part 1 – existing stormwater management system evaluation

Stormwater Master Plan Nassau County, FL

DRAFT

Part 1 – Existing Stormwater Management System Evaluation

Prepared For:

Prepared By:

5220 Shad Road, Suite 200 Jacksonville, Florida 32257

September 2008

TABLE OF CONTENTS SECTION PAGE

TABLE OF CONTENTS ............................................................................................. i

LIST OF TABLES .................................................................................................... iii EXECUTIVE SUMMARY ..........................................................................................1

1. INTRODUCTION AND BACKGROUND ...................................................................2 2. PRELIMINARY DRAINAGE DATA ...........................................................................5

2.1. Upper St. Marys Basin .................................................................................5 2.2. Middle and Lower St. Marys Basin ..............................................................5 2.3. Nassau River Basin .....................................................................................6

3. DATA COLLECTION AND EVALUATION ................................................................9

3.1. Existing Reports, As-Built Drawings, Survey Data.......................................9 3.2. Hydrologic Meteorological Records ..........................................................10 3.2.1. SJRWMD......................................................................................10 3.2.2. NOAA ...........................................................................................11 3.2.3. USGS ...........................................................................................11 3.3. Existing and Proposed Drainage Systems.................................................13 3.4. Documentation of Past Flooding Complaints .............................................13 3.5. Documented Finish Floor Elevations .........................................................13 3.6. Land Use Data............................................................................................13 3.7. Water Quality Data .....................................................................................15 3.8. Existing Water Bodies and Wetlands .........................................................16 3.9. Rules, Regulations, Ordinances, and Laws ...............................................16 3.9.1 Nassau County..............................................................................16 3.9.1.1. Codes of Law and Ordinances.....................................16 3.9.1.2. Comprehensive Plan ....................................................17 3.9.1.3. Development Review Regulations ...............................17 3.9.2. SJRWMD......................................................................................17 3.9.3. EPA...............................................................................................18 3.9.4. FDEP ............................................................................................19 3.10. Archaeological Resources..........................................................................21 3.11. National Wetlands Inventory Maps (NWI) ..................................................21 3.12. Florida Land Use Cover and Classification System Maps (FLUCCS) .......21 3.13. Proposed Wetland Mitigation Areas...........................................................24 3.13.1. Longleaf Mitigation Bank ............................................................24

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3.13.2. Northeast Florida Mitigation Bank ..............................................26 3.13.3. Loblolly Mitigation Bank..............................................................26 3.13.1. Thomas Creek Mitigation Bank ..................................................26 3.14. Soils ............................................................................................................29 3.15. GIS Data Collected.....................................................................................31 3.15.1. Florida Department of Environmental Protection .......................31 3.15.2. Florida Department of Transportation ........................................32 3.15.3. Nassau County...........................................................................33 3.15.4. Nassau County Aerials...............................................................34 3.15.5. St. Johns River Water Management District ..............................34

4. SYSTEM INVENTORY AND MAPPING .................................................................35 4.1. Base Maps..................................................................................................35 4.2. Local Problem Identification .......................................................................35 4.3. System Inventory........................................................................................36 4.4. Stormwater Model Schematic ....................................................................36 4.5. Survey Plan ................................................................................................38 4.5.1. Digital Terrain Model ....................................................................39 4.5.2. Hydraulic Feature Inventory .........................................................39 4.5.2.1. System Scale................................................................40 4.5.2.2. Field Reconnaissance..................................................41 4.5.2.3. Surveys.........................................................................43

5. WETLAND INVENTORY.........................................................................................48 6. WATER QUALITY ...................................................................................................49

6.1. 19010001 St. Mary’s River .........................................................................50 6.1.1. Web Address ................................................................................50 6.1.2. Basin Area ....................................................................................50 6.1.3. Location ........................................................................................50 6.1.4. Point Sources ...............................................................................50 6.1.5. St. Mary’s River Water Quality Summary.....................................50 6.2. 19020002 Nassau River.............................................................................52 6.2.1. Web Address ................................................................................52 6.2.2. Basin Area ....................................................................................52 6.2.3. Location ........................................................................................52 6.2.4. Point Sources ...............................................................................52 6.2.5. Nassau River Water Quality Summary ........................................53 6.3. Nassau River near Italia (NRI) ...................................................................54 6.3.1. Web Address ................................................................................54

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6.3.2. Basin Area ....................................................................................54 6.3.3. Location ........................................................................................54 6.3.4. Point Sources ...............................................................................54 6.3.5. NRI Water Quality Summary ........................................................55 6.4. SJA-HS-1018 (St. Marys River) .................................................................56 6.4.1. Web Address ................................................................................56 6.4.2. Basin Area ....................................................................................56 6.4.3. Location ........................................................................................56 6.4.4. Point Sources ...............................................................................56 6.4.5. SJA-HS-1018 Water Quality Summary ........................................57

7. DATA COLLECTION NEEDS ASSESSMENT........................................................58

7.1. Stream Flow Data.......................................................................................58 7.2. Rainfall Data ...............................................................................................58 7.3. Stream Flow Data.......................................................................................58 7.4. Additional Recommendations.....................................................................58

APPENDICES

Appendix A – Report Figures Appendix B – Base Maps Appendix C – Wetland Report Appendix D – Flood Prone Areas Appendix E – DVDs

LIST OF TABLES FIGURE NO. PAGE Table 1.1 Nassau County Land Summary ...................................................................2 Table 1.2 Nassau County Population Summary ..........................................................3 Table 2.1 Basin / Subbasin Summary ..........................................................................6 Table 3.1 Nassau County DRIs..................................................................................14 Table 3.2 Sections of Nassau County Code of Laws and Ordinance Related to Stormwater Master Planning..........................................................................................16 Table 3.3 Sections of Chapter 40, F.A.C. related to permitting..................................18 Table 3.4 FDEP Rules................................................................................................20 Table 3.5 FLUCCS Designations ...............................................................................21 Table 3.6 Nassau County Soils ..................................................................................30 Table 4.1 Stormwater Model Schematic Node / Subbasin Association .....................36 Table 6.1 St. Mary’s River Water Quality Summary...................................................51 Table 6.2 Nassau River Water Quality Summary ......................................................53 Table 6.3 Nassau River near Italia Water Quality Summary......................................55 Table 6.4 St. Marys River Water Quality Summary....................................................57

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Nassau County Stormwater Master Plan Page 1 of 58 Part I – Existing Stormwater Management System Evaluation Draft Report

Executive Summary Nassau County received funding from the St. Johns River Water Management District for development of a Stormwater Master Plan (SWMP). The SWMP is to be divided into three parts, as follows:

Part I Existing stormwater management system evaluation including inventory update, which is included in this Contract.

Part II Coordination with Nassau County contractor to perform engineering analysis of the existing stormwater system and identification of problem areas.

Part III Engineering analysis to develop management alternatives and/or regional

solutions. This report represents the results of Part I – Existing Stormwater Management System Evaluation. This report compiles available data, updates the open and closed system inventory, includes existing available engineering plans and studies, and map inventory features. The results of these efforts include the updating of stormwater flow patterns in the watershed, the determination of data gaps between existing data and data needed for modeling, and the preparation of a new scope of services to collect the additional needed data. In addition to the hard copy maps and information presented in this report, digital copies of all compiled information is also presented in Appendix E of this report, for use by others in future studies or engineering projects.


1. Introduction and Background Nassau County is located in the extreme northeast corner of Florida. It is bordered by the Atlantic Ocean on the east, Duval County on the south, by the State of Georgia on the north and on most of its western border, and by Baker County for a very short segment of its western border. The County encompasses 423,596 total acres of land (662 square miles). A location map (Figure A-1) is located in Appendix A. Table 1.1, below, provides a breakdown of the existing land distribution in Nassau County. Approximately 31 % of the total land is classified as wetlands. There are 366,750 acres of land available for potential development, which represents 87% of the total land area, though a significant portion of this land is classified as wetlands. Table 1.1 Nassau County Land Summary

Area Disposition Area

(acres) Percent of Total

Land Area Nassau County 423,596 100%

Wetlands 129,558 31% Uplands 294,037 69%

City Limits 11,449 3% Management Areas 30,582 7%

DRI Boundaries 14,813 3%


As noted above, Nassau County provides the northern border of Duval County, of which the City of Jacksonville encompasses the entire county limits. The Jacksonville area is a rapidly developing region, and this development has extended into Nassau County, as well, due to its proximity to the urban core. The report titled, Florida Estimates of Population 2006, compiled by the University of Florida’s Bureau of Economic and Business Research (BEBR) provided a population estimate for Nassau County of 68,188 for April 2006. This represents an increase of 10,525 from the April 2000 value of 57,663, representing a growth rate of over 18% since the year 2000. Nassau County contains three incorporated cities: Callahan, Fernandina Beach, and Hilliard. The remainder of the County consists of unincorporated areas. The 2006 population is broken down in Table 1.2, below. Table 1.2 Nassau County Population Summary

Location April 2000 Population

April 2006 Population

Numeric Change

% Increase

Nassau County 68,188 57,663 +10,525 18.3% Callahan 962 1,345 +383 39.8%

Fernandina Beach 10,549 11,815 +1,266 12.0% Hilliard 2,702 2,964 +262 9.7%

Unincorporated Areas 43,450 52,064 +8,614 19.8% Table 1.2 demonstrates that while the town of Callahan had the greatest percent increase in its growth between 2000 and 2006, the population in Callahan represents only a very small fraction of the overall County population. The vast majority of the growth in the county occurred in unincorporated areas, for which the Nassau County government is responsible for providing services, including road maintenance, flood control and development review. Services within the incorporated Cities are provided by the respective City governments, with coordination and cooperation with the County government on an as-needed basis. The County is committed to the goal of promoting economic development, but at the same time minimizing impacts to the natural environment. As development occurs and the population increases, it is also inherently important to ensure these developments are located and designed to ensure that they do not create drainage problems or contribute to preexisting drainage problems. As more developments are constructed in or near the numerous Nassau County wetlands and water bodies, areas that may have always been subject to drainage problems that had been unidentified due to no population in the area may suddenly become major issues as individuals and businesses move in. It is for these reasons that the development of a comprehensive stormwater management plan is so important for rapidly developing areas like Nassau County. Stormwater management plans (SWMPs) provide communities with a number of benefits. They generally establish drainage basin boundaries. The flood elevations developed in SWMPs help communities demand a reasonable level of flood protection for new development by requiring the finished floor elevations of new structures to be above these levels. SWMPs also demonstrate how flood elevations may increase if development occurs without adequate stormwater management. SWMPs provide a working model of the drainage structures and the open channels within a community’s major riverine systems. One very important aspect to SWMPs is the identification of existing flood-prone areas. In conjunction with the logging of


drainage complaints, a SWMP helps communities prioritize the resources available to improve their drainage infrastructure. From a water quality standpoint, SWMPs may include models for determining pollutant loads and transport for each basin and identify basins with water quality concerns. They may identify likely areas of high pollutant loading and high future pollutant loading. As a result, SWMP water quality models can assist communities in implementing their pollutant load reduction goals (PLRG’s) to meet total maximum daily loads (TMDL’s) of priority pollutants. Nassau County contributes to the St. Marys River and Nassau River basins, which lie within the limits of the St. Johns River Water Management District (SJRWMD). As the principal state level governmental entity responsible for promoting effective and sustainable use of public waters, SJRWMD supports the efforts of counties and municipalities in the areas of stormwater management and master planning. As noted previously, only a small percentage of the County lies in protected areas, and the remaining areas are rapidly undergoing a conversion from forested lands to developed areas, especially around the urban centers of Fernandina Beach, Amelia Island, Hilliard, Callahan, and Yulee. Along with proposals to acquire land to serve as buffers and easements, SJRWMD has been asked by local organizations (Nassau County and the St. Marys River Management Committee) to help support stormwater master planning including flood hazard protection and the maintenance of water quality. Funding has been provided by SJRWMD to begin the establishment of a SWMP for Nassau County. SJRWMD requires that the study be undertaken in three (3) parts:

Part I Existing stormwater management system evaluation including inventory update, which is included in this Contract.

Part II Coordination with Nassau County contractor to perform engineering analysis of the existing stormwater system and identification of problem areas.

Part III Engineering analysis to develop management alternatives and/or regional

solutions. This report represents the results of Part I – Existing Stormwater Management System Evaluation. This report compiles available data, updates the open and closed system inventory, includes existing available engineering plans and studies, and map inventory features. The results of these efforts include the updating of stormwater flow patterns in the watershed, the determination of data gaps between existing data and data needed for modeling, and the preparation of a new scope of services to collect the additional needed data.


2. Preliminary Drainage Data Nassau County encompasses three major drainage basins: Upper St. Mary’s River, the Middle and Lower St. Mary’s River and the Nassau River. In reality, there are very small areas in the extreme eastern areas of the County that drain either to the Intracoastal Waterway or directly to the Atlantic Ocean, but for the purposes of this report, all lands within Nassau County have been classified as falling into one of the three major basins. The climate in Nassau County is classified as humid subtropical, with an average summer maximum temperature of 90 degrees Fahrenheit. In the winter, the County experiences freezing temperatures from 3 to 10 times per year, starting as early as November 1 and extending to March 31. Average annual rainfall for the County is approximately 52 inches per year, with the highest rainfall occurring during the month of July. Over 65 percent of the average annual rainfall occurs in the months of June – October, when convective activity, caused by density differences in the atmosphere, generates showers and thunderstorms. A list of the tributaries within each of the three major basins is located at the end of this section. 2.1. Upper St. Marys Basin The Upper St. Marys Basin is located in the extreme southwestern tip of Nassau County, encompassing 28,453 acres of land area within the basin. For the purposes of this discussion, references to this basin mean areas that lie within Nassau County. There are 13 tributaries within this basin in Nassau County, of which the Brandy Branch is the principal tributary. Figure A-6 in appendix A depicts the Upper St. Marys Basin. The St. Marys River is a remote blackwater river that, for much of its length, forms the boundary between Florida and Georgia. In the Upper St. Marys Basin, the River forms the boundary between Nassau County and Baker County. Most of this basin is undeveloped and no urban areas are located within the basin limits in Nassau County. The river forms to the southwest of Nassau County and generally flow in a northern direction in the portion of the basin that lies in Nassau County. 2.2. Middle and Lower St. Marys Basin As its name would suggest, the Middle and Lower St. Marys Basin is immediately downstream from the Upper St. Marys Basin. This basin encompasses 301 square miles and contains 46 tributaries, the principal of which are Cabbage Creek, Deep Creek, Egans Creek, and Little St. Mary’s River. In this portion of Nassau County, the St. Marys River flows north, then east, forming the border between Nassau County and the State of Georgia. Figure A-7 depicts te middle and lower St. Marys Basin Much of this basin is undeveloped, though the towns of Hilliard and Fernandina Beach are located within this basin. Information from the St. Marys River Management Plan (located on CD in Appendix E), indicates the basin currently has good water quality with very few pollution discharge points. The predominant land use in the basin is silviculture. The streams in the St. Marys Basin are classified as Class III waters.


