STORMWATER MANAGEMENT REPORT FOR LAKE MEADE PARK – NEIGHBORHOOD PARK IMPROVEMENTS PROJECT CITY OF CAPE CORAL LEE COUNTY, FLORIDA Prepared for: City of Cape Coral 1015 Cultural Park Boulevard Cape Coral, Florida 33915 Prepared by: AECOM Technical Services, Inc. 7650 West Courtney Campbell Causeway – Suite 700 Tampa, FL 33607 DATE: March 2021 REV. DATE: Note: This stormwater management report is prepared to support applications to the South Florida Water Management District (SFWMD) and City of Cape Coral. PAGE 1 SIGNATURE PAGE PROFESSIONAL ENGINEER’S SEAL AECOM TECHNICAL SERVICES, Inc. 7650 West Courtney Campbell Causeway, Suite 700 Tampa, Florida 33607 813.286.1711 State of Florida Authorization No.: 00000002 Engineer in Responsible Charge: Kevin M. Westberry, PE Professional Registration No.: 65718 This document has been digitally DATE: 05/07/21 signed and sealed by: Printed copies of this document are not considered signed and sealed and the S.H.A. Authentication Code must be verified on any electronic copies. The above-named Professional Engineer shall be responsible for the proposed design content presented in this report in accordance with Rule 61G10-11.011, 61G15-23.005 and 61G15-23.004 (Digital), F.A.C. TABLE OF CONTENTS Page 1.0 INTRODUCTION & PROJECT DESCRIPTION ...................................................................................... 4 2.0 PURPOSE OF REPORT ....................................................................................................................... 5 3.0 EXISTING CONDITIONS SITE INFORMATION SUMMARY .................................................................. 5 3.1 Existing Conditions Development Summary and Prior Permit History ............................................ 5 3.2 Watershed / Basin ........................................................................................................................... 6 3.3 Geotechnical / Soils / Seasonal High Groundwater Table (SHGWT) Elevation Information ........... 6 3.4 Floodplain / Wetlands ...................................................................................................................... 7 4.0 DRAINAGE DESIGN INFORMATION & CRITERIA ............................................................................... 8 4.1 Design References ............................................................................................................................ 8 4.2 Design Analysis ................................................................................................................................. 9 4.3 Stormwater Management Facility (SMF) Design Criteria ................................................................ 9 5.0 EXISTING CONDITIONS STORMWATER ANALYSIS .......................................................................... 10 5.1 Existing Basins ................................................................................................................................ 11 5.2 Allowable Discharge ....................................................................................................................... 12 6.0 PROPOSED CONDITIONS STORMWATER ANALYSIS AND STORMWATER MGMT FACILITIES ........ 13 6.1 Proposed Basins ............................................................................................................................. 13 6.2 SMF Water Quality Treatment Summary ...................................................................................... 16 6.3 SMF Stormwater Attenuation Summary ....................................................................................... 17 7.0 OPERATION AND MAINTENANCE GUIDELINES .............................................................................. 19 7.1 Operation ....................................................................................................................................... 20 7.2 Maintenance .................................................................................................................................. 20 LIST OF TABLES 3.3.1 NRCS Soil Survey Information 6.2.1 Water Quality Treatment Volume Summary 6.3.1 25-Year Storm Frequency (Basins PR100 / PR400): Allowable vs. Proposed Condition Peak Discharges APPENDICES 1 Cover Sheet & Site Plans 2 Topographic & Boundary Survey by E.F. Gaines Surveying Services, Inc. – Lake Meade Park (dated 02/01/20) (Sheets V-100 – V-103 of plans) 3 SFWMD Drainage Basin Map 4 NRCS Soils Map and additional NRCS Information 5 SHGWT Boring Location Plan and Supporting Avg. SHGWT Elevation Calculations PAGE 2 6 Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) 12071C0255F (dated August 8, 2008) 7 City of Cape Coral Weir-Controlled Canal System Data (City Stormwater GIS) 8 Existing Conditions Drainage Basin