Calculating Buffer Zone Widths for Protection of Wetlands and Other Environmentally Sensitive Lands in St. Johns County
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Title: Calculating Buffer Zone Widths for Protection of Wetlands and Other Environmentally Sensitive Lands in St. Johns County
Alternate Title: JEA Project Np.: 19270-485-01
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Creator: Brown, Mark T.
Center for Wetlands and Water Resources
Publisher: Center for Wetlands
Place of Publication: Gainesville, FL
Publication Date: January 2000
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Subjects / Keywords: buffer zones
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Holding Location: University of Florida
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CALCULATING BUFFER ZONE WIDTHSFORPROTECTION OF WETLANDSANDOTHERENVIRONMENTALLY SENSITIVE LANDS IN ST. JOHNS COUNTY JEA PROJECT NO.: 19270-485-01Submitted to:ST. JOHNS COUNTY PLANNING DEPARTMENT4020 Lewis Speedway Road St. Augustine, Florida 32095 Submitted by:JONES, EDMUNDS&ASSOCIATES, INC.730 N.E. Waldo Road, Building A Gainesville, Florida 32641Incollaboration with:MARKT. BROWN, Ph.D. UNIVERSITY OF FLORIDA CENTER FOR WETLANDS AND WATER RESOURCESPostOffice Box 116350 Gainesville, Florida 32611-6350 andRICHARDHAMANN,ESQ. UNIVERSITYOFFLORIDA COLLEGE OFLAWPostOfficeBox117629 Gainesville, Florida 32611-7629 January 2000

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TABLEOFCONTENTS1.0INTRODUCTION.."..,1-11.1PROJECT GOALS1-11.2 ECOLOGICAL VALUEOFBUFFER ZONES1-22.0PROTECTING WETLAND-DEPENDENT WILDLIFE HABITAT2-12.1SPATIAL REQUIREMENTS2-13.0 PROTECTING WETLANDS FROM TURBIDITY AND SEDIMENTATION3-13.1SEDIMENTATION AND TURBIDITY LOOK-UP TABLE 3-2 3.1.1 Look-up Table 3-2 3.1.2 Calculation Procedure 3-2 4.0 PROTECTING WETLANDS FROM GROUNDWATER DRA WDOWN4-14.1MODELINGREQUIREMENTS AND LIMITATIONS4-14.2 DRA WDOWN IMP ACT CALCULATIONS FOR ST. JOHNS COUNTY.., 4-2 4.3 WETLAND DRA WDOWN LOOK-UP TABLES4-35.0 DETERMINATION OF A BUFFER WIDTH 5-1 5.1ALTERNATIVE BUFFER WIDTHS5-15.2 BUFFER ESTABLISHMENT5-15.3BUFFER HABITAT5-16.0 REFERENCES6-1APPENDICES Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Species ListofWetland-Dependent Native Wildlife SpeciesofSt. Johns County Spatial RequirementsbySpecies Listed in Ascending Order by Habitat Soils Information in St. Johns County (Source: St. Johns County Soil Survey) Hydrologic Methodologies for Predicting Peak Stormwater Discharge ListofThreatened and Endangered Species in St. Johns County Stormwater Guidelines"f." n"'l""7n\AQ<:n 1ninmRllfferReoort. wpdTABLE OF CONTENTS

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LIST OF FIGURES2.1Spatial Requirement(ft)A and B Cypress Wetlands 2-4 2.2 Spatial Requirement(ft)A and B Hardwood Swamp' 2-52.3Spatial Requirement(ft)A and B Freshwater Marsh 2-6 2.4 Spatial Requirement(ft)A and B Saltwater Marsh 2-72.5Spatial Requirement(ft)A and B Flatwoods 2-8 2.6 Spatial Requirement(ft)A and B Hammock 2-9 2.7 Spatial Requirement(ft)A and B Sandhill ; 2-104.1Simulated Drawdowns A&B 4-6 4.2 Simulated DrawdownsA&B'"4-7 4.3 Simulated Drawdowns A&B 4-8 4.4 Simulated Drawdowns A&B 4-105.1Environmentally Significant Lands 5-5W:\l 9270\4850 I 0700\BufferReport.wpdLISTOFFIGURES

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LIST OFTABLES2.1SummaryofPublished Data Describing Recommended Buffer Zones for ProtectionofWildlife Species 2-3 2.2 Spatial Requirement (ft) to Protect Various PercentagesofSpecies for Each Habitat Type (Data from Figures 2.1 2.7) 2-11 3.1 Recommended Wetland Buffers to Minimize Sedimentation in Wetlands and to Control Turbidity in Adjacent Open Waters 3-3 3.2 Mannings Roughness Coefficients (n) 3-4 4.1 Buffer Distances When Surficial Aquifer Drawdownof0.5 Feet is Acceptable 4-4 4.2 Buffer Distances When Surficial Aquifer Drawdownof1.0 Feet is Acceptable 4-5 5.1 Buffer Widths for St. Johns County as Proposed by County Planning Staff 5-2 5.2 Appropriate Plantings for Buffer Zones 5-3W\1 Q?7n\.:lR"fll 0700\RufferReoort.wndLISTOfTABLES

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1.0 INTRODUCTION St. Johns County's adopted 1990 Comprehensive Plan PoifcYF:.1.3.7 requires vegetative buffersofat least25feet to be maintained between natural drainage courses and developed areas to protect the water qualityofthe drainage course. This buffer requirementhasbeen expanded through ArticleIVofthe Land Development Code to require a 50-foot minimum natural upland buffer between development lands and the St. Johns River, Matanzas River, Guana River, TolomataRiver, and their associated wetlands and water bodies, regardlessofany other regulatory agency requirementofa lesser distance. However,inrecent years the countyhas determined a minimumof25or50 feet around wetlands in the county may not be sufficient to protect water quality given the varietyofwetlands and other environmentally sensitive lands. Further, the Comprehensive Plan requires that the county protect environmentally sensitive lands (wetlands adjacent to Outstanding Florida Waters [OFWs],Class II waters, Classillwaters, Aquatic Preserves, estuaries, wetlands adjacenttoshellfish harvesting areas, all major rivers, and headwaters to major creeks and estuaries) through the establishmentofbuffers. Jones, Edmunds&Associates, Inc. (lEA), is working in collaboration withDr.MarkT.Brown (UniversityofFlorida Center for Wetlands and Water Resources) and Dr. Richard Hamann andJeffWade (UniversityofFlorida Center for Governmental Responsibility) to develop a buffer zone ordinance that will further protect environmentally sensitive land from development activities. This report presents the methodology necessary for calculating buffer zone widths as determined through scientific studies for protecting wetland habitat. Additionally, it presents reduced buffer distances as suggested by county staff as alterative buffer widths and will subsequentlybeused to develop a buffer ordinance for St. Johns County.1.1PROJECT GOALS Upland vegetative buffers are widely regarded as necessary to protect wetlands, streams, and other aquatic resources. However, buffer size requirements have typically been establishedbypolitical acceptability, not scientific merit. This often leadstoinsufficiently buffered aquatic resources and the false perception that the resources are being properly buffered from potential impacts. Numerous scientific studies have shown that relatively wide buffers(1.50tomore than 300 feet) are necessary to protect wetland (JEA etal.1999). The dilemma exists that undersized buffers may place aquatic resourcesatrisk; however, buffers that are too large may unnecessarily deny landowners the useofa portionoftheir land. Therefore, it is importanttodetermine the minimum buffer width necessary for protectionofsensitive environmental resources. Three goals have been identified that are used to determine buffer sizes: protectionofwildlife habitat; minimizationofsediment transport into wetlands; and minimizationofgroundwater drawdown in wetlands. This buffer report provides the methodology for calculating buffer sizes necessary to achieve these three goals in St. Johns County. A single buffer width is then recommended thatisappropriate for protectingallthree wetland resources. Alternatives to one large buffer distance, as suggested by county staff, is also presented. A previous report summarizes the information that was reviewed and assessed for developing buffer zone widths for the county, including identification and classificationofecological habitats, reviewofother county ordinances, reviewofother wetland regulations, reviewofrelated reports and studies, and reviewoflegal imp lications (JEA etal.1999).INTRODUCTION

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1.2 ECOLOGICALVALUEOFBUFFERZONESThedifferences between developed lands and natural ecological areas are significant, and themoreintensely developed, the greater the differences. Frequentlyondeveloped lands, native vegetation is removed and replacedwithexotic ornamentals, soil drainage is altered, soils become compacted and covered with impervious materials,andwildlife species are displacedbyhuman activities.Thegradient in intensityofnoise, waste, temperature, light, structure, and activity from undeveloped to developed lands is intense.Inthis edge between development and natural areas, water runoff carries sediments, nutrients, and pollutants.Noiseand activities from development intrudes into the edge and interferes with wildlife activities. Wildlife populations also suffer greatly from predation from domesticated cats and dogs that are allowed to roam unconstrained and from predation from animalssuchas the brown-headed cowbird that flourishesindisturbed habitats and preysonsmaller andmorevulnerable birdssuchas the painted bunting, a prized residentofSt. Johns County and a speciesofgreat concernbythe Audubon Society and wildlife biologists.Thearea immediately adjacent to wetlands is often a transitionzonebetween wetlands and uplands and exhibits vegetation, soils, and hydrologic characteristics that are similar and intermediate between wetlands and uplands. To protect the values and functionsofwetlands, protectionmustbeafforded to the transition zone and adjacent upland. Disturbance and alterationofthetransitionzone and adjacent uplandcanresultineliminationofwildlife species thatutilizeboth uplandsandwetlands, a loss in plant species diversity, an increaseofsedimentation and erosion into the wetland, and alterationinhydrologic patterns within both the upland and wetland.Ithas long been regarded that the highest plant species diversity occursintransition zones between wetlands and uplands.StudiesofFlorida landscapes indicate that plant species diversity is higherintransition zones than either the adjacentwetland or upland (Clewell et al. 1982; Gross 1987; Hart 1984). Likewise, wildlife species richness also shows direct spatial relationships to the increaseddiversityofthetransitionzone. Vickers et al. (1985) found that species richness and abundanceofherptofauna were greater along the edgeofsix wetlandsinnorth central Florida thanineitherthewetlandorupland habitat. HarrisandVickers (1984) found that virtually all mammals resideintransition zones becauseoftheir cursorial mode oflocomotion and frequent herbivorous food habits, When water levels riseinwetlands, wildlife movement to peripheral areas also increases, suggestingtheimportanceoftransition zonesinproviding refuge for wildlife.Thewater quality benefitsofbuffer zones are related to the abilityofthe zone to abate erosive water velocities and quantitiesofpollutants carriedbysurfacerunofffrom uplands. Pollutants such as metals adhere to sedimentsandare thereby transportedbythe sediments. Also, degradationofpollutants from biological and other mechanisms can increase as surface runoff flows from an upland to a wetland. Thus, every effort shouldbemade to maintain a vegetative buffer between wetlandsanddevelopments, where vegetation can trap sediments and attached pollutants before they are deposited into wetlands and water courses. H/\ 1 Onfl\4R'inl 0700\Buffer Reoort.\vod rNTRODUCTION

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2.0 PROTECTING WETLAND-DEPENDENT WILDLIFE HABITAT The wildlife componentofthis study focused on developing a methodology for determining an appropriate buffer zone width that willprotect habitat for wildlife species that depend on both wetlands and adjacent uplands for portionsoftheir life cycle.Byfar the most common causeofwildlife population decline is alterationofthe natural landscape through construction, agricultural, and silvicultural activities. However, countless studies have documented the benefitstowildlife from preserving natural habitat in the formofbuffer zones and greenway corridors. A tabulationofbuffer zone widths recommended for protecting specific wildlife species is provided in Table 2.1. A more detailed literature review is presented in the Background Report submittedto5t. Johns County in supportofdeveloping a buffer zone ordinance (JEA etal.1999). As shown in Table 2.1, forest widths exceed 164 feet in all cases for protectionofwildlife species.Itis protectionofwildlife species that willinmost all cases dictate the overall buffer zone width. 2.1 SPATIAL REQUIREMENTS A detailed species list was developed that presents wildlife species that are reliant on both wetland and adjacent upland habitats inSt.Johns County (Appendix A). Spatial requirements as listed in Appendix A were then determined for each species based on published resultsofvariables related to buffers, such as minimum distance from humans tolerated, maximum distance an animal was seen from a wetland, maximum distance that a nest occurred from a wetland, home range diameter, minimum forest width that an animal occupies, and distance between capturesofthe same individual. Brown et al. (1990a and 1990b) compiled a listofspecies spatial requirements for determining similar buffer widths in east central Florida and the Econlockhatchee River basin, respectively. Spatial requirements from these two studies were usedasthe first step in compiling specific spatial requirements. More recent publications were then reviewedto identifY additional spatial requirement data that were not available for the Brown.et al. (1990a and199Gb)studies. Published spatial data were not available for all species on the species list, sointhose cases, spatial data were used for species that are closely related, similar-sized, found in comparable habitats, and/or maintain similar foraging and nesting habits. Spatial requirements by species are listed in ascending orderofspatial width for each habitat in Appendix B. The wildlife species table also presents wetland and upland habitats where each species is likelytooccur (Appendix A). Habitat graphs were developed for each wetland and upland habitat type to illustrate the spatial requirements by percentofanimals occurring in each habitat (Figures2.12.7). The top graph on each page includes all species foundinthat habitat and their associated spatial requirement. Several species in each habitat encompass a very large spatial requirement, suchasseveral speciesofsnakes, turtles,andfrogs that venture a substantial distance from wetlands. These data skewed the graphs in such a manner that it was difficulttointerpret spatial data within the 0 to 500 foot range where adopted buffer widths are likely to occur.Therefore, on the bottom graphofeach page, data for all species that contain a spatial requirement greater than 1,000 feet were omitted. These data were retained for data analysis but were not illustrated on the bottom graph. The data omitted from the bottom graph are listedastext on the right-hand sideofthe bottom graph for each habitat. These graphs illustrate the buffer width recommended for protecting a certainpercentageofwildlife species that occur in a specific habitat. For instance, a buffer widthof343 feet is recommended to" ...... ., ... Ao<:nl07(10\Q.,f ..... R.,.,...nrt\vnnPROTECTfNG WETLAND-DEPENDENT

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protect70percentofthe occurring in cypress wetlands, whereas 299 feet is suggested for protecting50percentofthe species in cypress wetlands (Figure 2.1). These data are also summarized in Table 2.2."I.,I "'.,....1'\,AO:I\, D ... ... .....-1 PROTECTING WETLANO-DEPENDENT

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Table2.1SummaryofPublishedDataDescribingRecommendedBufferZones forProtectionofWildlifeSpeciesRecommended Buffer Descriotiorl'of Study Width(feet) Reference to support forest interior species 164"Tassone 1981 such as Acadian Flycatcher, American Redstart, Hooded Warbler, Louisiana WatertluUsh to support Hairy and Pileated 164 to197Tassone 1981 Woodpeckers necessary to support Parula Warbler 262 Tassone 1981 Suggested widthofbuffer strips to protect intrinsic 328 Tassone1981wildlife value "-. 0.-Forest widthfound with more abundant neotropical >328 Triquet et al. rrugr;nlt"birds 1990 Forest width found with more abundant resident and short<328 Triquet et al. lived mlgraiitbifds 1990 Width necessarytoinclude90percentofthe bird species 492 Spackman and Hughes1995Width necessary to include95percentofthe bird species 574 Spackman and Hughes 1995 Width necessary to maintain a complete avian community1641Kilgo et al. in bottomland hardwood swamps1998Width necessary to protect wetland-dependent wildlife 322 to 732 Brown et al. species in East Central Florida 1990a Width necessary to protect wetland-dependent wildlife 322 to 550 Brown and species in freshwater riverine systems in Tomoka River Orell 1995 and Spruce Creek (Volusia County, Florida) Width necessary to protect wetland-dependent wildlife 322 Brown and species in salt marsh systems in Tomoka River and Spruce Orell 1995 Creek (Volusia County, Florida) Width necessary to protect wetland-dependent wildlife 536 Brown and species in the Wekiva River Basin (Central Florida) Shaffer 1987 Provided recommended set-back distances for14species 207 to 584 Rodgers andofbreeding colonial waterbirds between human---" Smith 1995 disturbance from both walking and motor boat approach directlytothe nest Provided recommended buffer widths for of220 to 413 Rodgers and waterbirds based on flushing distance Smith 1997W'\l QJ.70\48S010700\Buffer Reoort.wpdPROTECTING WETLAND-DEPENDENT ................""... T.,.. ...T'

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Figure 2,1. Spatial Requirement(tt)ofwildlife species that utilize cypress wetlands for some portionoflhelrlife cycie. Graph A inciudes all species. Graph B excludes all species with a spatial requirement greater than 1,000 feet. Spacial Requirement includes fiightorretreat distance, home range diameter, nest location along edge of wetland, maximum distance from nearest water source and between captures.A100908070 III" 60 'u"c. 50 (/) -040 03020100 /r Cypress Wetlands Ia SAO 70007S00 <000 000';>SOo'10 00'1S00 SOOo SSOo 6'000 6'SOo'>000 SpatialRequirement(tt)807060 III 50 0"c.(/) 40-0 30020100BExcludesallspecieswithaSpatiiRequirement> 1000 feet _0_>_ ...."-"-'-"-...._._-----_. __.----_.......__._-,-----_..._ .. __.'::" ChickenTurtle135( r-Cooter135( Florida Redbelly Turtle 135( /' StripedMudTurtle 135FloridaMudTurtle1351EasternMudTurtle135Cypress WetiandsLoggerheadMuskTurtle135( Bald Eagle 150 SpringPeeper400 / EasternNarrowmouth4001OakToad 633GopherFrog 63< j SpatialRequirement(tt)

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Figure 2.2. Spatial Requirement (ft)ofwiidlife species that utilize hardwood swamps for some portionoftheir life cycle. Graph A includes all species. Graph B excludes all species with a spatial requirement greater than 1,000 feet. Spacial Requirement includesf1ight.orretreat distance, home range diameter, nest location along edgeofwetland, maximum distance from nearest water source and between captures.A100908070lJ) ClI 60 '0ClI a.50 (f)... 040 03020100 f1 Hardwood Swamp IIJ oSpatial Requirement(tt)B807060 '"" 50 '0" a. (J) 40 ... 0 03020 10 0 -------_ .._-_.---_._----. .. ExcludesallspecieswithaSpal ..-Requiremenl> 1000 feetChickenTurtle 13: )Cooter135FloridaRedbellyTurtle 13E Hardwood SwampStripedMudTurtle FloridaMudTurtle EasternMudTurtle13!LoggerheadMuskTurtle 13E BaldEagle 15
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Figure 2.3. Spatial Requirement (It) of wildlife species that utilize freshwater marshes for some portion of their life cycle. Graph A includes all species. Graph B excludes all species with a spatial requirement greater than 1,000feet:Spacial Requirement includes flight or retreat distance, home range diameter, next location along edgeofwetland, maximum distance from nearest water source and distance between captures.A J,F Freshwater Marsh jfj 100908070 II)" 60 13"c. 50 (J) 040 .... 302010 0o 7<007800<1100 SpatialRequirement(tt)B90807060 II)"'0 50 "c.(J)400 .... 3020100Exdudesallspecieswitha SpalicF" Requirement>1000feet SandhillCrane12' Chfcken Turtle 13! Cooter 13f FloridaRedbellyTurtle13:StripedMudTurtle 13f FloridaMudTurtle13 .. EasternMudTurtle 13l/ Freshwater MarshLoggerheadMuskTurtle13 Sandtill Crane12' / BaldEagle 1500;>SO SpatialRequirement(tt)

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Figure 2.4. Spatial Requirement (ft)ofwildiife species that utilize saltwater marshes for some portion of their life cycle. Graph A includes all species. Graph B excludes all species with a spatial requirement greater than 1,000 feet. Spacial Requirement iricludes flight or retreat distance, home range diameter, next location along edgeofwetland, maximum distance from nearest water source and distance between captures.A100908070 VI.. 60 '0..Co 50 (J)040 3020100 .,..AJf 7Saltwater Marsh I)oSpatialRequirement(tt)BExcludesallspecieswithaSpa1Requirement> 1000 feet ..... FloridaRedbellyTurtle 1:= FloridaMudTurtle 1:= EastemMudTurtle1 loggerheadMuskTurtle 1:: BaldEagle 1!J7 /. -;;7 Saltwater Marsh 1-7 100908070 VI.. 60 '0..Co 50 (J) -040 3020100o50100150 200 250 300350400500550Spatial Requirement(ttl