2.3. Nassau River Basin The Nassau River Basin drains approximately 418 square miles in Northeast Florida. While the basin includes 29 tributary streams, there are only four principal tributaries: Alligator Creek, Thomas Creek, Boggy Creek and Lofton Creek. The Nassau River forms a portion of the boundary between Nassau County and Duval County. The basin generally drains in an eastern direction, ultimately discharging to the Atlantic Ocean. The Nassau River is classified as an “Outstanding Florida Water”, by the Florida Department of Environmental Protection (FDEP). Figure A-8 in Appendix A depicts the Nassau River Basin. The largest of the principal tributaries is Thomas Creek, which drains the southwestern portions of the Nassau River Basin. Thomas Creek encompasses a drainage area of 103 square miles and includes two major tributaries, including Ben Branch and Seaton Creek. The channel slope for Thomas Creek is nearly 3 feet per mile. Boggy Creek drains 72 square miles and contains four main tributaries, including Mills Creek, Little Boggy Creek, Spell Swamp and Tom Mann Swamp. Alligator Creek drains 4 square miles and contains the tributaries Cushing Creek and Little Mills Creek. Lofton Creek drains 57 square miles and its principal tributary is McQueen Swamp. Much of the land within the Nassau River Basin is currently undeveloped, though this basin does include the towns of Callahan and Yulee. A location map for Callahan is located in Appendix A (Figure A-2). The soils in the basin are mostly classified in hydrologic soil group D or B/D, indicating they are poorly drained. Further discussion of hydrologic soil groups can be found in Section 2.15. Table 2.1. Basin / Subbasin Summary

PRINCIPLE TRIBUTARIES PK_BASIN MINOR TRIBUTARIES ACRES TOTAL MIDDLE LOWER ST. MARY'S RIVER 2124 AMELIA RIVER 16803 2112 BRUSH CREEK 2641 2103 CABBAGE CREEK 6982 2108 COSSIERS CREEK 1480 2134 CROSS BRANCH 1865 2152 DEEP CREEK 3576 2196 DEEP CREEK 9939 2123 DUNN CREEK 4927 2127 EGANS CREEK 3435 2119 HILLIARD BRANCH 2814 2140 JACKSON CREEK 3235 2115 LITTLE DUNN CREEK 7186 2106 LITTLE ST. MARYS RIVER 20045 2117 LOWER SISTER CREEK 4210


Table 2.1. Basin / Subbasin Summary

PRINCIPLE TRIBUTARIES PK_BASIN MINOR TRIBUTARIES ACRES TOTAL 2159 MILL CREEK 9049 2105 PIGEON CREEK 5748 2097 ST. MARYS RIVER 21009 5005 ST. MARYS RIVER 4720 2097 ST. MARYS RIVER 581 5006 ST. MARYS RIVER 12837 2146 STAVE BRANCH 868 2098 UNNAMED BRANCH 1305 2101 UNNAMED BRANCH 472 2102 UNNAMED BRANCH 970 2104 UNNAMED BRANCH 905 2109 UNNAMED BRANCH 467 2110 UNNAMED BRANCH 428 2111 UNNAMED BRANCH 2428 2121 UNNAMED BRANCH 730 2126 UNNAMED BRANCH 1094 2128 UNNAMED BRANCH 3920 2137 UNNAMED BRANCH 676 2141 UNNAMED BRANCH 818 2144 UNNAMED BRANCH 2923 2150 UNNAMED BRANCH 1289 2154 UNNAMED BRANCH 1823 2160 UNNAMED BRANCH 2646 2167 UNNAMED BRANCH 4537 2180 UNNAMED BRANCH 2493 2099 UNNAMED CREEK 1797 2100 UNNAMED CREEK 1845 2185 UNNAMED CREEK 2399 2219 UNNAMED CREEK 2230 2107 UNNAMED STREAM 1084 2178 UNNAMED STREAM 1821 2113 WHITE OAK SWAMP 2042 2116 WILDER SWAMP 6015 193106UPPER ST. MARYS RIVER 2255 BALDWIN BAY DITCH 2634 2226 BRANDY BRANCH 11036 2245 DEEP CREEK 3446 5007 ST. MARYS RIVER 6 5007 ST. MARYS RIVER 1183 2289 UNNAMED BRANCH 108 2263 UNNAMED DITCH 622 2281 UNNAMED DITCH 942 2291 UNNAMED DITCH 328 2214 UNNAMED DITCHES 5001 2225 UNNAMED DRAIN 1418 2217 UNNAMED RUN 1474


Table 2.1. Basin / Subbasin Summary

PRINCIPLE TRIBUTARIES PK_BASIN MINOR TRIBUTARIES ACRES TOTAL 2275 UNNAMED SLOUGH 107 2313 UNNAMED SLOUGH 150 28453NASSAU RIVER 2153 ALLIGATOR CREEK 15388 2182 BEN BRANCH 3166 2177 BRADDOCK CREEK 3099 2162 CUSHING CREEK 5931 2169 FUNKS CREEK REACH 2345 2147 GARDNER CREEK 3295 2138 LITTLE BOGGY CREEK 1541 2157 LITTLE MILL CREEK 4611 2129 LOFTON CREEK 20466 2151 LUMBER CREEK 1068 2118 MCQUEEN CREEK 6868 2120 MILLS CREEK 25246 2148 NASSAU RIVER 15725 2174 NASSAU SOUND 1305 2130 PLUMMER CREEK 15042 2149 SOUTH AMELIA RIVER 10230 2135 SPELL SWAMP 5465 2161 THOMAS CREEK 830 2161 THOMAS CREEK 12790 2161 THOMAS CREEK 2844 2143 TOM MANN SWAMP 3128 2132 UNNAMED BRANCH 1099 2133 UNNAMED BRANCH 1667 2136 UNNAMED BRANCH 3995 2139 UNNAMED BRANCH 995 2145 UNNAMED BRANCH 2913 2155 UNNAMED BRANCH 3478 2156 UNNAMED BRANCH 2382 2172 UNNAMED BRANCH 2484 2175 UNNAMED BRANCH 1010 2184 UNNAMED BRANCH 2099 2166 UNNAMED DITCH 1950 2158 UNNAMED DRAIN 2106 2197 UNNAMED DRAIN 921 2212 UNNAMED DRAIN 3272 2193 UNNAMED DRAIN 0 2122 UNNAMED SLOUGH 2024 2125 UNNAMED SLOUGH 1463 2131 UNNAMED SLOUGH 1783 2142 UNNAMED SLOUGH 2373 2164 UNNAMED SLOUGH 0 2202 VERDIE BRANCH 3862 202257


3. Data Collection and Evaluation The foundation of Part I of the SWMP is the Data Collection and Evaluation task, which will provide a solid basis of information for the subsequent phases of the SWMP, to include Engineering Analysis of Existing Stormwater Systems and Identification of Problem Areas (Part II) and Development of Management Alternatives and/or Regional Solutions (Part III). The information collected in this section also will be helpful for individuals working on other projects within the County, including site development, roadway projects, and drainage studies. The Data Collection effort required within the scope for Phase I of this project includes a number of tasks. This section essentially consists of a summary of each task and describes the location in the appendices where the information is provided. 3.1. Existing Reports, As-Built Drawings, and Survey Data The County compiled all of the existing drainage studies, as-builts and survey information they had on-hand and the information has been combined into the CD’s presented in Appendix E. Most of the drainage studies were small, isolated projects. However, there are a few drainage studies which are large in scale and will provide valuable information as Part II of the SWMP is developed throughout the County. In addition, other reports were also obtained that will provide valuable insight to the County and other engineers. A few of the more significant drainage studies and other reports are summarized briefly, below. One significant drainage study is the Nassau River Basin Comprehensive Floodplain Management Study, completed by Ayres Associates in 1999. This study was developed for the U.S. Army Corps of Engineers and describes the data reconnaissance, model development, model calibration, and results of the hydrologic and hydraulic simulations of the Nassau River Basin. Models utilized included (1) the Hydrologic Modeling System (HEC-HMS) for hydrologic simulation, (2) One-Dimensional Unsteady Flow Through a Full Network of Open Channels (UNET) for routing and tidal hydraulics, and (3) the Riverine Analysis System (HEC-RAS) for hydraulic simulation. The study concluded that because of limited basin and calibration data, the hydrologic model component could be refined with additional data, which could include additional rain gages throughout the basin and stage/discharge gages on Lofton Creek and Boggy Creek. The report also recommended additional survey cross sections across wetland storage areas. Nonetheless, flood profiles were developed for the Nassau River and seven of its tributary streams including Boggy Creek, Alligator Creek, Thomas Creek, Cushing Creek, Funks Creeks, Cushing Creek Tributary, and Little Mills Creek. The accuracy of the profiles was estimated at one foot (1’) due to the limited calibration data and lack of as-built information for bridges and culverts. Another important, and widely disseminated study, is the Nassau County Flood Insurance Study (FIS), developed by FEMA. The most recently published study was obtained from FEMA, via the FEMA Map Mart website, and is dated May 4, 1988. However, the County has been informed that FEMA is in the process of updating the FEMA Flood Insurance Rate Maps (FIRMs) for the County, and the updated maps should be available by mid 2009. The 1988 Nassau County FIS does not contain flood profiles for County streams. In addition to the Nassau County FIS, the Callahan FIS and Fernandina Beach FIS were also obtained. The Callahan FIS contains a flood profile for Alligator Creek. The FEMA FIS reports for Nassau County are located in the Miscellaneous Reports Folder on compact disk (CD) in Appendix E.


Another report of note is the St. Marys River Management Plan, developed by the St. Marys River Management Committee in May 2003. This report contains information about the existing and future resources in the St. Marys River Basin, including water quality, groundwater, floodplains, natural systems, recreational and public use, economic development and government policy. Any detailed modeling studies performed as part of the SWMP within the St. Marys River Basin should refer to this Plan and follow its guidance. The St. Marys River Management Plan is also located in the Miscellaneous Reports Folder on CD in Appendix E. A number of reports from SJRWMD have also been incorporated into the data on CD in Appendix E. These include the 2005 SJRWMD Management Plan, the 2008 SJRWMD Consolidated Annual Report, and the Applicants Handbooks for Agricultural Surface Water Management Systems, Consumptive Uses of Water, Management and Storage of Surface Waters, and Regulation of Stormwater Management Systems. 3.2. Hydrologic Meteorological Records 3.2.1. SJRWMD SJRWMD manages a hydrologic data collection program that collects, processes, disseminates and manages hydrologic and meteorological data for consumptive use permitting, water shortage management, establishment of minimum flows and levels, water supply planning and management, environmental protection and restoration projects, and operation of flood control devices. This program is managed by the Division of Hydrologic Data Services (HDS) and includes over 1000 sites throughout the limits of SJRWMD as well as nearly 200 additional sites collected by county and municipal entities as well as the USGS. Information within Nassau County is available for Rainfall Data, Water Level, and Discharge. Rainfall sites include the following: • 16993368 – Bryceville Fire Department 4/16/2002 through Current • 01090081 – Callahan 10/9/1998 through Current • 02920256 – St. Marys WMA 10/17/1998 through Current • 00950064 – Egans Creek 10/9/1998 through Current Water Level sites include the following: • 62142216 – Elwood Branch North 4/20/1995 through 8/10/1995 • 16943306 – St. Marys Traders Hill 3/12/2002 through 10/9/2003 • 16093716 – St. Marys Road West 1/7/2003 through 8/27/2003 The only Discharge site is the following: • 16943306 – St. Marys Traders Hill 3/13/2002 through 9/26/2003 The web address of the SJRWMD GIS site where information is available for download is the following: http://arcimspub.sjrwmd.com/website/dahds/design/index.html. The data available to date has been provided on CD in Appendix E, but unfortunately, much of this information is not up to date.

http://arcimspub.sjrwmd.com/website/dahds/design/index.html


3.2.2. NOAA The NOAA National Weather Service (NWS) Forecast Office for Jacksonville, Florida provides meteorological data for stations in the following locations: • Jacksonville, Florida • Gainesville, Florida • Alma, Georgia • St. Simon’s Island, Georgia • Craig Field, Florida The website for the Jacksonville NWS is http://www.srh.noaa.gov/jax/climate.shtml. In addition, the NOAA National Climatic Data Center (NCDC) contains the worlds largest archive of climatic data. Two stations are located within Nassau County: • Fernandina Beach • Hilliard Much of the meteorologic information from NCDC is now provided for a small fee. This information has not been included on the CDs in this report, but the web address below is the site from which updated information may be obtained for use in future studies: http://lwf.ncdc.noaa.gov/oa/ncdc.html The NOAA NCDC 2008 Products and Services Guide has been provided on a CD in Appendix E. This is a 111-page report that provides detailed information about the data available and the means by which to acquire the data from the NCDC website. In addition, a spreadsheet developed by NCDC that summarizes the available data is also provided. 3.2.3. USGS The U.S. Geological Survey (USGS) is an unbiased, multi-disciplinary science organization that focuses on biology, geography, geology, geospatial information, and water. From the USGS website (http://waterdata.usgs.gov/nwis/sw): “Nationally, USGS surface-water data includes more than 850,000 station years of time-series data that describe stream levels, streamflow (discharge), reservoir and lake levels, surface-water quality, and rainfall. The data are collected by automatic recorders and manual measurements at field installations across the Nation. Data are collected by field personnel or relayed through telephones or satellites to offices where it is stored and processed. The data relayed through the Geostationary Operational Environmental Satellite (GOES) system are processed automatically in near real time, and in many cases, real-time data are available online within minutes. Once a complete day of readings are received from a site, daily summary data are generated and stored in the data base. Recent provisional daily data are updated on the web once a day when the computation is completed.

http://www.srh.noaa.gov/jax/climate.shtml

http://lwf.ncdc.noaa.gov/oa/ncdc.html

http://waterdata.usgs.gov/nwis/sw


Annually, the USGS finalizes and publishes the daily data in a series of water-data reports. Daily streamflow data and peak data are updated annually following publication of the reports.” Unfortunately, while the USGS has some Data Sites within Nassau County included on their web page, this data is not current. The USGS has no current stream flow or meteorological sites in Nassau County. Previous sites that have some historic flow data available include the following:

USGS 02231250 LITTLE ST. MARYS RIVER NR HILLIARD, FLA. Nassau County, Florida Hydrologic Unit Code 03070204 Latitude 30°43'55", Longitude 81°53'35" NAD27 Available Data: 00060 Discharge, cubic feet per second Date Range: 1965-01-01 through 1967-09-30 USGS 02231253 ST. MARYS RIVER NEAR GROSS, FLA. Nassau County, Florida Hydrologic Unit Code 03070204 Latitude 30°44'29", Longitude 81°41'17" NAD27 Available Data: 00060 Discharge, cubic feet per second Date Range: 1966-04-01 through 1990-08-31 USGS 02231253 ST MARYS RIVER NEAR GROSS, FL. Nassau County, Florida Hydrologic Unit Code 03070204 Latitude 30°44'29", Longitude 81°41'17" NAD27 Available data: 00060 Discharge, cubic feet per second Date Range: 1966-04-01 through 1989-09-29 Available Data: 00065 Gage height, feet Date Range: 1970-10-01 through 1989-09-30 USGS 02231268 ALLIGATOR CREEK AT CALLAHAN, FL Nassau County, Florida Hydrologic Unit Code 03070205 Latitude 30°33'59", Longitude 81°50'01" NAD27 Available data: 00060 Discharge, cubic feet per second Date Range: 1981-02-27 through 2004-09-30 Available Data: 00065 Gage height, feet Date Range: 1981-02-27 through 2004-09-28 USGS 02231280 THOMAS CREEK NEAR CRAWFORD, FL Duval County, Florida Hydrologic Unit Code 03070205 Latitude 30°27'39", Longitude 81°49'57" NAD27 Available data: 00060 Discharge, cubic feet per second Date Range: 1965-01-01 through 2004-09-30 Available Data: 00065 Gage height, feet Date Range: 1965-01-01 through 2004-09-30


