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1 Pit:*ASIi a DRAINAGE DESIGN DOCUMENTATION REPORT VOLUME I I75 CSR 931 From N of SR 52 to Pasco/Hernando Co Line Financial Project ID: Pasco County Amm/MA # EhlI"4?1?? /%/V 9//1?///V No i iami???9??? Southwest Florida V * 1#?i/ Water Manaaement District S/i V/(?Z"XM?"V?I/I/I/I/ AUG 2 O 2012 Prepared For: Received TAMPA RSB FLORIDA DEPARTMENT OF TRANSPORTATION DISTRICT SEVEN Prepared By: urs URS Corporation Southern?g?#e#e# 7650 W Courtney Campbell Causeway ZS N: Kpl : r kr/a9: wv tl 4 :p v e eod e Tampa Florida V::JGENSe < CA No EP) No 6WB e I fikvjbkq el Engineer of Record: *: A Tammy M Kreisle PE No August 2012 " qt?alaql : / I 9 FSF I 39; e 4 : (/ S e?te i /V 000 XLOR1050?/ *P (9* " 4?#ZF:6?p?: ;6t;4" "oo:ai#/?*

2 Soil Soil Figure Figure Figure Tables Figure Table Figure Figure Figure Figures Tables 1 A V Ims Section Title I75 (SR 93) FPID: TABLE OF CONTENTS 10 General Project Information1 Page 20 Drainage Reference and Resource Information2 30 Existing Drainage Characteristics5 40 Proposed Drainage Design10 LIST OF TABLES TABLE 1: USDA Conservation Service Soils Tables (See Appendix A A1 A10) TABLE 2: Summary of SHGWT (See Appendix A A11 A14) TABLE 3: Summary of Design Rainfalls (See Appendix A A15) LIST OF FIGURES FIGURE 1: Project Location Map (See Appendix B 1) FIGURE 2: Proposed and Existing Roadway Typical Section (See Appendix B 2A2 E) FIGURE 3: FEMA Flood Insurance Rate Maps Panel Numbers D & B (See Appendix B 3A3D) FIGURE 4: USDA Conservation Service Soils Map (See Appendix B 4A4D) FIGURE 5: SWFWMD Rainfall Contour Maps (See Appendix B 5A & 5B) FIGIJRE 6: FDOT Rainfall IntensityDurationFrequency Curve for Zone 6 (See Appendix B 6) FIGURE 7: FDOT Precipitation Data (See Appendix B 7A7B) FIGURE 8: DEP Verified Impaired WBID (See Appendix B FIGURE 9: SMF & FPC Location Maps (See Appendix H) 8A8B) Southwest Florida Water Management District AUG 2 O 2012 G:\ProjFDOT\V8\ Non ED\dramge\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORTJ12012doc 1 Received TAMPA RSB

3 URS I75 (SR 93) FPID: VOLUME I APPENDICES A Tables B Figures C Project Correspondence and Documentation D SWFWMD Coordination E Flood Insurance Rate Maps & Preliminary SWFWMD 100 year Flood Elevations F SMF & FPC Calculations (Basin 1 10) PreDev & PostDev ICPR Model Cross Drain Calculations Storm Sewer Tabulations and Roadside Ditch Calculations VOLUME II G Review Comments and Responses H SMF & FPC Locations 1* Existing Project Drainage Maps Proposed Drainage Maps and SWFWMD Aerials G:\ProjFDOT\V8\ NonED\drainage\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT812012doc ii

4 URS I75 (SR 93) FPID: GENERAL PROJECT INFORMATION 11 INTRODUCTION The project I75 (SR 93) is being undertaken by the Florida Department of Transportation (FDOT) District 7 FDOT has contracted with URS Corporation Southern (CRS) to perform engineering services for the project The purpose of this report is to document the proposed design of the Stormwater Management Facilities (SMFs) and conveyance systems for the project 12 SITE LOCATION AND DESCRIPTION The project is located in Pasco County within the jurisdiction of the Southwest Florida Water Management District (SWFWMD) It is located within the Cypress Creek Pitlachascotee River/Bear Creek and Toachodka Watersheds These Watersheds will discharge runoff to Hillsborough River Crews Lake Outlet and Withlacoochee River Basins and associated wetlands respectively It is located in Sections and 33 of Township 24 S Range 20 E and Sections 458 and 9 of Township 25 S Range 20 E A Location Map is provided in Appendix B Figurel The existing land use within the project limits ranges from agricultural to residential The existing fourlane roadway consists of two northbound lanes and two southbound lanes The project consists of widening an 82 mile section of I75 from North of SR 52 to the Pasco/Hernando Co Line The proposed project includes one lane to be added in each direction From SR 52 to the Pasco/Hernando County line the proposed typical roadway section will consist of six 12foot through lanes (three northbound and three southbound) 12foot inside and outside shoulders (10 feet paved) and a 40foot median The R/W width is 300 feet The drainage systems for the project drainage will include ditches and storm sewer for conveyance of the project runoff to the respective stormwater management facilities (SMF) for water quality treatment and water quantity attenuation The existing and proposed typical sections are provided in Appendix B Figure 2 For the purposes of this report SMF sites were sized to accommodate the PD&E ultimate 8lane section by including postdevelopment impervious area that extends from rightofway (R/W) line to R/W line However it is difficult to anticipate the methods to be used to implement the ultimate concept Options for widening may include breaking the cross sectional paving grade raising the profile or bifurcation of the roadway The selection and size of proposed SMF sites are based on full development of the existing I75 rightofway (100% impervious) hydraulic controls and the existing roadway profile Lowering the edge of pavement elevation for future roadway widening could require larger SMF sites than presented in this report G:\ProjFDOT\V8\ NonED\drainage\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT812012doc 1

