Engineer createshall and the input files needed to model existing stormwater ponds, lakes (Spring Johio), control structures, and cross-culverts. The Engineer shall coordinate with a geotechnical engineer to evaluate recharge rates and the inflow/outflow components of both lakes. c. Based on the existing basin characteristics and computer model, the Engineer shall analyze the existing stormwater facilities under various rainfall events. The Engineer shall select three (3) design storm events that are consistent with the Land Development 3 ' r Codes and Comprehensive Plan. The three (3) storm events will be analyzed in order to establish peak flood stages and address existing levels of service. It is anticipated that the selected storm events shall be the 10-, 25-, and 100-year storm events. d. The Engineer shall create an AutoCAD layer containing all existing drainage structures within the Spring Lake/Lake Johio Drainage Basins. e. The Engineer shall prepare a preliminary engineering report which will address the following: • Existing basin characteristics • Summary of peak flow rates and flood stages • Establish a level of service for each drainage subbasin and/or stormwater facility • Summarize levels of water quality treatment to receiving water bodies The Engineer shall meet with City staff and discuss their findings. The Engineer shall also provide a presentation to the City Commissioners and the general public to discuss and explain the existing conditions. III. PROPOSED CONDITIONS The Engineer shall analyze the Spring Lake/Lake Johio Drainage Basins under future land use conditions and establish future flood stages, flow rates, levels of service, and establish possible alternatives to address deficiencies. The Engineer will evaluate the possibility of interconnecting the two (2) lakes and design a control structure to regulate flood stages. The Engineer shall perform the following tasks: a. The Engineer shall establish future basin characteristics for each drainage subbasin which includes the following parameters: drainage subbasin area(acres), weighted runoff curve number (CN), time of concentration (Tc, minutes), and peak rate factor. b. The Engineer shall modify the stormwater model to account for future improvements with respect to stormwater facilities (e.g., Spring Lake Subdivision). The Engineer shall revise the input data files of the existing condition computer model in order to properly analyze existing and future stormwater facilities. c. Based on the future basin characteristics and computer model, the Engineer shall analyze the existing and future stormwater facilities for three (3) selected storm events. d. Based on the results of the computer modeling, the Engineer shall establish the levels of service under future conditions and identify possible deficiencies. If problem areas exist, the Engineer shall develop alternatives and establish preliminary construction costs, right- of-way requirements, and address permitability. This task will consist of an interactive meeting between City staff and the consultant to discuss one (1) rational and/or practical alternative for each identified problem area. 4 • e. The Engineer shall prepare a final engineering report which will include the following: • Existing and future basin characteristics. • Existing and future flow rates and peak flood stages for various design storm events. • Levels of water quality treatment to receiving water bodies under existing and future land use conditions. • Tabulate levels of service for each drainage subbasin and/or stormwater facilities under existing and future land use. • Identify problem areas and provide design alternatives taking into account various parameters. • Provide exhibits delineating limits of flooding and location of existing, future, and modified stormwater facilities. This task shall conclude with a presentation to the City Commissioners summarizing the results contained in the final engineering report. IV. CAPITAL IMPROVEMENTS The Engineer shall establish a capital improvements program designed to correct identified deficiencies in levels of service. The Engineer shall perform the following tasks: a. The Engineer shall coordinate with City staff concerning the selection of the desired alternatives/improvements. For each alternative selected, the Engineer shall prepare a detailed cost estimate which will include material costs and estimated land costs. b. Based on the selected alternatives, the Engineer shall determine the amount of additional right-of-way required in order to accommodate the proposed improvements. c. The Engineer shall summarize the project cost and right-of-way requirements for each alternative selected in an engineering report. The Engineer shall also outline an Operation and Maintenance Program in order to insure the long-term performance of the existing drainwells. V. COMPREHENSIVE PLAN The Engineer shall update the Drainage Sub-Element of the City's Comprehensive Plan and assist the City with the amendment to the Comprehensive Plan. 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