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Figure 2.5. Spatial Requirement(ttlofwildlife species that utilize flatwoods for some portion of their life cycle. Graph A includes all species, Graph B excludes all species with a spatial requirement greater than1,000feet. Spacial Requirement includes flightorretreat distance, home range diameter, nest location along edge of wetland, maximum distance from nearest water source and between captures. A1009080 1000feet r SandhillCrane1201ChickenTurtle135Cooter135 FloridaRedbellyTurtle 13t StripedMudTurtle135FloridaMudTurtle135EasternMudTurtle135LoggerheadMuskTurtle135RainbowSnake13.BaldEagle15C .4 PineWoodsTreefrog400/EasternNarrowmouth400FlatwoodsOakToad63:,GopherFrog63 /J /o Spatial Requirement(tt)

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Figure 2.6. Spatial Requirement (ft)ofwildlife species that utilize hammocks for some portion of their life cycle. GraphAincludes all species. GraphBexcludes all species with a spatial requirement greater than1,000feet. Spacial Requirement includes nightorretreat distance, home range diameter, nest location along edgeofwetland, maximum distance from nearest water source and between captures.A1009080 70 Ul"'u 60 "' 50 o40302010o ..... I j Hammockr .i a 7S00<000 1000 feet r ChickenTurtle 13e Cooter13! FloridaRedbellyTurtle13StripedMudTurtle13!FloridaMudTurtle 13t EasternMudTurtle13LoggerheadMuskTurtle131Rainbow Snake13' J SpringPeeper4C Pine WoodsTreefrog40'jHammockEastemNarrowmouth4C /../... SpatialRequirement(tt)

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Figure 2.7. Spatial Requirement(ftlof wildlife species that utilize sandhills for some portionoftheir life cycle. Graph A includes all species. "Graph B excludes all species with a spatial requirement greater than 1,000 feet. Spatial Requirement includes flight or retreat distance, home range diameter, next location along edgeofwetland, maximum distance from nearest water source and distance between captures.A100908070 ... 60 "'0" a.50 III'0,. 403020100807060 ... 50 "'0" a. 400 ... 3020100 ./" SandhillIoSpatial Requirement(tt)BExcludesallspecieswithaSpatiaRequirement> 1000 feet.--ChickenTurtle1350 r Cooler135CFloridaRedbellyTurtle1350StripedMudTurtle135C / FloridaMudTurtle1350EasternMudTurtle13S(LoggerheadMuskTurtle135(RainbowSnake 139: BaldEagle150( PineWoodTreefr09400( Barking Treefrog4001EasternNarrowmouth400EasternSpadefootToad400 .
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Table2.2 SpatialRequirement(ft)to Protect Various PercentagesofSpecies forEachHabitat Type(Datafrom Figures 2.1 2.7)%ofHardwood Freshwater Saltwater Species Cypress Swamp MarshMarsh Flatwoods Hammock Sandhill 100 6,336.0 4,000.04,000.0 1,500.0 6,336.0 4,000.0 6,336.0 90 1,230.1 1,257.1 850.5 339.8 1,307.11,097.3 1,343.5 80 616.6 813.3 342.4 299.7 497.0 401.4 489.670342.8 345.9 299.8299.2 336.4327.0 342.360299.9 312.6 299.3 253.4 299.8299.7 299.9 50 299.3 299.6 277.0 192.8 299.4 299.2 299.6 40 272.2 299.1 207.7165.1285.0 265.8 299.2 30 233.8 249.8 155.5 138.9 235.0 231.9 273.8 20 135.9 150.7 75.9 58.4 140.0 145.1 231.0 10 41.8 43.1 36.1 47.2 50.0 57.9 100.9W:\19270\485010700\BufferReport.wpdPROTECTING WETLAND-DEPENDENT ................. , n."..".,..

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3.0 PROTECTING WETLANDS FROM TURBIDITY AND SEDIMENTATION Sediments can erode from upland areas and be deposited in lowlands, wetlands, andlor aquatic systems (i.e., lakes and streams). These systems can eventually fill in and lossofwetland or aquatic habitat can occur. Water quality also declines from turbidity in wetlands and particularly aquatic systems. Turbidity can considerably decrease photosynthesisofsubmerged vegetation and phytoplanktoninthe watercoluITUl.Siltation can leave a coatingofclay/silt on vegetation and soil surfaces.Insufficient quantities it can change the infiltration propertiesofnatural soils and may affect the benthic ecologyofwetland and aquatic systems. Controlling erosion is critical during the construction phaseofa development. A vegetated buffer zone can effectively catch and retain sediment carriedbyoverland flow and can reduceoreliminate the amountof reaching surface waters. Vegetative buffers are far more effective than other typical erosion control techniques such as sediment screens and hay bales, which are more susceptibletoaccidental breachingbyheavy equipment or blowoutsbyhigh intensity rainstorm events. The design widthofa vegetated buffer for erosion control depends on a number offactors, including soil grain size, soil erosion potential, and topography or overland slope. Erosion is also influenced by hydrologic factors. These factors can effectively be rolled into one: water flow velocity over the soil surface. This intumis a functionoffactors such as rainfall intensity, amountofimpervious area versus vegetated areainthedrainage basin, and overland slope. Grain sizeofsoils canbegenerally classified into four categories (from smallesttolargest): Clay particles.002mm) Silt particles (0.002 0.05 mm) Fine sand (0.05 0.25 mm) Coarse sand (0.25 2.00 mm)Inmostofpeninsular Florida, sediments will consist primarilyofsands that, duetotheir larger size, settle more quickly and require less buffer width than finer grained silt and clay materials. When sediments contain silt, the required buffer willbeconsiderably wider. When sediments contain clay, vegetated buffers alone cannot sufficiently trap these finer sediments, and additional means maybeneededtoprotect against turbidity. These may include settling/holding ponds, filter fabric barriers, or sand filtration systems. When sediments contain both sands and clays, it may be besttoconfigure a system where overland flow will first flow over a vegetated buffertoremove mostofthe coarse grained sediments, then through a second treatment system for the fine-grained sediments.Inthis way the additional treatment system will more effectively capture the fine-grained sediments without being deluged with the coarse-grained sediments. Sieve analyses canbeconductedonsoils to establish which particle-size classification they will fall under.Inlieuofconducting sieve analyses, grain-size distributions for the various soil classifications can be found in the soil surveyofSt Johns County (SCS 1983). Select soil parameters for each soil series in the county is provided in AppendixC. Overland slope can be expressedasthe ratioofthe vertical drop per horizontal distance (i.e., feet peF feet, meter per meter). Steeper slopes will increase the velocityofoverland flow, which intum...,. ...,..... "...",,'n .. <"l'__ O.. ....,..1PROTECTfNG WETLANDS FROM

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increases sediment transport. Thus, the greater the slope, the wider the required buffer width. A buffer with too great a slope may be infeasible to serve as sediment controL Overland slope may be determined through site surveying or consulting topographical maps such as the U.S. Geological Survey Quadrangle series. The SCS soil survey also gives approximate rangesofslopes for identified soil units.3.1SEDIMENTATION AND TURBIDITY LOOK-UP TABLE Two different methods can be used to calculate a buffer width for protecting wetlands from sedimentation and turbidity. The first is a look-up table designed for quick reference, and the secondisa calculation method that is a more technical approach. 3.1.1 Look-up Table The look-up table was adopted from the east central Florida buffer zone study (Brown etaL1990a) and is presented as Table 3.1. This is a simple methodology that is used to determine buffer widths based on soil conditions, rainfall, and antecedent conditions that are typicalofSt.Johns County. This table assumes newly-graded soilsofhydrologic group D and a rainfall event with a 5-year frequency and 24-hour duration event giving 6.5 inchesoftotal rainfall. Hydrologic group D soils are considered to be very poorly drained (SCS 1986) and give a worst-case scenario as opposedtousing hydrologic groups A, B, orC.Using a 5-year frequency storm is somewhatofan average choice; it will predict a greater buffer width than a I-year frequency storm but will predict a smaller buffer width than a 10-year or 25-year frequency storm. Table3.1gives four buffer width values, one for eachofthe soil types described earlier. They are somewhat conservative and generalized values that do not consider site-specific conditions other than soil texture. Based on the look-up table, the most typical soils in St. Johns County, fine sands and coarse sands will need a 200-foot and 75-foot buffer, respectively, to protect wetlands from sedimentation and turbidity (Table 3.1). Table3.1is applicable only for sites with a slope less than 7 percentandcannot be applied to sites such as the ravines in the northwest partofthecounty. For a site with steep slopes (greater than seven percent), the buffer distance as indicated on Table 3.1 should be measured form the topofthe slope rather than the wetland/upland boundary. 3.1.2 Calculation ProcedureInlieuofusing the simple look-up table, more complicated calculations can be performed for determining a buffer zone that takes into account site-specific conditions. The calculation is based on the settling velocities for the four soil types discussed above and applicationofthe Manning Equation to overland flow. This method assumes the buffer consistsofa planeofconsistent slope and roughness conditions along its entire length. While this is seldom the case, itisusually appropriatetospecify average values for slope and roughness. The roughness conditions primarily depends on the thickness and typeofvegetation and is specifiedasMannings"n"values (Table 3.2). The calculation demonstrates that these two parameters are criticalforthe effectivenessofthe buffer in settling out eroded sediments.Itdemonstrates that buffers perform best when they have a very flat slope and high roughness (thick vegetation). For buffers with steep slopes and low roughnesses,W\l Q170\4R'iOl0700\Buffer Repon.wpdPROTECTING WETLANDS FROM..... 'nn'r.l'TV-\",In(:CnTr.AJ=NTATrON

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Table3.1RecommendedWetlandBufferstoMinimizeSedimentationinWetlandsandtoControlTurbidityinAdjacentOpenWaters(AdoptedfromBrown,et. al.1990a)USDASoilTypeBufferRequirements Clay Sedimentation and turbidity control cannotbemet withbufferrequirements alone Silt450feet from wetland/upland boundary Fine Sand200feet from wetland/upland boundary Coarse Sand 75 feet from the wetland/upland boundary The values are based on soil condition, rainfall, and antecedent conditions that are typicalofSt.Johns Countyandtotheconditions that wouldbeexpected during construction. That is,thesoil hydrologic group is D, the soils are newlygraded,andtherainfall eventisa 5-year stonnof6.5inches in a 24-hour period.Thus,therecommended buffer widths are basedonaverage expected conditions, except for soil hydrologic group.\1/.\1 O'l7I'l\AQ<;nln7nmR"ff,.rRenort.wod PROTECTING WETLANDS FROM

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Table3.2ManningsRoughnessCoefficients(n)UnlandGroundcoverBare Sand 0.010 Bare Clay-loam (eroded) 0.012 Graveled Surface 0.012 Snarse Vel!etation 0.050 Rano-e (clinned) 0.080 Rano-e (natural' 0.130 Short Grass nrairie 0.150 Dense Grass 0.240 Bermuda Grass 0.410 Woods 0.450WetlandGroundcoverPasture 0.025 0.035 Lil!ht Brush 0.040 0.070 Dense Brush 0.075 0.160 Trees onlv (dense PTowth) 0.080I T____...:.1. T 1.n ,,::n Source: Roberts 1991.W'\l Onn\.dR.c:;Ol 0700\BufTerReoort.wodPROTECTING WETLANDS FROM-----_.-. ... ...... ,,.............,.1

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this procedure may indicate that finer sediments may not settle out regardlessofbuffer size but rather will stay in continuous suspension. When this is the case, then additional sedimentation facilities (e.g., settling basins) maybe needed. This method does not account for trappingofwater (and thus transported sediment) in depressions that may existinsome natural buffers.Ifa buffer has a significant amountofdepressional storage, then it will have a higher capacity for trapping sediments than this method will predict, and calculated buffer lengths maybe over-estimated. This method also allows for comparisonofdifferent predicted buffer lengths based on different design storms. This includes differing return frequencies (e.g., 5-year, 25-year, 100-year) and storm duration (e.g., 8-hour, 24-hour). The calculation procedure is as follows:1.Determine the soil typeofthe upland area immediately adjacent to the wetland. Once the soil type is known, the corresponding hydrologic group and USDA soil classification can be determined from the St. Johns County soil surveyor from AppendixC.2.Calculate peak discharge identified as"Q"for one acreofthe proposed developed site. The peak discharge flow rate willbeused to determine overland flow velocity. The higher the peak flow the higher the sediment transport. Methodologies for determining peak discharge from a site are numerous. Two methods, the SCS method and' the Rational method, are discussed in Appendix D. The SCS method should primarilybeused for agricultural and rural applications, and the Rational Method should be used for urban sites or small sites with a high percentageofimpervious area. The TR-55 computer model or other stormwater computer models may also be appliedtodetermine peak discharge from a one-acre portionofthe site.3.The widthofthisacre plot should be determined by dividing the area(1acre=43,560ft2)bythe length along the longest continuous slopeofthe drainage basin, as this will be the worst-case scenario.Ifthe length exceeds 300 feet, overlimd sheet flow will begin concentrating into channels and channelized flow will form. Channelized flow has higher erosion potential than sheet flow, and additional conservation measures in the calculative procedures should be made. This is based on procedures described in SCS TR-55 "Urban Hydrology for Small Watersheds" (SCS 1986).4.The peak discharge,Q,predicted in Step 2 will be in dimensionsofvolume per time (Length3/Time or L 3ff).This value must be divided by the widthofthe one-acre plot to give a volumetric flow per unit width(L3 /TIL), orq.The units may either be English or metric, per user preference, but the unit system must be consistent throughout the procedure. For the English system, length is in feet; for metric, length is meters. Time should always be in seconds.q=Q/wThis will be the flow entering the buffer per unit width.U.I.\ I O"}ifl\dR"n1n7"n\Rllffer Reoort.wod(I)PROTECTING WETLANOS FROM-----_ _...... .....A'T"lr"... '

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5.Byapplying the continuity equation:andMannings equation:q=v.d(2)(3) the overland flow velocity, v,canbecalculated as: where: M=1/n (metric),1.486/n (English)Sb=overland slopeofthe buffer q=flowperunitwidth from Step4n=Mannings roughness coefficient (4) Mannings roughness coefficient values are given for various terrainsinTable 3.2. 6. Calculate overland flow depth:d=q/v(5)7. Determine the appropriate particle settling velocity, V" for the soil type. Values are given below for the four basic soil textures (assume silts to be the same as loamy soils). Settling velocities can alsobecalculated for a specific soil based on a sieve analysis usingStoke'sequation, but the details arenotincluded here. Stoke's Equation is explainedinMetcalfand Eddy, 1991.8.Soil Type Clays Loamy soilsandMucks Fine sands Sands Determine particle settling slope: V, (ft/sec) 0.000010 0.000263 0.001093 0.002500S,=V,lvV, (m/sec) 0.00000305 0.0000802 0.0003331 0.0007620(6)Notethat the settling slope,S"mustbe greater than the overland slope,Sb'inorderfor sediments to settle out. Otherwise, this method predicts that sediments willremaininsuspenSIOn. 9. Calculate the required settling length:(7)Anappropriate safety factor,F"should be applied. 1O.Aninitial transition zone is needed at the interfaceofthe developed site with the buffer. This allows the overland flow to adjust to the hydrologic conditionsofthebuffer (i.e., slope and roughness). This distance, L" is recommended to be 10 feet.II.Finally, the required widthofthe buffer is calculated as follows: 19270\48501 0700\BllfferReport.wpdPROTECTING WETLANDS FROM-.---.. ,TII"'Y!\I

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These calculationsmayormay not resultina lower buffer width than indicated in the look-up table (Table 3.1).Inmost cases,itwouldbemore conservative togowith the largerofthe two predicted values.Inany case, the buffer width should neverbeless than 75 feet as indicated in Table 3.1, as this is the smallest widththatprevents erosion and sedimentation based on soil texture.w\I Q710\4R"iOI0700\Buffer Reoort.wodPROTECTINGWETLANDS FROM

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4.0 PROTECTING WETLANDS FROM GROUNDWATER DRA WDOWN During development activities, it is often necessary to improve site drainage to reduce the level or frequencyofflooding and/or high groundwater levels. Drainage modifications typically involve constructionofswales, ditches, canals, or underdrains. These structures are usually designedsothat the water table is loweredbyan amount sufficient to meet the drainage needsofthe development. Calculating a buffer distancetoprotect wetlands from drawdown will not be necessaryifno drainage structures are planned for a site.Inthose instances, this sectionofthe methodology would not apply. Lowering the water tableinwetlands can be the single most destructive action imposed on wetlands. A lowered hydroperiod can resultinlossofwildlife habitat, lossofflood storage capacity, lackofhydrophytic vegetation, and lossofwater quality improvements. Various methods have been used in previous buffer zone studies to predict the buffer width necessarytoprotect wetland hydrology from surficial aquifer drawdown. While these methods were appropriate or appeared appropriate a decade ago, they have been supersededbymore sophisticated groundwater models. The latest guidelines usedbythe Southwest Florida Water Management District (SWFWMD) to review water table drawdown duetoditching and subsurface drains were established by Higganbotham (1996). That report suggests that groundwater drawdown radiusofinfluence calculatiOIlsbemade and site-specific permeability tests be performed.Itrecommends that the applicant use computer software to perform radiusofinfluence calculations but provides no information on what is considered an acceptable levelofdrawdown. The radiusofinfluence calculations are usedbythe SWFWMDtodetermineifadverse impacts are likely, but no general policy such as "0.1 foot after 30 days with no recharge" is used. Each application is reviewed individually, and decisions are made on a case-by-case basis. The St. Johns River Water Management District (SJRWMD) also reviews wetland impacts on a case-by-case basis. Radiusofimpact calculations are used along with information regarding the particular wetland areas. Predicted impactsoflessthan0.1foot after90days with no recharge are generally considered sufficienttonot cause adverse impactstowetlands, but in other cases a greater amountofdrawdown maybeconsidered acceptable. The SFWMD uses a guidelineof1 footofsurficial aquifer drawdown at the edgeofthe wetland. These policies provide flexibility and discretion to the districts in their evaluationofpermit applications and reflect the difficulties inherent in generalizing and simplifYing the complex interrelationship between wetlands and hydrology.4.1MODELING REQUIREMENTS AND LIMITATIONS Computer programs allow for rapid simulationofa wide rangeofgroundwater flow scenarios. As discussed above, the SJRWMD, which is the applicable water management district for St. Johns County, has essentially adopted the useofcomputer models as their standard method to determine drawdowns. A relatively simple model canbedeveloped and run under a varietyofconditions to determine appropriate buffer distances. However, these simulations are accurate onlyifthe data usedasinput are accurate. It is typically necessary to make simplifying assumptions when developing a model, and other asslimptions are inherently a partofthe model. Site-specific information improves the reliabilityofthe results.Itmust be recognized that geologic variationsinparameters such as aquifer thickness and hydraulic conductivity may result in large differences between simulated and actual drawdowns.W:\l 9270\4850 10700\Buffer Report.wpd d.' PROTECTING WETLANDS FROM GROUNDWATERDRAWDOWN