USGS 02231289 NASSAU RIVER NEAR HEDGES, FL Nassau County, Florida Hydrologic Unit Code 03070205 Latitude 30°34'28", Longitude 81°36'32" NAD27 Available data: 00060 Discharge, cubic feet per second Date Range: 1983-06-10 through 2004-09-30 Available Data: 00065 Gage height, feet Date Range: 1983-04-19 through 2004-09-30 USGS 02231291 NASSAU RIVER NEAR TISONIA, FL Duval County, Florida Hydrologic Unit Code 03070205 Latitude 30°33'02", Longitude 81°35'24" NAD27 Available Data: 00010 Temperature, water, degrees Celsius Date Range: 1986-02-01 through 1988-07-14 Available Data: 00095 Specific conductance, water, unfiltered, microsiemens per

centimeter at 25 degrees Celsius Date Range: 1985-08-13 through 1988-07-14

3.3. Existing and Proposed Drainage Systems GIS information was obtained from Nassau County, FDEP, SJRWMD and FDOT which includes numerous shape files documenting existing drainage systems in Nassau County. Figure A-17 in Appendix A depicts the Hydrography in Nassau County. A detailed list of the GIS information obtained is provided in Section 3.15 and the GIS data itself is provided on CD in Appendix E. 3.4. Documentation of Past Flooding Complaints The County documents past flooding complaints via computer records. This information is planned to be added to the County GIS database in the future, but it has not yet been incorporated. Nonetheless, the County can access this information as needed. 3.5. Documented Finished Floor Elevations The County does not currently maintain records of documented finish floor elevations. This is one set of data that will be vital as the County develops future phases of the SWMP. It is recommended that the County require all builders submit finish floor elevations for every inhabited structure for future flood planning and Level of Service establishment. 3.6. Land Use Data County existing and proposed land use, development agreements, and concurrency roads, among other data, has been incorporated into the County’s GIS database. In addition, GIS data was obtained from SJRWMD that included Environmental Resource Permit (ERP) Applications, District Parcels, conservation easements and management areas, just to name a few. Detailed lists of all of the GIS data gathered for this task is included at the end of this section. Figure A-15 in Appendix A depicts the locations of each of the ERPs in Nassau County. Also of significance are the DRIs, PUDs and other developments in the County. The table below


provides this information. Figure A-19 in Appendix A depicts new and proposed developments in Nassau County. Table 3.1. Nassau County DRIs

Development Status Property Type Development Agreement Acres

A1A COMMERCE CENTER PROPOSED COMMERCIAL 12.64

AMELIA NATIONAL NEW EXISTING / PROPOSED RESIDENTIAL YES 864.24

AMELIA BAY NEW EXISTING RESIDENTIAL PUD 64.04AMELIA CONCOURSE SUBDIVSION PROPOSED RESIDENTIAL YES 197.29

SHOPES OF AMELIA NEW EXISTING / PROPOSED COMMERCIAL YES 167.97

AMHURST OAKS PROPOSED RESIDENTIAL 41.02BELL'S RIVER ESTATES NEW EXISTING RESIDENTIAL PUD 76.44BLACK HEATH PARK PROPOSED RESIDENTIAL YES 23.57BRADY POINTE NEW EXISTING RESIDENTIAL 189.02BRENTS COVE PROPOSED RESIDENTIAL 2961.84BUCKHEAD PHASE 2 PROPOSED RESIDENTIAL 62.53CAPTAINS POINTE NEW EXISTING RESIDENTIAL 15.84CLEAR LAKE ESTATES PROPOSED RESIDENTIAL 270.04CRANE ISLAND PROPOSED RESIDENTIAL PUD 139.02CREEKSIDE NEW EXISTING RESIDENTIAL PUD 42.91CYPRESS PALM GARDENS NEW EXISTING RESIDENTIAL YES 36.34DEEP CREEK PLANTATION PROPOSED RESIDENTIAL 881.56LOFTON COMMERCIAL CENTER COMMERCIAL YES 9.77TRADEPLEX YES 239.13EAGLES CROSSINGS PROPOSED COMMERCIAL YES 1.23EASTGATE PROPOSED RESIDENTIAL YES 39.51EVERGREEN ESTATES PROPOSED RESIDENTIAL 25.20

FLORA PARKE NEW EXISTING / PROPOSED RESIDENTIAL PUD 220.75

GRANDE OAKS NEW EXISTING RESIDENTIAL 45.80GREENE TERRACE PROPOSED RESIDENTIAL 88.27GRESSMAN DAIRY PROPOSED RESIDENTIAL 143.38HAMPTON LAKES PROPOSED RESIDENTIAL YES 682.24HERITAGE GREEN PROPOSED RESIDENTIAL 57.45

HERON ISLES NEW EXISTING / PROPOSED RESIDENTIAL PUD 395.07

HIDEWAY PROPOSED RESIDENTIAL PUD 151.64LOFTON POINT NEW EXISTING RESIDENTAIL YES 55.63LUMBER CREEK PROPOSED RESIDENTIAL 146.18MARSH LAKES PROPOSED COMMERCIAL PUD 9.82

MARSHES @ LANCEFORD NEW EXISTING / PROPOSED RESIDENTIAL 46.32

MCKENDREE ACRES (aka Creekside III/IV) PROPOSED RESIDENTIAL 71.96

NASSAU CENTER NEW EXISTING / PROPOSED PUD 269.14


Table 3.1. Nassau County DRIs

Development Status Property Type Development Agreement Acres

NASSAU CROSSINGS PROPOSED RESIDENTAIL PUD 203.51LOFTON RESERVE RESIDENTIAL YES 25.71NASSAU LAKES PROPOSED COMMERCIAL PUD 15.70

NORTH HAMPTON NEW EXISTING / PROPOSED RESIDENTIAL YES 541.41

OLD BLUFF PROPOSED RESIDENTIAL 4.42PLUMMERS CREEK PROPOSED RESIDENTIAL PUD 415.58

RIVER GLEN NEW EXISTING / PROPOSED RESIDENTIAL PUD 371.01

ROCKING HORSE FARMS PROPOSED RESIDENTIAL 75.51Roses Bluff NEW EXISTING RESIDENTIAL 52.41STONEY CREEK PROPOSED RESIDENTIAL 126.28THE HOMESTEAD PROPOSED RESIDENTIAL 37.05THE PRESERVE AT SUMMER BEACH PROPOSED RESIDENTIAL 43.91THREE RIVERS DRI PROPOSED MULTI USE 1587.73TIMBER CREEK NEW EXISTING RESIDENTIAL YES 271.81TIMBER CREEK NEW EXISTING COMMERCIAL YES 12.95TIMBER RIDGE PROPOSED RESIDENTIAL 94.50TIMBERLAKE PROPOSED RESIDENTIAL YES 72.99TUCSCANY PROPOSED MULTI-FAMILY PUD 14.79TUPELO PLANTATION PROPOSED RESIDENTIAL 1423.38TURNING LEAF PROPOSED RESIDENTIAL 53.17WATERMANS BLUFF PROPOSED RESIDENTIAL YES 50.65WATERWAY OAKS @ OYSTER BAY HARBOUR

NEW EXISTING / PROPOSED RESIDENTIAL PUD 72.89

WATERWAY OAKS @ OYSTER BAY HARBOUR

NEW EXISTING / PROPOSED RESIDENTIAL 28.13

WEST MEADOW PLANTATION PROPOSED RESIDENTIAL 25.16WOODBRIDGE PROPOSED RESIDENTIAL YES 299.92OAKS AT BRISTOL RESIDENTIAL YES 34.86WALGREENS COMMERCIAL YES 1.87YPC COMMERCIAL YES 50.14AMELIA POINT Commercial YES 60.99 Total 14813.26

3.7. Water Quality Data Water quality data was obtained from SJRWMD. Downloaded water quality data is provided on CD in Appendix E. In addition, the water quality monitoring sites are discussed in detail in Section 6, later in this report. Figure A-18 depicts the FDEP STORET Node Locations Map. From FDEP’s website (http://www.dep.state.fl.us/water/storet/index.htm): “STORET—an acronym for STORage and RETrieval database—is the currently used database for the storage of biological, chemical, and physical data for ground and surface waters. While

http://www.dep.state.fl.us/water/storet/index.htm


the United States Environmental Protection Agency designed STORET as a national water quality database, Florida’s STORET database design is dictated by a state regulation called the “Impaired Waters Rule” (Chapter 62-303, Florida Administrative Code). Florida DEP is in the process of developing an IWR-directed water quality data exchange program that will be designed with constructive input from our data providers. Our ultimate goal will be to ease the process of data contribution and loading for all.” 3.8. Existing Water Bodies and Wetlands GIS data on existing water bodies and wetlands were obtained from Nassau County and SJRWMD. Figure A-17 in Appendix A depicts the Hydrography in Nassau County. This data is presented on CD in Appendix E. 3.9. Rules, Regulations, Ordinances, and Laws There are rules, regulations, ordinances and laws that pertain to water quantity, water quality, water use from a variety of government agencies, ranging from Nassau County itself, to SJRWMD, the United States Environmental Protection Agency (EPA), and the Florida Department of Environmental Protection (FDEP). The subsections below describe some of the most pertinent laws and rules with links to internet web pages containing the information. 3.9.1. Nassau County

3.9.1.1. Code of Laws and Ordinances The Code of Laws and Ordinances for Nassau County covers topics ranging from Administration (Chapter 1) to Welfare (Chapter 33). Chapters and appendices most applicable to this Stormwater Master Plan include the following, presented in Table 3.2.

Table 3.2. Sections of Nassau County Code of Laws and Ordinances Related to Stormwater Master Planning Chapter / Appendix Title Chapter 10 Fish and Wildlife

Chapter 10 ½ T Floodplain Management Chapter 20 ½ Planning And Development Chapter 21 Public Works Chapter 23 Recreation And Water Conservation And Control Districts Chapter 29 Subdivision And Development Review Chapter 31 Waterways APPENDIX D Roadway And Drainage Standards

The Nassau County Laws and Ordinances Document is available from the by Municipal Code corporation via a link on the Nassau County Website main page, located at http://www.nassaucountyfl.com/. The Municipal Code Corporation is a private sector host for City/County ordinances. The Nassau County Laws and Ordinances can also be accessed via their website at www.municode.com.

http://www.nassaucountyfl.com/

http://www.municode.com/


3.9.1.2. Comprehensive Plan A comprehensive plan is essentially the County’s plan for growth and development, with considerations for environmental protections, for a given time period. In general, comprehensive plans do not contain regulations that must be enforced on a day to day basis, but rather form a framework and long range targets which will take the County from the current situation to the future state that the County aspires to. Comprehensive plans have a major impact on the drainage needs and impacts in a county. As such, Nassau County’s Comprehensive Plan 2000 – 2010 is provided on CD in Appendix E. It can also be located through the Nassau County webpage link provided in Section 3.9.1.1. 3.9.1.3. Development Review Regulations Nassau County’s Development Review Regulations were established by County Ordinance (2000-40) to ensure that both individual land owners and developers meet the same requirements in constructing new roadways and drainage improvements. It also established uniform subdivision regulations and site development for the unincorporated areas in Nassau County. These regulations are provided on CD in Appendix E. As with the Comprehensive Plan, the Development Review Regulations are also available through the Nassau County webpage link provided in Section 3.9.1.1.

3.9.2. SJRWMD Florida is divided into five water management districts to preserve and manage Florida’s water resources. The St. Johns River Water Management District (SJRWMD) is responsible for managing groundwater and surface water supplies in all or part of 18 counties in northeast and east-central Florida, including Nassau County. Duties of SJRWMD include the following:

• Issuing permits that regulate water withdrawals and limiting how various activities, such as construction, can impact water resources

• Buying land to preserve or restore vital wetlands and water resources • Conducting research about the quality and quantity of groundwater and surface

water resources • Mapping groundwater and surface water resources • Conducting outreach and public education programs

This Nassau County Stormwater Master Plan itself is evidence of SJRWMD’s role in promoting effective and sustainable use of public waters in that the project was funded in part with moneys provided by SJRWMD. Perhaps the most visible role played by SJRWMD is as issuer of permits for water withdrawals and construction activities. The most pertinent rules related to SJRWMD and its role in permitting is Chapter 40 of the Florida Administrative Code (F.A.C). Table 3.3, below, provides a list of the pertinent sections of Chapter 40. A link to these is available via the SJRWMD web page at the following address: http://sjr.state.fl.us/rules/index.html.

http://sjr.state.fl.us/rules/index.html


Table 3.3 Sections of Chapter 40, F.A.C. related to permitting Rule No. Title Revised on Chapter 40C-1 Organization and Procedure 08/12/2008 Chapter 40C-2 Permitting of Consumptive Uses of Water 02/13/2008 Chapter 40C-20 Standard General Water Use Permits 08/04/1998 Chapter 40C-21 The Water Shortage Plan 11/11/2003 Chapter 40C-22 Noticed General Permits For Consumptive Uses 10/02/1996 Chapter 40C-23 Water Resource Caution Area 09/10/1996 Chapter 40C-24 Xeriscape Landscaping Incentive Program 11/11/2003 Chapter 40C-3 Water Wells 05/20/2008

Chapter 40C-4 Environmental Resource Permits: Surface Water Management Systems 05/13/2008

Chapter 40C-40 Standard General Environmental Resource Permits 12/03/2006 Chapter 40C-400 Noticed General Environmental Resource Permits 05/13/2008

Chapter 40C-41 Environmental Resource Permits: Surface Water Management Basin Criteria 12/03/2006

Chapter 40C-42 Environmental Resource Permits: Regulation of Stormwater Management Systems 12/03/2006

Chapter 40C-43 General Silvicultural Surface Water Management Permits After Notice (Repealed. Incorporated into 40C-4)

10/03/1995

Chapter 40C-44 Environmental Resource Permits: Agricultural Surface Water Management Systems 12/03/2006

Chapter 40C-5 Artificial Recharge 01/11/1999 Chapter 40C-8 Minimum Flows and Levels 05/24/2007 Chapter 40C-9 Water Management Lands Acquisition and Management 06/07/2004

3.9.3. EPA The United States Environmental Protection Agency was established on December 2, 1970 to consolidate under one federal agency a variety of federal research, monitoring, standard-setting and enforcement activities to ensure environmental protection. EPA's mission is to protect human health and to safeguard the natural environment—air, water, and land. As such, EPA’s major role is to enforce the laws enacted by Federal Congress and to promulgate it’s own rules for the protection of the natural environment. While most of the laws and rules put forth by the EPA are enforced on a state level by corresponding state agencies like the Florida Department of Environmental Protection and SJRWMD, the EPA does provide a wealth of information about the rules and regulations which must be followed across the country. The following webpage provides a portal for the rules and regulations enforced and enacted by the EPA: http://www.epa.gov/lawsregs/index.html.

http://www.epa.gov/lawsregs/index.html


3.9.4. FDEP The Florida Department of Environmental Protection (FDEP) is the State of Florida’s lead agency for protection of the State’s air, water, and land. The Department is divided into three primary areas: Regulatory Programs, Land and Recreation, and Planning and Management. Florida’s environmental priorities include restoring America’s Everglades, improving air quality, restoring and protecting the water quality in state springs, lakes, rivers and coastal waters, conserving environmentally-sensitive lands and providing citizens and visitors with recreational opportunities. Table 3.4 provides the Florida rules most applicable to stormwater management planning (from the F.A.C.). The web page where these may be accessed is at: http://www.dep.state.fl.us/legal/Rules/mainrulelist.htm. Table 3.4. FDEP Rules.