5 Figure Table Figure URS I75 (SR 93) FPID: SOIL CHARACTERISTICS Soils information was obtained from the Soil Conservation Service (NRC:S) Soil Survey of Pasco County Florida Project Basins: Generally the soils vary from poorly drained soil (primarily hydrologic group B/D) to well drained soil (hydrologic group A) See Appendix B 4 for soils map and Appendix A Table 17 & 16 for soils data SMF Locations: Generally the soils vary from poorly drained soil (primarily hydrologie group B/D) to well drained soil (hydrologic group A) Seasonal High Water Table Summary: See Appendix A 2 Soils Map: See Appendix B 4 14 FLOOD PLAIN INFORMATION Floodplain information was obtained from the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) Panels D (September ) B (November ) and (April ) Pasco County These panels show that much of the project falls in floodplain areas Floodplain elevations were obtained from the SWFWMD watershed model and were utilized to determine floodplain encroachments and compensation volumes See Appendix B Figure 3 2 DRAINAGE REFERENCE AND RESOURCE INFORMATION 21 MEETINGS 211 FIELD REVIEW / DISCUSSION WITH FDOT MAINTENANCE ICA has been contracted by FDOT to perform maintenance along I75 within the project limits ICA stated that there were no known flooding problems within the project limits (see Appendix C for discussion) 212 SWFWMD PREAPPLICATION MEETING th A PreApplication Meeting was held on December at 9:30 am at the SWFWMD Brooksville office The meeting minutes are included in Appendix D 213 SWFWMD COORDINATION MEETING A Coordination Meeting was held on May at 9:00 am at the SWFWMD Brooksville office The meeting minutes are included in Appendix C G:\ProjFDOT\V8\ NonED\drainage\Report$\ 2 PHASE JI DRAINAGE DES?GM DOCUMENTATION REPORT812012doc

6 U? I75 (SR 93) FPID: FDOT POND SITING RIGHTOFWAY REQUIREMENT MEETING A Pond Siting RightofWay Requirement Meeting was held on April at 3:00 pm at the FDOT District 7 office The meeting minutes are included in Appendix C 22 CURVE NUMBERS The SCS method to estimate hydrology as outlined in TR 55 was used to establish a Curve Number (CN) The weighted CN calculation for project runoff calculations includes grass cover in good condition (> 75%) for pre and post development Land Use CN A C B/D Open Space Grass Cover > /80 75% Road Pavement 98 Water RAINFALL INTENSITY DATA Rainfall data was obtained from several sources The 24hour rainfall depths were obtained from the SWFWMD Environmental Resource Permitting Information Manual Part D These rainfall depths are used for the SWFWMD water quantity modeling of the SMFs Rainfall Event 24Hour Rainfall Depth 2Year 45 inches 233 Year 50 inches 5Year 60 inches 10Year 75 inches 25Year 90 inches 50Year 105 inches 100Year 120 inches The Rainfall IntensityDuration Frequency Curve for Zone 6 on Page B7 in the FDOT Drainage Manual is used for the FDOT Critical Duration Rule 1486 modeling of the SMFs G:\ProjFDOT\VB\ Non ED\drainage\Reports\ 3 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

7 Table URS I75 (SR 93) FPID: RAINFALL DEPTHS FOR CRITICAL DURATION ANALYSIS 2 YEAR 5 YEAR 10 YEAR 25 YEAR 50 YEAR 100 YEAR 1 1 x 230"/hr 1 x 280"/hr 1 x 320"/hr 1 x 370"/hr 1 x 400"/hr 1 x 450"Air HOUR 230" 280" 320" 370" 400" 450" 2 2 x 140"/hr 2 x 175"/hr 2 x 200"/hr 2 x 240"/hr 2 x 265"/hr 2 x 300"/hr HOUR 280" 350" 400" 480" 530 " 600" 4 4 x 085"/hr 4 x 108"/hr 4 x 125"/hr 4 x 145"/hr 4 x 160"/hr 4 x 180"/hr HOUR 340" 432" 500" 580" 640" 720" 8 8 x 052"/hr 8 x 066"/hr 8 x 077"/hr 8 x 090"/hr 8 x 100"/hr 8 x 115"/hr HOUR 416" 528" 616" 720" 800" 920" x 024"/hr 24 x 031"/hr 24 x 037"/hr 24 x 044"/hr 24 x 048"/hr 24 x 054"/hr HOUR 580" 744" 890" 1060" 1152" 1300" Copies of the above items are provided in Appendix A Figures 56 & 7 24 RESOURCES FOR ANALYSIS 3 and Appendix B Existing Studies / Plans / Reports e Cypress Creek Watershed Management Plan by URS 2000 o Alternative Stormwater Management Facility Report for FDOT (PD&E) by HW Lochner June 2007 e Existing AsBuilt I75 roadway plans from FDOT e Pond Siting Report for FPID by URS Technical Reference and Regulation Material e FDOT Drainage Manual FDOT Drainage Handbooks e Technical Release "55" (TR 55)Urban Hydrology for Small Watersheds e SWFWMD Environmental Resource Permitting Information Manual SWFWMD Aerial Contour Maps e Soil Survey for Pasco County by NRCS e Flood Insurance Study and Flood Insurance Rate Map Panels by FEMA Aerial Photography and Survey e Aerial Contour Maps (1" = 200 scale onefoot contours) by SWFWMD e REDI Aerial Photographic Maps (2003) G:\ProjFDOT\V8\4 I 10 I lnonel)\drainage\reports\ 4 PHASE 11 DRAJNAGE DESIGN DOCUMENTATION REPORT doc

8 ?i??iiil?===*?i? URS I75 (SR 93) FPID: All references / resources as well as the project design utilize the NGVD 1929 datum 3 EXISTING DR ATNAGE CHARACTERISTICS The project is within the jurisdiction of the Southwest Florida Water Management District (SWFWMD) Currently there are no permitted treatment or attenuation facilities within the project limits There is some existing treatment provided by grass swales and wet ditches that were created during the original roadway construction 31 EXISTING WATERSHED DESCRIPTIONS This project currently discharges to three watersheds: Cypress Creek Pithlachascotee River/Bear Creek and Toachodka River Cypress Creek Watershed (Station to ): The project area from North of SR 52 (Station ) to Lake Iola Road (Station ) lies in the Cypress Creek Watershed Basin which is part of the Hillsborough River Basin In the existing condition runoff from the project area sheet flows to roadside swales which convey flow to cross drains that ultimately discharge to Cypress Creek Basins 1 through 7 are in the Cypress Creek watershed and are considered open basins Pithlachascotee River/Bear Creek Watershed (Station to ): The project area from Lake Iola Road (Station ) to County Road 41 (Station ) lies in the Pithlachascotee/Bear Creek Basin In the existing condition runoff from the project area sheet flows to roadside swales and outfalls to Moody Lake Basin 8 and 9 flows to Moody Lake and are considered closed basins Toachodka Watershed (Station to ): The project area from County Road 41 (Station ) to the Pasco/Hernando County line (Station ) lies in the Toachodka Basin which is part of the Coastal River Basin Ill the existing condition runoff from the project area sheet flows to roadside swales and outfalls to Mud Lake Basin 10 flows to Mud Lake and is considered a closed basin See the SWFWMD meeting minutes in Appendix C 32 EXISTING DRAINAGE BASIN DESCRIPTIONS 321 Existing Basin 1 Basin 1 drainage area extends from Station to Station A portion ofthe runoff from the project between Station to Station G:\P?jFDOT\V8\ Non ED\dmmage\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc 5

