ENVIRONMENTAL RESOURCE PERMIT APPLICATION FOR Shingle Creek Regional Trail – North Phase 2B City of Kissimmee Osceola County, Florida Prepared For City of Kissimmee February 2017 Prepared By: Kelly, Collins & Gentry, Inc. 1700 North Orange Ave., Suite 400 Orlando, Florida 32804 (407) 898-7858 Certificate of Authorization No. 7350 Herman D. Tirado, Florida P.E. No. 36910 Date: February 8, 2018 ERP Application Shingle Creek Regional Trail – North Phase 2B TABLE OF CONTENTS 1.0 General Information 1 1.1 Project Location 1 1.2 Purpose 2 1.3 Existing Drainage Patterns 2 1.4 Floodplains 2 1.5 Rules & Regulations/Regulatory Agency Coordination 3 2.0 Stormwater Management Analyses 3 3.0 Floodplain Compensation Analysis 4 4.0 Cross Drains 4 LIST OF APPENDICES Appendix Description A Exhibits - Project Aerial and Location Map - USGS Quadrangle Map Exhibit - Soils Exhibit - Floodplain Exhibits - Drainage Maps B Floodplain Compensation Calculations C Cross Drain Calculations D Permit Information: Weston Reserve Pond E Permit Information: Flora Lakes Pond (aka Stonefield) F SFWMD Pre-Application Meeting Minutes i ERP Application Shingle Creek Regional Trail – North Phase 2B 1.0 General Information 1.1 Project Location The Shingle Creek Regional Trail (SCRT) system is a recreational pathway network that will ultimately extend from the Osceola / Orange County line south along the east and north sides of Shingle Creek to Lake Tohopekaliga (Lake Toho), and along the west side of Lake Toho from Shingle Creek north to the Kissimmee Lakefront Park in the City of Kissimmee, Florida. A portion of this multi-use trail system from Vine Street (US 192) south to the intersection of Future Hoagland Boulevard with Pleasant Hill Road is already constructed or to be constructed under separate contract. This permit application addresses the trail segment located within the North Project Area that extends from the Osceola / Orange County line to Vine Street (US 192). This application will be for Phase 2B of the North Project Area which includes a segment located north of the Tapestry Development and ends just south of Osceola Parkway to the trail system. The Project Location Map in Appendix A shows the proposed project limits. The North Phase 2B of the SCRT is proposed to include an extension of the existing SCRT. This segment begins at the north end of the Tapestry Development where it connects to an existing 12’ trail. The trail transitions to 14’ and continues north along the berms of the wet detention pond for the Weston Reserve and Stonefield Subdivisions. This segment will include two boardwalk crossings to minimize impacts of wetlands and floodplains. The trail will have a geometric design speed for an 18 mph bicyclist user. All segments of the SCRT will comply with ADA requirements. The SCRT is located within Section 6 and 7 of Township 25 South, Range 29 East. The project traverses over lands owned by the City of Kissimmee and Osceola County, and travels through water management parcels owned by Weston Reserve HOA and Stonefield HOA. The SCRT will include drainage features to collect runoff originating on-site and direct it to either existing downstream locations or to existing or proposed on-site storm water management facilities. Drainage features to collect runoff will typically include a pipe or storm inlet that will convey runoff to either a downstream location or storm water management facility. Segments of the trail located along previously permitted developments having storm water management facilities may discharge runoff into the existing facilities. Storm water management facilities will be required when not exempted by the rules of the SFWMD. Per SFWMD rules, recreational paths that have a width of 12’ or less and are not located within wetlands or other surface waters are exempt per Chapter 40D-4.051(12). 1 ERP Application Shingle Creek Regional Trail – North Phase 2B This project was designed using the NGVD (National Geodetic Vertical Datum) 1929. Referenced data, such as 100-year flood elevations documented by FEMA, uses the NAVD (North American Vertical Datum) 1988. At this project location, NAVD88 elevations can be converted to NGVD29 elevations by adding 0.925’. For example, the 100-year flood elevation in Shingle Creek immediately south of the Osceola Parkway bridge is 76.2’ NAVD88, which converts to approximately elevation 77.1’ NGVD29. 1.2 Purpose The purpose of this report is to document the stormwater management design required for the proposed improvements which include the following: (1) Available capacity of existing wet detention ponds for water quality treatment (2) Excavated area for 100-year floodplain compensation 1.3 Existing Drainage Patterns The project limits lie along the banks of Shingle Creek and either have direct sheetflow runoff through bordering uplands and wetlands to the creek or runoff is collected by existing wet detention systems that discharge to Shingle Creek. The existing wet detention pond systems along the SCRT alignment include ponds serving Weston Reserve and Stonefield. Copies of the SFWMD Permits and Technical Staff Reports (TSRs) are included in the Appendices of this report. 