Chapter of F.A.C. Title Effective Date

General Department Rules 62-4 Permits 04-02-08

62-8 Ad Valorem Tax Assessment Rules Guidelines for Tax Assessors 01-01-90

62-40 Water Resource Implementation Rule 05-07-06

62-43 Surface Water Improvement and Management Act 05-03-90

62-104 Administrative Procedures for the Water Resources Restoration and Preservation Program 11-28-96

62S-4 Coastal Management Program Grants 09-11-05

Impaired Waters and TMDLs (Total Maximum Daily Loads) 62-303 Identification of Impaired Surface Waters 09-04-07

62-304 Total Maximum Daily Loads 06-03-08

Surface Water and Wetlands Rules 18-14 Administrative Fines for Damaging State Lands or Products 07-07-85

18-18 Biscayne Bay Aquatic Preserve 06-05-96

18-20 Florida Aquatic Preserves 05-27-99

18-21 Sovereignty Submerged Lands Management 01-01-06

62-4 Permits 10-01-07

62-25 Regulation of Stormwater Discharge 08-30-88

62-29 Conceptual Agency Review 07-04-95

62-40 Water Resource Implementation Rule 05-07-06

62-45 25-Year Permits for Maintenance Dredging in Deepwater Ports

Deepwater Ports Maintenance Dredging and Disposal Manual 08-28-85

62-113 Delegations 07-16-01

62-301 Surface Waters of the State 01-08-96

http://www.dep.state.fl.us/legal/Rules/mainrulelist.htm


Table 3.4. FDEP Rules. Chapter of

F.A.C. Title Effective Date

62-302 Surface Water Quality Standards 04-02-08

62-312 Dredge and Fill Activities 03-15-07

62-330 Environmental Resource Permitting 08-02-06

62-340 Delineation of the Landward Extent of Wetlands and Surface Waters 07-01-94

62-341 Noticed General Environmental Resource Permits 10-01-07

62-342 Mitigation Banking 05-21-01

62-343 Environmental Resource Permit Procedures 10-10-07

62-344 Delegation of the Environmental Resource Program to Local Governments 08-29-95

62-345 Uniform Mitigation Assessment Method 09-12-07 62-345.900(1) Part I - Qualitative Description 02-02-04

62-345.900(2) Part II - Quantification of Assessment Area 02-02-04

62-345.900(3) Mitigation Determination Formulas 09-12-07 62-346 Environmental Resources Permitting In Northwest Florida 10-01-07

62-620 Wastewater Facility and Activities Permitting 04-02-08

62-621 Generic Permits 02-07-07

62-624 Municipal Separate Storm Sewer Systems 01-28-04

Water Quality Standards Rules 62-4 Permits 10-01-07

62-301 Surface Waters of the State 01-08-96

62-302 Surface Water Quality Standards 08-05-07

62-303 Identification of Impaired Surface Waters 09-04-07

62-304 Total Maximum Daily Loads 05-01-07

62-520 Ground Water Classes, Standards, and Exemptions 12-09-96

Water Management District Rules Adopted by Reference by DEP 40C-1 Organization and Procedure 10-03-95

40C-4 Environmental Resource Permits: Surface Water Management Systems 10-03-95

40C-8 Minimum Flows and Levels 06-08-95

40C-40 Standard General Environmental Resource Permits 10-03-95

40C-41 Surface Water Management Basin Criteria 10-03-95

40C-42 Regulation of Stormwater Management Systems 10-03-95

40C-1 Organization and Procedure 10-03-95

40C-4 Environmental Resource Permits: Surface Water Management Systems 10-03-95


Table 3.4. FDEP Rules. Chapter of

F.A.C. Title Effective Date

40C-8 Minimum Flows and Levels 06-08-95

40C-40 Standard General Environmental Resource Permits 10-03-95

3.10. Archaeological Resources Nassau County has incorporated archaeological resources into its GIS data coverage. This information is provided on Figure A-20 in Appendix A and the GIS information is provided on CD in Appendix E. 3.11. National Wetlands Inventory Maps (NWI) Nassau County has incorporated the National Wetlands Inventory Maps into its GIS data coverage. This information is provided on Figure A-14 in Appendix A and the GIS information is provided on CD in Appendix E. As previously described in Section 1, nearly a third of Nassau County’s land area is designated as wetlands. This provides challenges not only for development, but also creates greater potential for flooding. Wetland areas are not only low-lying, but are also characterized by poorly drained soils. Individuals living in wetland areas that have been filled or living near the boundaries of wetlands have a much greater likelihood of experiencing flooding. 3.12. Florida Land Use Cover and Classification System Maps

(FLUCCS) Nassau County has incorporated the FLUCCS Maps into its GIS data coverage. This information is provided on Figure A-11 in Appendix A. In addition, Table 3.5 lists each of the FLUCCS designations found in Nassau County. Table 3.5. FLUCCS Designations FLUCCS LEVEL TWO DESCRIPTION

1100 URBAN AND BUILT-UP

1100 RESIDENTIAL, LOW DENSITY <LESS THAN TWO DWELLING UNITS PER ACRE>



1200 RESIDENTIAL, MEDIUM DENSITY <TWO-FIVE DWELLING UNITS PER ACRE> 1290 RESIDENTIAL, MEDIUM DENSITY <TWO-FIVE DWELLING UNITS PER ACRE> 1300 RESIDENTIAL, HIGH DENSITY <SIX OR MORE DWELLING UNITS PER ACRE> 1390 RESIDENTIAL, HIGH DENSITY <SIX OR MORE DWELLING UNITS PER ACRE> 1400 COMMERCIAL AND SERVICES 1480 COMMERCIAL AND SERVICES 1490 COMMERCIAL AND SERVICES 1520 INDUSTRIAL 1523 INDUSTRIAL


Table 3.5. FLUCCS Designations FLUCCS LEVEL TWO DESCRIPTION

1550 INDUSTRIAL 1600 EXTRACTIVE 1610 EXTRACTIVE 1620 EXTRACTIVE 1632 EXTRACTIVE 1650 EXTRACTIVE 1660 EXTRACTIVE 1670 EXTRACTIVE 1700 INSTITUTIONAL 1810 RECREATIONAL 1820 RECREATIONAL 1840 RECREATIONAL 1850 RECREATIONAL 1860 RECREATIONAL 1890 RECREATIONAL 1900 OPEN LAND 1920 OPEN LAND 2000 AGRICULTURE 2110 CROPLAND AND PASTURELAND 2120 CROPLAND AND PASTURELAND 2130 CROPLAND AND PASTURELAND 2140 CROPLAND AND PASTURELAND 2150 CROPLAND AND PASTURELAND 2160 CROPLAND AND PASTURELAND 2200 TREE CROPS 2310 FEEDING OPERATIONS 2320 FEEDING OPERATIONS 2400 NURSERIES AND VINEYARDS 2410 NURSERIES AND VINEYARDS 2430 NURSERIES AND VINEYARDS 2500 SPECIALTY FARMS 2510 SPECIALTY FARMS 2520 SPECIALTY FARMS 2540 SPECIALTY FARMS 2610 OTHER OPEN LANDS <RURAL> 3000 RANGELAND 3100 HERBACEOUS (DRY PRAIRIE) 3200 SHRUB AND BRUSHLAND 3300 MIXED RANGELAND 4000 UPLAND FORESTS 4110 UPLAND CONIFEROUS FORESTS 4120 UPLAND CONIFEROUS FORESTS 4130 UPLAND CONIFEROUS FORESTS 4200 UPLAND HARDWOOD FORESTS 4210 UPLAND HARDWOOD FORESTS 4340 UPLAND HARDWOOD FORESTS


Table 3.5. FLUCCS Designations FLUCCS LEVEL TWO DESCRIPTION

4400 TREE PLANTATIONS 4410 TREE PLANTATIONS 4430 TREE PLANTATIONS 5000 WATER 5100 STREAMS AND WATERWAYS 5200 LAKES 5250 LAKES 5300 RESERVOIRS 5400 BAYS AND ESTUARIES 5430 BAYS AND ESTUARIES 5600 SLOUGH WATERS 6000 WETLANDS 6110 WETLAND HARDWOOD FORESTS 6170 WETLAND HARDWOOD FORESTS 6181 WETLAND HARDWOOD FORESTS 6210 WETLAND CONIFEROUS FORESTS 6220 WETLAND CONIFEROUS FORESTS 6250 WETLAND CONIFEROUS FORESTS 6300 WETLAND FORESTED MIXED 6410 VEGETATED NON-FORESTED WETLANDS 6420 VEGETATION 6430 VEGETATION 6440 VEGETATION 6460 VEGETATED NON-FORESTED WETLANDS 6500 NON-VEGETATED WETLANDS 7000 BARREN LAND 7100 BEACHES OTHER THAN SWIMMING BEACHES 7200 SAND OTHER THAN BEACHES 7400 DISTURBED LAND 7410 DISTURBED LAND 7420 DISTURBED LAND 7430 DISTURBED LAND 8000 TRANSPORTATION, COMMUNICATION AND UTILITIES 8110 TRANSPORTATION 8120 TRANSPORTATION 8140 TRANSPORTATION 8180 TRANSPORTATION 8200 COMMUNICATIONS 8310 UTILITIES 8320 UTILITIES 8330 UTILITIES 8340 UTILITIES 8350 UTILITIES 8370 UTILITIES 9000 SPECIAL CLASSIFICATIONS 9999 SPECIAL CLASSIFICATIONS


3.13. Proposed Wetland Mitigation Areas According to SJRWMD, projects in Nassau County could potentially use one of four wetland mitigation banks:

• Longleaf Mitigation Bank • Northeast Florida Mitigation Bank • Loblolly Mitigation Bank • Thomas Creek Mitigation Bank

Figure A-12 in Appendix A depicts the location of the first three area wetland mitigation banks and the GIS information is provided on CD in Appendix E. Information on the exact location of the Thomas Creek Mitigation Bank was not available. The following subsections describe each of the mitigation banks. 3.13.1. Longleaf Mitigation Bank One of Florida’s major wetland mitigation banks is located in Nassau County. The Longleaf Mitigation Bank (Longleaf), owned and managed by Timbervest, LLC, is located in the western area of Nassau County, and services all of Nassau County, most of Duval and Baker Counties, and small portions of Clay, Columbia, and Union Counties. The basins serviced by Longleaf include the Upper St. Mary’s River Basin, the Middle and Lower St. Mary’s River Basin, The Nassau River Basin, and the Northern St. Johns River and Northern Coastal Basin. The Longleaf Mitigation Bank is located east of SR 121, west of US 301, and south of SR 108. The figure on the following page, obtained from FDEP, depicts the Longleaf Mitigation Bank. According to information obtained from the National Wetland Mitigation Banking Association, Longleaf is comprised of three ecologically and hydrologically related tracts of land totaling 3,021 acres. These three tracts are known as the Northwest Site, East Site, and South Site. The following description was obtained from SJRWMD about the Longleaf Mitigation Bank. The information is also provided on CD in Appendix E in the Wetlands Folder. “The northwest site contains waters and wetlands of Crosby Bay and Mill Creek. The East Site contains headwater wetland systems of Thomas Creek and Mill Creek. The South Site contains waters and wetlands associated with Deep Creek, Brandy Branch, and Crosby Bay. Crosby Bay is a large, headwater wetland system that connects the three bank sites. The site is dominated by a densely planted slash pine plantation. Wetlands on the site include hydric pine plantation, along with cypress sloughs, hardwood sloughs, and creek bottomlands. The following ecological enhancement activities have been proposed or implemented at this mitigation bank: 1. Cessation of silviculture development practices. 2. Hydrologic enhancement. 3. Implementation of a Forestry Stewardship Plan, which includes pine removal, planting of appropriate native species, and hunting restrictions. 5. Perpetual preservation.” The Longleaf Mitigation bank was permitted by SJRWMD in April 2004, and has authorization for the ultimate release of 813 SJRWMD mitigation credits. The Army Corps of Engineers subsequently permitted Longleaf in September 2004 and authorized for the ultimate release of 1,031 ACOE mitigation credits. To date there are 577.54 remaining SJRWMD credits at this bank.

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3.13.2. Northeast Florida Mitigation Bank The Northeast Florida Wetlands Mitigation Bank encompasses a total of 774 acres, and is located approximately 8 miles west of the Jacksonville International Airport in Duval County. The site is located north of Acree Road, west of the Seaboard System Railroad, and adjacent to the Thomas Creek floodplain swamp. The figure on the following page, obtained from FDEP, depicts the Northeast Florida Mitigation Bank. According to SJRWMD website: “Habitats and land uses present on the site include cattle pastures and dairy facilities, pine plantation, upland hardwood hammock, wet prairie floodplain swamp, and mixed hardwood wetlands. The following ecological enhancement activities have been proposed or implemented at this mitigation bank: 1. Recording of a Conservation Easement to prevent future activities not consistent with the preservation of natural communities. 2. Elimination of dairy and cattle activities. 3. Removal of structures and other improvements associated with the dairy. 4. Removal of accumulated cattle waste from surface waters. 5. Native habitat restoration through elimination of inappropriate species and planting of target native wetland and upland trees. 6. Hydrologic restoration through filling and relocation of drainage ditches. 7. Creation of forested wetlands through clearing, excavating, and planting an upland pine plantation. 8. Implementation of a perpetual preservation and management plan, including fire management, conducive to maintaining natural native habitats. “ The Northeast Florida Wetlands Mitigation Bank has 16.92 remaining wetland credits through SJRWMD. 3.13.3. Loblolly Mitigation Bank The Loblolly Mitigation Bank encompasses 6,247 acres and is located in southwestern Duval County. It is located east of US 301 and north of CR 228. A figure depicting the Loblolly Mitigation Bank, obtained from FDEP, follows the Northeast Florida Mitigation Bank figure on the following page. The Loblolly Mitigation Bank has 72.9 remaining wetland credits through SJRWMD. According to SJRWMD website: “The site is dominated by an intesnsely managed, densely planted, slash pine plantation with small areas of native forest consisting primarily of cypress. The following ecological enhancement activities have been proposed or implemented at this mitigation bank: 1. Cessation of silviculture activities and elimination of most planted pines. 2. Hydrologic restoration. 3. Restoration of native forests by nurturing native species and supplemental tree plantings. 4. Elimination of hunting leases. 5. Implementation of a native-community-promoting fire management plan. 6. Implementation of a perpetual preservation and management plan, conducive to maintaining natural native habitats.” 3.13.4. Thomas Creek Mitigation Bank The Thomas Creek Mitigation Bank encompasses 594.5 acres in Nassau County, approximately 2 miles west of I-95, and south of SR 200 between Callahan and Yulee. A FDEP figure depicting the Thomas Creek Mitigation Bank was not available. The Thomas Creek Mitigation Bank has 20.91 remaining wetland credits through SJRWMD. According to SJRWMD website: “The site is bordered on the north and east by the Nassau River, which is classified as an Aquatic Preserve downstream of the bank site, and on the south by Thomas Creek. The site consists of historic mesic flatwoods and hydric pine savannah communities converted to pine