9 URS I75 (SR 93) FPID: flows via sheetflow shallow concentrated flow and roadside ditches along I75 to cross drain 1 at Station A portion of the runoff from the area between to Station is conveyed via roadside ditches to cross drain 2 that conveys flow from the east side of the alignment to the west Discharge from cross drain 1 and cross drain 2 continues westerly through an Unnamed Drain (WBID 1425) and Bayou Branch Drain (WBID 1418A) that ultimately outfalls into Cypress Creek Existing runoff along portions of the alignment is not conveyed to cross drains 1 or 2 As a result the existing basin drainage area is smaller than the proposed basin area The existing basin l roadway drainage area is 5378 acres See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 1 drainage area cross drain 1 and cross drain 2 and outfall locations 322 Existing Basin 2 Basin 2 drainage area extends from Station to Station Runoff from the project is conveyed via roadside ditches to Station at cross drain 3 that conveys flow from the east side of the alignment to the west Discharge from cross drain 3 continues westerly through Bee Tree Branch (WBID 1410) that ultimately outfalls into Cypress Creek The existing basin 2 roadway drainage area is 822 acres (551 acres of I75 rightofway and 271 acres of SMF 2 site) See existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 2 drainage area cross drain 3 and outfall locations 323 Existing Basin 3 Basin 3 drainage area extends from Station to Station Runoff from the project is conveyed via roadside ditches to cross drain 3 at Station that conveys flow from the east side of the alignment to the west Discharge from cross drain 3 continues westerly through Bee Tree Branch (WBID 1410) and ultimately outfalls into Cypress Creek (North) The existing basin 3 drainage area is 2656 acres (2169 acres of I75 rightofway and 487 acres of SMF 3 site) G:\ProjFDOOV8\ NonED\drainage\Reports\ 6 PHASE Il DRAINAGE DESIGN DOCUMENTATION REPORT doc

10 URS I75 (SR 93) FPID: See the existing proj ect drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 3 drainage area cross drain 3 and outfall locations 324 Existing Basin 4 Basin 4 drainage area extends from Station to Station Runofffrom the project is conveyed via roadside ditches to cross drain 4 at Station Roadway runoff from northbound lanes is collected by the eastern roadside ditch that conveys flow to the upstream end of cross drain 4 From Station to Station roadway runoff from the southbound lanes is collected by the western roadside ditch that conveys flow to the downstream end of cross drain 4 Discharge from cross drain 4 continues westerly through a lateral ditch that outfalls directly into Cypress Creek (North) (WBID 1440E) A portion of the runoff along the west side of the alignment from Station to sheet flows westerly away from I75 to the lateral ditch downstream of the mainline that outfalls directly into Cypress Creek (North) (WBID 1440E) The existing basin 4 drainage area is 2749 acres (2238 acres of I75 rightofway and 511 acres of SMF 4 site) See the existing proj ect drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 4 drainage area cross drain 4 and outfall locations 325 Existing Basili 5 Basin 5 drainage area extends from Station to Station Runoff from the project is conveyed via roadside ditches to cross drain 5 at Station Discharge from cross drain 5 continues westerly along the south side of St Joseph Road through a roadside ditch that outfalls directly into Cypress Creek (North) (WBID 1440E) The existing basin 5 drainage area is 972 acres (729 acres of I75 rightofway and 243 acres of SMF 5 site) See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 5 drainage area cross drain 5 and outfall locations G:WrojFDOT\V8\ NonED\dr/inage\Repolts\ PHASE II DRAINAGE DESIGN DOCUMENTAWON REPORT 8]2012doc 7

11 URS I75 (SR 93) FPID: Existing Basin 6 Basin 6 drainage area extends from Station to Station Roadway runoff from Station is conveyed via roadside ditches to cross drain 7 at Station where onsite and offsite flow is directed easterly along a lateral ditch away from I75 This lateral ditch meanders away from I75 in a southeasterly direction then changes to a westerly direction and crosses I75 in cross drain 5 that outfalls directly into Cypress Creek (North) (WBID 1440E) Roadway runoff from Station to Station as well as onsite and offsite flow from the eastern lateral ditch is conveyed to the west side of the alignment downstream of cross drain 6 at Station on I75 Discharge from cross drain 6 continues westerly along the lateral ditch that outfalls directly into Cypress Creek (North) (WBID 1440E) The existing basin 6 drainage area is 6916 acres (5297 acres of I75 rightofway and 1619 acres of SMF 6 site) See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 6 drainage area cross drain 6 cross drain 7 and outfalllocations 327 Existing Basin 7 Basin 7 drainage area extends from Station to Station Roadway runoff from Station is conveyed via roadside & lateral ditches to the downstream end of cross drain 8 at Station where onsite and offsite flow is directed westerly along a lateral ditch away from I 75 Discharge from cross drain 8 continues westerly along the lateral ditch that outfalls directly into Cypress Creek (North) (WBID 1440E) The existing basin 7 drainage area is 2535 acres (1894 acres of I75 rightofway and 641 acres of SMF 7 site) See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 7 drainage area cross drain 8 and outfall locations 328 Existing Basin 8 Basin 8 is a volume sensitive closed drainage basin Basin 8 drainage area extends from Station to Station Roadway runoff is conveyed via roadside ditches to cross drain 11 at Station G:\ProjFDOT\VB\ NonED\drainage\Reports\ 8 PHASE il DRAINAGE DESIGN DOCUMENTATION REPORT doc

12 Ims I75 (SR 93) FPID: Discharge from cross drain 11 continues westerly through the adjacent floodplain that outfalls directly into Moody Lake (West) (WBID 1392D) The existing basin 8 drainage area is 6485 acres (5510 acres of I75 rightofway and 975 acres of SMF 8 site) See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 8 drainage area cross drain 11 and outfall locations 329 Existing Basin 9 Basin 9 is a volume sensitive closed drainage basin Basin 9 drainage area discharges to two closed basins I75 rightofway from Station to discharges to Moody Lake (2686 acres of I75 rightofway) I75 rightofway from Station to Station discharges to cross drain 14 at Station that discharges to Mud Lake (482 acres of I75 rightofway) The existing basin 9 area draining to Moody Lake is 3260 acres (2686 acres of I75 rightofway and 574 acres of SMF 9 site) See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 9 drainage area cross drain 13 and outfall locations 3210 Existing Basin 10 Basin 10 is a volume sensitive closed drainage basin Under existing conditions roadway runoff from Station to Station drains to Mud Lake which outfalls directly into the Withlacoochee River (WBID 1329F) The existing basin 10 roadway drainage area is 3732 acres (3215 acres of I 75 rightofway and 517 acres of SMF 10 site) See the existing project drainage maps SWFWMD aerial contour maps and project contour maps for predevelopment conditions in Appendix I for drainage patterns the basin 10 drainage area cross drains 15 and 16 and outfalllocations G:\ProjFDOT\VZ\ NonED\dramage\Reports\ 9 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