Map 9 Allowable Discharge Drainage Calculations 10 Proposed Conditions Drainage Basin Map 11 Proposed Conditions Drainage Calculations (Basin & Sub-Basin Calcs, WQTV Calcs, Ponds Summary, Dry Detention Orifice Bleed-down Calcs) 12 Proposed Conditions ICPR Analysis (Basin-Node Diagram, Node Min/Max, All Input, 100Yr-3Day Zero Discharge Node Min/Max (Building FFE Check)) PAGE 3 1.0 INTRODUCTION & PROJECT DESCRIPTION The City of Cape Coral is proposing to develop Lake Meade Park on approximately 45.6 acres of undeveloped open land, located adjacent to residential neighborhoods. The development of this park is in accordance with the approved Parks Master Plan adopted by City Council in 2016, and the Lake Meade Park Concept Plan, officially adopted in December of 2019. This neighborhood park is intended to meet residents’ basic recreational, fitness, and social needs within walking or bicycling distance from their homes. The Project is located adjacent to Kismet Parkway East, near the intersections with NE 1tth and 12th Avenues, in Section 31, Township 43 South, Range 24 East, in Cape Coral, Lee County, Florida. The address is 1116 NE 22nd Street, Cape Coral, Florida 33909, with approximate central coordinates of Latitude 26.693537° N, Longitude -81.949855° W (Site ID #10146434). The Project is within the South Florida Water Management District’s (SFWMD) north coastal drainage basin and the project area is within the freshwater canal system of the City. Refer to location maps within Appendix 1, Cover Sheet and Site Plan, and Sheet C-199 of the construction plans for more information. This report accompanies the plans and documents representing the stormwater design approach for the project. Per the project survey, the elevations in the project plans and in this report are referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29). The geographic coordinate system for horizontal control is North American Datum of 1983 (NAD83)(2011), State Plane Coordinate System, Florida West Zone. Development includes the construction of the following park features and amenities: grass/sod-covered open space areas, enhancing the existing vegetation with infill planting, constructing multiuse and walking pathways, paved and grass overflow standard parking areas, boat trailer parking area, shaded and unshaded picnic shelter areas, dog park, playground, boat launch ramp, basketball courts, tennis courts, pickleball courts, shuffleboard, event staging area with utilities, a recreational center (future phase), fitness stations (future phase), skate park (future phase), boardwalk (future phase), beach (future phase), floating dock (future phase), and fishing pier (future phase). An inter-connected stormwater management system is proposed to provide water quality treatment and manage stormwater runoff generated by the addition of impervious surfaces. Other elements of the project include selective road/utility demolition (site is mostly vacant but previously intended for a neighborhood), selective removal of trees, site grading, utilities installation, and landscaping. Refer to Appendix 1 for Cover Sheet and Site Plan information. PAGE 4 2.0 PURPOSE OF REPORT This report documents the design of the drainage systems for the site improvements. The drainage design will adhere to South Florida Water Management (SFWMD) and City of Cape Coral criteria. The drainage design includes interconnected ponds, ditches/swales and closed storm sewer conveyance systems to drain the site to the onsite stormwater management facility (SMF) with final outfalls to the existing canal system, pursuant to existing drainage patterns. A summary of the methodology and analytic procedures used in the design of the drainage system is included in this report. 3.0 EXISTING CONDITIONS SITE INFORMATION SUMMARY 3.1 EXISTING CONDITIONS DEVELOPMENT SUMMARY AND PRIOR PERMIT HISTORY As this land is intended for a neighborhood and neighborhood park space, the project site originally consisted of numerous parcels throughout the 45 acres+/- (approx. 100 at one point in time). The City is currently securing any remaining properties within the project limits, and also will be re-platting the property for this use and development. City Deed documentation is available and will be included with the permit applications. The current site is mainly vacant, undeveloped lots with mainly grasslands, bahia grass, brush and trees present. There are couple of remaining homes that will be demoed by the City. Existing neighborhood streets with roadside swales are also present. The project area is comprised one (1) land use/vegetative cover types, which was characterized using Florida Land Use, Cover and Forms Classification System (FLUCFCS) designations (FDOT 1999). This is “Undeveloped