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plantation, previously harvested forested hardwoods wetlands with pine encroachment along the edges, herbaceous wetlands associated with Thomas and Nassau Creeks, and isolated open water areas. The following ecological enhancement activities have been proposed or implemented at this mitigation bank: 1. Recording of a Conservation Easement to prevent future activities not consistent with the preservation of natural communities. 2. Cessation of silviculture practices. 3. Elimination of unwanted pine plantation trees. 4. Hydrologic restoration activities by eliminating various drainage improvements. 5. Preservation of native vegetation and supplemental planting in accordance with the mitigation bank plan. 6. Implementation of a hunt management plan. 7. Implementation of a perpetual preservation and management plan, including prescribed burning, conducive to maintaining native natural habitats.” 3.14. Soils The County GIS database contains detailed soils information. On a map showing the entire county, the scale would be too small to see each individual soil type well. Instead, for the purposes of this report, a drawing was created showing soil types in terms of the hydrologic soil group. Figure A-10, in Appendix A, depicts the Soils in Nassau County. Put simply, soils are assigned to a hydrologic soils group based on their ability to drain. The following descriptions were obtained from the National Engineering Handbook – Hydrology, Section 630, Hydrologic Soils Groups, developed by the U.S. Department of Agriculture, National Resource Conservation Service (NRCS). “Group A - Soils in this group have low runoff potential when thoroughly wet. Water is transmitted freely through the soil. Group A soils typically have less than 10 percent clay and greater than 90 percent sand or gravel and have sand or gravel textures. Some soils having loamy sand, sandy loam, loam or silt loam textures may e placed in this group if they are well aggregated, of low bulk density, or contain greater than 35 percent rock fragments. “ “Group B - Soils in this group have moderately low runoff potential when thoroughly wet. Water transmission through the soil is unimpeded. Group B soils typically have between 10 percent and 20 percent clay and 50 percent to 90 percent sand and have loamy sand or sandy loam textures. Some soils having loam, silt loam, silt or sandy clay loam textures may be placed in this group if they are well aggregated, of low bulk density, or contain greater than 35 percent rock fragments. “ “Group C - Soils in this group have moderately high runoff potential when thoroughly wet. Water transmission through the soil is somewhat restricted. Group C soils typically have between 20 percent and 40 percent clay and less than 50 percent sand and have loam, silt loam, sandy clay loam, clay loam, and silty clay loam textures. Some soils having clay, silty sclay, or sandy clay textures may be placed in this group if they are well aggregated, of low bulk density, or contain greater than 35 percent rock fragments.” “Group D - Soils in this group have high runoff potential when thoroughly wet. Water transmission through the soil is restricted or very restricted. Group D soils typically have greater than 40 percent clay, less than 50 percent sand and have clayey textures. In some areas, they also have high shrink-swell potential. All soils with a depth to a water impermeable layer less than 50 centimeters [20 inches] and all soils with a water table within 60 centimeters [24 inches]


of the surface are in this group, although some may have a dual classification, as described in the next section, if they can be adequately drained”. “Dual hydrologic soil groups – Certain wet soils are placed in group D based solely on the presence of a water table within 60 centimeters [24 inches] of the surface even though the saturated hydraulic conductivity may be favorable for water transmission. If these soils can be adequately drained, then they area assigned to dual hydrologic soil groups (A/D, B/D, and C/D) based on their saturated hydraulic conductivity and the water table depth when drained. The first letter applies to the drained condition and the second to the undrained condition. For the purpose of hydrologic soil group, adequately drained means that the seasonal high water table is kept at least 60 centimeters [24 inches] below the surface in a soil where it would be higher in a natural state.” Another important designation for soils is whether they can be classified as hydric soils. As defined by the NRCS, “hydric soils are formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part. Hydric soil lists have a number of agricultural and nonagricultural applications. These include assistance in land-use planning, conservation planning, and assessment of potential wildlife habitat. A combination of the hydric soil, hydrophytic vegetation, and hydrology properties define wetlands as described in the National Food Security Act Manual (Soil Conservation Service, 1994) and the Corps of Engineers (COE) Wetlands Delineation Manual (Environmental Laboratory, 1987) and COE Regional Supplements. Therefore, an area that meets the hydric soil definition must also meet the hydrophytic vegetation and wetland hydrology definitions in order for it to be correctly classified as a jurisdictional wetland.” Table 3.6 lists each of the soils found in Nassau County, along with the Hydrologic Soils Group assigned to each and whether the soils are considered hydric or not. Table 3.6 Nassau County Soils Soil Type MU ID Hydrologic Soil Group Hydric (Y/N) ALBANY 089051 C N AQUALFS 089032 C N ARENTS 089002 C N BEACHES 089003 D Y BLANTON 089021 B N BOULOGNE 003011 B/D N BROOKMAN 089040 D Y BUCCANEER 089015 D Y CENTENARY 089026 A N CHAIRES 089011 B/D N COROLLA 089044 D N CROATAN 089034 D Y ECHAW 089004 A N ELLABELLE 003018 D Y EVERGREEN 031022 D Y FRIPP 089005 A N GOLDHEAD 089013 B/D N HURRICANE 089006 C N KERSHAW 089031 A N


Table 3.6 Nassau County Soils Soil Type MU ID Hydrologic Soil Group Hydric (Y/N) KINGSFERRY 003026 B/D Y KINGSLAND 089007 A/D Y KUREB 089008 A N LEEFIELD 089047 C N LEON 003023 B/D N LYNN 089018 D Y LYNN HAVEN 031035 B/D Y MANDARIN 031036 C N MASCOTTE 003029 B/D N MAUREPAS 031040 D Y MEADOWBROOK 089055 B/D Y MEGGETT 089037 D Y NEWHAN 089012 A N OCILLA 089023 C N ORTEGA 089020 A N OSIER 003046 A/D Y OUSLEY 003035 C N PANTEGO 003036 B/D Y PELHAM 003037 B/D N PENNEY 089057 A N PLUMMER 003039 B/D N POTTSBURG 003043 B/D N RESOTA 089029 A N RIDGEWOOD 089027 A N RUTLEGE 031062 A/D Y SAPELO 031063 B/D N SURRENCY 031066 D Y TISONIA 031068 D Y URBAN 089017 U N URBAN LAND 031069 X X YONGES 031078 C/D Y YULEE 031079 D Y

3.15. GIS Data Collected The following summarizes the GIS information obtained as part of this study. 3.15.1. Florida Department of Environmental Protection Format: Shapefiles 1. CountyShore_Areas.shp – Detailed shoreline with county boundaries (polygon) 2. CountyShore_Lines.shp – Detailed shoreline with county boundaries (polyline) 3. Lake_Areas.shp – Primary lakes in north and central Florida (polygon) 4. Mitigation_Bank_Service_Areas.shp – Mitigation Service Areas (polygon) 5. Mitigation_Banks.shp – Florida mitigation banks (polygon) 6. Parks_And_Rec_Areas.shp – Florida State Park Boundaries (polygon)


7. Sinkholes.shp – Florida sinkhole locations (point) 8. Springs.shp – Florida spring locations (point) 9. Storet_305B_2000.shp – Florida STORET Stations (point) 10. TMDL_Basin_Groups.shp – Major basin group within the rotating TMDL basin assessment

program (polygon) 11. WBIDS.shp – Water Body Identification number (WBID) (polygon) 3.15.2. Florida Department of Transportation Format: Personal Geodatabase Feature Class 1. aadt – Annual Average Daily Traffic section breaks 2. access_management – Florida Access Management Roadways 3. basemap_arcs – Florida Basemap Arcs 4. basemap_route_road – Florida Basemap Routes 5. basemap_routes – Florida Basemap Routes 6. bridges – Florida Bridges and overpasses 7. county_roads – Florida County Roads 8. district_arcs – Florida DOT District Boundaries in polyline form 9. district_bnd – Florida DOT District Boundaries in polygon form 10. divided – Florida Divided Highways 11. fahwysys – Roads designated as on the Federal Highway System 12. fihs – Part of the State Highway System (SHS) 13. funclass – Functional Classification Roadways 14. hpms – Highway Performance Monitoring System Roadways 15. interchange – Florida Interchanges and Exits 16. intersection – Florida Intersections 17. interstates – Florida Interstate highways 18. localnam – Florida Roads with the name of the section as posted on the roadway 19. maxspeed – Maximum Speed Limits on Florida Roadways 20. median_type – Florida Median Types 21. median_width – Florida Median width in feet 22. nhs – Florida Roads designated as NHS by Congress 23. number_of_lanes – Number of through highway lanes 24. off_system – Florida roads not maintained by FDOT 25. oldfasys – Historical record of Federal-Aid designation 26. on_system – Active main-line roads maintained by FDOT 27. pavement_conditions – pavement condition ratings 28. ptms – Florida Portable Traffic Monitoring Sites 29. REST_Welcome_FDOT – Florida Roads with rest areas, welcome centers, wayside parks,

and weigh stations 30. road_status – status of Florida roadways 31. roadway – Florida Roads in RCI 32. sis_roads – Existing and emerging SIS roads 33. state_roads – Florida State Roads 34. surface_width – width of the roadway in feet for each segment in database 35. toll_roads – Florida Toll Roads 36. traffic_signal_locations – locations of traffic signals in RCI 37. truck_volume – Truck average annual daily traffic 38. ttms – Florida Telemetered Traffic Monitoring Sites 39. urban – areas identified as urban 40. us_roads – Florida U.S. Highways


41. weigh_in_motion – Information on sites where vehicles are weighed in the mainline road at the highway speed

3.15.3. Nassau County Format: Personal Geodatabase Feature Class 1. Archaeogical_Sites – Archaeological site locations 2. Beach_Access_Points – Beach access points 3. Concurrency_Roads – Concurrency roads 4. Conservation_Easement – Conservation easement within the SJRWMD 5. County_Maintained_Roads – County maintained roads 6. Creeks – Creeks 7. Cross_Culvert_Pipes – Cross culvert pipes 8. Culverts – Culvert outfalls 9. Dev_Agreements – Development agreements 10. Driveways – Driveways 11. Equipment_Laydown_Location – Equipment laydown locations 12. Evacuation_Roads – Evacuation roads 13. FEMA_FloodZones – FEMA flood zones 14. Fire_Hydrants – Fire hydrant locations 15. Flooding_Complaints – Flooding complaints (BLANK) 16. FLUCCS – Florida Land Use Cover and Classification System 17. Future_Land_Use – Future land use 18. Incorporated_Areas_Bndy – Incorporated areas boundary 19. Land_Parcels – Parcel lines 20. Landbase – Land base 21. Major_Basins – Major basins 22. Minor_Basins – Minor basins 23. Nassau_County_Bndy – Nassau County boundary (polygon) 24. Nassau_County_Bndy_line – Nassau County boundary (polyline) 25. Nassau_Parks_and_Recreation – Nassau County parks and recreation areas 26. Nassau_soils – Nassau County soil survey 27. NWI – National Wetland Inventory 28. Parks_Conservation_State_Lands - Parks and conservation lands own by the State 29. PLSS – Public Land Survey System 30. Rail_Road - Rail roads 31. Road_Classification - Road classification 32. Roads – Nassau County roads 33. ROW – Rights-of-Way boundaries 34. RR_Crossings – Railroad crossings 35. Storm_Surge - Storm surge 36. Storm_Zone – Storm zones 37. Stormwater_locations – ERP permit locations (point) 38. Sub_Sub_Nassau_River_Basin – Nassau River Basin Subbasin 39. Subdivisions – Subdivisions 40. Surrounding_Counties - Surrounding counties 41. Topography – 1’ contours 42. Water – bodies of water 43. Water_Quality – Water quality (polygon) (BLANK)


3.15.4. Nassau County Aerials Format: Sid & Tif 1. 2005 1’ Aerials (sid format) 2. USGS Quadrangle Maps (tif format) 3.15.5. St. Johns River Water Management District Format: Shapefiles 1. spingsseep.shp - Springs & Seeps 2. mitig_basins.shp - Regulatory Mitigation Basins 3. erp_bnd.shp - ERP boundaries 4. ERP Stormwater points 5. 2007_mflpri_lks.shp - Minimum Flows and Levels 6. SJRWMD_Parcels.shp - District parcels 7. cons_easements.shp - Conservation Easements 8. MA_Boundaries.shp - Management Areas 9. hydro24_poly_nassau.shp - Hydrography 1:24,000 10. fl_bnd.shp - State Boundary 11. city_pts.shp - City Points 12. sjr_bnd24.shp - SJRWMD Boundary 13. lulc2004_nassau.shp - 2004 Land use 14. ssurgo_nassau.shp - Soils 15. nwi_nassau.shp - National Wetlands Inventory


4. System Inventory and Mapping 4.1. Base Maps GIS information obtained in the Data Collection and Evaluation task of this project were used to develop base maps of Nassau County and each of the basins in the project. The base map provided with this report includes an aerial photograph (2005), roads, National Wetland Inventory, existing water bodies, and available topographic information (5-foot contours). These maps are printed in Appendix B and are also provided on CD in Appendix E.

4.2. Local Problem Identification Local problem identification became one of the most significant aspects of Part I of the SWMP. Because of a significant amount of turnover in County staff over the past 10 years, there was little historical knowledge of the flooding problems within the County. However, information was obtained that documented reported flooding that occurred after Hurricane Francis in 2004. Then, as the report development was nearing its completion, Tropical Storm Fay (TS Fay) made landfall in Northeast Florida on August 21, 2008. TS Fay was a slow-moving, nearly stationary storm that brought enormous quantities of rainfall to the area. Following this storm a large number of additional flood problem areas were discovered.

Due to the low-lying nature of Nassau County, combined with large areas of wetlands, the flooding that occurs throughout the County is broad based. Entire sections of roads lie underwater. Information provided by the County described roads that were closed due to flooding, with no specific information available regarding individual sites where flooding was problematic.

Ayres Associates took the County’s list of flooded roads, and applied this to the County Base Maps. Looking at locations where the roads crossed wetlands and water bodies, we made assumptions to attempt to pinpoint problem areas. Figure A-23 in Appendix A depicts a Country-wide view if flood prone areas and Appendix B contains detailed maps on quarter-quad scale showing each of the identified flood prone areas. It was originally intended to visit each flood prone site and take photos and obtain additional documentation about the flooding. However, as previously discussed, the investigation indicated that the identified flooding is broadbased, with only roadway names identified, not specific sites. Site visits would not provide helpful information in this case. Instead, it is recommended that flood prone areas be investigated in greater detail during Part II of the Master Stormwater Plan, when more time and attention can be paid to each basin and subbasin.

Of particular concern to the County at this time is the Thomas Creek Basin. The County has indicated that during TS Fay, the Thomas Creek basin received over 14-inches of rain. Flooding in the Thomas Creek basin was severe, with numerous properties actually having floodwater inside the homes. Residents concerned about the flooding approached the Nassau County Commission and a public meeting was held on September 17, 2008 to allow residents to describe the flooding and provide the County with their concerns. Photographs provided by local residents are included in Appendix B along with media reports about the flooding. This information is also provided digitally in Appendix E.