13 URS I75 (SR 93) FPID: PROPOSED DRAINAGE DESIGN 41 DESIGN APPROACH 411 STORMWATER MANAGEMENT DESIGN APPROACH SMF low side of berm elevations were set at onefoot above the roadway low edge of pavement The 100year peak stage in the SMFs is limited to one foot below the SMF low side of berm or equal to the roadway low edge of shoulder Additional assumptions used in preparation of 60% SMF calculations: I Predevelopment peak rate factor (PRF) 256 Postdevelopment PRF 323 SCS SWFWMD Type II Florida Modified rainfall distribution Impervious area from R/W to R/W for postdevelopment condition o SMF control elevations based on a combination of wetland SHW in receiving waters and Seasonal High Ground Water Table (SHGWT) at the SMF sites e Two feet of freeboard (from the back of berm elevation) is provided above the 100year peak stage e SMF areas are measured in microstation 20foot width berm with 1:4 side slope and 1:4 back slope from back of berm to existing ground 412 FLOODPLAIN COMPENSATION DESIGN APPROACH The SWFWMD recommends a cup for cup approach for the determination and design of floodplain encroachment/compensation volumes As directed by FDOT floodplain impacts were based on the assumption that the future roadway footprint will extend from R/W to R/W The encroachment volumes were calculated between the 100year flood elevation and the greater of seasonal high water elevation (SHW) or existing ground elevation using roadway cross sections and the average end area method of calculation Compensation volumes were calculated as proposed excavation volumes in floodplain compensation sites within or adjacent to the floodplain between the 100year flood elevation and the SHW in the floodplain Flood Insurance Rate Maps (FIRM) for Pasco County (1992) were utilized to identify four locations where potential fioodplain compensation is available These maps do not indicate the 100year flood elevations Floodplain locations and information at the proposed floodplain compensation sites were requested from the SWFWMD URS received maps from Mr David Arnold and Mr Richard Mayer indicating the 100year (1 day and 5 day) peak stages for the G:\ProjFDO nv8\4 t NonED\drainage\Reports\ 10 PHASE 11 DRAjNAGE DESIGN DOCUMENTATION REPORT 8I2012doc

14 10 7) 10) Ims I75 (SR 93) FPID: project limits This information is provided in Appendix E Encroachment Calculations Floodplain The 100year 5 day flood elevation was used to calculated floodplain encroachment and compensation volumes The areas of interest were identified on the SWFWMD Preliminary Floodplain Map Where the project area fell between two nodes of the SWFWMI) model the 100year flood elevation was interpolated The floodplain maps along with a table indicating the 100year flood elevations (lday and 5day) are provided in Appendix E Floodplain Encroachment Calculations In open basins (basins 1 floodplain compensation (IFPC) sites were sized to provide compensatory floodplain volume for full encroachment into the 100year floodplains In closed basins (basins 8 floodplain compensation (FPC) sites were sized to provide compensatory floodplain volume for full encroachment into the 100year floodplains plus increased 100year 24hour runoff volumes due to basin shifts and due to a 100% impervious rightofway 42 DESIGN CRITERIA Water Quality Treatment Water quality criteria for the project are as specified in Part B Chapter 5 of the Southwest Florida Water Management District Environmental Resource Permitting Information Manual In general the provided water quantity volume for wet and dry detention is conservatively based on 1 inch over the impervious area which is assumed to be R/W to R/W Water Quantity At:tenuation SWFWMD Analysis: Water Quantity criteria for the project are as specified in Part B Chapter 4 of the Southwest Florida Water Management District (SWFWMD) Environmental Resource Permitting Information Manual The project includes 10 drainage basins ofwhich basins 17 are considered open and basins 8 are closed For SWFWMD open basin criteria the postdevelopment discharge rate should not exceed the predevelopment discharge rate for the 24 year 24hour storm For closed basin criteria water quantity att:enuation volume will be provided in the FPC sites adjacent to the SMF Therefore recovery volume is not required e Critical Duration (FDOT Rule Chapter 1486) FDOT Critical Duration Analysis: In open basins for each frequency and duration the postdevelopment peak discharge rate will be no greater than the predevelopment peak discharge rate The SMF size is based on 100year 8hour and 100year 24hour storm event For closed basins the SMF size is based on attenuation of the postdevelopment discharge volume as necessary to be less than G:\PrnjFDOT\V8\ NonED\drainage\Reports\ 11 PHASE II DRAJNAGE DESIGN DOCUMENTATION REPORT doc

15 URS I75 (SR 93) FPID: or equal to the predevelopment discharge volume The SCS Curve Number Method was utilized with FDOT rainfall distributions For wet detention and dry retention the initial stage in the SMF was set to the top of the water quality treatment volume for open basins For closed basins the initial stage is set at the top of water quality treatment volume and 100year 24hour pre v/s post SWFWMD rainfall runoff volume difference o SMF Design: SMF berms will have a 20 width at a 1:20 slope Side slopes will be 1:4 Back slopes and tiedown slopes will be 1:4 Desirable inside berm radius will be 50 (35 minimum) SMF sites will be fenced regardless of side slopes Skimmer devices will be used on all SMF control structures from 6" below the weir elevation to at or above the 100year SMF peak stage For wet detention ponds a turndown bleeder device will be used to discharge the water quality treatment volume The back of berm elevation will be set for two feet of freeboard above the 100year SMF peak stage Lined SMF It is anticipated that SWFWMD will require liners for the SMF sites where the control elevations are significantly lower than the ground water at the SMF site to eliminate groundwater draw down impacts on adjacent properties I Impaired Water Body Treatment Impaired Water Body treatment criteria for the project are based on the Best Management Practice Analysis Aid provided from the Southwest Florida Water Management District Web site In general the provided water quality and quantity volume for wet and dry detention treatment train is calculated from the Design Aid Spreadsheet o Tailwater and Outfall Conditions Tailwater elevations were estimated based on SHW in the receiving water rising to 100year high water at hour 12 Seasonal High Waters were estimated based on SWFWMD aerial contours cross drain stain lines and wetland vegetation 100year high waters were based on top of bank elevation of drainage ways and floodplain elevations p Floodplain Encroachment/Compensation Floodplain encroachment/compensation criteria for the project were evaluated based on requirements specified in Part B Chapter 4 of the SWFWMD Environmental Resource Permitting Information Manual G:\ProjFDOT\VB\ NonED\drainage\Reports\ 12 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