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Becauseofthecomplexityofgroundwater flow equations, several major assumptions must be made to simplify the model. One is that the surficial aquiferisuniform across the entire model area. Hydraulic conductivity and specific yield are assumed to be constant throughout the model area. Another key assumption is that a completely impermeable horizontal layer is present beneath the surficial aquifer. These assumptions are rarely met in real world situations. The near-surface sediments in St. Johns County vary widely over relatively short distances. Widely varying conditions are commonly found over lateral distancesof100 feet or less. These assumptions, however, are necessary to allow calculationofdrawdown, unless a significant amountofdetailed, site-specific information is available. Variables such as size and typeofwetland and local hydrologic and rainfall conditions make determinationofbuffer distances complex. Some wetlands within the county may be perched on topofnear-surface low permeability hardpans that impede infiltrationofrainfall. Other wetlands may result from the surficial aquifer being filled to capacity. The effectofaquifer drawdown on these two typesofwetlands wouldbedifferent. This is one reason the water management districts judge each permit application individually and make decisions on aquifer drawdown on acase-by-case basis. The problemofpredicting the impact on wetlands from surficial aquifer drawdownofseveral inches or even 1 foot is compoundedbythe fact that water levels are not static and vary from year to year and within each year. 4.2 DRAWDOWNIMPACT CALCULATIONS FOR ST. JOHNS COUNTY A simple groundwater flow model was developed using the MODFLOW computer program and can be used with site-specific data to predict the buffer width for protecting wetland hydrology. Other groundwater models are availabletopredict drawdown in wetlands in addition to MODFLOW. MODFLOW was selected for this project as it is an industry standard and widely accepted, itispublic domain and widely available, it is applicabletoSt.Johns County, and it is sufficiently sensitive to a wide rangeofconditions.Inthe model, preand post-processing were aided through useofthe Groundwater Modeling System (GMS) software package. The model was utilized to simulate surficial aquifer drawdowns resulting from drainage structures. Several assumptions for the simplified MODFLOW model developed for St. Johns County areasfollows: The aquiferisisotropic and homogeneous. The drainage structure and the wetlandedge are parallel andofinfinite length. Thewetlandisdirectly connectedtothe surficial aquifer, and the hydraulic propertiesofthe wetland are the same as the surficial aquifer. The water table is initially flat. The drainage structureisinstalled instantaneously. The entire surficial aquifer is underlain by an impermeable confining layer. No recharge occurs during the model run. Nowater exists as surface water within the modeL The length and widthofthe model grid are 2,000 feet. It is a one-layer model consistingof50rows and 98 columns. The widthofthe cells ranges from 5 feet near the western edge to45feet at the eastern edge. The cell heightisconstant at 40 feet. The cellsofthe westernmost column are setupPROTECTINGWETLANDSFROM---....--'''..........nn..1

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as drains, representing the proposed drainage structure. The eastern boundary is modeled as a constant head boundary. The northandsouth edges consistofactive model cells. The initialheadis set at 0 feetinall cells.Theelevationofthe drain is set to the amountofwater tabledrawdownproposed for the drainage structure. For example,ifa design calls for 2 feetofwater table drawdown, the elevationofthe drain willbeset at-2feet. Themajorvariables thatmustbeinput into the model are hydraulic conductivity, thicknessofthe surficial aquifer, specific yield,andproposed drawdown. Ideally, site-specific information should be collected at each development site. For this project, rangesofpossible values were simulated and then tabulated.Theresults show the impact that constructiOllofa drainage structure will haveonwater levels.Ifthe simulated drawdown at some location is 1 foot, this suggests that the water level at that location willbe1 foot lower thanitwouldbewithout the ditch. Toapplythe model, the horizontal hydraulic conductivitycanbe calculated using permeability information from the St. Johns County soil survey (SCS 1983) (Appendix C). Horizontal hydraulic conductivity is estimated from the soil survey data using a method usedbythe SWFWMD (Higganbotham 1996) as follows: Horizontal permeabilityineach soil horizonisassumedtobe1.5times the vertical permeability for that horizon. The horizontal penneabilityofeach soil layer is multiplied by thiclmess ofthat soil layer andtheresults for each soil horizon are totaled. This totalisdivided by the total thiclmess ofthe soil to give a weighted average hydraulic conductivity which can be usedinthemodel. 4.3 WETLANDDRAWDOWNLOOK-UP TABLESInlieuofdeveloping and runningMODFLOWorother suitable hydrologic model, look-up tablescanbeused to determine an appropriate buffer width necessary for protecting wetlands from groundwater drawdown.Thetwo look-up tables allow either 0.5 footofdrawdown (Table 4.1)or1.0 footofdrawdown (Table 4.2). These tables were generated from datarunin the MODFLOW model. The user determines the appropriate hydraulic conductivity, aquifer thickness, and amountof drawdowp. allowed to occurinthe drainage structure.Ifsoil boring information isnotavailable,aquiferthickness and depth to the impermeable layer mustbeassumed tobesome constant value such as 10 feet. Basedonthese variables, a buffer distance canbedetermined from either Table 4.1 or 4.2.Ifsite conditions deviate substantially from the hydraulic conductivity and aquifer thickness provided in Tables 4.1 and 4.2,orthe assumptions made for this model donotapply to the site, then it willbenecessary to run a model using site-specific conditions, rather than using oneofthe look-up tables. Buffer distances basedonhydraulic conductivity and depth to the impermeable layer are illustratedinFigures 4.1 through 4.3. The curve representing the amountofdrawdown at the proposed drainage structure is selected, and the appropriate buffer distance is read. A seriesofruns were made for surficial aquifers with initial saturated thicknessesof6 feet and 10 feet. Hydraulic conductivities ranging from 6.5 to 19.5 incheslhour were simulated. The specific yieldofthe aquifer was set to 0.20, which is typical for soils composed primarilyoffine sand. Themodelruns simulated the drawdown that would result after 90 days with zero recharge to the system.W:\19270\485010700\Buffer Report.wpdPROTECTING WETLANDS FROM r-nnT"'''''''''TeonoA wnnWN

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Table4.1BufferDistancesWhenSurficial AquiferDrawdownof0.5Feetis Acceptable Aquifer 1 Foot 2 Foot 3 Foot 4 Foot 5 Foot Thiclrness Drop in Drop in Drop in Drop in Drop in Hvdraulic Conductivity (feet) Ditch Ditch Ditch Ditch Ditch 6.5 InchesIHour 6 160 270 31533534013InchesIHour 6 225 380 440 475 490 19.5 InchesIHour 6 280 455 540 580 600 6.5 InchesIHour10210355430 475 49013InchesIHour10305 510 600 660705 19.5 InchesIHour10370 620 730815850PROTECTING WETLANDS FROM

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Table4.2BufferDistancesWhenSurficialAquiferDrawdownof1.0FeetisAcceptableAquifer I-Foot 2-Foot 3-Foot 4-Foot 5-Foot Thickness DropinDropinDrop in Drop in Drop in Hvdraulic Conductivity (feet) Ditch Ditch Ditch Ditch Ditch 6.5 IncheslHour 6--150 200 22524513IncheslHour 6--200 280 320 345 19.5 IncheslHour 6--250 340 395 415 6.5 IncheslHour10--200285335 37013IncheslHour10--280 400 485 510 19.5 IncheslHour10--355 490 575 620PROTECTING WETLANDS FROM--"..-....--...' ....."'"..... ,

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Figure 4.1 Simulated drawdownsofthe surficial aquifer. AssumptionsforGraph A&Bare:Hydraulic Conductivity=6.5 inlhr, Specific Yield=0.20,Time=90 Days Graph A Assumes Thickness=6ft. Graph BAssumesThickness=10ft.A -1-___ 5' Drawdown Q)-2C-8-4' Drawdown ;:--.!r3'Drawdown0 'tJ--*-2' Drawdown -3 -lIf-1' Drawdown c-4-5 0 200 400 600 800 1000 Distance, feetB0 -1 --$5'Drawdown.. -2-8-4' Drawdown C;:--.!r-3' Drawdown0 'C-X2'Drawdown -3-lIf-1' Drawdown c-4 -502004006008001000Distance, feet

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Figure 4.2 Simulated drawdownsofthesurficial aquifer. Assumptions for Graph A&Bare:Hydraulic Conductivity=13 in/hr, Specific Yield=0.20, Time=90 Days Graph A Assumes Thickness=6ft. Graph B AssumesThickness=10ft.A __ 5'Drawdown -8-4' Drawdown -.'r-3' Drawdown -*2' Drawdown __ 1' Drawdown 1000BOO600400200-5 -6-l-__ --'-....L....L__ --' a -4f1-J---j----t----\------j----/...ll -2 F---:"r-:Ij----t----\------j----/c'C -3 K--Ill"l--+----\-----j------1-----1.. cDistance, feetB __ 5' Drawdown -8-4' Drawdown -.'r-3' Drawdown -*-2' Drawdown __ 1' Drawdown 1000 800 600 !loa 200-5 --l-__ .........I-..L..__ --' a -4ti----,}2'---j----+----\----+----1...i -2 t'C -3 .. cDistance, feet ,

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Figure4.3Simulated drawdownsofthe surficial aquifer. Assumptions for Graph A&Bare:Hydraulic Conductivity=19.5 in/hr, Specific Yield=0.20, Time=90 Days Graph A Assumes Thickness=6ft. Graph B Assumes Thickness=10ft.A0-1 'Z__ S'Drawdown .e -2 c:-B-4' Drawdown >:---.!.3'Drawdown0 'D Drawdown -3 ... l'Drawdown0-4-S0 200 400 600 800 1000Distance, feetB0-1__ S'Drawdown '".e! -2 -B-4' Drawdown ---.!.-3' Drawdown 'D Drawdown -30 l'Drawdown-4 -S0 200 4006008001000 Distance, feet

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The lengthoftime simulated in the model run has a significant effect on the amountofdrawdown. For example, using a hydraulic conductivityof13inches/hour and a 3-foot loweringofthe water tableatthe drainage structure, the distance at which the water table willbelowered 1 foot is approximately215feetat30 days and 400 feet at 90 days. This effect is illustrated in Figure 4.4A. Thicknessofthe aquifer also resultsina significant difference. For 90-day runs with hydraulic conductivityof13inches/hour and a drainage depthof3 feet, the I-foot drawdown occurs at a distanceofapproximately 280 feet for a6 foot aquifer thickness and at roughly 400 feet for a10foot thick aquifer. The simulated drawdown is even greater for thicker aquifers, as showninFigure 4.4B. A modeled drawdownof0.5 feet reflects drawdown within the aquifer, where muchofthe volume is made upofsoil.Themodel uses a valueof2.0 for specific yield, which is the amountofwater that will drain from the soil under the forceofgravity. This means that the 0.5 feetofdrawdowninthe aquifer can be replenished by only 0.1 feetofrecharge. When the effectofsurface water storage in the wetland is taken into account, a drawdownof0.5 feet in the aquifer after 90 days with zero rechargeisconsidered unlikely to resultinadverse impactstowetlands.W:\19270\485010700\Buffer Report.v,,-pd .... "_.1'\')",on4.0 PROTECTING WETLANDS FROM GROUNDWATER DRAWDOWN

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Figure 4.4 EffectofTime on Simulated Drawdownsofthe Surficial Aquifer. Graph A Assumes Hydraulic Conductivity=13 in/hr., Specific Yield=0.20, Thickness=10ft, Drawdown at Ditch=3 ft. Graph B EffectofAquifer Thickness on Simulated Drawdowns Assumes Hydraulic Conductivity=13 in/hr., Specific Yieid=0.20, Time=90 DaysA Qj -1 i-------jI.l'----r-:7T'---------t-----j-------1oJ!!1c -2 i---jO-."f-:;I5-+-----t---------jj----------i-----1 4 ___ 30 Days -8-60 Days --tr90 Days

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(/ 5.0 DETERMINATION OF A BUFFER WIDTH A reviewofthe scientific literature was conducted to determine the buffer distance necessary for protecting wetland habitat. This review is detailed in an earlier report submitted to St. Johns County (JEA et al. 1999). Basedonthe scientific literature, buffer distances were then evaluated specifically for St. Johns County and are describedinthis report in Sections 2.0, 3.0, and 4.0 for wildlife, water quality, and water quantity, respectively. From the scientific literature and county-specific calculations, a buffer widthof300 feet was determined tobethe distance necessary to protect a viably functioning wetland ecosystem. A 300-foot buffer would also protect approximately 50 percentofthe wetland-dependent wildlife species in freshwater wetlands and protect water quality from erosionofcoarse and fine sands. In some site-specific cases, suchaswith siltorclay soils,orfrom large draw-down structures, a buffer distance greater than 300 feet wouldbenecessary to protect the wetland. 5.1 ALTERNATIVEBUFFERWIDTHS As indicated above, a buffer distanceof300 feet is necessary to protect wetland functions and ecological resources within a wetland. Any reduction in the buffer width below 300 feet can impose adverse impacts to the wetland, particularly to wetland-dependent wildlife species that require a wide surrounding upland areainwhich to feed, forage, and use as protection from human disturbances. Alternatives to a 300-foot buffer would still IJrovide protection to wetlands; however, any declineinthe buffer can quality from erOsion-bffinesediii:i.ents:'-Arooucffiino[ a buffer'below 300 feet will be basedonpolicy deeisionsmiidebyCOUl1.tystaff. Four conditions were recommendedbycounty planningstaffasalternatives to a 300-foot buffer. These alternatives are describedinTable 5.1. 5.2 BUFFER ESTABLISHMENT The buffer distance shallbemeasured from the SJRWMDorFlorida DepartmentofEnvironmental Protection (DEP) wetland jurisdictional line.Insome cases, unavoidable impacts will occur to jurisdictional wetlands and will resultina reduced buffer near the areaofwetland impacts.Inother cases, unavoidable impacts will occur to the buffer such that the buffer is less than the distance specified in Table 5 .1. no instance shall the upl:JP:dbuffer beless than 25 feet, even at points where unavoidable wetland: Uripacts have been approved andpemiittedby'fhesffiW':Mb orDEP. The buffer area shallbeclearly depicted on all site plans, development plans, and other documents submitted to the county to review for development.Incases where the buffer is reduced near permitted wetland impacts,itis the discretionofthe county planning staff to require a larger buffer than that specified in Table 5.1 in other areasofthe development in order to compensate for the smaller buffer. 5.3 BUFFER HABITAT Native, undisturbed habitat should occur within the designated buffer area in order to maximize the habitatofwetland-dependent wildlife. species. Buffer areas that are devoidofnatural associationsofnative vegetation shouldbeplanted with,orsupplemented by, appropriate native vegetation. Vegetation plantingoftrees and shrubs should be performed onanequivalencyof10-foot spacings to achieve 400 treesorshrubs per acre. Plantings should occur in staggered and clumped patterns to reflect more natural plant occurrences. A suggested listofplant species to be planted in disturbed buffer zones in St. Johns County is provided in Table 5.2.W:\192701485010700\8uffer Report.wpdJanuarv4. 7.000 5 LANDUSE ACTIVITIES RELATEDTORtIFFER ZONES

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TableS.1BufferWidthsforS1.JohnsCountyasProposedbyCountyPlanningStaffBuffer Buffer Determination Criteria Distance Scientific Basis (feet) Developmentofsingle-familyortwo2SN/Afamily dwellings onplattedor legalanddocumented lotsofrecord existing prior to September 15, 1999, as providedinSection 4.01.02 Eofthe Land Development Code Any development adjacent to water bodies 75 Based on protectingwaterquality from and jurisdictional wetlands that do notmeetsiltation and erosionofcourse sands. anyofthe conditions listed below. Protects habitat for15percentofwetland-..dependent wildlife in freshwater wetlandareas. Any development adjacent to Aquatic 200bBased on protecting water quality from Preserves' siltationanderosionoffine sands. Protects habitat for approximately 50 percentofwetland-dependent wildlife speciesinsaltwater marshes.Anydevelopment adjacent to areas which300'Based on protectionof50 percentofthe support threatened or endangered plant or wetland-dependent wildlife species in animal species in the wetlandorwithin freshwater wetlands.Atthe Federal level, 300 feetofthe wetland, (Appendix E) as 300 feet is considered sufficient to documented during a field surveybya adequately protect wetland resources in the trained biologist. Wetland Rapid Assessment Procedure (Miller and Gunsalus 1997) Aquatic Preserves include Guana River Marsh and Pellicer Creek (Figure 5.1).bThis distance may be reducedto75feetiftheapplicant followstheguidelines specified in Chapter 40C-42oftheSJRWMD Applicant's Handbookforadvanced stormwater treatment (Appendix F).'Intheeventthatlisted plant or animal speciesarefound withfu thewetland or within 300 feet ofthe wetland, thentheFlorida Fish and Wildlife Commission, U.S. Fish and Wildlife Service, SJRWMD, DEP, or Florida Natural Areas Inventory shouldbeconsulted for input in developing a listed species management plan.Ifoneofthese agencies determine that a 75-foot buffer will adequately protect the listed species,thenthe buffer can be reducedto75feet.W:\19270\4850t0700\Buffer Report.wpd !;lnllllrv 4?non5-2LANOUSE ACTIVITIES RELATED TO BUFFER ZONES

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Table5.2 Appropriate Plantings forBufferZonesinSt.JohnsCounty(Page 1of2)Scientific Name Common Name Tree (T) or Shrub (S)Acernegundoboxelder TAronia arbutifoliared chokeberry SCallicarpa americanabeautyberry SCalycanthus floridussweet shrub SCarya glabrapignut hickory TCeltis laevigatasugarberry TCerdscanadensisredbud TClethra alnifoliasweet pepperbush SCornus floridadogwood TCrataegus aestivalismay haw TEuonymus americanastrawberry bush SFagus grandifoliaAmercian beech TFraxinus americana.white ashTHamamelis virginianawitchhazel Sflex glabragallberry S Jle, cassinedahoon hollyT fie, coriaceasweet gallberry Sflex opacaAmerican hollyTflex vomitoriayauponTflex myrtifoliamyrtle hollyTJuniperus siJicicolasouthern red cedarTLindera benzoincommon spicebush SLiquidambar styracifluasweetgum TLiriodendron tulipiferatulip poplar TLyoniaferruginearusty Iyonia SLyoniafruticosastaggerbush SLyonialuddafetterbush S Maf!nolia f!randif/oraSouthern magnoliaTW:\19270\485010700\Buffer Report.wpdJanuarv4,20005-3LAND USE ACTIVITIES RELATEDTORTIFFF.R 70NEC;;;

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Table5.2AppropriatePlantingsforBufferZonesinSt.JohnsCounty(Page2of2) Scientific Name Common Name Tree (T) or Shrub (S)Morus rubrared mulbeny TMyrcianthes fragransSimpson stopper*TMyrica ceriferawax myrtle SNyssa sylvatica var. bifloraswamp tupelo TOsmanthus americanuswild olive TOstrya virginianaEastern hop hornbeam TPersea borboniaredbay TPinus elliottislash pine TPinus glabraspruce pine TPinus palustrislongleaf pine TPinus taedaloblolly pine TPrunus angustifoliachickasaw plum TPrunus carolinianaCarolina laurelcheny TQuercus albawhite oak TQuercus haemiphericalaurel oak TQuercus michauxiiswamp chestnut oak TQuercus laurifoliadiamond-leaf oak TQuercus nigrawater oak TRhapidophyllum hystrixneedle palm SSabal palmettocabbage palm TSabal minorbluestem palmetto SSassafras albidwnsassafras TSerenoa rep enssaw palmetto SSymploeos tinetoriacommon sweetleaf STilia earolinianaCarolina basswood TVaeeinium arboreumsparkIebeny SVaeciniwn corymbosumhighbush bluebeny SZanthoxylum c1ava-hereulisHercules club TW:\19270\485010700\ButTerReportwpdJanuarv4. 2000 < LANDUSE ACTIVITIES RELATED

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IFigure5.1Environmentally Significant Lands ,lNI'ERCOA$1'ALWATERWA N i LEGEND I.:\IMIiJor RoadsNLoca1RoadJS.......County Boundary......SurfKe Water ClusIf1t11.t1onICLASS 1 (Potlbla Water) CLASS2(ShelI1IshIiropagatlon or Harvesting) CLASS' St.JohDI River OIltstaadIDgFloridaWalen:Aqua"cheson'eI SonrcelDEP sr. AUGUSTINE.McaSCALE...Miles 1:200000 __ .. J"'.::