4.3. System Inventory Using the County’s GIS database, a Structure Inventory Map was generated showing each of the identified drainage structures throughout the County. The County’s GIS database contains pipe length, size, location, and invert elevations. This information will be extremely valuable when the County begins to develop detailed hydraulic models in Part II of the SWMP. Figure A-16 in Appendix A provides a County-wide view of the locations where structures were inventoried and information is available. 4.4. Stormwater Model Schematic A stormwater model schematic was developed that includes the connectivity between drainage sub-basins. This schematic will form the basis of the future modeling that takes place in Parts II and III of the SWMP. It provides a clear view of the connectivity and allows for instant recognition of interlinked subbasins within each major basin. Figure A-22 in Appendix A provides a visual depiction of the Model Schematic and Table 4.1, below, provides the Model Node designation with the subbasin it is associated with. Table 4.1 Stormwater Model Schematic Node / Subbasin Association

Principle Tributaries Pk_Basin Minor Tributaries Model Node

MIDDLE LOWER ST. MARY'S RIVER 2097 ST. MARYS RIVER B-33 2098 UNNAMED BRANCH B-4 2099 UNNAMED CREEK B-5 2100 UNNAMED CREEK B-6 2101 UNNAMED BRANCH B-7 2102 UNNAMED BRANCH B-8 2103 CABBAGE CREEK B-9 2104 UNNAMED BRANCH B-10 2105 PIGEON CREEK B-11 2106 LITTLE ST. MARYS RIVER B-12 2107 UNNAMED STREAM B-13 2108 COSSIERS CREEK B-14 2109 UNNAMED BRANCH B-15 2110 UNNAMED BRANCH B-16 2111 UNNAMED BRANCH B-17 2112 BRUSH CREEK B-18 2113 WHITE OAK SWAMP B-19 2115 LITTLE DUNN CREEK B-21 2116 WILDER SWAMP B-22 2117 LOWER SISTER CREEK B-24 2119 HILLIARD BRANCH B-26 2121 UNNAMED BRANCH B-28 2123 DUNN CREEK B-30


Table 4.1 Stormwater Model Schematic Node / Subbasin Association


2124 AMELIA RIVER B-31 2126 UNNAMED BRANCH B-34 2127 EGANS CREEK B-35 2128 UNNAMED BRANCH B-36 2134 CROSS BRANCH B-42 2137 UNNAMED BRANCH B-45 2140 JACKSON CREEK B-48 2141 UNNAMED BRANCH B-49 2144 UNNAMED BRANCH B-52 2146 STAVE BRANCH B-54 2150 UNNAMED BRANCH B-58 2152 DEEP CREEK B-60 2154 UNNAMED BRANCH B-62 2159 MILL CREEK B-67 2160 UNNAMED BRANCH B-68 2167 UNNAMED BRANCH B-73 2178 UNNAMED STREAM B-81 2180 UNNAMED BRANCH B-82 2185 UNNAMED CREEK B-85 2196 DEEP CREEK B-87 2219 UNNAMED CREEK B-93 5005 ST. MARYS RIVER B-23 5006 ST. MARYS RIVER B-20 UPPER ST. MARYS RIVER 2214 UNNAMED DITCHES A-91 2217 UNNAMED RUN A-92 2225 UNNAMED DRAIN A-95 2226 BRANDY BRANCH A-94 2245 DEEP CREEK A-98 2255 BALDWIN BAY DITCH A-99 2263 UNNAMED DITCH A-100 2275 UNNAMED SLOUGH A-101 2281 UNNAMED DITCH A-102 2289 UNNAMED BRANCH A-103 2291 UNNAMED DITCH A-104 2313 UNNAMED SLOUGH A-105 5007 ST. MARYS RIVER A-97 NASSAU RIVER 2118 MCQUEEN CREEK C-25 2120 MILLS CREEK C-27 2122 UNNAMED SLOUGH C-29 2125 UNNAMED SLOUGH C-32 2129 LOFTON CREEK C-37 2130 PLUMMER CREEK C-38


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2131 UNNAMED SLOUGH C-39 2132 UNNAMED BRANCH C-40 2133 UNNAMED BRANCH C-41 2135 SPELL SWAMP C-43 2136 UNNAMED BRANCH C-44 2138 LITTLE BOGGY CREEK C-46 2139 UNNAMED BRANCH C-47 2142 UNNAMED SLOUGH C-50 2143 TOM MANN SWAMP C-51 2145 UNNAMED BRANCH C-53 2147 GARDNER CREEK C-55 2148 NASSAU RIVER C-56 2149 SOUTH AMELIA RIVER C-57 2151 LUMBER CREEK C-59 2153 ALLIGATOR CREEK C-61 2155 UNNAMED BRANCH C-63 2156 UNNAMED BRANCH C-64 2157 LITTLE MILL CREEK C-65 2158 UNNAMED DRAIN C-66 2161 THOMAS CREEK C-69 2162 CUSHING CREEK C-70 2164 UNNAMED SLOUGH C-72 2166 UNNAMED DITCH C-71 2169 FUNKS CREEK REACH C-78 2172 UNNAMED BRANCH C-75 2174 NASSAU SOUND C-76 2175 UNNAMED BRANCH C-77 2177 BRADDOCK CREEK C-79 2182 BEN BRANCH C-83 2184 UNNAMED BRANCH C-84 2193 UNNAMED DRAIN C-86 2197 UNNAMED DRAIN C-88 2202 VERDIE BRANCH C-89 2212 UNNAMED DRAIN C-90

4.5. Survey Plan This survey plan is adapted from the Watershed Management Program Guidelines and Specifications developed by the Southwest Florida Water Management District (SWFWMD). These guidelines are very detailed and it may be necessary to modify and/or reduce scope items on a basin by basin basis depending on the level of funding available for the completion of the modeling studies in Part II. The following will be used to develop a scope for the Part II


survey and data acquisition needed. The scope development should occur when the County has completed its prioritization of the basins for future modeling. 4.5.1. Digital Terrain Model This first step in any watershed management program is the acquisition of digital topographic data. The County already has an inventory of the drainage structures county-wide. However, topographic information will be needed across each basin as well. In general, this task would include the following items:

• Development of 1’ accuracy contour information using LiDAR technology • Location of topographic voids • Identification of surveys required to fill in the topographic voids • Identification of areas that should be remapped • Identification of lake, pond, and wetland initial water surface boundaries • Assembly of a DTM for the watershed

The County has already begun the process of developing 1-foot accuracy topographic elevation data County-wide using LiDAR methodology. This technology provides a fast and cost-effective method of developing topographic data. A LiDAR system consists of an ABGPS with attendant GPS base stations that ascertain the in-flight 3D position of the sensor; an inertial measuring unit that delivers precise information about the altitude of the sensor; and the light-emitting scanning laser. The County is currently in the process of securing funding to complete the LiDAR topographic mapping. LiDAR is not full-proof, and particularly in areas with extensive, dense tree-cover, there are often topographic voids. Topographic void areas are defined as those areas where the available topographic information does not represent the current topography due to: (1) land alterations that have occurred, (2) limitations of aerial photogrammetric projection methods, or (3) the topography is not available. Land alteration voids occur in areas where land cover changes have superceded the available topography. Photogrammetric voids are typically found in heavily wooded areas that block the view of the ground so that aerial photogrammetric techniques do not work. These void areas shall be identified using aerial topographic maps, the latest available color infrared photography, land cover maps, and ERP information and then field reviewed to determine whether the current topographic information represents the land surface. Areas where topographic information does not represent the existing condition should be noted and a remedy specified, particularly in significant storage and conveyance areas. Remedies shall include “As-Built” information, surveys by a professional land surveyor, or aerial topographic remapping. A GIS coverage should be generated that indicates the location of the suspect areas, whether the information should be replaced, and the method recommended for replacing or updating the topographic information. 4.5.2. Hydraulic Feature Inventory While a macro hydraulic feature inventory has been completed County-wide in this report, it will be necessary to confirm the information on a subbasin by subbasin basis prior to modeling. In addition, the County’s current inventory consists only of drainage structures. During Part II, the inventory should be expanded to include storage and conveyance features. The four major components of the hydraulic inventory are: (1) the storage areas (lakes, ponds, wetlands, and stormwater management storage areas [SMSAs]), (2) the hydraulic control


features (culverts, overland flow saddles, bridges, channels, etc.), (3) hydraulic interconnectivity, (4) the associated data needed for characterization, and (5) system scale. As with the subbasin identification (hydrologic inventory), a methodical approach is to be developed prior to conducting the hydraulic feature inventory. The following should be considered as part of the inventory process:

• A review of USGS Quadrangles, Aerial Topographic Maps, FIRMs, and the National Wetland Inventory shall be conducted.

• An attributed polygon coverage shall be developed that defines the areas of all lakes,

ponds, wetlands, SMSAs, other depressions that meet the threshold criteria (1 acre and 2-foot depth). This coverage is required as part of the DTM of the watershed. If this information is not preexisting, it shall be generated as part of the hydraulic feature inventory. Elevations of the water bodies shall be included in the coverage as an attribute for identification purposes.

• Subwatershed areas associated with major tributaries should be identified so that the

hydraulic information can be inventoried as a group. • Annotated maps (preferably 1” = 200’ scale 1-foot contour maps) of the watershed

should be developed that contain major sub-watershed breakouts; runoff flow patterns; the Section Township and Range (S-T-R); and a coordinate grid system for locating the conveyance structures. These annotated maps will be incorporated into a Technical Support Data Notebook.

• An Inventory Coverage shall be developed that will be used to index and locate hydraulic

feature information encountered during the field reconnaissance. Further discussions concerning the Inventory Coverage development are presented in the following section.

• A Junction/Reach Coverage shall be developed, if one is not available, that

demonstrates the hydraulic connectivity and assumed flow directions between subbasins and the storage areas for watershed modeling purposes. Junctions should be centrally located within the storage areas, while the hydraulic connections shall follow the observed flow paths. Naming of the junction and reaches should not be performed early in the process due to the editing that will be required as the inventory is developed.

4.5.2.1. System Scale During the development of the watershed inventory, an evaluation of the conveyance system shall be performed to assign a system scale to its various components. A system scale shall be assigned to the reaches identified in the Inventory and Junction/Reach Coverages. The three categories of system scale are Regional, Intermediate, and Local. A Regional scale system primarily includes rivers. An Intermediate scale system includes: coastal streams, natural conveyance systems that directly discharge to rivers and/or conveys runoff from multiple entities along its path such as private land owners and subdivisions. Local systems typically include man-made conveyance systems constructed specifically for an agricultural, development, or industrial purpose and consist of roadside ditches, swales, culverts, inlets and SMSA.


4.5.2.2. Field Reconnaissance Field reconnaissance of the hydraulic features should be verified during the wet season as practical to obtain hydraulic parameters that are representative of field conditions expected during flood events. Field reconnaissance shall include meeting with the local government maintenance personnel to acquire knowledge of known conveyance and maintenance issues. Field reconnaissance and investigation shall include but not be limited to a search for historic flooding and flood damage information from County records for model verification.

Locate and identify all hydraulic features (culverts, bridges, weirs, streams, etc.) and SMSAs and other storage areas that will be hydraulically modeled. Collection systems discharging to SMSAs are not to be inventoried unless specified. Only their tributary areas need to be verified. Digital photos, sketches, and dimensions of the hydraulic features shall be collected and assembled into an Inventory Coverage and Technical Support Data Notebook (TSDN). The Inventory Coverage will use points and arcs to locate and index the hydraulic features. The Inventory Coverage is used to identify, locate, and inventory structures encountered within the watershed until sufficient information and detail is obtained to identify the hydraulic connectivity. When this occurs, the inventory information will be transferred to the Junction/Reach Coverage.

Specific observations that shall be noted during the reconnaissance include the following items:

• Hydraulic Feature ID. • Location description that includes: section, township, range; XY coordinate based

upon map, location based on distance in feet upstream or downstream from a road or major landmark, or Global Positioning System (GPS).

• Condition of natural or man-made conveyance ways encountered (i.e., well

maintained or overgrown, highly eroded, noticeable sediment build¬up, sloughing of embankment, contiguous land use, tidal influence, dry or wet condition, overhanging trees, natural or channeled/altered appearance, spoil areas, steep banks, mild sloping banks, etc.).

• Condition, setting and use of the lake, pond, SMSA, etc. encountered (i.e., well

maintained, overgrown, sediment build-up, condition of outlet, littoral zone, natural, man-made, modified dredged and filled system, mining or borrow, approximate surface area, contiguous land use, used for water supply, dry or wet condition).

• Condition of Wetland – dry, drained, moderately drained, or wet with a

description of the hydraulic control feature. • Required survey information such as inverts, cross section, bathymetric

transects, vegetative transects, structural dimensions, associated roadway low points, elevation of cut squares or Temporary Bench Marks (TBMs), etc. Cut squares to be surveyed shall be marked with florescent paint.


• Secondary measurements of the structure can be made in lieu of surveys by a Professional Land Surveyor and Mapper provided all measurements are made from a TBM located on or in the vicinity of a structure. Vertical elevation establishment for the TBM (cut-square) shall be performed by a Registered Professional Land Surveyor.

• Accessibility for maintenance (i.e., are there obvious access roads, adjacent

large trees, fences, buildings, or residential structures to conveyance ways or SMSAs.)

Two forms have been provided at the end of this section as check lists for the performance of the water resource inventory, an index and a survey requirement form.

Technical Support Data Notebook (TSDN) Since most of the work effort specified within the Watershed Management Program is focused on flood protection, many of the FEMA documents will be required; one such item is the Technical Support Data Notebook (TSDN) required by FEMA. During the course of the Watershed Management Program, watershed information will be collected, generated, and assembled. To maintain this data, a TSDN shall be created that contains originals of the study work products. Guidelines for the format of the notebook are found in Appendix M: Guidance for Preparing and Maintaining Technical and Administrative Support Data in the Guidelines and Specifications for Flood Hazard Mapping Partners, Federal Emergency Management Agency (FEMA), February 2002. The following is a condensed outline of the document that shall have the major data elements indexed according to Section, Township, and Range (S-T-R) where applicable:

• General Documentation (e.g. Special Problems Reports, telephone conversation records, meeting minutes/reports, and general correspondence)

• Engineering Analyses (e.g. data and references to all watershed data and parameters used in the analyses, and computer results)

• Flood Insurance Study (FIS) Report Data

• Mapping Information (base maps, topographic maps, working maps, aerial photographs, etc., indexed to S-T-R)

• Reference Materials (field surveys, previous watershed studies, and other miscellaneous reports)

Location and Identification of Hydraulic Features During the field reconnaissance, the horizontal coordinate location(s) of fixed hydraulic features (bridges, culverts, weirs, dams, etc.) centers shall be determined to within 20 feet. This accuracy is based on the use of maps with a horizontal feature accuracy of ± 5 feet at a scale of 1” = 200’ or the use of a beacon receiver. Points will represent the center locations of the structures in the Inventory Coverage. Arcs will be used to represent open channel GIS alignments while points will be used to show the location of structures and representative cross sections where channel information is to be collected. Spreadsheet information in Database Format (DBF) shall be developed for the


structures so that the Inventory Coverage can be easily generated using GIS import techniques. ID Naming of the hydraulic features inventoried shall be based on the Section-Township-Range (S-T-R) they are located and a sequential number assignment. The hydraulic ID shall be six characters in length and look as follows: 273025_001. The S-T-R is “27-30-25” and the hydraulic feature number “001” which is the sequential number assignment within the section.