16 URS I75 (SR 93) FPID: POND SITE SELECTED The Pond Siting Report evaluated alternate SMF sites and recommended pond sites for final design The evaluation were consider not only the hydraulic adequacy of the sites but also the IUW cost additional construction cost wetlands Threatened & Endangered (1&E) species hazardous materials cultural resources and utilities The recommended sites were accepted by FDOT for inclusion in the project Estimated seasonal high groundwater (SHGW) was provided by Tierra Inc (an environmental and geotechnical consultant) for each SMF site In order to minimize acreage required for the SMF sites for wet detention SMFs the control elevations were set at the seasonal high water elevations in the outfalls which are considerably lower than the seasonal high groundwater elevations at the SMF sites In cases where the control elevation is lower than SHGW it is anticipated that SWFWMD will require impermeable liners to isolate the SMFs from the adjacent groundwater to avoid impacts to the groundwater in the adjacent areas See Appendix H for SMFs with access easements and Appendix I for the existing project drainage maps proposed drainage maps for post development conditions SWFWMD aerial contour maps cross drains and the outfalllocations 431 Open Basin (Basins and 8) 4311 Proposed Drainage Basin 1 Runoff from the basin 1 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to a combined SMF being designed under FPID This combined SMF will be provided for a portion ofthe adjacent project to the south and basin 1 south of station on the west side of I75 The proposed basin l roadway drainage area is 5647 acres This SMF will provide treatment and attenuation of combined basins runoff and will discharge to the downstream (west) end of cross drain 2 after passing through our FPC 1 The discharge continues westerly through an Unnamed Drain (WBID 1425) and Bayou Branch Drain (WBID 1418A) that ultimately outfalls into Cypress Creek Our project will send 5647 acres of impervious I75 rightofway from station to Station to SMF 1 The low edge ofpavement elevation of 9121 at station will control design high water stages in SMF 1 The treatment volume recovery will be provided by an orifice bleeddown device See Appendix I for the SWFWMD aerial contour maps cross drain 1 and cross drain Proposed Drainage Basin 2 Runoff from the basin 2 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to G:\ProjFDOT\V8\4 I NonED\drainage\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc 13

17 Ims I75 (SR 93) FPID: SMF 2 The proposed basin 2 drainage area is 822 acres (551 acres of I75 rightofway and 271 acres of SMF 2 site) SMF 2 will provide treatment and attenuation for basin 2 runoff and will discharge to the downstream (west) end of cross drain 3 continue westerly through Bee Tree Branch (WBID 1410) that ultimately outfalls into Cypress Creek See Appendix H for SMF 2 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 2 drainage area cross drain 3 and outfalllocation Basin 2 Stormwater Management Facility (SMF) SMF 2 is located near Station on the west side of I75 Discharge from this SMF site outfalls downstream of cross drain 3 on the west side of the alignment The landuse on this undeveloped site consists of a single parcel that includes mostly grass Existing ground elevations estimated at the corners o f the SMF site were averaged to approximately 940 According to the SCS Soils Survey of Pasco County Wauchula soils exist on the site with a SHW of approximately 00 feet to 10 feet below the ground surface with an average depth of 05 feet The estimated SHW table is elevation 935 Also according to Tierra Inc the average SHW table is elevation 935 Stormwater management requirements will be met using wet detention and treatment volume recovery will be met using an orifice bleeddown device The proposed tailwater elevation of 908 NAVD = 916 NGVI) is the average ofnode NA0420 and NA 0400 with 100year 5 day elevations of 864 NAVD and 952 NAVD respectively The outfall structure is located between these nodes on the west side of the alignment downstream of cross drain 3 These node elevations are part of the Cypress Creek model prepared for the SWFWMD The estimated parcel size for SMF 2 is 271 acres 4313 Proposed Drainage Basin 3 Runoff from the basin 3 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to SMF 3 The proposed basin 3 drainage area is 2656 acres (2169 acres of I75 rightofway and 487 acres of SMF 3 site) The proposed SMF will provide treatment and attenuation ofbasin runoff and will discharge to cross drain 3 continues westerly through Bee Tree Branch (WBID 1410) that ultimately outfalls into Cypress Creek See Appendix H for SMF 3 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 3 drainage area cross drain 3 and outfalllocation O:\ProjFDOT\V8\ NonED\drainage\Reports\ 14 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

18 URS I75 (SR 93) FPID: Basin 3 Stormwater Management Facility (SMF) SMF 3 is located near Station feet west of I75 Discharge from this SMF site outfalls downstream of cross drain 3 on the west side of the alignment The landuse at this undeveloped site consists of a single parcel that includes grass shrubs and a few trees Existing ground elevations estimated at the corners of the SMF site were averaged to approximately 96 According to the SCS Soils Survey ofpasco County Newman soils exist on the site with a SHW of approximately 15 feet to 25 feet below the ground surface with an average depth of 2 feet The estimated SHW table by Tierra Inc the environmental and geotechnical engineers is elevation 946 NGVD Stormwater management requirements will be met using wet detention and treatment volume recovery will be met using an orifice bleeddown device The proposed tailwater elevation is based on Node NA0400 with 100year 5 day elevation of 952 NAVD = 960 NGVD This node is located onthe west side of the alignment downstream of cross drain 3 and is part of the Cypress Creek model prepared for the SWFWMD The estimated parcel size for SMF 3 is 487 acres 4314 Proposed Drainage Basin 4 Runoff from the basin 4 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to SMF 4 The proposed basin 4 drainage area is 2749 acres (2238 acres of I75 rightofway and 511 acres of SMF 4 site) The SMF will provide treatment and at:tenuation ofbasin runoff and will discharge to the downstream (west) end of cross drain 4 mainline that outfalls directly into Cypress Creek (INorth) (WB1D 1440E) This WBID is listed as an Impaired Water Body per the 303(d) Impaired Water Bodies lists generated by the Florida Department of Environmental Protection (FDEP) The impairinents listed for this WBID are dissolved oxygen and nutrients (chlorophyll) See Appendices A and B for verified impaired water bodies lists and WBID maps See Appendix H for SMF 4 with access easements and Appendix I for the SWFWMI) aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 4 drainage area cross drain 4 and outfall location Basin 4 Stormwater Management Facility (SMF) SMF 4 is located near Station on 150 feet west of I75 Discharge from this SMF site outfalls to the downstream end of cross drain 4 on the west side of the alignment The landuse at this undeveloped site consists of a single parcel that includes mostly grass Existing ground elevations estimated at the corners of the SMF site were averaged to approximately 1055 NGVD According to the SCS Soils Survey of Pasco County Blichton and Pomona soils exist on the site with a SHW of approximately 00 feet to 10 feet below G:\ProjFDOT\V8\ ?NonEED\dmmage\Reports\ 15 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT 8l2012doc