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6.0REFERENCES Brown, M.T., and J.M. Schaefer. 1987.Anevaluationoftheapplicabilityofupland buffers forthewetlandsoftheWekivaBasin. Report prepared fortheSt. JohnsRiverWater Management District. Florida. Publ. No.SJ87-SP7. Brown, M.T., J.M. Schaefer, and K.H. Brandt. 1990a. Buffer zones for water, wetlands, and wildlife in East Central Florida. Report prepared for the East Central Florida Regional Planning Council.CFWPubl. #89-07. Brown, M.T., C.S. Luthin,1.Tucker, R. Hamann,1.Schaefer,1.Wayne andM.Dickinson. 1990b. Econlockhatchee River basin natural resources development and protection plan. Report to the SJRWMD. Publ. No. SJ9l-SPl.Brown, M.T. and Orell. 1995. Tomoka River and Spruce Creek Riparian Habitat Protection Zone. Report fortheSJRWMD. Palatka, FL. Clewell,AF.,J.AGoolsby, andAG.Shuey. 1982. Riverine forestsofthe SouthProngAlafiaRiver System, Florida. Wetlands 2:21-72. Florida DepartmentofTransportation, State Topographic Bureau, Thematic Mapping Section. 1985. Florida Land Use, Cover and Forms Classification System. Second Edition. Procedure No. 550 OlO-OOl-a. Florida Natural Areas Inventory (FNAl) and Florida DepartmentofNaturalResources (FDNR). 1990. Guide to the Natural CommunitiesofFlorida. Gross, F.E.H. 1987. Characteristicsofsmall stream floodplain ecosystemsinNorthandCentral Florida. MS Thesis (CFW-87-0l). Gainesville, FI. Univ.ofFL,pp. 167. Harris, 1.D. and C.R. Vickers. 1984. Some faunal community characteristicsofcypress pondsandthe changes inducedbyperturbations. Pages171 185.InEwel, K.C. and H.T. Odum. (Eds.), Cypress Swamps. Gainesville, Florida. University PressesofFlorida. Hart, R.L. 1984. Evaluationofmethods for sampling vegetation and delineating wetlands transition zones in coastal West-Central Flonda, January 1979-May 1981. Technical Report Y-84-2 U.S.AnnyEngineers Waterways Experiment Station. Washington, DC: NTIS. REFERENCES

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Higganbotharn, Jr., HenrY H. 1996. Southwest Florida Water Management District Resource Regulation Training Memorandum. Jones, Edmunds, and Associates, Inc. (JEA); the UniversityofFlorida Center for Wetlands and Water Resources, and the UniversityofFlorida Center for Govemmental Responsibility. 1999. Background report in supportofdevelopmentofa wetland buffer zone ordinance. SubmittedtoSt. Johns County Planning Department. St. Johns County, Florida. Kilgo, J .C.,R.A.Sargent, H.R. Chapman, and K.V. Miller, 1998. Effectofstand widthandadj acent habitat on breeding bird communities in bottomland hard.woods. J. Will. Manage. 62:72-83. Metcalf and Eddy, Inc. 1991. Wastewater Engineering. Third Edition. McGraw Hill, Inc. New York. Miller, R.E., Jr., and B.E. Gunsa1us. 1997. Wetland Rapid Assessment Procedure (WRAP). South Florida Water Management District. Techn. Publ.REG-DO1.Roberts, R.M. 1991. Hydrologic Computer ModelingofLake Drainage Basins for Predicting Lake Stage and Floodplains. M.E. Thesis, UniversityofFlorida, Gainesville, Florida Rodgers, J.A. and H.T. Smith. 1995. Set-back distances to protect nesting bird colonies from human disturbances in Florida. Cons. Biology 9:89 -99Rodgers, J.A. and H.T. Smith. 1997. Buffer zone distancestoprotect foraging and loafing waterbirds from human disturbances in Florida. Wildlife Society Bull. 25(1):139 145. Soil Conservation Service (SCS). 1986. Urban Hydrology for Samll Watersheds, TR-55. Soil Conservation Service (SCS). 1983. Soil SurveyofSt. Johns County. USDA DepartmentofAgriculture. Spackman, S.C., and J.W. Hughes. 1995. Assessmentofminimum stream corridor width for biological conservation: Species richness and distribution along mid-order streams in Vermont. USA BioI. Conserv. 71:325-332. Tassone, J.F. 1981. Utilityofhardwood leave strips for breeding birds in Virginia's central piedmont. MS Thesis. Blacksburg, VA: Virginia Polytechnic and Institute and State College83pp.REFERENCES

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Triquet, A.M., G.A. McPeek, and W.C. McComb. Songbird diversity in clearcuts with and without a riparian buffer strip.1.Soil and Water Conserv. 45:500-503. Vickers, C.R., L.D. Harris, and B.S. Swindel. 1985. Changes in herpetofauna resulting from ditchingofcypress ponds in coastal plains flatwoods. Forest Ecology and Management. 2:17-29. --- ...........",.....n ..... _..:1 REFERENCES

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, .; I I ; ,, : I i: !;. APPENDIX ASPECIESLISTOF WETLAND-DEPENDENT NATIVEWILDLIFESPECIESOFST. JOHNSCOUNTY

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IwETLANDcDEPENDENT NATIVEWlLDLIFESPECIES Of ST.JOHNSCOUNTYSpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDReq(ft)AMPHIBIANS OakToadB,oAlBufo quercicusFL,SH,Similar to gopher frog 6,336CYSouthern Toad oA2 Bufo terrestrisFL,FM,Similar to green treefrog 180HK,SH, HS Florida Cricket Frog BA3Acris gryllus dorsalisCY,FL,Similar to green treefrog 180HS,FM,HK, Green TreefrogB,OA4Hyla cinereaFL,FM,Maximum distance found from 180HK,SH,closest water CY Pinewoods Treefrog",G A6Hyla femoralisFL,HK,Similartospring peeper 4,000HS,SHBarking Treefrog"'o A7Hyla gratiosaFM,SH,Similartospring peeper 4,000 HS Squirrel Treefrog"'o A8Hyla squirellaHS,CY,Similar to green treefrog 180FL,HK,SH Little GrassFrogB,GA9Pseudacris ocularisCY, FL, Similartogreen treefrog 180HKSouthern Spring Peeper B GA5Pseudacris cruciferCY,HK,Maximum distance from 4,000bartramianaHS breeding pond Ornate Chorus Frog" AIOPseudacris ornataCY,FL,Similartogreen treefrog 180HK,HSSouthern Chorus FrogCPseudacris nigritaCY,HKSimilartogreen tree frog 180 Eastern NarrowmouthToadoAllGastrophryneHS,FL,Similar to spring peeper 4,000carolinensisHK,SH,CY lEastern Spadefoot Toad oAI2Saphiopus holbrookiiSH Similartospring peeper 4,000 holbrookiiFlorida Gopher FrogB G A13Rana capito aesopusFL,SH,Distance between capturesof6,336SSe)CY same individuals 13ullfrog",G AI4Rana catesbeianaCY,FL,Maximum distance found from 350HK,HS,permanent water SH

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Iw'ETLAND"DEPENDENT NATIVEWILDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies Scientific Name HabitatE. Spatial Requirements Notes Spatial'CodeDReq(ftPig Frog"G Al5Rana gryUoFL,FM, Similar to bullfrog 350HKHS,SH River FrogBAl6RanaheckscheriCY,FL, Similar to bullfrog 350FM,HKHS,SHBronze FrogCRana clamitans clamitansFL,FM,Similar to bullfrog 350HKHS,SH Southern Leopard Frog GAl7Rana utriculariaCY,FL, Similar to bullfrog 350FM,HKHS,SHpwarf Salamander" Al9Eurycea quadridigitataHS,CY, Similar to green treefrog 180 FL,FM, HK 1M:0le Salamander cAmbystoma talpoideumFM,CY, Similar to green treefrog 180 FL,HK,HS NewtBA20NotophthalmusCY,FLSimilar to green treefrog 180perstriatusHK,SH k:;entral NewtCNotophthalmusSH,CY, Similar to green treefrog 180viridescens louisianensisFL kJ,.eater SirenGSiren lacertinaHS,HK,Very aquatic habits, needs 50FL,CYenough adjacent land to provide good water quality iREPTILES Alligator G (SSe) RIAlligator mississippiensisHS,CY, Needs land for sunning and 50 1'SfA) FL,HK, nesting SM,SH, FM Florida Snapping TurtleBR2ehelydra serpentinaCY,FL, Home range diameter 497. osceolaHK,HS,SH,FM thicken TurtleB GR3Deirochelys reticulariaCY,FL, Similar to striped mud turtle 1,350FM,HK,HS,SH

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!wETLAND-DEPENDENT NATIVEWILDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies Scientific Name HabitatS Spatial Requirements Notes SpatialCodeDReqCft)Carolina Diamondback R4Malaclemys terrapinCY,FL,Similar to Florida snapping 497 TerrapinscentrataFM,HK,turtle HS, SH, SM, Peninsula Cooter B GR5Pseudemys floridanaCY,FL,Similar to striped mud turtle 1,350IpeninsularisFM,HK,HS,SH!'Iorida RedbellyTurtleB,GR6Pseudemys nelsoniFM,CY,Similar to striped mud turtle 1,350FL,HK,HS,SH,SM Striped Mud Turtle B .GR9Kinosternon bauriiCY,FL, Maximum distance from closest 1,350FM,HK,water to winter hibernation siteHS,SH I1'lorida Mud Turtle B .GRIOKinosternon subrubrumCY,FL,Similartostriped mud turtle 1,350steindachneriHK,HS,SH,SM,FM lEastern Mud TurtleCKinosternon subrubrumCY, FL, Similar to striped mud turtle 1,350subrubrumHK,HS,SH,SM,FM Il-oggerhead Musk TurtleGStemotherus minorminorCY, FL, Similartostriped mud turtle 1,350HK,HS,SH, SM. FM k;ommon Musk TurtleCStemotherus odoratusCY,FL, Similar to striped mud turtle 1,350HK,HS,SH,SM. FM !Florida Softshell Turtle BRl2Apalone feroxCY, FL, SimilartoFlorida snapping 497FM,HK,turtleHS,SH Turtle cClemmys guttataCY,FL, Similar to Florida snapping 497FM,HK,turtle.HS,SH \Eastern Mud SnakeGF arancia abacuraCY,FL, Needs land for sunning and 50abacuraFM,HK,laying eggsHS,SH

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!WETLAND-DEPENDENT NATIVEWILDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies Scientific Name HabitatESpatial Requirements Notes SpatialCodeDReq(ft)Rainbow Snake" R21Farancia erytrogrammaFL,HK,Similarto Eastern garter snake 1,395SHFlorida Water Snake G lVerodiaj'asciata CY,FL,Needs land for sunning and 50pictiventrisFM,HK,givingbirthHS,SHStriped Crayfish Snake GRegina alleniCY,FL,Needs land for sunning and 50FM,HK,laying eggsHS,SH l]lossy Crayfish Snake" R31Regina rigidaCY,FL,Similar to green water snake 884HK,HS,SH North Florida SwampSeminatrix pygaeaHS,CY,Needs land for sunning and 50 pygaeaFL,FM,laying eggsHK,SHPeninsula Ribbon Snake G."R35Thamnophis sauritusCY,FL,Home range diameter 333sackeniiHK,SH,HS florida Cottonmouth GAgkistrodon piscivorusCY,FL,Needs land for sunning and 50FM,HK,giving birthHS,SH !BIRDS Grebe cPodiceps auritusFM,SMSimilar to pied-billed grebe 240 Loon cGavia immerFM,SM,Similar to pied-billed grebe 240HK,SH,FLPied-Billed Grebe"BIPodilymbus podicepsFM,HK,Minimum distance from 240FL,SHhumans tolerated Brown PelicanF(SSe)Pelecanus occidentalisSM Recommended buffer basedon351 flush distance American White Pelican cPelecanus erythrorynchosSM,FMSimilar to brown pelican 351 Double-Crested CormorantF. Phalacrocorax auritusSM,SHRecommended buffer based on 335 flush distance Anhinga"Anhinga anhingaFM,CY,Minimum distance from292HS,HK,humans tolerated while nestingFL,SH

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WETLAND-DEPENDENT NATIVE WILDLIFE SPECIES OF ST. JOHNS COUNfY SpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDReq(ft)American BitternS B24Botaurus lentiginosusFM,HK Minimum distance from 180 humans tolerated Least BitternS B31Ixobrychus exilisFM Minimum distance tolerated 180 from humans Great Blue HeronFB23Ardea herodiasSM,FM, Recommended buffer based on' 328CY,HS,flush distanceFL,SHGreat EgretFB27Ardea albaSM,FM,Recommended buffer based on 299 CY,HS, flush distanceHK,FL,SH S'uowy Egret" (SSe)Egretta thulaSM,FM, Recommended buffer based on285CY,HS, flush distanceHK,FL,SH !--ittle Blue HeronF (SSe) Egretta caeruleaSM,FM, Recommended buffer based on341CY,HK, flush distanceFL,SH:Tricolored HeronF (SSe) Egretta tricolorSM,FM, Recommended buffer basedon269CY,HK,flush distanceFL,SHReddish Egret".(SSC) (W)Egretta rufescensSM,FM, Similartotricolored heron 269 CY,HK, FL, SH Cattle EgretHBubulcus ibisCY,HS, Recommended set back230HK,FL, distance SH Green HeronFButorides vires cansSM,FM, Similartotricolored heron 269 CY,HS, HK,FL, SH fLimpkinF(SSe) Aamus guaraunaFM, CY, Similar to tricolored heron 269HS,HK CraneGGirus canadensisFM,FLTends to nest away from roads 1,200 and other development activities

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[wETLAND-DEPENDENT NATIVE WILDLIFE SPECIES OF ST. JOHNS COUNTYSpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDRea(ftIBlack-crownedNycticorax nycticoraxSM,FM, Recommendedsetback318!Night-HeronHCY,HS,distanceHK,FL,SH IY ellow-crowned cNyctanassa violaceaSM,FM, Similar to black-crowned night-318!Night-HeronFCY,HS, heronHK,FL,SH Iwhite IbisH(SSe)Eudocimus albusFM,CY,Minimum distance from249HS, HK, humans tolerated while feedingFL,SHGlossy Ibis cPlegadis falcinellusFM,CY,Similar to white ibis249SH,HS,HK,FLRoseate Spoonbill cAjaia ajajaSM Similar to great egret299SSC)(W) Wood Stork" (E)(E)Mycteria americanaFM,CY,Recommended set back253HS,HK, distanceFL,SHFulvous Whistling-DuckGDendrocygna bicolorSimilar to wood duck300Black-belliedDendrocygnaautumnalisFM,CY,Similar to wood duck300Whistling-DuckCHS,HK,FL,SH,SM Snow Goose cChen caerulescensFM,CY,Similar to wood duck300HS,HK,FL,SHCanada Goose cBranta CanadensisFM, CY, Similar to wood duck300HS,HK,FL,SH lwoodDuc0 Aix sponsaFM,CY,Minimum distance from300HS,HK,humans tolerated while feedingFL,SH iAmerican Black Duck c (W)Anas rubripesFM,CY,Similar to wood duck300HS,HK,FL,SH

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iWETLANDcDEPENDENT NATNEWILDLIFE SPECIES OF ST. JOHNS COUNTYSpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDReg(ft)MottledDuck",G(W)BlOAnas julvigulaSM,FM,Minimum distance from120HK,FL,humans tolerated while feeding SH Mallard"BllAnasplatyrhynchasFM,HK,Similar to mottled duck120FL,SH Northern PintailCAnas acutaFM,HK,Similar to woo d duck300FL,SH,SM Bufflehead cBuchephala albealaFM,HK,Similar to wood duck300FL,SH,SM Greater ScaupcAythya marilaFM,HK,Similar to wood duck300FL,SH, SMSlackScoter CMelanitta nigraFM,HK, Similar to wood duck300FL,SH,SM Scoter CMelanitta perspicillataFM,HK, Similar to wood duck300FL, SH, SM Scoter CMelanitta fuscaFM,HK,Similar to wood duck300FL,SH,SM Teal" B8Anas caralinensisSM,CY, Similar to American wigeon300HS,SH 8lueWinged Teal cAnas dis carsSM,EM, Similar to American wigeon300HK,FL,SHNorthern Shoveler" B7Anas clypeataCY,HS, Minimum distance from300SH humans tolera ted Gadwall cAnas streperaSM,FM, Similar to American wigeon300 . CY,HS, SH AmericanWigeon"CB6Anas americanaSM,FM, Minimum distance from300CY,HS, humans tolerated SH

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WETLAND-DEPENDENTNATNEWILDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDReq(ft) Canvasback" Aythya valisineriaSM,FM,Similar to wood duck 300CY,HS,SH Aythya americanaSM,FM,Similar to wood duck 300CY,HS,SH Duck"G B12Anthya col/arisFM,HK,Similar to American wigeon 300FL,SH,and wood duck SM ,-,esser ScaupcAythya affinisFM,HK,Similar to wood duck 300 FL, SH, SM iHooded Merganser" B13Lophodytes cucul/atusFMSimilar to American wigeon 300 iRed-Breasted MerganserCMergus serratorFM,HK,Similar to American wigeon 300 FL,SH, SM iRuddy Duck cOxyura jamaicensisFM,HK,Similar to wood duck 300FL,SH,SM OspreyS B20Pandion haliaetusSM,FM,Very tolerantofhumans near 20CY,HS,nest siteFL,SHSwallow-Tailed KiteS(W)B17Elandides forficatusCY,HS,Similar to red-shouldered hawk 795HK,FLBaldEagleS,G(T) B18Haliaeetus leucocephalusSM,FM,Secondary restrictive activity 1,500CY,HS,zone around nestsFL,SHClapper Rail cRal/us longirostrisSM,FMSimilar to king rail 50 King Rail GRal/us elegansSM,FMNeeds enough adj acent land to 50 provide good water quality VirginiaRai1cRal/us limicolaSM,FMSimilar to king rail 50 Porzana carolinaSM,FMSimilar to king rail 50 lPurple Gallinule G Porphyrula martinicaFMNeeds enough adjacent land to 50 provide good water quality Moorhen GGallinula chloropusFM Needs enough adjacent land to 50 provide good water quality

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IwETLANDcDEPENDENT NATIVEWlLDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDReq(ft) CootGFulica americanaSM,FMNeeds enough adjacent land to50provide good water quality !Black-bellied Plover cPluvialis squatarolaSM Similar to Wilson's plover60 Plover c ('li)(T) Charadrius melodusSM Similar to Wilson's plover60 lWilson's Plover"B47Charadrius wi/soniaSM,FMFairly tolerantofhumans60 PloverFCharadrius semipalmatusRecommended buffer basedon249flushing distance American Oystercatcher"B44Haematopus palliatusSMMinimum distance from180SSC) humans tolerated--!Black-Necked StiltGHimantopus mexicanusSM,FMNeeds enough adjacent land to50provide good water quality American AvocetCRecurvirostra americanaSM,FMSimilartoAmerican180oystercatcher kJreater Yellowlegs"BS7Tringa melanoleucaSMMinimum distance from180humans tolerated iLesser Yel1owlegs"BS6Tringa flavipesSM Minimum distance from180humans tolerated Sandpiper cTringa solitariaSM Similartogreater yellowlegs180 lWilletF (W)CatoptrophorusSM Recommended buffer based on243semipalmatusflush distance Sandpiper"B48Actitis maculariaSM Fairly tolerantofhumans60 !whimbrel c Numenius phaeopusSM,FMSimilar to greater yellowlegs180Long-billed Curlewc(W) Numenius american usSM,FMSimilar to greater yellowlegs180Marbled GodwitCLimosaJedoaSM,FMSimilar to greater yellowlegs180Red Knotc(W)Calidris canutusSM,FMSimilartogreater yellowlegs180SanderlingFCalidris albaSMRecommended buffer basedon220flush distance Semipalmated Sandpiper cCalidris pusillaSM Similar to greater yellowlegs180 IW estern SandpiperFCalidris mauriSM Recommended buffer based on223flush distance fLeast Sandpiper"BSICalidris minutillaSM Minimum distance from240humans tolerated