Digital Photos of Features Digital photos shall be taken looking at the upstream and the downstream portions of the fixed hydraulic features (bridges, culverts, weirs, etc.). Additional photos may be required to provide adequate representation of a feature and to identify special items such as temporary bench marks (TBM). Cross section photos shall be taken looking up and downstream in the immediate vicinity of the cross section. For large cross sections, additional photos shall be included that look across the section. The digital photos shall be labeled with the following: hydraulic feature ID, XY coordinate, horizontal datum, structure type, and photo orientation (see Appendix “A”). Digital photos shall be 4” tall by 5.333” long, landscape oriented, in JPEG format, and at a minimum of 150-pixel resolution. Digital printouts can be larger provided that the aspect ratio is maintained. All digital information for structures (photos, scanned field books, etc.) shall be indexed by Section, Township, and Range as the main subdirectory with the hydraulic ID as the subdirectory for containing the individual file information. See the

Hydraulic Feature Data Development Certain hydraulic measurements (i.e., lengths, widths, heights, orientations, configurations, roadway overtopping elevations, inverts, etc.) can be collected during the field reconnaissance provided that the information is obtained under the supervision of a professional engineer, vertical control (TBM) or reference point information for the structure is established by a professional land surveyor, and measurements are made to the accuracy standards dictated in the following section (4.5.2.3) entitled, “Surveys.” This type of information is termed incidental survey or secondary measurements. Secondary measurements conducted for fixed structures such as culverts, weirs, bridges, etc. and are to be provided on field sketches and in field books. Field sketches shall include the configuration, orientation, physical dimensions, TBMs, construction material, etc. The sketches shall be labeled similar to the photos with the addition of a north arrow and flow orientation. Cut-squares (TBMs) shall be chiseled into the concrete portion of all fixed structures and referenced in sketches. Cut-squares shall be made at each end of a structure in a conspicuous location and used as a reference for collecting secondary measurements such as inverts and roadway profiles at structures. The professional land surveyor will establish the cut-squares as TBMs when this method is used. For pipes without concrete headwalls, upstream and downstream inverts can be used as TBMs.

4.5.2.3. Surveys The following specifications are for surveys required to complete the watershed resource inventory and watershed modeling. Hydraulic feature information needed to complete the watershed inventory shall be surveyed under the direction of a Florida Registered Professional Surveyor and Mapper. Surveys will determine vertical reference mark information (cut-squares) used for the incidental (secondary) measurements, or specific


elevation data and dimensions regarding the hydraulic features, or both.

Vertical control datums (NGVD29 or NAVD88) shall be approved by the project manager prior to identification of vertical bench mark controls that will be used to establish hydraulic feature elevation information. Vertical benchmark controls shall be National Geodetic Survey (NGS) benchmarks.

Vertical Closure Specifications for Hydraulic Feature Surveys All hydraulic feature vertical surveys described in this section shall be based upon the vertical control network described above. Establishment of elevations for the hydraulic features shall be in accordance with the Minimum Technical Standards (MTS) as referenced in Florida Administrative Code (FAC), Chapter 61G17-6. Under no circumstances are Global Positioning System (GPS) or Differential Global Position System (DGPS) techniques to be used to establish elevations for the hydraulic features.

Horizontal Location of Hydraulic Features All hydraulic features described in this section shall be located to within ± 10 feet or better and referenced to the horizontal datum and coordinate system approved (State Plane, Feet, Florida Eastern Zone, NAD83). The horizontal location can be determined from maps with sufficient accuracy, or GPS and DGPS techniques. The horizontal coordinates provided to the surveyor for locating the structure are not determined to the horizontal accuracy specified for survey locations. In the case where the coordinates provided do not meet the accuracy specified, the surveyor shall adjust and report the revised coordinate location.

Gaging Station Surveys For some watersheds, gaging station data are available to verify watershed model results. In most cases, the datums used for reporting water surface elevations are referenced to the National Geodetic Vertical Datum of 1929. If hydraulic feature surveys are to be in NAVD 1988, the gaging station shall be rectified to the NAVD 1988 datum by a Professional Surveyor. The surveyor shall provide the engineer with the correction value so that existing data can be adjusted to the new datum. Elevations and horizontal locations shall be reported to the accuracy specified.

Hydraulic Fixed Structures For structures such as bridges, culverts, weirs, etc., all reported elevations for reference marks, inverts, headwalls, low chords, road centerlines over structures, etc. shall be acquired in accordance within the vertical accuracy specified. All dimensional information reported such as lengths, widths, diameters, etc. shall be measured to within an accuracy of ± 0.01 feet. The center of the structure shall be located to the horizontally accuracy specified. Descriptions of the hydraulic feature data to be collected are provided in the Survey Work Requirement Form, inserted at the end of this section and shall include all elements listed in accordance with FEMA Standards, February 2002, Appendix A: “Guidance for Aerial Mapping and Survey.” The Hydraulic-ID (Hyd-ID) will be used to index and identify all field surveys for a structure or cross section. All documentation regarding field survey information shall be referenced to the Hyd-ID as provided in the Survey Work Requirement Form.


Cross Sections and Stream Channel Alignment Cross sections within the stream reach shall be located to within ± 10 feet or better of the coordinate location as provided on the Survey Work Requirement Form and shall be oriented perpendicular to the stream. Cross section data points shall be referenced to the specified horizontal coordinate system and datum. Ground elevations shall be collected with an accuracy of ± 0.1 feet. If soft material is encountered (i.e., organic mud of flocculent silt) the cross section top of muck shall be determined within ± 0.5 feet vertically using a “standard USACE sounding disc.” Horizontal distances between cross section data points shall be determined within ± 0.1 feet and referenced to the horizontal location.

The Guidelines and Specifications provided in the FEMA Standards, February 2002, Appendix A: “Guidance for Aerial Mapping and Survey” for establishing cross section data points shall be followed. Cross section survey points shall be required according to the FEMA Standards. The full length of the cross section as indicated in the survey work description shall be surveyed and is to extend beyond the 0.2% chance floodplain. Cross section survey points to define the conveyance way beyond the main channel will be taken at major changes in grades and/or vegetation lines to accurately represent the conveyance of the reach. Each survey point will have a hydraulic ID, an “XY” coordinate, a “Z” elevation, and an associated cross section point descriptor for top of bank, toe of slope, and the center of channel. Order of the cross section survey points shall be from a left to right progression looking from the upstream side of the cross section. Bathymetric and other transect survey information for Stormwater Management Areas or other identified water bodies shall be performed according to the same standard as cross sectional information.

Open channels specified for survey in heavily wooded areas that are not visible from aerial photographs shall be surveyed so as to identify the centerline alignment at any location within ± 10 feet horizontally. Straight sections of the channel shall be represented by a minimum of two points with a maximum spacing of 500 feet between points. An arc or curve within the channel shall be defined with a minimum of three points with a maximum spacing of 200 feet. Cross section data points will be surveyed in accordance with the location specified in the survey work order.


5. Wetland Inventory A wetland assessment was provided by Ayres Associate’s ecologists. A hard copy of this report is provided in Appendix C and a digital copy of the report is provided on CD in Appendix E.


6. Water Quality SJRWMD provides seventy-three (73) water quality monitoring sites across the overall SJRWMD. Of these, four (4) are located within Nassau County’s watersheds. The information, photos and graphics in the subsections below were obtained directly from the SJRWMD watershed fact page for each monitoring site (information copied verbatim is identified with italics). A link to each web address is provided so the site may be accessed as needed to evaluate updated information as needed. In addition to SJRWMD, the FDEP maintains a database of water quality information called STORET. The STORET database is a clearinghouse where agencies (FDEP and others) can submit data so it can be available to all for browsing and downloading. An informational slideshow developed by FDEP about STORET is provided on CD in Appendix E under the Water Quality folder. From FDEP’s website (http://storet.dep.state.fl.us/WrmSpa/): “STORET is a database administered by the U.S. Environmental Protection Agency (EPA). STORET is an acronym derived from STOrage and RETreival. It is a data repository used to store water quality data for the nation. Scientists across the nation have been storing their water quality data in STORET for over 30 years. In late 1999 EPA deployed a new STORET database, herein referred to as Modernized STORET. The historical database (pre Modernized STORET) is referred to as Legacy STORET. STORET is a primary data source used to create the National Water Quality Inventory Report to Congress (305(b) report), which evaluates the status of water quality in the nation every two years. Data from STORET along with other sources are used to determine which of the state's waters fail to meet water quality standards and require the development of Total Maximum Daily Loads (TMDLs). For more information on TMDLs, please visit http://www.dep.state.fl.us/water/tmdl . STORET is also used in watershed analysis, monitoring program evaluation and planning, water quality standards evaluation, public information requests, and evaluation of water quality conditions for habitat and fishery restoration. Many organizations contribute information to STORET, including federal, state, and local agencies, academic institutions, and private laboratories. In addition, many volunteer organizations have elected to use STORET to manage and store their data. Florida's Water Resource Implementation Rule (Chapter 62-40.540(3), F.A.C.) requires government agencies to place appropriate water quality monitoring data in STORET within one year of collection. Another Florida administrative code, Chapter 62-303 also called the Impaired Waters Rule (IWR), states that organizations wanting data to be considered in the Department's annual evaluation of waters for impairment should place their data in STORET (Section 62-303.320(2), IWR).” The website where the STORET data can be accessed is located at the following address: http://storet.dep.state.fl.us/WrmSpa/

http://storet.dep.state.fl.us/WrmSpa/

http://www.dep.state.fl.us/water/tmdl

http://storet.dep.state.fl.us/WrmSpa/


6.1. 19010001 St. Mary’s River 6.1.1. Web Address http://sjr.state.fl.us/archydro/factPages/19010001.html 6.1.2. Basin Area 3,699.293 km² 6.1.3. Location Latitude 30°44’29.233”, longitude 81° 41’ 14.311”, GPS datum—WGS-1984 Station 19010001 is located on the St. Marys River at U.S. Highway 17 on the Georgia-Florida border. 6.1.4. Point Sources There are no wastewater treatment facilities upstream within a five-mile radius and within the drainage basin of this water quality site. The sampling site is located on the St. Marys River at U.S. Highway 17 on the Florida–Georgia state line. It is approximately 10 miles north of Yulee, Fla., and has a public boat ramp available for launching boats. The boat ramp is on the north side of the U.S. Highway 17 bridge in Georgia and has limited parking for vehicles and trailers. This part of the St. Marys River is still tidal and its shoreline vegetation is like that found in a coastal marine environment. The local area is sparsely populated, with most of the terrain being salt marsh or pine forests. The St. Marys River is popular with fishermen and boaters. The river’s water level and currents can increase dramatically after periods of heavy rain and boaters should use caution. 6.1.5. St. Mary’s River Water Quality Summary The St. Marys River is sampled monthly, by contract with FDEP, from the bridge at U.S. Highway 17. The river is about 8.8 meters deep at the sampling site and has a typical temperature range. At the sample site, the river is influenced by tidal action, and the area exhibits some characteristics of an estuary. When compared to other streams, conductivity measurements are high along with correspondingly high major ion concentrations, resulting in hard water. The median dissolved oxygen value is just above the FDEP standard for Class 3 surface waters. The water at the site is acidic and poorly buffered, as both the pH and the median alkalinity are below the state standard. Although total nitrogen, total phosphorus, and chlorophyll are at lower concentrations, total organic carbon, color, and total suspended solids are at higher concentrations than what might be found in a typical stream. Secchi depth and

http://sjr.state.fl.us/archydro/factPages/19010001.html



coliform counts were at typical values when compared to other streams. The river at this site has fair water quality, according to the water quality index. Table 6.1, below, obtained from SJRWMD website, summarizes the water quality parameters for this monitoring site (data downloaded September 28, 2008). Table 6.1 St. Mary’s River Water Quality Summary

Analytes Data Yrs

n Data Min Q1 Median Q3 Max Range

water temperature (degrees C) 10 89 10.65 16.70 22.40 27.50 30.39 mid Secchi disc transparency (meters) 10 46 0.20 0.30 0.50 0.60 1.00 mid

color (platinum-cobalt units) 3 11 150.00200.00 225.00 300.00 600.00 mid-hispecific conductance field

(uhmhos/cm@25°C) 10 94 46.00 323.002506.5011350.00 29700.00 high

sampling station depth (meters) 10 94 0.30 0.50 0.50 0.50 4.50 high dissolved oxygen analysis by probe

(mg/L) 10 94 1.82 3.95 5.17 6.69 10.24 mid

pH (standard units) 10 94 4.40 5.63 6.35 6.64 7.24 low total alkalinity (mg/L as CaCO3) 10 93 0.65 8.00 17.00 32.00 65.00 low total nonfiltrable residue (mg/L) 10 95 2.00 6.00 10.00 16.00 37.00 mid-hi

total nitrogen (mg/L as N) 10 86 0.38 0.93 1.10 1.26 3.42 mid-lototal phosphorus (mg/L as P) 10 94 0.02 0.04 0.05 0.06 0.38 low

total organic carbon (mg/L as C) 10 88 8.80 20.60 26.00 40.00 83.80 mid-hitotal calcium (mg/L as Ca) 10 95 2.45 6.20 g22.20 88.00 187.00 mid-lo

total magnesium (mg/L as Mg) 10 95 0.99 5.40 57.10 237.00 567.00 high total sodium (mg/L as Na) 10 95 3.23 40.00 454.00 1930.00 4610.00 high

total potassium (mg/L as K) 10 95 0.39 2.55 18.80 70.80 181.00 high total chloride (mg/L) 10 95 5.70 63.00 834.00 3700.00 8800.00 high

total sulfate (mg/L as SO4) 10 95 0.00 11.00 121.00 500.00 1300.00 high wqi 10 95 24.08 49.89 55.71 61.57 75.67 mid

fecal coliform (MF M-FC broth 44.5°C) 10 85 10.00 46.00 74.00 110.00 2400.00 mid trichromatic uncorrected chlorophyll-a

(ug/L) 4 20 0.01 0.01 1.55 6.37 13.00 mid-lo

total filtrable residue (mg/L dried at 180°C) 10 93 77.00 228.001420.00 5630.00 15100.00 high

lab turbidity (NTU) 3 11 2.70 5.20 6.10 6.60 6.90 mid-hisample site depth (meters) 10 91 1.00 7.70 8.80 9.70 11.50 high hardness (mg/L Ca+Mg) 10 95 10.19 38.51 293.57 1176.97 2794.35 high


6.2. 19020002 Nassau River 6.2.1. Web Address http://sjr.state.fl.us/archydro/factPages/19020002.html 6.2.2. Basin Area 680.738 km² 6.2.3. Location Latitude 30°34’29.720”, longitude 81°36’31.088”, GPS datum—WGS-1984 Station 19020002 is on the Nassau River at U.S. Highway 17. 6.2.4. Point Sources There are no wastewater treatment facilities upstream within a five-mile radius and within the drainage basin of this site. The sampling site is located on the Nassau River at U.S. Highway 17, approximately 4 miles south of Yulee, Fla. There is a private boat ramp located at a fish camp on the north side of the bridge and boaters may use the ramp for a small fee. Highway 17 is an extremely busy roadway and caution is advised when entering or leaving the fish camp. The area is a coastal marine environment, dominated by salt marsh, and is sparsely populated. It offers great fishing and the local fish camp offers fishing tournaments throughout the year. The city of Fernandina Beach and the resorts of Amelia Island are located approximately 10 miles to the northeast and offer many opportunities for visitors, such as golf, boating, shopping, dining, and the beach.