19 URS I75 (SR 93) FPID: the ground surface with an average depth of 05 feet The estimated SHW table by Tierra Inc the environmental and geotechnical engineers is elevation 1069 NGVD Stormwater management requirements will be met using pretreatment/wet detention treatment train to provide net improvement in nutrient loading The floodplain elevation is based on Node NI 1460 with a 100year 1day elevation of 978 NAVD 986 NGVD This node is located = on the west side of the alignment downstream o f cross drain 4 and is part of the Cypress Creek model prepared for the SWFWMD The tailwater is based on the top of bank contour line (elevation 104) for the lateral ditch as shown on the SWFWMD aerial contour map SEC 29 TWP 24 RNG 20 The estimated parcel size for SMF 4 is 511 acres 4315 Proposed Drainage Basin 5 Runoff from the basin 5 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to SMF 5 The proposed basin 5 drainage area is 972 acres (729 acres of I75 rightofway and 243 acres of SMF 5 site) The SMF will provide treatment and attenuation of basin runoff and will discharge to the downstream (west) end of cross drain 5 that outfalls directly into Cypress Creek (North) (WBID 1440E) This WBID is listed as an Impaired Water Body per the 303(d) Impaired Water Bodies lists generated by the Florida Department of Environmental Protection (FDEP) See Appendix H for SMF 5 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 5 drainage area cross drain 5 and outfall location Basin 5 Stormwater Management Facility (SMF) SMF 5 is located near Station feet west of I75 Discharge from this SMF site outfalls to the downstream end of cross drain 5 on the west side of the alignment The landuse at this undeveloped site consists of a single parcel of mostly grass Existing ground elevations estimated at the corners ofthe SMF site were averaged to approximately 1075 NGVD According to the SCS Soils Survey of Pasco County Pomona soils exist on the site with a SHW of approximately 00 feet to 10 feet below the ground surface with an average depth of 05 feet The estimated SHW table by Tierra Inc the environmental and geotechnical engineers is elevation 1073 NGVD Stormwater management requirements will be met using pretreatment/wet detention treatment train to provide net improvement in nutrient loading The proposed SMF 5 discharge point is within Node NI 1330 with 100year 5 day elevations 9912 NAVD = 9993 NGVD that serves as the tailwater for G:\ProjFDOT\V8\ Non ED\drainage\Reports\ 16 PHASE Il DRAINAGE DESIGN DOCUMENTATION REPORT doc

20 URS I75 (SR 93) FPID: SMF 5 These node elevations are part of the Cypress Creek model prepared for the SWFWMD The estimated parcel size for SMF 5 is 243 acres 4316 Proposed Drainage Basin 6 Runoff from the basin 6 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to the respective SMF The proposed basin 6 drainage area is 6916 acres (5297 acres of I75 rightofway and 1619 acres of SMF 6 site) The SMF will provide treatment and attenuation of basin runoff and will discharge to the downstream (west) end of cross drain 6 that outfalls directly into Cypress Creek (North) (WBID 1440E) This WBID is listed as an Impaired Water Body per the 303(d) Impaired Water Bodies lists generated by the Florida Department of Environmental Protection (FDEP) The impairments listed for this WBID are dissolved oxygen and nutrients (chlorophyll) See Appendices A and B for verified impaired water bodies lists and WBID maps See Appendix H for SMF 6 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 6 drainage area cross drain 6 cross drain 7 and outfall location Basin 6 Stormwater Management Facility (SMF) SMF 6 is located near Station feet west of I75 Discharge from this SMF site outfalls to the downstream end of cross drain 6 on the west side ofthe alignment The landuse at this site includes grass and a few trees Existing ground elevations estimated at the corners of the SMF site were averaged to approximately 1055 NGVD According to the SCS Soils Survey of Pasco County Pomona soils exist on the site with a SHW of approximately 00 feet to 10 feet below the ground surface with an average depth of 05 feet The estimated SHW table by Tierra lnc the environmental and geotechnical engineers is elevation 1026 NGVD Stormwater management requirements will be met using pretreatment/wet detention treatment train to provide net improvement in nutrient loading The outfall control structure is located within Node NI 1020 with a 100year 5 day elevation of NAVD = NGVI) that serves as the tailwater for SMF 6 These node elevations were obtained from the Cypress Creek model prepared for the SWFWMD This node is located on the west side of the alignment downstream of cross drain 6 The estimated parcel size for SMF 6 is 1619 acres 4317 Proposed Drainage Basin 7 Runoff from the basin 7 drainage area between Station and Station will be conveyed by roadside ditches and storm efrain systems to the respective SMF The proposed basin 7 drainage area is 2535 acres (1894 G:\ProjFDOT\V8\4110 t NonED\drainage\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc 17