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IwETLAND-DEPENDENT NATIVEWJLDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies Scientific Name Habitat" Spatial Requirements Notes SpatialCodeDReq(ft) Punlin B53Calidris alpinaSM Minimum distance from 300 humans tolerated Sandpiperc(W) Calidris himantopusSM Similar to greater yellowlegs 180 lRuddy TurnstoneFArenaria interpresSMRecommended buffer based on 236 flush distance Dowitchet'(W) B54Limnodromus griseusSM Minimum distance from 180 humans tolerated !,-,ong-Bi1led Dowitcher" B55LimnodromusSM Minimum distance from 180scolopaceushumans tolerated Common Snipe" B58Gallinago gallinagoSM,FMMinimum distance from 180 humans tolerated American Woodcock" B59Scolopax minorHK,FLMinimum distance from180humans tolerated Laughing Gull" B60Larus atricillaSM Fairly tolerantofhumans 60 Bonaparte's GuileLarus philadelphiaSM Similar to laughing gull60Lesser Black-backGu1lcLarus fuscusSM Similartolaughing gull 60 Greater Black-back Gulf Larus marinusSM Similartolaughing gull 60 Ring-Bi1ledGu1l"B61Larus delawarensisSM Fairly tolerantofhumans60HerringGu1lcLarus argentatusSM Similar to laughing gull60Gun-Billed Tern" B64Sterna niloticaSM Minimum distance from180humans tolerated Sandwich Tern c .Sterna sandvicensisSM Similar to gu1l-billed tern 180 Common Tern cSterna hirundoSM Similar to gull-bi1led tern 180 Forster's Tern" B63Sterna forsteriSM Minimum distance from 180 humans tolerated Least TernH(']i')B62Sterna antillarumSM Recommended set back.505distance 1R0yai Tern" B65Sterna maximaSM Minimum distance from 180 humans tolerated IBlackTern c Chilidonias nigerSM Similar to royal tern 180 Tern cSterna caspiaSM Similar to royal tern 180 IBlack Skimmer"(SSlC) Rynchops nigerSM Flush distance279

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WETLAND-DEPENDENTNATIVEWILDLIFESPECIESOFST.JOHNSCOUNTYSpeciesASpecies ScientificNameHabitatESpatial Requirements Notes SpatialCodeo Req(ft)BeltedKingfisher'GB70Ceryle alcyonFM,HK,Fairlytolerantofhumans 60FL,SHSedgeWrenBB79Cistothorus platensisSM,FMSimilartomarsh wren 196 Marsh WrenBB78Cistothorus palustrisSM,FMHomerange diameter 196 Saltmarsh Sharp-tailedAmmodramus caudacutusSM,FMSimilartoseaside sparrow 196 SparrowC (W) Nelson's Sharp-tailedAmmodramus nelsoniSM,FMSimilarto seaside sparrow 196Sparrowc fleaside Sparrow" (W)B94Ammodramus maritimaSMHomerange diameter 196 SparrowBB95Melospiza georgianaCY,HSHomerange diameter 196 Red-Winged Blackbird GB9lAgelaius phoeniceusSM,FMNeedsenough adjacent land to 50maintaingood water quality MAMMALS .Marsh Rabbi!"G M3Sylvilagus palus/J'isFMMaximumdistance found from 700shore /{ound-Tailed MuskratGNeofiber alieniFMNeedsenough adjacentlandto50maintaingood water quality 1vfarsh RiceRatGOryzomys palustrisSM,CYNeedsenough adjacentlandto50maintaingoodwaterquality River OtterGLutra canadensisSH,FM,Needsland for denning 100CY,HS,HK,FLMink" MIOMustela visonFM,CY,Maximumdistanceofden from 300HS,HK,closestwaterFL,SHNotes:AE=Endangered T=Threatened T(S/A)='Threatened/SimilarityofAppearance SSC=SpeciesofSpecial Concern W=Species listed on the NationalAudubGnSGcietyWatchList.Wheretwoabbreviations are listed,the fITst oneisa state listed species listed by the FloridaGameand Freshwater Fish Commission (FGFWFC), and the second is a federal listed species listed by the U.S. FishandWildlife Service (USFWS). Becausenospatial requirement data were foundforthese species, the numbers used here are reported by Brown eta1.1990a (for B footnote) and Brown eta1.1990b (for G footnote)torepresent spatial requirements for species that are closely related, similar-sized, or foundincomparable habitats.

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c Because no spatial requirement data were found for these species, the numbers used here are reportedbythe JEA Project Teamtorepresent spatial requirements for species that are closely related, similar-sized, or found in comparable hahitats (from JEA Project Team).DSpecies code corresponds to code used in Brown eta!.1990a. E Habitats:CYFLFMHI
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APPENDIXBSPATIAL REQUIREMENTS BYSPECIESLISTEDINASCENDINGORDERBY HABITAT

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CypressSpecies Osprey Marsh Rice Rat Florida Water Snake Striped Crayfish Snake Eastern Mud Snake American Alligator Greater Siren Cottonmouth North Florida Swamp Snake River Otter Cricket Frog Green Treefrog Squirrel Treefrog Little Grass Frog Ornate Chorus Frog Southern Chorus Frog Dwarf Saiamander. Striped Newt Swamp Sparrow Cattle Egret White Ibis Glossy Ibis Wood Stork Tricoiored Heron Reddish Egret Green Heron Limpkin Snowy Egret Anhinga Great Egret Wood Duck Green-Winged Teal Northern Shoveler American Wigeon Mink Biack-bellied Whistling Duck Snow Goose Canada Goose American Black Duck Gadwall Canvasback Redhead Black-crowned Night Heron Yellow-crowned Night Heron Great Blue Heron Peninsula Ribbon Snake Little Blue Heron Bullfrog Spatial Requirement (feet) 20 50 50 50 50 50 50 50 50 100 180 180 180 180 180 180 180 180 196 230 249 249 253 269 269 269 269 285 292 299 300 300 300 300 300 300 300 300 300 300 300 300 318 318 328 333341350%ofSpecies Protected 20%ofspecies=135.9 30%ofspecies=233.8 40%ofspecies=272.2 50%ofspecies=299.3 60%ofspecies=299.9 70%ofspecies=342.8 .

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River Frog Southern Leopard Frog Snapping Turtle Diamondback Terrapin Florida Softshell Spotted Turtle Swallow-Tailed Kite Glossy Crayfish Snake Chicken Turtle Cooter Florida Redbelly Turtle Striped Mud Turtle Florida Mud Turtle Eastern Mud Turtle Loggerhead Musk Turtle Bald Eagle Spring Peeper Eastern Narrowmouth Oak Toad Gopher Frog350 350 497 497 497 497 795 884 1350 1350 1350 1350 1350 1350 1350 1500 4000 4000 6336 6336

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FlatwoodsSpecies Osprey Florida Water Snake Striped Crayfish Snake North Florida Swamp Snake Eastern Mud Snake American Alligator Greater Siren Cottonmouth Belted Kingfisher River Otter Reddish Egret Mottled Duck Mallard Cricket Frog Green Treefrog Squirrei Treefrog Little Grass Frog Ornate Chorus Frog Dwarf Salamander Striped Newt American Woodcock Southern Toad Cattle Egret Pied-Billed Grebe Common Loon White Ibis Glossy Ibis Wood Stork Tricolored Heron Little Blue Heron Green Heron Snowy Egret Anhinga Great Egret Wood Duck Blue-winged Teal Ring-Necked Duck Mink Black-bellied Whistling Duck Snow Goose Canada Goose American Black Duck Northern Pintail Bufflehead Greater Scaup Black Scoter Surf Scoter White-winged Scoter Spatial Requirement (feet) 20/ 50 50505050 50 50 60 100 104 120 120 180 180 180 180 180 180 180 180 180 230 240 240 249 249 253 269 269 269285292 299 300 300 300 300 300 300 300 300 300 300 300 300 300 300%ofSpecies Protected 20% of species=140.0 30% of species=235.0 40%ofspecies=285.0 50%ofspecies=299.4 60% of species=299.8

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Lesser Scaup Red-breasted Merganser Ruddy Duck Black-crowned Night Heron Yellow-crowned Night Heron Great Blue Heron Peninsula Ribbon Snake BUllfrog Pig Frog River Frog Southern Leopard Frog Bronze Frog Snapping Turtle Diamondback Terrapin Florida Softshell Turtle Spotted Turtle Swallow-Tailed Kite Glossy Crayfish Snake Sandhili Crane Chicken Turtle Cooter Florida Redbelly Turtle Striped Mud Turtle Florida Mud Turtle Eastern Mud Turtle Loggerhead Musk Turtle Rainbow Snake Bald Eagle Pine Woods Treefrog Eastern Narrowmouth Oak Toad Gopher Frog 300 300 300 318 318 328 333 350 350 350 350 350 497 497 497 497 795 884 1200 1350 1350 1350 1350 1350 1350 1350 1395 15004000.4000 6336 6336 70%ofspecies= 366.4

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HammockSpecies Cottonmouth Florida Water Snake Striped Crayfish Snake North Florida Swamp Snake Eastern Mud Snake American Alligator Greater Siren Belted Kingfisher River Otter Mottled Duck Maliard Cricket Frog Green Treefrog Squirrel Treefrog Little Grass Frog Ornate"Chorus Frog Southern Chorus Frog Dwarf Salamander Striped Newt American Woodcock American Bittern Southern Toad Cattle Egret Pied-Billed Grebe Common Loon White Ibis Glossy Ibis Wood Stork Tricolored Heron Reddish Egret Green Heron Limpkin Snowy Egret Anhinga Great Egret Wood Duck Blue-winged Teal Ring-necked Duck Mink Black-bellied Whistling Duck Snow Goose Canada Goose American Black Duck Northern Pintail Bufflehead Greater Scaup Black Scoter Surf Seater Spatial Requirement (feet)50 5050 50 50 50 5060 100 120 120 180 180 180 180 180 180 180 180 180 180 180 230 240 240 249 249 253 269 269 269 269 285 292 299 300, 300 300 300 300 300 300 300 300 300 300 300 300%ofSpecies Protected 20% of species=145.1 30% of species=231.940% of species=265.8 50% of species=299.2 60% of species=299.7

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White-winged Scoter Lesser Scaup Red-breasted Merganser Ruddy Duck Black-crowned Night-Heron Yellow-crowned Night-Heron Peninsula Ribbon Snake Little Blue Heron Bullfrog Pig Frog River Frog Southern Leopard Frog Bronze Frog Snapping Turtle Diamondback Terrapin Florida Softshell Spotted Turtle Swallow-tailed Kite Glossy Crayfish Snake Chicken T urtie Cooter Florida Redbelly Turtle Striped Mud Turtle Florida Mud Turtle Eastern Mud Turtle Loggerhead Musk Turtle Rainbow Snake Pine Woods Treefrog Spring Peeper Eastern Narrowmouth Toad 300 300 300 300 318 318 333341350 350 350 350 350 497 497 497 497 795 884 1350 1350 1350 1350 1350 1350 1350 1395 4000 4000 4000 70%ofspecies=327.0

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Snowy Egret Anhinga Great Egret Wood Duck Blue-winged Teal American Wigeon Ring-Necked Duck Hooded Merganser Mink Black-bellied Whistling Duck Snow Goose Canada Goose American Black Duck Northern Pintail Bufflehead Greater Scaup Black Seater Surf Seater White-winged Seater Gadwall Canvasback Redhead Lesser Scaup Red-breasted Merganser Ruddy Duck Black-crowned Night-Heron Yellow-crowned Night-Heron Great Blue Heron Little Biue Heron Pig Frog River Frog Southern Leopard Frog Bronze Frog American White Pelican Snapping Turtle Diamondback Terrapin Florida Soflshell Spotted Turtle Marsh Rabbit Sandhill Crane Chicken Turtle Cooter Florida Redbelly Turtle Striped Mud Turtle Florida Mud Turtle Eastern Mud Turtle Loggerhead Musk Turtie Bald Eagle Barking Treefrog 285 292 299 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 318 318 328341350 350 350 350351497 497 497 497 700 12001350 1350 1350 1350 1350 1350 13501500 4000 .60%of species=299.370%ofspecies=299.8

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FreshwaterMarsh Species Osprey Round-Tailed Muskrat Cottonmouth Fiorida Water Snake Striped Crayfish Snake North Florida Swamp Snake Eastern Mud Snake American Alligator American Coot Red-Winged Blackbird Biack-Necked Stilt King Rail Purple Gaiiinule Common Moorhen Virginia Rail Sora Clapper Rail Wilson's Plover Belted Kingfisher River Otter Mottied Duck Mallard Cricket Frog Green Treefrog Dwarf Salamander Common Snipe American Bittern Least Bittern Southern Toad American Avocet Whimbrel Long-billed Curler Marbled Godwit Red Knot Sedge Wren Marsh Wren Saltmarsh Sharp-tailed Sparrow Nelsons Sharp-tailed Sparrow Pied-Billed Grebe Horned Grebe Common Loon White Ibis Giossy Ibis Wood Stork Tricolored Heron Reddish Egret Green Heron Limpkin Spatial Requirement (feet) 2050 50 50 50 50 50 50 50 50 50 5050 5050505060 60100 120 120 180 180180180 180180180180180180 180 180 196196196196 240 240 240 249 249253269' 269 269 269%of Species Protected 20% of species = 75.9 30% of species = 155.5 40%ofspecies = 207.7 50%ofspecies = 277.0

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Western Sandpiper Ruddy Turnstone Least Sandpiper Horned Grebe Common LoonWHletTricoiored Heron Reddish Egret Green Heron Biack Skimmer Snowy Egret Great Egret Roseate Spoonbill Green-Winged Teal Blue-Winged Teal American Wigeon Black-bellied Whistling Duck Northern Pintail Bufflehead Greater Scaup Black Seater Surf Scater White-winged Scoter Gadwall Canvasback Redhead Lesser Scaup Red-breasted Merganser Ruddy Duck Ring-necked Duck Black-crowned Night-Heron Yellow-crowned Night-Heron Great Blue Heron Double-Crested Cormorant Little Blue Heron Brown Pelican American White Pelican Diamondback Terrapin Least Tern Florida Redbelly Turtle Florida Mud Turtle Eastern Mud Turtle Loggerhead Musk Turtie Bald Eagle 223 236 240 240 240 243 269 269 269 279 285 299 299 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 318 318 328 335341 351351497 505 1350 1350 1350 1350 1500 60%ofspecies=253.4 70%ofspecies=299.2

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SaltwaterMarshSpecies Osprey Marsh Rice Rat American Alligator American Coot Black-Necked Stilt King Rail Virginia Rail Sora Rusty Blackbird Clapper Rail Wilson's Plover Spotted Sandpiper Laughing Gull Bonaparte's Gull Lesser Black-back Gull Greater Black-back Gull Herring Gull Black-bellied Plover Piping Plover Ring-Billed Gull Mottled Duck American Oystercatcher Greater Yellowlegs Lesser Yellowlegs Short-Billed Dowitcher Long-Billed Dowitcher Common Snipe Gull-Billed Tern Sandwich Tern Common Tern Forster's Tern Royal Tern Black Tern Caspian Tern American Avocet Whimbrel Long-billed Curler Marbled Godwit Red Knot Solitary Sandpiper Semipalmated Sandpiper Stilt Sandpiper Sedge Wren Marsh Wren Saltmarsh Sharp-tailed Sparrow Nelson's Sharp-tailed Sparrow .Seaside Sparrow Sanderling Spatial Requirement (feet) 20 50 50 50 50 50 50 50 50 50 60 60 60 60 60 60 60 606060 120 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 180 196 196 196" 196 196 220%of Species Protected 20%ofspecies=58.4 30%ofspecies=138.9 40%ofspecies=165.1 50%ofspecies=192.8

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'
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SandhillSpecies Osprey Fiorida Water Snake Eastern Mud Snake American Alligator Cottonmouth Striped Crayfish Snake North Florida Swamp Snake River Otter Mottled Duck Mallard Green T reefrog Squirrel Treefrog Striped Newt Beited Kingfisher Southern Toad Cattle Egret Pied-Billed Grebe Common Loon White Ibis Glossy Ibis Wood Stork Tricolored Heron Reddish Egret Green Heron Snowy Egret Anhinga Great Egret Wood Duck Green-Winged Teal Blue-Winged Teal Northern Shoveler American Wigeon Ring-Necked Duck Mink Black-bellied Whistling Duck Snow Goose Canada Goose American Black Duck Northern Pintail Bufflehead Greater Scaup Black Scoter Surf Scoter White-winged Scoter Gadwall Canvasback Redhead Lesser Scaup Spatial Requirement (feet) 20 505050 5050 50100 120 120 180 180 180 180 180 230 240 240 249 249 253 269 269 269 285 292 299 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300%ofSpecies Protected 20% of species=231.0 30% of species=273.8 40% of species=299.2 50%ofspecies=299.6 60% of species=299.9

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Florida Softshell Turtle 497 Spotted Turtle 497 Swallow-Tailed Kite 795 Glossy Crayfish Snake 884 Chicken Turtle 1350 Cooter 1350 Florida Redbelly Turtie 1350 Striped Mud Turtle 1350 Florida Mud Turtle 1350 Eastern Mud Turtle 1350 Loggerhead Musk Turtle 1350 Bald Eagle 1500 Spring Peeper 4000 Pine Woods Treefrog 4000 Barking Treefrog 4000 Eastern Narrowrnouth Toad 4000

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HardwoodSwampSpecies Osprey Eastern Mud Snake American Alligator Greater Siren Striped Crayfish Snake Florida Water Snake North Florida Swamp Snake Cottonrnouth River Otter Cricket Frog Squirrel Treefrog Ornate Chorus Frog Dwarf Salamander Hooded Warbler Southern Toad Swamp Sparrow Cattle Egret White Ibis Glossy Ibis Wood Stork Green Heron Limpkin Snowy Egret Anhinga Great Egret Wood Duck Green-Winged Teal Northern Shoveler American Wigeon Mink Black-bellied Whistling Duck Snow Goose Canada Goose American Black Duck Gadwall Canvasback Redhead Black-crowned Night-Heron Yellow-crowned Night-Heron Great Blue Heron Peninsula Ribbon Snake Bullfrog Pig Frog River Frog Southern Leopard Frog Bronze Frog Snapping Turtle Diamondback Terrapin Spatial Requirement (feet) 20 5050 50 50 505050100 180 180 180 180 180 180 196 230 249 249 253 269 269 285 292 299 300 300 300 300 300 300 300 300 300 300 300 300 318 318 328 333 .350 350 350 350 350 497 497%ofSpecies Protected 20% of species=150.7 30%ofspecies=249.8 40% of species=299.1 50%ofspecies.= 299.6 60% of species = 312.6 70% of species = 345.9

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': ,. ..-APPENDIXC SOILSINFORMATIONIN ST.JOHNSCOUNTYSOURCE: ST. JOHNSCODNl'YSOILSURVEY

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TableA-1Soils SeriesinSt. Johns County, Florida Source: Soil SurveyofSt. Johns County, Florida Soil Series Erosion Factor Soil Series USDA Soil Type Hydrologic Group Permeability(tons/acrelHighWaterTable and Depth from Surface (in) (in/hr) unit rainfall) depth(ft)months 1 Adamsville Fine Sand 0-8 C 6.0-20 0.10 2.0-3.5 Jun-Nov 8-80 C 6:0-20 0.10 2 Astatula Fine Sand 0-80 A >20 0.10 >6.0 3 Myakka Fine Sand 0-23BID6.0-20 0.10 0-1.0 Jun-Nov 23-53BID0.6-6.0 0.15 53-80BID. 6.0-20 0.10 4 Myakka Fine Sand 0-1706.0-20 0.10 +2-1.0 Jun-Feb 17-3100.6-6.0 0.15 31-8006.0-20 0.10 5 St. Johns Fine Sand 0-1306.0-20 0.10 +2-1.0 Jun-Apr 13-2506.0-20 0.10 25-5000.2-2.0 0.15 50-8006.0-20 0.10 6 Tavares Fine Sand 0-7 A 6.0-20 0.10 3.5-6.0 Jun-Dec 7-80 A 6.0-20 0.10 7 Immokalee Fine Sand 0-8BID6.0-20 0.10 0-1.0 Jun-Nov 8-40BID6.0-20 0.10 40-64BID0.6-2.0 0.15 64-80BID6.0-20 0.10 8 Zolfo Fine Sand 0-5 C 6.0-20 0.10 2.0-3.5 Jun-Nov 5-66 C 6.0-20 0.10 66-80 C 0.6-2.0 0.159Pomona Fine Sand 0-6BID6.0-20 0.10 0-1.0 JUI-Sep 6-21BID6.0-20 0.10 21-31BID0.6-2.0 0.15 31-47BID6.0-20 0.10 47-63BID0.2-0.6 0.20 63-80BID6.0-20 0.1011Smyrna Fine Sand 0-14 NO 6.0-20 0.10 0-1.0 Jul-Oct 14-21 NO 0.6-6.0 0.15 21-32 NO 6.0-20 0.10 32-45 NO 0.6-6.0 0.15 45-80 NO 6.0-20 0.10Appendix C.xls Sheetl