1.4 Floodplains The SCRT will be located along and within the 100-year floodplains associated with Shingle Creek. Estimated peak flood stages for the 100-year flood stages of Shingle Creek are published by the Federal Emergency Management Agency (FEMA) in the Flood Insurance Study for Osceola County, Florida and Incorporated Areas, dated May 7, 2001 and pending revision. Floodplain Exhibits are provided in Appendix A which depict the limits of the 100-year floodplain and floodway as provided by Osceola County for the proposed Flood Insurance Rate Map (FIRM) revisions currently under review by FEMA. The revised FIRM’s will update the currently published Map Numbers 12097C- 0055F and 12097C-0065F dated June 6, 2001. The revised FIRM’s reflect refinements to the delineation of the floodplains along Shingle Creek by using a digital terrain model generated from 2006 LiDAR data supplied by the City of Kissimmee. There are no proposed changes to the 100-year flood stages along Shingle Creek by the revised FIRM, only refinements to the delineation of the floodplain limits based on improved terrain model information. The SCRT will be built as near to at-grade where possible and above the 10-year flood stage along this segment. Any segments of the SCRT that require filling within the 100- year floodplain will need to offset the lost floodwater storage capacity by providing 2 ERP Application Shingle Creek Regional Trail – North Phase 2B compensatory storage. The compensating storage will be provided by an excavation area within the floodplain. The resulting compensatory storage for fill within the floodplain will result in no net loss of floodwater storage capacity. 1.5 Rules & Regulations/Regulatory Agency Coordination The stormwater management facilities for this project will be designed in accordance with the design standards, criteria, and guidance of the South Florida Water Management District (SFWMD), City of Kissimmee, and Osceola County. Water quality treatment and water quantity attenuation are two main categories of the criteria established by these governmental agencies for the required detention facilities. The SFWMD design criteria for the stormwater management system are documented in Environmental Resource Permit Information Manual Volume IV. (1) Water Quality Criteria The proposed stormwater management system will consist of the direction of runoff to adjacent existing wet detention ponds when the SCRT is located on a pond berm. The required water quality treatment volume by the SFWMD for a wet detention system will be the greater of either the first inch of runoff from the developed project or the total runoff of 2.5 inches times the percentage of imperviousness. For retention, a 50% credit is applied to the wet detention criteria. For dry detention, a 25% credit is applied to the wet detention criteria. An additional 50% of treatment volume is required due to downstream impaired waters. Recreational paths that have a width of 12’ or less and are not located within wetlands or other surface waters are exempt per Chapter 40D-4.051(12). (2) Water Quantity Criteria Per discussion at the Pre-Application Meeting with SFWMD staff (see Meeting Minutes in Appendix H), the project is expected to have an insignificant impact on water quantity as the project will have discharge runoff via sheetflow directly off-site. Hence, no hydrographs or water quantity calculations have been performed for this project. 2.0 Stormwater Management Analyses The SCRT North Phase 2B segment is a 14’ wide trail that will be located on existing wet detention pond berms and will have runoff directed to the pond for treatment. Segment “500” will discharge into the adjacent wet detention ponds at the Weston Reserve and Stonefield subdivisions. Both wet detention pond systems were designed to include runoff from a perimeter 10’ wide paved recreational trail that was intended to entirely ring around each of the ponds. A 10’ wide paved trail was constructed on the 3 ERP Application Shingle Creek Regional Trail – North Phase 2B sides of the ponds adjacent to Shingle Creek, however the paved trail was not constructed on the sides of the ponds adjacent to homes, unless needed for access to the trail along the creek. Expanding the 10’ wide trail to a 14’ wide trail that is located only along Shingle Creek in lieu of a paved trail that was supposed to be entirely ringing around each pond will result in less impervious area that will be contributing runoff to each pond system. In summary, there is no net increase of runoff into the pond systems due to the trail system than what was originally intended by the permitted design. 3.0 Floodplain Compensation Analysis The SCRT will require filling within the 100-year floodplain as delineated by FEMA.