21 URS I75 (SR 93) FPID: acres of I75 rightofway and 641 acres of SMF 7 site) The SMF will provide treatment and attenuation of basin runoff and will discharge to the downstream (west) end of cross drain 8 that outfalls directly into Cypress Creek (North) (WBID 1440E) This WBID is listed as an Impaired Water Body per the 303(d) Impaired Water Bodies lists generated by the Florida Department of Environmental Protection (FDEP) The impairments listed for this WBID are dissolved oxygen and nutrients (chlorophyll) See Appendices A and B for verified impaired water bodies lists and WBID maps See Appendix H for SMF 8 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 7 drainage area cross drain 8 and outfall location Basin 7 Stormwater Management Facility (SMF) SMF 7 is located near Station feet west of I75 Discharge from this SMF site outfalls to the channel downstream of cross drain 8 on the west side ofthe alignment The landuse at this site includes a few trees Existing ground elevations estimated at the corners of the SMF site were averaged to approximately 1500 NGVD According to the SCS Soils Survey ofpasco County Pomona soils exist on the site with a SHW of approximately 00 feet to 10 feet below the ground surface with an average depth of 05 feet The estimated SHW table by Tierra Inc the environmental and geotechnical engineers is elevation 1328 NGVI) Stormwater management requirements will be met using pretreatment/wet detention treatment train to provide net improvement in nutrient loading The proposed tailwater elevation is 1400 NGVI) which is top ofbank elevation of the drainage channel at the SMF 7 outfall This tailwater elevation is above the 100year 1 day elevation 1202 NGVI) of the downstream Node NI 0700 of the SWFWMD Cypress Creek model The estimated parcel size for SMF 6 is 641 acres 432 Closed Basin (Basin 8 9 and 10) The project area that lies within Basins 89 and 10 are within closed basins The SMFs in these basins have been sized to accommodate the 100year 24hour pre v/s post runoff volume difference as well as the treatment volume These volumes are provided by excavation in upland next to the floodplain 4321 Proposed Drainage Basin 8 Basin 8 is a volume sensitive drainage basin and SMF 8 includes closed basin design criteria Runoff from the basin 8 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to SMF 8 The proposed basin 8 drainage area is 6485 acres (5510 acres of I75 G:\ProjFDOT\VS\ NonED\drainage\Reports\ 18 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

22 ImS I75 (SR 93) FPID: rightofway and 975 acres of SMF 8 site) The SMF will provide treatment of basin runoff and will discharge to the downstream (west) end of cross drain 11 Runoff from drainage basin 8 discharges to Moody Lake (West) (WBID 1392D) a volume sensitive floodplain Water quantity attenuation will be provided by excavating in an upland next the floodplain of Moody Lake Therefore recovery volume within the SMF is not required Basin 8 Stormwater Management Facility (SMF) SMF 8 is located near Station on the west side of I75 Discharge from this SMF site outfalls to Moody Lake SMF 8 is on low levels of two undeveloped parcels with landuse of grass and groves Existing ground elevations estimated at the corners of the SMF site were averaged to approximately 1280 ranging from elevations 108 to 143 Although the site will require considerable excavation to provide stormwater management below the low edge of pavement elevation of 1154 SMF 8 will require only parts oftwo parcels The SCS Soils Survey of Pasco County indicates the SMF site consists of Blichton soils with a SHGW ranging from 00 feet to 10 feet below the ground surface The SMF site also consists of Sparr soils with a SHGW ranging from 15 feet to 35 feet below the ground surface Since SMF 8 is located adjacent to Moody Lake the SHGW will typically be lower than that indicated by the soil survey Therefore the control elevation of 1084 was set by adding onehalf foot to the observed water surface elevation of Moody Lake (see the SWFWMD Contour Map February 1987) The estimated SHGW table by Tierra Inc the environmental and geotechnical engineers is elevation 1144 NGVD because the soil boring was performed in the middle of pond site on a steep slope Stormwater management requirements will be met using wet detention and treatment volume will be met using an orifice bleeddown device The proposed tailwater elevation is based on Node NA0100 with a 100year 5 day elevation of NAVD = NGVI) This node is located on the west side of the alignment downstream of cross drain 11 The node elevation is part of the Cypress Creek model prepared for the SWFWMD The estimated parcel size for SMF 8 is 975 acres See Appendix H for SMF 8 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 8 drainage area cross drain 13 and outfalllocation 4322 Proposed Drainage Basin 9 Basin 9 is a volume sensitive drainage basin and SMF 9 includes closed basin design criteria Runoff from the basin 9 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to SMF 9 The proposed basin 9 drainage area is 3742 acres (3168 acres of I75 O:\ProjFDOT\V8\ NonED\drainage\Reports\ PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc 19

23 URS I75 (SR 93) FPID: rightofway and 574 acres of SMF 9 site) Stormwater management for this basin will required a SMF that provides water quality treatment for closed basin criteria The SMF will be a wet system sized to provide the water quality treatment before discharging to the floodplain of Moody Lake(East) (WBID 1392E) a volume sensitive floodplain The SMF will discharge to an adjacent FPC site where it will store water quantity attenuation volume therefore no recovery volume is required The water quality treatment volume for the wet SMF will utilize a bleeddown orifice Since SMF 9 is located adjacent to the Moody Lake floodplain the SHW will typically be lower than that indicated by the soil survey or by Tierra the environmental and geotechnical engineers The SHW elevation of 1084 was estimated by adding onehalf foot to the observed water surface elevation of Moody Lake (see the SWFWMD Contour Map February 1987) See Appendix H for SMF 9 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 9 drainage area cross drain 13 and outfalllocation Basin 9 Stormwater Management Facility (SMF) SMF 9 is located near Station feet east of I75 Discharge from this SMF site outfalls to Moody Lake on the east side of the alignment SMF 9 is on the low slopes of three undeveloped parcels with landuse of mostly trees and shrubs Existing ground elevations estimated at the corners ofthe SMF site were averaged to approximately 1278 The SCS Soils Survey of Pasco County indicates the SMF site consists of Sparr soils with a SHW ranging from 15 feet to 35 feet below the ground surface with an average depth of 25 feet below existing ground The estimated SHGW table by Tierra Inc the environmental and geotechnical engineers is elevation 1164 NGVD Stormwater management requirements will be met using wet detention and treatment volume will be met using an orifice bleeddown device The proposed 100year tailwater elevation is based on Node NA0060C with a 100year 5 day elevation of NAVD which is equal to NGVD This node is located on the east side of the alignment downstream end o f cross drain 13 The node elevation is part of the Cypress Creek model prepared for the SWFWMD The estimated parcel size for SMF 9 is 574 acres 4323 Proposed Drainage Basin 10 Basin 10 is a volume sensitive drainage basin and SMF 10 includes closed basin design criteria Runoff from Station to Station will be shifted to basin 9 The basin 10 drainage area between Station and Station will be conveyed by roadside ditches and storm drain systems to SMF 10 The proposed basin 10 roadway drainage area is 3272 acres (2755 acres of I75 rightofway and 517 acres of SMF 10 site) The SMF will be a treatment G:\ProjFDOT\VB\ Non ED\dminage\Reports\ 20 PHASE Il DRAJNAGE DESIGN DOCUMENTATION REPORT doc