6.2.5. Nassau River Water Quality Summary The Nassau River is sampled monthly at U.S. Highway 17, in northern Duval County, under an FDEP contract. The river is about 6.75 meters deep at the sample site and has a typical temperature range. At the sampling site, the river is tidally influenced, and the area exhibits characteristics of an estuary. Although conductivity measurements are a little low for estuaries, the major ion concentrations are high, resulting in very hard water. The median dissolved oxygen value is just above the FDEP standard for Class 3 surface waters. The water is moderately buffered and slightly acidic. The low Secchi depth is most likely due to elevated concentrations of total organic carbon and color. Concentrations of total suspended solids, turbidity, total nitrogen, total phosphorus, chlorophyll, and coliform counts were all higher than what is typically found in an estuary. These constituents were likely responsible for the poor water quality rating at the site, according to the trophic state index. Table 6.2, below, obtained from SJRWMD website, summarizes the water quality parameters for this monitoring site (data downloaded September 28, 2008). Table 6.2 Nassau River Water Quality Summary

Analytes Data Yrs


water temperature (degrees C) 10 95 10.20 16.80 22.40 27.60 30.50 mid-loSecchi disc transparency (meters) 10 40 0.20 0.30 0.48 0.50 0.90 low

color (platinum-cobalt units) 3 11 120.00150.00 200.00 250.00 300.00 high specific conductance field

(uhmhos/cm@25°C) 10 95 134.004781.0014500.0026400.00 40300.00mid-lo

sampling station depth (meters) 10 95 0.30 0.50 0.50 0.50 3.90 mid-hidissolved oxygen analysis by probe

(mg/L) 10 95 1.62 4.60 5.85 7.32 9.77 mid-lo

pH (standard units) 10 94 5.88 6.49 6.84 7.05 7.52 low total alkalinity (mg/L as CaCO3) 10 93 8.00 33.00 54.00 73.70 100.00 mid-lototal nonfiltrable residue (mg/L) 10 95 3.00 17.00 26.00 39.00 300.00 mid-hi

total nitrogen (mg/L as N) 10 87 0.49 0.99 1.20 1.38 3.69 mid-hitotal phosphorus (mg/L as P) 10 90 0.04 0.11 0.14 0.18 1.70 high

total organic carbon (mg/L as C) 10 90 6.20 15.00 20.00 25.00 48.40 high tsi 10 83 8.09 56.47 61.65 65.31 74.53 high

total calcium (mg/L as Ca) 10 95 5.00 39.00 122.00 216.00 399.00 mid-hitotal magnesium (mg/L as Mg) 10 95 3.20 109.00 346.00 644.00 1180.00 mid-hi

total sodium (mg/L as Na) 10 95 16.50 1340.002930.00 5280.00 9470.00 mid-hitotal potassium (mg/L as K) 10 95 2.00 36.60 107.00 191.00 427.00 mid-hi

total chloride (mg/L) 10 95 25.00 1700.005310.00 9600.00 17000.00mid-hitotal sulfate (mg/L as SO4) 10 95 0.43 230.00 640.00 1300.00 2400.00 mid-hi

fecal coliform (MF M-FC broth 44.5°C) 10 82 1.00 20.00 36.00 70.00 830.00 mid-hitrichromatic uncorrected chlorophyll-a

(ug/L) 4 20 0.01 0.53 7.67 11.95 113.00 mid

total filtrable residue (mg/L dried at 180°C) 10 92 124.002685.008185.00 16123.50 26900.00mid-hi

lab turbidity (NTU) 3 11 3.00 6.90 12.70 16.30 31.00 high sample site depth (meters) 10 92 1.00 4.15 6.75 7.80 11.70 high hardness (mg/L Ca+Mg) 10 95 27.29 546.25 1729.46 3198.84 5838.06 mid-hi


6.3. Nassau River near Italia (NRI) 6.3.1. Web Address http://sjr.state.fl.us/archydro/factPages/NRI.html 6.3.2. Basin Area 349.867 km² 6.3.3. Location Latitude 30°34’53.263”, longitude 81°41’08.789”, GPS datum—WGS-1984 Station NRI is located on the Nassau River near Italia. 6.3.4. Point Sources There are no point sources within a five-mile radius or within the drainage basin of this water quality site. This site is located on the Nassau River in Nassau County in northeastern Florida, approximately 5 miles southwest of Yulee. It is an extremely beautiful location on the river that must be accessed by boat. The site is just west of a picturesque “humpback” bridge, which is located on private property. The area is popular for fishing and boating throughout the year. A county boat ramp is located approximately 4 to 5 miles east of the site and south of State Road 200/A1A. The vegetation surrounding the area is that of a saltwater, tidal environment, but depending on the amount of rainfall, the salinity and pH of the water at the site can vary widely due to an influx of freshwater from the tributaries in the area. The area is abundant with wildlife and waterfowl that can be seen throughout the year. Pine forest and salt marsh are the dominant geographical features in the area. There are some private residences in the area along the shoreline and increasing development to the north.

http://sjr.state.fl.us/archydro/factPages/NRI.html


6.3.5. NRI Water Quality Summary The Nassau River is located in northern Duval County. It is sampled every other month as part of the ambient monitoring program. The sample site is about 4.7 meters deep and has a typical temperature range. The major ion concentrations are high enough to result in moderately hard water. The median dissolved oxygen concentration is just above the FDEP standard for Class 3 surface waters. The water is poorly buffered and slightly acidic, and the pH is below the state standard. When compared to other streams, the total organic carbon concentrations and color are elevated, resulting in lower Secchi depth. Total suspended solids and turbidity are also elevated. Total nitrogen and chlorophyll concentrations are less than those typically found, while total phosphorus and coliform concentrations are elevated. The river has poor water quality at the site, according to the water quality index. Table 6.3, below, obtained from SJRWMD website, summarizes the water quality parameters for this monitoring site (data downloaded September 28, 2008). Table 6.3 Nassau River near Italia Water Quality Summary

Analytes Data Yrs


water temperature (degrees C) 11 52 10.70 16.25 23.15 27.75 30.35 mid Secchi disc transparency (meters) 11 30 0.25 0.40 0.45 0.70 0.95 mid-lo

color (platinum-cobalt units) 11 48 50.00 162.50 300.00 400.00 800.00 high specific conductance field

(uhmhos/cm@25°C) 11 57 0.89 217.00 490.00 2070.00 21400.00 mid

sampling station depth (meters) 11 55 0.50 0.50 0.50 0.50 3.30 high dissolved oxygen analysis by probe (mg/L) 11 56 0.27 3.51 5.26 6.38 9.10 mid

pH (standard units) 11 57 3.40 6.17 6.41 6.61 7.82 low total alkalinity (mg/L as CaCO3) 11 55 10.39 18.00 22.67 28.00 48.00 low total nonfiltrable residue (mg/L) 11 57 3.00 5.00 9.00 14.00 45.00 mid-hi

total nitrogen (mg/L as N) 11 56 0.85 1.07 1.19 1.47 5.70 mid-lototal phosphorus (mg/L as P) 11 57 0.05 0.11 0.16 0.20 0.34 mid-hi

total organic carbon (mg/L as C) 11 57 15.50 23.70 28.54 37.90 54.91 mid-hitotal calcium (mg/L as Ca) 11 57 6.11 8.74 13.42 30.20 258.00 low

total magnesium (mg/L as Mg) 11 57 2.69 5.83 13.04 48.94 491.00 mid-hitotal sodium (mg/L as Na) 11 57 7.65 28.86 101.99 380.83 3500.00 mid-hi

total potassium (mg/L as K) 11 57 1.75 3.10 6.80 15.27 196.00 high total chloride (mg/L) 11 57 11.20 48.00 206.00 629.88 9480.87 mid-hi

total sulfate (mg/L as SO4) 11 54 1.00 10.83 25.22 75.81 1308.54 mid wqi 11 57 40.57 52.84 64.32 70.15 89.61 mid-hi

fecal coliform (MF M-FC broth 44.5°C) 4 13 10.00 80.00 96.00 610.00 1300.00 mid trichromatic uncorrected chlorophyll-

a(ug/L) 11 56 0.00 0.89 1.84 4.81 18.50 mid-lo

total filtrable residue (mg/L dried at 180°C) 11 57 112.00198.00 430.00 1330.00 12900.00 mid-hilab turbidity (NTU) 11 48 2.10 3.70 5.41 8.48 28.60 mid-hi

sample site depth (meters) 11 56 1.50 3.50 4.65 5.60 7.00 high hardness (mg/L Ca+Mg) 11 57 26.42 48.14 91.83 281.11 2666.16 mid-lo


6.4. SJA-HS-1018 (St. Marys River) 6.4.1. Web Address http://sjr.state.fl.us/archydro/factPages/SJA-HS-1018.html 6.4.2. Basin Area 3,029.933 km² 6.4.3. Location Latitude 30°46’45.276”, longitude 82°01’16.7”, GPS datum—WGS-1984 Station SJA-HS-1018 is located on the St. Marys River between station 19010001 at U.S. Highway 17 and Site 19010006 at State Road 2. 6.4.4. Point Sources There are no wastewater treatment facilities upstream within a five-mile radius or within the drainage basin of this water quality site. This site is located on the St. Marys River about a mile upstream of the boat ramp at Traders Hill, Ga. It can also be accessed using a Nassau County boat ramp at Scott’s Landing located east of U.S. Highway 1 at Boulogne, Fla. The site is located approximately 4 miles west of Boulogne, as the crow flies. This area is incredibly beautiful with the dark tannic waters of the St. Marys River accented by sugar white sand on the banks. It is a lightly populated area so the shorelines are mostly undisturbed. The St. Marys River is a very popular area for local boaters, fishermen, and campers. There are several areas along the shoreline that people utilize for campsites. Boaters should use caution during and after inclement weather since the St. Marys River is influenced by heavy rainfalls that create quickly rising waters and increased flow. The city of Hilliard, Fla., is located approximately 7 miles southwest of the Scott’s Landing boat ramp and the city of Folkston, Ga., is approximately 5 miles north of there.

http://sjr.state.fl.us/archydro/factPages/SJA-HS-1018.html


6.4.5. SJA-HS-1018 Water Quality Summary The St. Marys River is sampled west of Trader’s Hill. The site is a blackwater stream, and it is sampled every other month as part of the ambient monitoring program. The river is about 2.1 meters deep at the sample site and has a typical temperature range. When compared to other blackwater stream sites, conductivity and major ion concentrations are lower than typically found, resulting in soft water. The median dissolved oxygen concentration is above the FDEP standard for Class 3 surface waters. The water is poorly buffered and acidic, and both the median pH and alkalinity are below the state standard. Total organic carbon concentrations and color are elevated, resulting in a lower Secchi depth. Total suspended solids and turbidity are also elevated. Total nitrogen concentrations are typical, while total phosphorus concentrations are lower. However, both nutrients exceed recommended EPA nutrient criteria. Chlorophyll concentrations were typical, and coliform counts were low. The river has good water quality at the site, according to the water quality index. Table 6.4, below, obtained from SJRWMD website, summarizes the water quality parameters for this monitoring site (data downloaded September 28, 2008). Table 6.4 St. Marys River Water Quality Summary

Analytes Data Yrs


water temperature (degrees C) 5 8 12.03 13.05 18.97 25.57 28.40 mid-loSecchi disc transparency (meters) 5 21 0.30 0.40 0.45 0.70 1.60 mid-lo

color (platinum-cobalt units) 5 20 70.00300.00 400.00 550.00 1000.00 mid-hispecific conductance field

(uhmhos/cm@25°C) 5 21 34.00 61.00 74.00 92.00 153.00 mid-lo

sampling station depth (meters) 5 21 0.50 0.50 0.50 0.50 1.35 high dissolved oxygen analysis by probe (mg/L) 5 21 2.37 5.63 6.36 8.93 10.37 mid

pH (standard units) 5 21 4.30 4.70 5.67 6.70 7.30 mid-lototal alkalinity (mg/L as CaCO3) 5 18 0.00 0.50 1.65 13.15 45.11 low total nonfiltrable residue (mg/L) 5 21 1.30 2.10 5.00 5.00 24.00 mid-hi

total nitrogen (mg/L as N) 5 21 0.43 0.91 1.01 1.25 1.58 mid total phosphorus (mg/L as P) 5 21 0.03 0.04 0.05 0.06 0.09 mid-lo

total organic carbon (mg/L as C) 5 21 9.85 29.62 35.46 45.29 62.01 mid-hitotal calcium (mg/L as Ca) 5 21 2.73 3.29 4.98 7.18 12.52 mid-lo

total magnesium (mg/L as Mg) 5 21 0.81 1.46 1.99 3.02 5.81 mid total sodium (mg/L as Na) 5 21 2.22 5.10 6.26 7.44 9.59 mid

total potassium (mg/L as K) 5 21 0.17 0.67 0.89 1.02 1.22 mid-hitotal chloride (mg/L) 5 21 3.52 7.51 9.83 10.57 12.72 mid-lo

total sulfate (mg/L as SO4) 5 19 -0.51 1.83 3.27 4.41 9.30 mid-lowqi 5 21 16.19 26.24 28.93 33.11 63.51 mid

fecal coliform (MF M-FC broth 44.5°C) 1 1 24.00 24.00 24.00 24.00 24.00 low trichromatic uncorrected chlorophyll-a (ug/L) 5 20 -0.19 0.09 0.33 1.11 6.05 mid total filtrable residue (mg/L dried at 180°C) 5 20 34.00 85.00 98.00 120.00 155.00 mid

lab turbidity (NTU) 5 20 1.70 2.30 3.40 4.95 46.20 mid-hisample site depth (meters) 5 21 1.00 1.60 2.10 2.70 4.10 mid-hihardness (mg/L Ca+Mg) 5 21 10.19 14.24 20.41 30.37 55.17 mid-lo


7. Data Collection Needs Assessment 7.1. Stream Flow Data Streamflow data are needed to verify the simulated runoff resulting from a historical rainfall event. Hourly stages and flows are available from the USGS, while daily and some hourly data are available from SJRWMD as discussed in Section 3.2. Water surface elevation and flow data acquired shall be evaluated for accuracy. Hydrograph comparison, hydrograph deconvolution, baseflow analysis, and volumetric analysis can be used to determine the validity of the simulation model parameters. Unfortunately, review of USGS Waterwatch website reveals that the USGS currently has NO stream flow gages within Nassau County. As described in Section 3.2, SJRWMD only has a record of one monitoring site that recorded stream flow and this was limited to the years 2002/2003 and three that record water level, which also are not current. The County should consider placing stream flow monitors at locations on the two major rivers (St. Marys and Nassau River) and at strategic locations on significant tributaries to these rivers, including the following in the Upper St. Marys River Basin: Brandy Branch; the following in the Middle and Lower St. Marys River Basin: Deep Creek, Cabbage Creek, Little St. Marys River, and Mill Creek; and the following streams in the Nassau River Basin: Mills Creek, Alligator Creek, Thomas Creek and Lofton Creek. Each of the aforementioned streams contain tributary streams, so gaging the main stream would help in model calibration if the entire stream watersheds are modeled. 7.2. Rainfall Data There are currently four rain gages located throughout Nassau County. They are located generally near populated areas. While additional rain gages would be helpful, the four existing gauges at least provide a broad based coverage of the County. 7.3. Water Quality At this time, no additional water quality stations are recommended. The County has no water quality requirements (such as TMDL) which would necessitate additional sites be located on tributary streams. The County should monitor the regulatory environment, however, and if potential funding acquisition could be eased by the County’s development of a water quality program or if the County passes the threshold for requirement of a Phase II NPDES permit, additional sites may be warranted. 7.4. Additional Recommendations The next step that must be taken in the development of the SWMP is a prioritization of the County’s basins for modeling. It is understood that due to the flooding which occurred following TS Fay, the County has chosen to model Thomas Creek and Alligator Creeks as their highest priority subbasins. Following those, however, the County should prepare a matrix showing potential for future development, existing drainage problems and existing land use to provide a means to prioritize the remaining subbasins for additional study.

part 1 – existing stormwater management system evaluation

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