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Soil Series Erosion Factor Soil Series USDA Soil Type Hydrologic Group Permeability(tonslacrelHigh Water Table and Depth from Surface (in) (in/hr) unit rainfall) depth (ft) months12Ona Fine Sand0-8BID6.0-20 0.10 0-1.0Jun-Nov8-25BID0.6-2.0 0.15 25-80BID6.0-20 0.10 13Sl. Johns Fine Sand0-10BID6.0-20 0.10 OC1.0 Jun-Apr10-15BID6.0-20 0.10 15-28BID0.2-2.0 0.15 28-42BID6.0-20 0.10 42-66BID0.2-2.0 0.15 66-80BID6.0-20 0.1014Cassia Fine Sand0-18C6.0-20 0.10 1.5-3.5Jul-Jan18-32C0.6-6.0 0.15 32-75C6.0-20 0.10 75-80C0.6-6.00.1515Pomello Fine Sand0-45C>20 0.10 2.0-3.5Jul-Nov45-57C2.0-6.0 0.15 57-80C6.0-20 0.1016Orsino Fine Sand0-18A>20 0.10 3.5-5.0Jun-Dec18-80A>20 0.10 18Floridana Fine Sand0-18D6.0-20 0.10 0-1.0Jun-Feb18-28D6.0-20 0.10 28-80D<0.2 0.24 19Pompano Fine Sand0-80BID>20 0.10 0-1.0Jun-Nov21Wabasso Fine Sand0-25BID6.0-20 0.10 0-1.0Jun-Oct25BID0.6-2.0 0.15 32-45BID<0.2 0.24 45-80BID6.0-20 0.1022Manatee Fine Sandy Loam0-13D0.6-2.0 0.10 0-1.0Jun-Feb13-34D0.6-2.0 0.24 34-52D0.6-2.0 0.24 52-80D0.6-2.0 0.2423Paola Fine Sand0-17A>20 0.10 >6.0 17-80A>20 0.1024Pellicer Silty Clay Loam0-10D0.06-0.2 0.32 0-0.5Jan-Dec10D<0.06 0.24 70-80D6.0-20 0.24Appendix C.xls Sheetl11/29/1999 2

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Soil Series Erosion Factor Soil Series USDA Soil Type Hydrologic Group Permeability(tons/acrelHigh Water Table and Depth from Surface (in) (in/hr) unit rainfall) depth(It)months 25 Parkwood Fine Sandy Loam 0-10BID6.0-20.0 0.10 0-1.0 Jun-Oct 10-55BID0.06-0.6 0.15 55-80BID6.0-20 0.10 26 Samsula Muck0-31BID6.0-20 +2-1.0 Jan-Dec 31-80BID6.0-20 0.1727St. Augustine Fine Sand 0-10C6.0-20 0.10 1.5-3.0 Jut-Oct 10-80C2.0-20 0.15 28 Beaches No Data Provided 29 Satellite Fine Sand 0-6 A >20 0.10 1.0-3.5 Jun-Nov 6-80 A >20 0.10 30 Wesconnett Fine Sand 0-8 D 6.0-20 0.10 0-1.0 Jun-Feb 8-34 D 0.6-6.0 0.15 34-45 D 6.0-20 0.10 45-80 D 0.6-6.0 0.1531Fripp Fine Sand No Data Provided 32 Palm Beach Fine Sand 0-80 A >20 0.10 >6.0 33 Jonathan Fine Sand 0-4 B 6.0-20 0.10 3.0-5.0 Jun-Oct4-71B 6.0-20 0.24 71-80 B <0.2 0.28 34 Tocoi Fine Sand 0-13BID6.0-20 0.10 0-1.0 Aug-Feb 13-23 BID 2.0-20 0.15 23-45 BID 6.0-20 0.10 45-76 BID 2.0-6.0 0.15 76-80 BID 0.6-20 0.15 35 Hontoon Muck 0-55 BID 6.0-20 2-1.0 Jan-Dec 55-80 BID 6.0-20 0.15 36 Riviera Fine Sand 0-23CID6.0-20 0.10 0-1.0 Jun-Dec 23-28CID<0.2 0.24 28-71CID<0.2 0.24 71-80CID0.6-6.0 0.15 38 Pitts No Data ProvidedAppendix C.xls Sheetl11/29/19993

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Soil Series Erosion Factor Soil Series USDA Soil Type Hydrologic Group Permeability(tonslacrelHigh Water Table and Depth from Surface (in) (in/hr) unit rainfall) depth (ft) months 40 Pottsburg Fine Sand 0-60 BID 6.0-20 0.10 0-1.0 Jul-Mar 60-80BID0.6-2.0 0.1541Tomoka Muck 0-21BID6.0-20 +1-0 Jun-Apr 21-80 BID 0.6-6.0 0.2842Bluff Sandy Clay Loam 0-3 D 6.0-20 0-1.0 Jul-Dec3-9D 0.2-0.6 0.28 9-25 D 0.06-0.2 0.28 25-53 D 0.06-0.2 0.28 53-80 D 0.06-0.2 0.28 44 Sparr Fine Sand0-3C6.0-20 0.10 1.5-3.5 Jul-Oct 3-68C6.0-20 0.20 68-80C0.6-2.0 0.24 45 SI. Augustine Fine Sand 0-21C6.0-20 0.10 1.5-3.0 Jul-Oct 21-48C2.0-20 0.15 48-53C0.2-0.6 0.20 53-80C<0.06 0.32 46 Holopaw Fine Sand 0-53 BID 6.0-20 0.100-1.0 Jun-Nov53-72BID0.2-2.0 0.20 72-80BID6.0-20 0.15 47 Holopaw Fine Sand 0-50 D 6.0-20 0.10 0-1.0 Jun-Feb 50-68 D 0.6-2.0 0.24 68-80 D 6.0-20 0.15 48 Winder Fine Sand 0-11BID6.0-20 0.10 0-1.0 Jun-Dec 11-16BID0.2-0.6 0.20 16-42 BID <0.2 0.24 42-80 BID <0.2 0.24 49 Moultrie Fine Sand 0-22 D >20.0 0.10 0-1.0 Jan-Dec 22-29 D 2.0-20 0.10 29-80 D >20.0 0.10 50 Narcoossee Fine Sand, Shelly Substratum 0-3C>20 0.102.0-3.5 Jun-Nov3-11C>20 0.10 11-14'C>20 0.10 14-80C6.0->20 0.1051SI. Augustine Fine Sand 0-10C6.0-20 0.10 1.5-3.0 Jul-OctAppendix C.xls Sheet!11/29/19994

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Soil Series Erosion Factor Soil Series USDA Soil Type Hydrologic Group Permeability (tons/acrel High Water Tabie and Depth from Surface (in) (in/hr) unit rainfall) depth (ft) months 10-80C2.0-20 0.15 52 Durbin Muck 0-5906.0-20 0-0.5 Jan-Dec 59-8006.0-20 0.10 53 Immokalee Fine Sand 0-6 BID 6.0-20 0.10 0-1.0 Jun-Nov 6-42 BID 6.0-20 0.10 42-66 BID 0.6-2.0 0.15 66-80 BID 6.0-20 0.10 54 Astatula Fine Sand 0-80 A >20 0.10 >6.0 55 Arents No Data Provided 57 Adamsville Variant Fine Sand 0-10C>20 0.10 2.0-3.5 Jun-Nov 10-80C6.0-20 0.10 58 EauGallie Fine Sand 0-17 BID 6.0-20 0.10 0-1.0 Jun-Oct 17-23 BID 0.6-6.0 0.15 23-53 BID 6.0-20 0.10 53-58 BID 0.06-2.0 0.20 58-80 BID 0.6-6.0 0.1561Riviera Fine Sand 0-2506.0-20 0.10 +2-1.0 Jun-Dec 25-35 D <0.2 0.24 35-55 D <0.2 0.24 55-8000.6-6.0 0.15 62 Floridana Fine Sand0-1106.0-20 0.10 0-1.0 Jun-Feb 11-3006.0-20 0.10 30-800<0.2 0.24 63 Placid Fine Sand 0-12 BID 6.0-20 0.10 0-1.0 Jun-Mar 12-80 BID 6.0-20 0.10 64 Ellzey Fine Sand 0-12 BID 2.0-6.0 0.10 0-1.0 Jun-Oct 12-37 BID 2.0-6.0 0.10 37-58 BID 0.6-2.0 0.17 58-80 BID 2.0-6.0 0.10 65 Riviera Fine Sand 0-28CID6.0-20 0.10 0-1.0 Jun-Dec 28-40CID<0.2 0.24 40-65CID<0.2 0.24 65-80CID0.6-6.0 0.15Appendix C.xls Sheet] 11129/19995

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Soil Series Erosion Factor Soii Series USDA Soii Type Hydrologic Group Permeability (tons/acrel High Water Table and Depth from Surface (in) (in/hr) unit rainfaU) depth (tt) months 66 Terra Ceia Muck 0-80 BID 6.0-20 0-1.0 Jan-Dec 67 Tisonia Mucky Peat 0-18 D 6.0-20 0-0.5 Jan-Dec 18-65 D <0.06 0.20 68 Winder Fine Sand 0-10 BID 6.0-20 0.10 0-1.0 Jun-Dec 10-14 BID 0.2-0.6 0.20 14-56 BID <0.2 0.32 56-80 BID <0.2 0.32 69 Bakersville Muck 0-5 D 6.0-20 +2-1.0 Jul-Mar5-41D 2.0-6.0 0.10 41-59 D 0.6-2.0 0.15 59-86 D 2.0-6.0 0.10AppendixC.xlsSheet111/29/1999 6

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APPENDIXDlIYDROLOGICMETHODOLOGIESFORPREDICTINGPEAKSTORMWATERDISCHARGE

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HYDROLOGICMETHODOLOGIESFORPREDICTINGPEAKSTORMWATERDISCHARGEMETHODOLOGYONE:THERATIONALFORMULATheRationalFonnulais a simple physically-basedmodelthat applies welltourbansettings, and particularlysmalldevelopment siteswithahighpercentageofimpervious areas (parking lots, buildings, etc.).Thefirst step istodecideona design storm including the return frequency time period andthestormduration time as this will establish the input parametersoftheequation.Theequation calculatesthedischarge rate usingtheform:Q=ciAwhere:(C-l)Qisthe volumetric discharge (UIT) c istherunoffcoefficient (dimensionless) i istherainfall intensity(UT)A is the areaofthedrainage basinorsite(L')Therunoffcoefficient, c,isdefmed as that fractionofthe rainfall that willberealized asrunoffduring astonnevent as opposed to being abstractedbyinfiltration, depressional storage,canopyinterception, and/or evaporation. This varies withthelandusetype, soil type,andtopography.Therainfall intensity,i,willbedeterminedbythe choiceofdesign storm;itincreases asthereturn frequency time period increases, and decreases as the storm durationtimeincreases. For the applicationathandthedrainage area is defined as one acre, soAbecomes a constant.Whenworkinginthe English System, the lengthunit(L) shouldbeinfeet andthetimeunit(T) shouldbeinseconds. Technically speaking,ishouldbein feet/secondandAshouldbeinsquare feet suchthatQ is calculatedincubic feetpersecond (cfs). This meansAshouldbeexpressed as 43560ft'.However,ifiis expressed as inchesperhourandAis expressed as 1 acre, thenQwill stillbecalculatedincfs within 1 percent accuracy.Thislatter system generallymakesthe calculative process easier.Forapplying the metric system, the length unit (L)isinmeters and the timeunit(T)isinseconds.Thismeans that for the dischargetobecalculated as cubic meterspersecond,therainfall intensitymustbeexpressedinmeterspersecond and the areamustbeexpressedinsquare meters. ThusAshouldbeset equalto4047m',the equivalentof1 acre. MaterialsfromtheFDOTdrainagemanualhavebeenreproduced here for reference, andthecalculative canbeperformedbyfollowing these steps:1.Choosea design stornl; this requires the specificationofthe return frequency time period andthestorm duration time. Typically, the latterisset equal to thetimeofconcentration forthedrainage area for design purposes. 2.Therainfall intensity canbedetermined forthedesign stormbyusingFDOTFigure 5-6.Thisfigure is the Rainfall Intensity-Duration-Frequency Curve forZone5ofFlorida,whichincludes St. Johns County as showninFigure 5-1. Thevalueofishouldbeexpressedinincheslhour, ft/sec,orm/sec, depending on theuser'schoiceofunitsystem.W:II92701485010700IAppendix D.wpd

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3.The runoff coefficient can be determined through the useofTables 5-5 and 5-6. Table 5 5 establishes a value for given slopes, land use, and general soil type for return periodsofless than10years. Table 5-6 gives a multiplication factor to use for higher return periods. 4. The valueofAshould be expressed as 1 acre, 43560ft2,or 4047 m 2 depending on the user's choiceofunit system. 5. EquationC-lcan thenbeapplied to calculate the peak runoff volumetric discharge. The valueofQwillbeexpressedincfs (approx.), cfs (exact),orm3/sec, depending on the user's choiceofunit system. This is the final value that will thenbeapplied in the erosion buffer width determination (Method #2). METHODOLOGY TWO: THE SCS CURVE NUMBER METHOD The SCS methodology was originally developed for agricultural and rural settings, but has also been adapted for more urban settings as well.Itis based on a curve number (CN) system which indicates the runoff potential for a given land use and hydrologic conditionofa site. The higher theCNvalue, the higher the runoff for a given storm event. The processofdetermining the appropriate CN value and the peak runoff flow rate is described in the following seriesofsteps. Tables from the FDOT drainage manual and other sources are utilized.1.Classify the soil accordingtorunoff potential. Soils are categorized as A through D which goes from low runoff to high runoff potential. FDOT Table 5-7 gives a descriptionofthe 4 types.2.Determine the antecedent moisture condition (AMC)ofthe soil. This conditionisdescribed as AMC1,AMC II, or AMC ill, and are described as follows:AMCI:AMCII:AMCill:Dry soils,norecent rains. Typical conditions that may exist prior to seasonal flooding Saturated soils due to significant rainfall occurring during the 5 days priortostorm. 3. Classify the hydrologic conditionofthe soilaseithergood, fair,orpoor.This could also be considered a vegetative cover condition, and is generally detenninedasfollows: good: 75% plant cover (lightly grazed) fair: 50% 75% plant cover (not heavily grazed) poor: <50% plant cover (heavily grazed) FDOT Table 5-10 gives additional guidelines for determining the hydrologic condition.4.From the parameters determined from the previous three steps, a CN value can nowbedetermined using either FDOT Table 5-8 or Table 5-9. Please note that these tables apply for AMC II pre-existing condition. The CN value can be determinedasa compositeW:\19270\485010700\Appendix"D.wpd

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value for varying land uses or hydrologic conditions within the drainage basin using a weighted-area method. 5. This step is only necessaryifthe user desires to represent either the AMC 1 or AMC III condition. Table 6.8 (Lindeburg, 1989) canbeuse to convert theCNvalue for AMCIIto eitherofthese other conditions. 6. This step is only necessaryifthere are significant impervious areas within the basin that are not otherwise accounted for. These areas should be assigned aCNvalueof100, and a new area weighted compositeCNvalue should be determined for the basin. 7. Choose a design storm. Generally, a 24-hour duration storm is used when applying the SCS method. Determine the total rainfall for this design storm.8.The net rainfall, or runoff canbedetermined through the following seriesofcalculative steps:a.Calculate S, the storage capacityofthe soilas:S=1000/CN 10b.Calculate the initial abstractionas: r. =0.2Sc.The gross rain, P&'mustbegreater than1.or there will be no runoff.d.Determine the runoff (net rain)asfollows: PN=(Pg 1,)2 /(Pg+0.8S) All the parameters, exceptCNare expressed in inches.9.Anapproximationofthe peak discharge can then be determined by determining the maximum incremental valueofthe SCS Florida-modified rainfall distribution. Table C1,which was derived from the FDOT Table 5-19, shows that the maximum incremental rainfall occurs during the one-half hour between 11.5 and 12.0 hours for the 24-hour storm and is equal to 0.299ofthe total rainfall. This fraction can be multipliedbythe net rain,PN'and dividedby0.5 hourstogive a runoff intensity in inchesperhour. This is then multiplied by theIacre area (convertingtoappropriateunitsifnecessary) to give a peak discharge: .Q=0.299/0.5.PN'1acre (C-2) Equation C-2 will give the discharge rate in cfsifPNis expressed in inches. This step assumes that the runoff rate is similarly distributedtothe rainfall rate, whichisa good assumption for a small basin (suchas1 acre) and is a conservative assumption for larger basins. This is the fmal value that will thenbeapplied in the erosion buffer width determination (Method #2).W:\19270\485010700IAppendix D.wpd l.'.... ..n'>h ..r 1.. 1 QQQ

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-,LCollierFIGURE5-1Zones for Precipitation Intensity-Duration-Frequency (IDF) Curves Developed by the Department 10 _Brow.rd, '-Q.f::5gst "0 o iiig.:loiil:;.JiCD:!:'":lCEC

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<15 f_15 ?l -....._.fC \.. f-... 0"'-_----_.. ;;:: I---._..--.--.0___.---.-_ -"m, 10 f\.) 9I 8 :n o7 0 2 Yearm60 0:5 5m MIl 5 Year ffi 4 10Yea-4 c. 25Year '"til 3 3 0 mJ: --'--t-gu z.100Yea 3_ ro Z2 2 ;? 0 -. ;iii z '" z _."_ OJ I'-.. 1:0 g.-it. .9 .9 0z.88 i 5' 0:.7 .7 J'l .6.0.. B .. '" .5ZONE..-.5 .4.3.4 --..-...-_..-.-o.0,101520304050602 345102024I.215MINUTES1!HOURSFIGURE5-6DURATIONRainfallintensity-Duration-Frequency Curves for Zone 5 "en

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625-040-205-a Page50of98Table 5-5 RUNOFFCOEFFICIENTS aFORA DESIGNSTORMRETURNPERIODOF10YEARSORLESS.SandySoilsClaySoilsSlopeLandUseMin.Max.Min.Max.FlatWoodlandsb0.10.0.150.15 0.20(0-2%)pasture,grass,andfarmland0.150.200.200.25Rooftopsandpavement0.950.950.950.95Perviousc0.750.950.900.95pavementsSFR: "-acre lotsandlarger0.300.350.350.45Smallerlots0.350.450.40 0.50Duplexes0.350.450.40 0.50 MFR: Apartments,townhouses,andcondominiums0.450.600.500.70ConunercialandIndustrial0.500.950.50 0.95RollingWO'odlandsb0.150.200.20 0.25 (2-7%) pasture,grass,andfarmland0.200.250.250.30Rooftopsandpavement0.950.950.95 0.95. c0.800.950.90 0.95PerV1QUSpavementsSFR: "-acre lotsandlarger0.350.500.40 0.55Smallerlots0.400.550.450.60Duplexes0.400.550.45 0.6C MFR:Apartments,townhouses,andcondominiums0.50 0.700.60 0.80CommercialandIndustrial0.500.950.600.95SteepWoodlandsb0.200.250.250.30( 7%+) Pasture,grass,andfarmland0.250.350.300.40Rooftopsandpavement0.950.950.950.95. c0.850.950.900.95 pavementsSFR: "-acre lotsandlarger0.400.550.500.65Smallerlots0.450.600.55 0.70Duplexes0.450.600.550.70MFR:Apartments,townhousestandcondominiums0.600.75 0.650.85CommercialandIndustrial0.600.95 0.650.95aweightedcoefficientbasedonpercentageofimpervioussurfacesandgreenareasmustbeselectedforeachsite.bcoefficientsassume groundcoverandconservationtreatment.CDependsondepthanddegree'ofpermeabilityofunderlyingstrata.Note:SFRMFR=SingleFamilyResidentialMulti-FamilyResidentialcmR299b/06b

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625-040-205-aPage51of98.Table5-6DESIGNSTORMFREQUENCYFACTORSFORPERVIOUSAREARUNOFFCOEFFICIENTS*ReturnPeriod(years)2to1025501001.01.1 1.2 1.25Reference:Wright-McLaughlinEngineers(1969).*DUETOTHEINCREASE INTHEDURATIONTIMETHATTHEPEAKORNEARPEAKDISCHARGERATEISRELEASEDFROMSTORMWATERMANAGEMENTSYSTEMS,THEUSEOFTHESESHORTDURATIONPEAKRATEDISCHARGEADJUSTMENTFACTORSARENOTAPPROPRIATEFORFLOODROUTINGCOMPUTATIONS.