24 urs I75 (SR 93) FPID: train providing treatment of basin runoff in the dry and permanent pool portions The water will then discharge to FPC 10 that is connected to Mud Lake which outfalls directly into the Withlacoochee River (WBID 1329F) Attenuation volume is provided in the FPC site therefore recovery is not required This WBID is listed as an Impaired Water Body per the 303(d) Impaired Water Bodies lists generated by the Florida Department of Environmental Protection (FDEP) The impairment listed for this WBID is mercury (in fish tissue) See Appendices A and B for verified impaired water bodies lists and WBID maps See Appendix H for SMF 10 with access easements and Appendix I for the SWFWMD aerial contour maps and proposed drainage maps for post development conditions drainage patterns basin 10 drainage area cross drain 15 cross drain 16 and outfalllocation Basin 10 Stormwater Management Facility (SMF) SMF 10 is located near Station feet west ofi75 Discharge from this SMF site outfalls to FPC 10 that is connected to Mud Lake SMF 10 is on the slopes of two undeveloped parcels with landuse of mostly trees Existing ground elevations estimated at the corners of the SMF site were averaged to approximately 1220 The SCS Soils Survey ofpasco County indicate the SMF site consists of Flemington and Pompano soils with a SHGW ranging from 00 feet to 10 feet below the ground surface The estimated SHW table by Tierra Inc the environmental and geotechnical engineers is elevation 1177 NGVD Since SMF 10 is located adjacent to a floodplain the SHGW will typically be lower than that indicated by the soil survey The estimated SHGW table of adjacent wetland (Mud Lake) by Tierra the environmental and geotechnical engineers is elevation 1030 NGVD Therefore the SHGW elevation of 1050 NGVD was estimated by adding two feet to the observed SHW of Mud Lake Stormwater management requirements will be met using a treatment train where treatment volume will be provided The proposed 100year tailwater elevation is based on Node NA1680 with a 100year 5 day elevation of NAVD = NGVD This node is located on the east side of the alignment upstream end of cross drain 16 Node NA1680 is part ofthe Withlacoochee River model (Toachodka data) model prepared for the SWFWMD The estimated parcel size for SMF 10 is 517 acres G:\ProjFDOT\V8\ NonED\dramage\Repods\ 21 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

25 URS I75 (SR 93) FPID: FLOOD PLAIN COMPENSATION AREA (FPC) EVALUATIONS 441 Basin 1 FPC A portion of Basin 1 is located within the 100year FEMA floodplain From Station to Station fioodplain encroachments due to ditch berms and roadway embankment will require compensation Below is the description of FPC 1 site e Floodplain Compensation Site 1 (FPC 1) This is a vacant undeveloped parcel adjacent to I75 It is located approximately at Station feet west of I75 Access to this site would be provided thru I75 R/W This is a private property and will be partially impacted FPC 1 will be directly connected to the downstream (west) end of cross drain Basin 2 FPC A portion of Basin 2 is located within the 100year FEMA floodplain From Station to Station floodplain encroachment due to SMF berms / volume ditch berms and roadway embankment will require compensation Below is the description of FPC 2 site Floodplain Compensation Site 2 (FPC 2) This is a partially developed parcel located approximately at Station feet east of I75 Access to this site would be provided thru I75 R/W This is a private property and will be partially impacted 443 Basin 3 FPC Basin 3 is located entirely outside of the 100year FEMA floodplain; floodplain compensation will be required therefore no 444 Basin 4 FPC Basin 4 is located entirely outside of the 100year FEMA floodplain; floodplain compensation will be required therefore no 445 Basin 5 FPC Basin 5 is located entirely outside of the 100year FEMA floodplain; therefo: e no floodplain compensation will be required G:\ProjFDOT\V 8\ NonED\dramage\Reports\ 22 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

26 URS I75 (SR 93) FPID: Basin 6A FPC A portion of Basin 6A is located within the 100year FEMA floodplain From Station to Station floodplain encroachment due to SMF berms / volume ditch berms and roadway embankment will require compensation Below is the description of FPC 6A site Floodplain Compensation Site 6A (FPC 6A) This is a vacant undeveloped parcel located approximately at Station feet west of I75 Access to this site would be provided by an easement adjacent to I75 R/W This is a private property and will be completely impacted 447 Basin 68 FPC A significant portion of Basin 6B is located within the 100year FEMA fioodplain From Station to Station floodplain encroachment due to SMF berms / volume ditch berms and roadway embankment will require compensation Below is the description of FPC 6B site Floodplain Compensation Site 6B (FPC 6B) This is a vacant undeveloped parcel located approximately at Station feet east of I75 Access to this site would be provided thru I75 R/W This is a private property and will be partially impacted 448 Basin 7 FPC Basin 7 is located entirely outside of the 100year FEMA floodplain; therefore no floodplain compensation will be required 449 Basin 8 FPC A portion of Basin 8 is located within the 100year FEMA ftoodplain and a closed basin From Station to Station floodplain encroachment due to SMF berms / volume ditch berms and roadway embankment will require compensation Below is the description of FPC 8 site Floodplain Compensation Site 8 (FPC 8) This is a vacant undeveloped parcel adjacent to I75 It is located approximately at Station feet west of I75 Access to this site would be provided thru I75 R/W This is a private property and will be partially impacted In addition to floodplain compensation volume this site will provide 100year prepost runoff volume for basin 8 G:\ProJFDOT\VS\ ?Non ED\drainage\Repo# PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc 23

27 ers I75 (SR 93) FPID: Basin 9 FPC Basin 9 is located entirely outside of the 100year FEMA floodplain within a closed basin; therefore no floodplain compensation will be required FPC 9 will provide 100 year prepost runoff volume for basin 9 0 Floodplain Compensation Site 9 (FPC 9) This is a vacant undeveloped parcel adjacent to I75 It is located approximately at Station feet east of I75 Access to this site would be provided thru I75 R/W This is a private property and will be partially impacted 4411 Basin 10 FPC A portion of Basin 10 is located within the 100year FEMA floodplain and a closed basin From Station to Station floodplain encroachment due to SMF berms / volume ditch berms and roadway embankment will require compensation Below is the description of FPC 10 site Floodplain Compensation Site 10 (FPC 10) This is a vacant undeveloped parcel adjacent to I75 It is located approximately at Station feet west of I75 Access to this site would be provided thru I75 R/W This is a private property and will be partially impacted In addition to floodplain compensation volume this site will provide 100year prepost runoff volume for basin 10 G:\ProjFDOT\V8\ NonED\drainage\Reports\ 24 PHASE II DRAINAGE DESIGN DOCUMENTATION REPORT doc

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