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625-040-205-aPage52of98Table5-7DEFINITIONSOFFOURSCSHYDROLOGICSOILGROUPSHydrologicSoilGroupDefinitionA LowRunoffPotentialSoilshavinghighinfiltrationratesevenwhenthoroughlywetted,consistingchiefly ofdeep,well-to-excessively-drainedsandsorgravels.Thesesoilshaveahighrateofwatertransmission.BModeratelyLowRunoffPotentialSoilshavingmoderateinfiltrationrateswhenthoroughlywettedandconsistingchieflyofmoderatelydeeptodeep,moderatelyfinetomoderatelycoarse textures.Thesesoilshaveamoderaterateofwatertransmission.CModeratelyHighRunoffPotentialSoilshavingslowinfiltrationrateswhenthoroughlywettedandconsistingchieflyofsoilswithalayerthatimpedesdownwardmovementofwater,soilswithmoderatefinetofinetexture,orsoilswithmoderatewatertables.Thesesoilshaveaslowrateofwatertransmission.DHighRunoffPotentialSoilshavingveryslowinfiltrationrateswhenthoroughlywettedandconsistingchieflyofclaysoilswithhighswellingpotential,soilswithapermanenthighwatertable,soilswithaclaypanorclaylayeratornearthesurface,andshallowsoilsovernearlyimperviousmaterial.Thesesoilshaveaveryslowrateofwatertransmission.Reference:USDA,SCS,NEH-4(1972).gnR299b/06d

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625-040-205-a Page 52of98Table5-7DEFINITIONSOFFOURSCSHYDROLOGICSOILGROUPSHydrologicSoilGroupDefinitionA LowRunoffPotentialSoilshavinghighinfiltrationratesevenwhenthoroughlywetted,consistingchieflyofdeep,well-to-excessively-drainedsandsorgravels.Thesesoilshaveahighrateofwatertransmission.BModeratelyLowRunoffPotentialSoilshavingmoderateinfiltrationrateswhenthoroughlywettedandconsistingchieflyofmoderatelydeeptodeep,moderatelyfinetomoderatelycoarse textures.Thesesoilshaveamoderaterateofwatertransmission.CModeratelyHighRunoffPotentialSoilshavingslowinfiltrationrateswhenthoroughlywettedandconsistingchieflyofsoilswithalayerthatimpedesdownwardmovementofwater,soilswithmoderatefinetofinetexture,orsoilswithmoderatewatertables.Thesesoilshaveaslowrateofwatertransmission.DHighRunoffPotentialsoilshavingveryslowinfiltrationrateswhenthoroughlywettedandconsistingchieflyofclaysoilswithhighswellingpotential,soilswithapermanenthighwatertable,soilswithaclaypanorclaylayeratornearthesurface,andshallowsoilsovernearlyimperviousmaterial.Thesesoilshaveaveryslowrateofwatertransmission.Reference:USDA,SCS,NEH-4(1972).gnR299b/06d

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625-040-205-aPage51of98Table5-6DESIGNSTORMFREQUENCYFACTORSFORPERVIOUSAREARUNOFFCOEFFICIENTS*ReturnPeriod(years)2to1025501001.0 1.11.21.25Reference: Wright-McLaughlinEngineers(1969).*DUETOTHEINCREASE INTHEDURATIONTIMETHATTHEPEAKORNEARPEAKDISCHARGERATEISRELEASEDFROMSTORMWATERMANAGEMENTSYSTEMS,THEUSE OF THESESHORTDURATIONPEAKRATEDISCHARGEADJUSTMENTFACTORSARENOTAPPROPRIATEFORFLOODROUTINGCOMPUTATIONS.

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625-040-205-aPage53of98Table5-8SCSRUNOFFCURVENUMBERSFORSELECTEDAGRICULTURAL,SUBURBAN,ANDURBANLANDUSELandUseDescription ---., HydrologicABSoilGroupCDCultivatedLanda:Withoutconservationtreatment With conservationtreatment7262817188789181Pastureorrangeland: PoorconditionGoodconditionMeadow:goodconditionWoodorForestLand: Thin stan?B poorcover,no mulchGoodcover683930452579615866 55 86747177 70 89 80788377OpenSpaces,Lawns, Parks,GolfCourses,Cemeteries:Goodcondition:grasscoveron 75% ormoreoftheareaFaircondition:grasscoveron50%to75%oftheareaPoorcondition:grasscoveron 50% orlessoftheareaCommercial andBusinessAreas (85% impervious)3949 68 89 61 6979927479 86 94 80 84 89 95PavedParkingLots,Roofs,Drivewayse:9287 86 85 84 98939198 90838180798898 8575 7270 68 817761 57 54 51 98Average % Irnpervious d6538302520IndustrialDistricts (72% impervious)Residentialc :Averagelotsize1/8acreorless1/4acre1/3acre1/2acre1acreStreetsand Roads:Pavedwithcurbsandstormsewerse GravelDirtPavedwithopenditches Newly gradedarea(novegetationestablished}f987672837798 8582898698 898792 919891899394aFar a moredetailed.descriptionofagriculturallandusecurve numbers,refertoTable5-9.bGoodcoverisprotectedfromgrazingandlitterandbrushcoversoil.cCurve numbersarecomputed assumingtherunofffromthehouse and drivewayisdirectedtowardthestreetwithaminimumofroofwaterdirectedtolawns whereadditionalinfiltrationcouldoccur a dTheremainingperviousareas(lawn)areconsideredtobeingoodpastureconditionforthesecurvenumbers.ernsome warmerclimatesofthecountry,acurvenumberof96maybeused.fUsefortemporaryconditionsduringgradingandconstruction a Note:Thesevaluesarefor.AntecedentMoistureConditionII,and I a O.2Sa Reference:USDA,SCS, TR-55(1984).gnR299b/06e

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625-040-205-aPage54of98Table5-9SCSRUNOFFCURVENUMBERSFORAGRICULTURAL LAND USESCover TreatmentHydrologicHydrologicSoilGroupLandUseorPracticeConditionABCDFallowStraightrow 77 869194RowcropsStraightrow Poor7281 8891StraightrowGood67 78 8589Contoured Poor7079 8488ContouredGood65 75 8286andterracedPoor66 748082andterracedGood 62717881SmallgrainStraightrowPoor65 76 8488StraightrowGood6375 8387ConlouredPoor63748285ContouredGood61738184ContouredGood55697883andterracedPoor 61727982andterracedGood5970 7881Closeseeded legumesa StraightrowPoor66 77 8589orrotationmeadowStraightrowGood58728185ContouredPoor64 75 8385andterracedGood 55697883ContouredPoor6373 8083andterracedGood 51677680PastureorrangePoor68 79 8689Fair49697984Good39617480ContouredPoor476781 88ContouredFair25597583ContouredGood6357079MeadowGood30 587178WoodsPoor45 667783Fair36 607379Good2555 7077Farmsteads 59 74 8286Roads(dirtlb b 72 82 8789(hardsurface)7484 9092aClose-drilledorbroadcast.brnc1udingright-of-way.Note:ThesevaluesareforAntecedent MoistureConditionII,andr 0.2S.aReference:USDA,SCS,NEH-4(1972) gnR299b/06f

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625-040-205-aPage55of98Table5-10SCS CLASSIFICATIONOFVEGETATIVECOVERSBYTHEIRHYDROLOGICPROPERTIESVegetativeCoverCroprotationHydrologicConditionPoor:Containsahighproportionofrowcrops,smallgrains,andfallow.Good:Containsahighproportionofalfalfaandgrasses.NativepastureorrangePoor:plantarea.Heavilygrazedorhavingcoveronlessthan50%oftheWoodlandsFair:Moderatelygrazed 1 50-75%plantcover.Good:Lightly grazedl morethan75%plantcover.PermanentMeadow:100%grasscover.Poor:Heavilygrazedorregularlyburnedsothatlitter,smalltrees,andbrusharedestroyed.Fair:Grazedbutnotburned;theremaybe litter.Good:Protectedfromgrazingsothatlitterandshrubscoverthesoil.Reference:USDA,SCS,NEH-4(1972).gnR299b/06g

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Table6.8Curve Numbers for AMC IandAMC III CorrespondingON'sONforAMClI10095908580757065605550 454035 30252015105AMCI1008778706357514540353126221815129642AMCIII1009896949188.8582787470656055504337302213Source: Lindeburg1992

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Table C-1:SCSTypeIIFlorida-modified Rainfall Distributions Time (hrs)C!JmlJlatjveIncremental0.0 0.000 0.5 0.006 0.006 1.0 0.012 0.006 1.5 0.018 0.006 2.0 0.025 0.007 2.5 0.032 0.007 3.0 0.039 0.007 3.5 0.0460.007 4.0 0.054 0.008 4.5 0.062 0.008 5.0 0.071 0.009 5.5 0.080 0.009 6.0 0.089 0.009 6.5 0.099 0.010 7.0 0.110 0.011 7.5 0.1220.012 8.0 0.135 0.013 8.5 0.149 0.014 9.0 0.164 0.015 9.5 0.181 0.017 10.0 0.201 0.020 10.5 0.226 0.025 11.0 0.258 0.032 11.5 0.307 0.049 12.0 0.6060.299 12.5 0.718 0.112 13.0 0.757 0.039 13.5 0.785 0.028 14.0 0.807 0.022 14.5 0.826 0.019 15.0 0.842 0.016 15.5 0.857 0.015 16.0 0.870 0.013 16.5 0.882 0.012 17.0 0.893 0.011 17.5 0.903 0.010 18.0 0.913 0.010 18.5 0.922 0.009 19.0 0.931 0.009 19.5 0.939 0.008 20.0 0.947 0.008 20.5 0.955 0.008 21.0 0.962 0.007 21.5 0.969 0.007 22.0 0.976 0.007 22.5 0.983 0.007 23.0 0.989 0.006 23.5 0.995 0.006 24.0 1.000 0.005 1.000 (Total check)

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APPENDIXELISTOFTHREATENED AND ENDANGERED SPECIESINST.JOHNSCOUNTY

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8t Johns County Occurrence SummaryFlorida Natural Areas InventoryPage1of6Species and Natural Community Summary forStJohns CountyFish Amphibians Reptiles Birds Mammals Invertebrates Plants Natural Communities Other Explanations and Definitions: Global/State Rank. Federal/State Status Occurrence StatusICommon NameIGlobal State Federal State Occurrence Scientific NameRankStatus Status StatusRankIFISHIAcipenser brevirostrumshortnose sturgeon1m IEJILE IAcipenser oxyrinchusI IE:JEJDEJc=J oxyrinchus Agonostomusmountain mullet t=JEJDEJc=J monticolaIAmeiurus brunneusIIsnailbullheadG4 IIAwaous tajasicaIIrivergobyasIISIS211N IMicrophis brachyurusIIopossum pipefish,GS INotropis cummingsaeIIdusky shinerIIGS IEJIN IPetromyzon marinusIIsea lampreylias IEJIN IAMPHIBIANSNotophthalmusIstriped newt IEJEJDEJr=J perstriatusIRanacapitoIIgopher frogIIG4 IlREPTILESIAlligatorAmericanalligator t=JEJIT(S/A)IEJc=J mississippiensisICaretta carettaIIloggerhead11m I

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St JohnsCountyOccurrenceSummaryPage2of6IChelonia mydasIIgreenturtle11m IJILE I IClemmys guttata"spottedturtleIIGS !]INIEJlc 1Crotalus adamanteuseastern LJLJDLJD diamondbackrattlesnakeIDermochelys coriaceaIIleatherback11m !JILE IDrymarchon coraiseasternindigosnake E:JEJEJEJc=J couperiIGopherus polyphemus"gophertortoise11m IJ!N IILepidochelys kempiiIIKemp'sridley11m IEJILE IPituophisFloridapinesnake E:JEJDEJc=J melanoleucus mugitusIBIRDS,IAccipiter cooperii"Cooper'shawkIIG4 !]IN IEJlp I, Aimophila aestivalisIIBachman'ssparrow11m 1JINIEJlp IIAjaia ajajaIIroseatespoonbillIIGSIIS2S311N I IAramus guarauna!!limpkinIIGS IJIN IIArdeaalbaIIgreategretIIGS IEJINIEJlc I ICharadrius melodusIIpipingplover11m IJILTIEJlc IIEgretta caeruleaIIlittleblueheronIIGS IEJIN IIEgretta thulaIIsnowyegretIIGS IEJIN IIEgretta tricolorIItricoloredheronIIGS IEJIN I IElanoides forficatusIIswallow-tailedkiteIIG4IIS2S311N IEJlc IIEudocimus albus"whiteibisIIGS IEJIN I IFalco columbariusIImerlinIIGS !]IN IEJIp ,IFalco peregrinusIIperegrinefalconIIG4 IJILE IFalco sparveriussoutheasternI GST3T4IEJDEJr=J paulusAmericankestrelHaematopus palliatusAmerican r=JEJDEJr=J oystercatcher '1OOQ

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St Johns County Occurrence Summary Page 3of6HaliaeetusIbald eagle leucocephalusIIxobrychus exilis" least bitternIIGS IEJlp IILaterallus jamaicensisIIblackrailIIG4 I@DINIEJlp IIMycteria americanaIIwood stork IIG4 INyctanassa violaceayellow-crowned EJEJDrJr==J night-heronNycticorax nycticoraxblack-crowned EJEJDrJr==J night-heronIPandion haliaetusIIospreyIIGSIIS384IINIILS**IIpIIPelecanus occidentalisIIbrown pelican JIG4 IPicoides borealisred-cockaded EJEJEJEJr==J woodpeckerIPicoides villosusIIhairywoodpeckerIIGS I@DINIEJlp I IP legadis falcinellusglossy ibisIIGS IEJlp IIRynchops nigerblack skimmerIIGS I ISterna antillarumleast tern IIG4 I ISterna caspiaCaspian ternIIGS I@DINIEJlp IISterna maximaIIroyal ternIIGS IEJIC IISterna sandvicensisIIsandwich tern IIG5. IEJlp I!MAMMALSICorynorhinusRafinesque's bigEJEJDrJr==J rafinesquiieared bat IEubalaena glacialisIIblack right whale11m IMustela jrenatasoutheastern weasel EJEJDrJc=J olivacea Mustela vison lutensisAtlantic salt marsh minkNeofiber alleniround-tailed EJEJDrJr==J muskrat httnffwww.fuai.ondSTJO-8UM.HTMOS/24/1999

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StJohnsCountyOccurrenceSummaryPage4of6Peromyscus polionotusAnastasiabeach EJEJEJEJLJ phasmamouseIPodomys floridanusIIFloridamouse11m IEJIN ISciurus niger shermaniSherman'sfox EJEJDEJt==J squirrelSorex longirostrissoutheasternshrew EJEJDrJt==J longirostrisITrichechus manatusIImanatee..'IIG2? IJ!LE IUrsus americanusFloridablackbear EJEJDILT**ILJ floridanusIVASCULARPLANTSIAdiantum tenerumbrittlemaidenhair EJEJDEJr==J fernIAsclepias viridulaIIsouthernmilkweedIIGZ IEJIN IBaptisia calycosavarCanby'swildindigo EJEJDrJLJ calycosaICalamovilja curtissiiIICurtiss'sandgrass11m IEJIN ,ICalydorea coelestinaIIBartram'sixiaIIGZ IEJIN IChamaesycesand-dunespurge EJEJDEJLJ cumulicolaICheiroglossa pa/mataIIhandfernIIG4 IEJIN ICtenium floridanumFloridatoothache EJEJDrJLJ grass, Glandularia maritimaIIcoastalvervain11m IEJ1N IHedyotis nigricansvarnarrow-leaved E:JEJDrJLJ pulvinatabluetsIHelianthus carnosusIIlake-sidesunflowerIIGlG2IISlS211N IILitsea aestivalisIIpondspice11m IEJIN IMonotropsisIpigmy IEJEJDEJLJ reynoldsiaeINemastylis floridanaIIfall-floweringixiaIIGZ IEJIN IINolina atopocarpaIIFloridabeargrass11m IEJIN I '\.-.++...... // ... "...".. fT,<;It HTMOS/24/1999

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StJohnsCounty OccurrenceSummaryPage5of6Pterog!ossaspisIwildcoco IE:JEJDEJLJ ecristata PycnanthemumFlorida mountainEJEJDrJLJ floridanummintRhynchosporapinelandbeakrush EJEJDrJLJ punctataIRudbeckia nitidaIISt.John'sSusanIIGIG2IIS1S211N IRuellia noctiflorawhite-floweredwild E:JEJDEJLJ petuniaISpiranthes polyanthaI green ladies'-tresses IG3G5IIS1S211N IVerbesina heterophyllavariable-leaf EJEJDrJLJ crownbeardINATURAL COMMUNITIESIIBasinSwamp"IIG4? IEJINIEJIC IIBaygallIIG4? I]!NIEJlc I IBeach DuneIIG4? IEJINIEJIC IICoastal Grassland1103 IEJINIEJIC ICoastalInterdunal IEJEJDrJLJ SwaleICoastal Strand II03? IEJINIEJlc IIDepressionMarshIIIIG4? IEJINIEJIC I IDomeSwampIIIIG4? 1@2JINIEJIC II EstuarineTidalMarshII1104 IEJIN.IEJIC I IFloodplainSwamp"1107 I]INIEJlc IIHydricHammockII1107 I]/NIEJlc IIMaritimeHammockIIIIG4 IEJINIEJIC IIMesicFlatwoodsII1107 IEJINIEJlc I ISandhillIIIIG203 IEJINIEJlc IIScrubbyFlatwoodsII1103 IEJINIEJlc IIScrubII1102 IEJINIEJlc Ihttp://www.fnai.orglSTJO-SUM.HTM05124/1999

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St Johns County Occurrence Summary Page6of6IXeric HammockIIIIG? IEJINIEJIC IIOTHERIIBird rookeryIIIIlOIN IEJIC I**See Rank and Status Explanations and Definitions, Special Animal ListingsFederal and State StatusCountyOccurrenceStatusVertebratesandInvertebrates:C=(Confirmed) Occurrence status derived from a documented record in the FNAl data base. P=(potential) Occurrence status derived from a reported occurrence for the county or the occurrence lies within the published rangeofthe taxon. N=(Nesting) For sea turtles only; occurrence status derived from documented nesting occurrences. Plants,NaturalCommunities.andOther:C=(Confirmed) Occurrence status derived from a documented record in the FNAl data base or from a herbarium specimen.R=(Rep orted) Occurrence status derived from published reports. TopofPage County List ..... HomeFlorida Natural Areas Inventory 1018 ThomasvilleRd.,Suite 200-C Tallahassee,FL32303-6374 Phone: 850-224-8207 Fax: 850-681-9364mailto:webmaster@fnai.orgData Current to December1997http://www.fnai.orgfSTJO-SUM.HTM05/2411999

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1.0 INTRODUCTION St.JohnsCounty contracted the teamofJones, Edmunds&Associates, Inc. (JEA),MarkBrown,PhD.(UniversityofFlorida Center for Wetlands and Water Resources), Richard Hamann, Esq., andJeffWade, Esq. (UniversityofFlorida CollegeofLaw) to develop a buffer zone ordinance which will further protect environmentally sensitive land from development activities. St. Johns County is committed to balancing strong development pressures with protection and preservationofunique, imperiled, and vulnerable habitats. The county's adopted 1990 Comprehensive Plan PolicyF.l.3.7 requires vegetative buffersofat least 25 feet tobemaintained between natural drainage courses and developed areas to protect the water qualityofthedrainage course. This buffer requirement hasbeenexpanded through ArticleIVofthe Land Development Code to require a 50-foot minimum natural vegetative upland buffer between development landsandthe St. Johns River, Matanzas River, Guana River, Tolomato River,andtheir associated wetlandsandwater bodies regardlessofany other regulatory agency requirementofa lesser distance. However,inrecent years the county has determinedthat a minimum 25or50foot buffer around wetlandsmaynotbesufficient to protect water quality given the varietyofwetlands and other environmentally sensitive lands. Further, the Comprehensive Plan requires that the county protect environmentally sensitive lands (wetlands adjacent to Outstanding Florida Waters (OFWs), Class II waters, Classillwaters, Aquatic Preserves, estuaries, wetlands adjacent to shellfish harvesting areas, all major rivers, headwaters to major creeks and estuaries) through the establishmentofbuffers. Natural hydroperiodof wethinds and similar areas mustbemaintained according to the type and natureofthe wetlandorwaterbodybeing impacted.1.1PROJECT GOALS Upland vegetated buffers are widely regarded as being necessary to protect wetlands, streams, and other aquatic resources. Buffer size requirements, however, have typically been establishedby political acceptability rather than scientific merit. This often leadstoinsufficiently buffered aquatic resources and the false perception that resources are being properly buffered from potential impacts. Numerous scientific studies have shown that relativelywidebuffers(ISOto over300feet) are necessary to protect wetland resources. In general, wider buffers are needed to protect wetland dependent wildlife, whereas more narrow buffers will adequately protect water qualityandwater quantity.Anexception is for steep slopes where a wider buffer is necessary to counteract potentially high erosive forces. The goalofthisproject is to determine the appropriate buffer width(s) that will protect environmentally sensitive landsinSt. Johns County, basedonresults publishedinthe scientific literature. Three goals have been identified that willbeused to detennine buffer sizes for wetlands: protectionofwater quantity from groundwater drawdown, protectionofwater quality from erosion and sedimentation, and protectionofwildlife habitat through preservationofnative vegetation. Buffers that are undersized may place aquatic resources at risk; however, buffers that are larger than neededmayunnecessarily deny landowners the useofa portionoftheir land. Therefore,itis important tobeable to determine the minimum bufferwidthnecessary for aquatic resource protection.W:\19270\485010600\BackgroundReportFinal.wpdINTRODUCTION

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This background report has assembled information and data on habitat types within the county, existing buffer ordinances from other municipalities, existing buffer ordinances from federal and state regulations, buffer requirements from scientific literature, and a legal reviewofbuffer zones. The information compiled ih this background report has been usedtodevelop a buffer zone ordinance for the county. 1.2 ECOLOGICAL VALUE OF BUFFER ZONES The differences between developed lands and natural ecological areas are significant, and the more intensely developed, the greater the differences. Frequentlyondeveloped lands, native vegetation is removedand replaced with exotic ornamentals, soil drainage is altered, soils become compacted and covered with impervious materials, and ,wildlife species are displaced duetohuman activities. The gradient in intensityofnoise, waste, temperature, light, structure, and activity from undevelopedtodeveloped lands is intense.Inthis edge between development and natural areas, water runsoffdeveloped areas carrying sediments, nutrients, and pollutants. Noise and activities from development intrudes into the edge and interferes with wildlife activities. Wildlife populations also suffer greatly from predationbydomesticated cats and dogs that are allowed to roam unrestrained. Wildlife populations also suffer from predation from animals such as the brown-headed cowbird that flourishes in disturbed habitats and preys on smaller and more vulnerable birds such as the painted bunting, a prized residentofS1.Johns County and a speciesofgreat concern to the Audubon Society and wildlife biologists. The area inunediately adjacenttowetlands is often a transition zone between wetlands and uplands. It is a zone that exhibits vegetation, soils, and hydrologic characteristics that are similar and intermediate between wetlands and uplands. To protect the values and functionsofwetlands, protection mustbeafforded to the transition zone and adjacent upland. Disturbance and alterationofthe transition zone and adjacent uplands result in eliminationofwildlife species that utilize both uplands and wetlands, a loss in plant species diversity, and alteration in hydrologic patterns within both the uplands and wetlands.Ithas long been regarded that the1Jighest plantspecies diversity occurs in transition zones between wetlands and uplands. StudiesofFlorida landscapes indicate that plant species diversity is higher intransition zones than either the adjacent wetland or upland (Clewell et al. 1982, Gross 1987, Hart 1984). Likewise, wildlife species richness also shows direct spatial relationships to the increased diversityofthe transition zone. Vickers et al. (1984) found that species richnessand abundanceofherpetofauna were greater along the edgeofsix wetlands in north central Florida than in either the wetland or upland habitat. Harris and Vickers (1984) found that virtually all manunals, becauseoftheir cursorial mode oflocomotion and frequent herbivorous food habits, reside in transition zones. Presumably, these species utilize both uplands and wetlands in their life cycles. When water levels rise in wetlands, wildlife movementtoperipheral areas also increases, suggesting the importanceoftransition zones in providing refuge for wildlife. The water quality benefitsofbuffer zones are related to the abilityofthezone to abate destructive water velocities and quantitiesofpollutants carried by surface runoff from uplands into the wetland. Pollutants adhere to sediments and enable sediments to provide a vehiclebywhich pollutants are transported. Thus, every effort should be made to maintain a vegetative buffer between wetlandsW:\l9270\4gS010600\BackgroundReportFina1.wpdrNTRODUCTION

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Florida Natural Areas InventoryMay1997RANK EXPLANATIONSforFNAIGlobalRank,FNAIStateRank,FederalStatus,andStateStatusThe NatureConaervlncyandthe Natural HcritaicProa'ramNetwork (ofwbichFNAIi.a part) defino an .. aayexemplary or rarecomponent ofthe natura.l environment, IUch ... 'Pecie.,natural community, bird rookec:y,'Pring,sinkhole, cave,or other ecological(eabJrc. Anelement OCCUrrence (EO)isingle extanthabitatthatIUstaiQ.l or otherwise contributestothe IlUrvivd ofa population or a distinct,IClf-suwioil1l example of. particular ctcmeol.Using. ranking.yJteatdeveloped byThe Nature Coascrvancyandtho Natural Heritage Program Nctwork:,'thc Florida NaturalArea.Inventoryauigw:twon.nb to each element. The a10balrank i.bued on anclement'. worldwide atatul; the staterank i. baled onthe atul oCtheclement in Florida. Elementranbarebased 00 manyfacton.theIll.Ctimportantbeingeatimatednumber of Flomentoccurrence"cltimatedabundance (numberof individuall for lpCCiea;area for natural COmmunitiCI), tanaC,cltimatc.d adequatelyprotected BOa,. relalivethreat of destruction, and ecologicalfragility.FederaJandStAte.tatu,information isfromtheU.S. F"Phand W .... ldlife Service; andtheFlorida GamoaDdFreshwater Fish CommiAion(anlma1B), andtheFloridaDepartmentofAgriculture andConsumerService.(plantl),respectively. not yet ranked (temporary) Either very rare and local throughout its range(21-100occurrencesor less than10,000individuals)orfound locallyina rest.ricted rangeorvulnerabletoextinctionofother factors.apparently secure globally (mayberare in partsofrange) demonstrably secure globallyofhistorical occurrence throughoutits range, mayberediscovered(e.g., ivory-billed woodpecker) believedtobeextinct throughout range extirpated from thewildbutstillknownfromcaptivityorcultivationtentative rank (e.g.,G21)rangeofrank;insufficient data toassign specific globalrank(e.g.,G2G3) rank of a taxonomic subgroup such as a subspecies orvariety;theGportionoftherank refers to the entire species and theTportion referstothe specific subgroup; numbers have same definition as above(e.g.,G3Tl)rankofquestionable species ranked as species but questionable whether it is speciesor subspecies; numbers have same dermition as above(e.g.,G2Q) sameas above,butvalidity assubspecies -orvarietyisquestioned . duetolackofinfonnation. norankorrangecanbeassigned(e.g.,Gun).FNATGI.OBALRANKDEFINITIONS Critically imperiled globally becaUle of extreme rarity (5orfewer oceurrences orless than1000individuals)or because of extreme vulnerabilityto extinction dueto &Orne naturalor man-made factor.Imperiled globally becauseofrarity (6to20 occurrences orless than3000individuals)or because ofvulnerabilitytoextinctionduetosomenaturalorman-made factor.G1=G2=G3 G4 G5=GH GXGXC GN?GNGNGNUGNQG#T#Q =GUG?FNAISfATERANKDEFINITIONSS151S3 S455Critically imperiledinFloridabecauseof extremerarity (5or fewer occurrences orless than 1000 individuals) or because of extreme vulnerabilitytoextinction duetosomenaturalor factor. Imperiled inFlorida because ofrarity(6to20 occurrences or less than3000individuals) or because ofvulnerabilitytoextinction duetosomenaturalorman-made faCtor. Either very rare and local throughoutitsrange (21-100 occurrences orless than10,000individuals) or found lo<:ally ina restrieted rangeor vulnerable to extinction ofother appazently secure in Florida (mayberareinpartsofrange) demonstrably secureinFlorida FNAISTATERANKDEFINITIONS(CODt,)SHofhiJtorica1 occurrence throughout ill range, mayberediscovered(e.g.,ivory-billed woodpecker)

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sxSASESNSUS?N= ===believed tobeextinct throughout range accidental inFlorida, Le .notpartofthe established biotaan exotic species established in Floridamay be nativeelsewhereinNorthAmencaregularly occurring, hutwidely and unrelia.bly distributed; sites for conservation hard todetennincdueto lackofinfonnation, no rank orrange can be assigned (e.g., SUT2). notyetranked(temporary)LEGALSTATUS Not currently listed,norcurrentlybeingconsidered for listing, bystateorfederal agencies. FEDERAL(Listedbythe U.S.Fish and Wddlife Service USFWS)PTC=E(S/A)=T(S/A)LEPELT= = Li&tedas Endangered Species in the ListofEndangered and Threatened Wddlife and Plants under the provisionsofthe Endangered Species Act. Dermed u any species which is indangerofextinction throughoutaUora significant portionof its range.Proposed for addition totheListofEndangered and Threatened Wddlife and Plants as Endangered Species. Listed as Threatened Species. Deftned as any species which is likelytobecome an endangered specieswithinthe foreseeable future throughout allora significant portionofitsrange. Proposed for listing as Threatened Species. CandidateSpeciesfor additiontothe listof Endangered and Threatened Wildlife and Plants. Defined as those species for whichtheUSFWScurrently bas onfilesufficient information on biological vulnerability and threats to support proposing to listthespecies as endangeredor threatened. Endangereddueto similarityofappearance.Threateneddueto similarityof appearance.SLUEAnimals (ListedbytheFloridaGameandFresh WarerFish CommissionFGFWFC)LELTLS= =ListedasEndangered Species by the FGFWFC.Defined as a species, subspecies,orisolated population which is sorareordepletedinnumberorso restricted inrangeofhabitatduetoanyman-madeornatural factorsthatit isinimmediatedangerofextinctionorextirpation fromthestate,orwhichmayattain such a statuswithintheimmediatefuture. ListedasThreatenedSpeciesbythe FGPNFC. Defmedas a species, subspecies,orisolated population whichisacutelyvulnerableto environmental alteration, declining innumberata rapid rate, orwhoserangeorhabitatis decreasing in area. ata rapidrateandasa consequence is destinedorverylikely to become an endangered species withintheforeseeable future. ListedasSpeciesofSpecial Concern by.theFGFWFC.Defmed as a popUlation whichwarrantsspecial protection, recognition,orconsideration because it has an inherent significant vulnerability to habitat modification, environmental alteration,humandisturbance,or substantial human cxploitationwhich,intheforeseeablefuturc, mayresultin itsbecoming a threatened species. Plants(Listed by the Florida DepartmentofAgriculture and Consumer Services FDACS)LELT= =Listed as EndangeredPlantsinthe PreservationofNative FloraofFlorida Act. Defmedasspeciesofplants native tothestatethatarein imminent dangerofextinction withinthe state, thesurvivalofwhich is unlikelyifthe causesofa declineinthenumberofplants continue, andincludesall species determinedtobeendangeredorthreatenedpursuanttotheFederalEndangered Species Actof1973,asamended. ListedasThrea:tened Plants inthc PRscrvation ofNative Floraof Florida. Act. Defmed as species native to the state thatarein rapiddeclineinthcnumberofplants withinthe state, butwhich have not so decreasedinsuchnumber as tocausethem to be endangered. '

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.VN.. 1FNAI );\ I '::) I .'1 ,..'.FloridaNatural Areas InventoryIV!O Tallahassee,FL32303 (850) 224ElementOcurrences:LEGEND cr> Stale Usted Only .. ,\\ '.\ \. \ \\\.,,,,"i,, ., \,\'\ \1 ,!\\ \., "\," ePrincipalhighways Secondary highwayx Local roadsC) FederallylistedSpecies (may also ba slata listed) NPrepared byJ.Oetting21May 1999 Data Source: FNAI 2/99 /0\.....<..... \ '-;::Ji:@\84;\\ I /. I -./I \,' ".J.---' 1.--_-/41'J<6 5 0510 !5 2025303540 45 50Miles

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APPENDIXFSTORMWATERGUIDELINES

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40C42.026Specific DesignandPerfonnanceCriteria.(1)Retention systems shall:(a)Provide for oneofthe following:1.Off-line retentionofthe first one half inchofrunoff or1.25inchesofrunoff from the impervious area, whicheverisgreater;2.On-line retention of an additional one half inchofrunoff from the drainage area over that volume specified in subparagraph1.,above;3.On-line retention that provides for percolationofthe runoff from the three year,one-hour storm; or11

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4.On-line retention of the runoff from one inchofrainfallor1.25 inches of nrnoff from the imperviousarea,whicheverisgreater, for systems which serveanarea with less than40percent impervious surface and that contain only U.S. Department of Agriculture Soil Conservation Service (SCS) hydrologic group "A" soils.(b)Provide retention in accordance with oneofthefolloWingfor those systems which have direct dischargetoClassr.Class II, Outstanding Florida Waters, or Class III waters which are approved, conditionally approved, restricted, or conditionally restricted for shellfIsh harvesting:1.At least an additional fIfty percentofthe applicable treatment volume specified in subparagraph1.,above. Off-line retention mustbeprovided foratleast the first one half inch of runoff or 1.25 inchesofrunoff from the impervious area, whicheverisgreater,ofthe total amountofrunoff requiredtobe treated;2.On-line retentionofan additional fifty percentofthe treatment volume specifIed in subparagraph2.,above;3.On-line retention that provides percolationofthe runoff from the three-year,one-hour storm; or4.On-line retention that provides at least an additional50percentofthe runoff volume specified in subparagraph 40C-42.026(1)(a)4., above, for systems which serve an area with less that40percent impervious surface and that contain onlyU.S.DepartmentofAgriculture Soil Conservation Service(SCS)hydrologic group "A" soils.(c)Provide the capacity for the appropriate treatment volume of stormwater specifiedinparagraphs(a)or(b)above, within72hoursfolloWingthe storm event assuming average antecedent moisture conditions. The storage volume mustbeprovided by a decrease of stored water caused only by percolation through soil, evaporation or evapotranspiration.(d)Be stabilized with pervious material or permanent vegetative cover. Permanent vegetative cover mustbeutilized, except for pervious pavement systems, when U.S. DepartmentofAgriculture Soil Conservation Service(SCS)hydrologic group "A" soils underlie the retention basin.(2)Underdrain stormwater management systems shall:(a)Provide for eitherofthefollOWing:1.Off-line storageofthe fIrst one half inchofnrnoff or 1.25 inchesofrunoff from the impervious area, whichever is greater; or2.On-line storage of an additional one half inch of runoff from the drainage area over that volume specilled in subparagraph 1., above.(b)Provide either of the following for those underdrain systems which have direct dischargetoClassr.Class II, Outstanding Florida Waters, or Class III waters which are approved, restricted, or conditionally restricted for shellfIsh harvesting:1.At least an additional fIfty percentofthe applicable treatment volume specified in subparagraph1.,above. Off-line storage must beproVidedfor at least the fIrst one half inch of runoff or 1.25 inches of nrnoff from the impervious area, whicheverisgreater,ofthe total amountofrunoff required to be treated; or2.On-line storageofthe runoff from a three-year,one-hour storm or an additional fIfty percentofthe treatment volume specilled in subparagraph2.,above, whicheverisgreater.(c)Provide the capacity for the appropriate treatment volumeofstormwater specifiedinparagraphs(a)or(b),above, within Tl hours following a storm event. The storage volume mustbe12

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provided by a decreaseofstored water caused only by percolation through soil with subsequent transport through the underdrain pipes, evaporation or evapotranspiration.(d)Provide at least two feetofindigenous soil between the bottomofthe stormwater holding area and the underdrain pipe(s).(e)Be designed with a safety factor of at least two unless the applicant affrrmatively demonstrates based on plans, test results, calculations or other information that a lower safety factor is appropriate for the specific site conditions. Examples of howtoapply this factor include but are not limitedtoreducing the design percolation rate by halfordesigning for the required drawdown within36hours insteadof72 hours.(f)Contain areasofstanding water onlyfollOWinga rainfall event.(g)Be stabilized with permanent vegetative cover.(h)Include, at a minimum, a capped and sealed inspection and cleanout ports which extendtothe surfaceofthe groundatthe following locations of each drainage pipe:1.The terminus; and2.Every 400 feet or every bendof45or more degrees, whichever is less.(i)Utilize filter fabric or other means used to prevent the soil from moving and being washed out through the underdrain pipe.(3)Underground exfI1tration trench systems shall: .(a)Provide for eitherofthefollOWing:1.Offline storageofthe first one half inch of runoff or 1.25 inchesofrunoff from the impervious area, whichever is greater; or2..On-line storageofan additionalonehalf inchofrunoff from the drainage area over that volume specified in subparagraph1.,above.(b)Provide either of thefollOWingforthose exfiltration trench systems which have direct dischargetoClass 1, ClassII,Outstanding Florida Waters, or Class III waters which are approved, conditionally approved, restricted, conditionally restricted for shellfish harvesting:1.Atleast an additional fifty percentofthe applicable treatment volume specified in subparagraph 1., above.Off-line storage mustbeprovided for at least the frrst one half inchofrunoff or 1.25 inchesofrunoff from the impervious area, whicheverisgreater,ofthe total amountofrunoff requiredtobe treated; or2.On-line storageofthe runoff from thethree-year,one-hour storm oranadditional fifty percentofthe treatment volume specifiedinsubparagraph 2., above, whicheverisgreater.(c)Provide the capacity for the appropriate treatment volumeofstormwater specifiedinparagraphs(a)or(b),above, within72hours following a storm event assuming average antecedent moisture conditions. The storage volume mustbeprovided by a decreaseofstored water caused only by percolation into the soil.(d)Be designed with a safety factor of at least two unless the applicant affrrmatively demonstrates based on plans, test results, calculations or other information that a lower safety factor is appropriate for the specific site conditions. Examples of howtoapply this factor include but are not limitedtoreducing the design percolation rate by half or designing for the required drawdown within36hours insteadof72hours.(e)Be designed With a twelve(12)inch minimum pipe diameter.(f)Be designed with a three(3)foot minimum trench width.(g)Be designed so that aggregate inthetrenchisenclosed in fIlter fabric.13

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(h)Provide cleanout and inspection structures which extendtothe surfaceofthe ground at the inlet and terminusofeach pipe. Inlet structures should include sediment sumps.(i)Be designedsothat the invert elevationofthe trench mustbeatleast two feet above the seasonal high ground water table elevation unless the applicant demonstrates based on plans, test results, calculations or other information that a alternative designisappropriate for the specific sit conditions. G) Be designed so that the system must have the capacitytoretain the required treatment volume without considering dischargestoground or surface waters.(4)Wet detention stormwater management systems shall:(a)Provide a treatment volumeofthe greaterofthe following:1.First one inchofrunoff; or2.2.5inchesofrunofffrom the impervious area.(b)Be designed so that the outfall structures shall bleed down one-half the volumeofstormwater specified in paragraph(a),above, within48to60 hours following a storm event, but no more than onehalfofthis volume willbedischarged within the first 48 hours.(c)Contain a permanent poolofwater sizedtoprovideanaverage residence timeofatleast14days during the wet season(JuneOctober).(d)1.Provide a littoral zonetobe designed as follows:a.The littoral zone shallbegently sloped(6:1or flatter). At least30percent of the wet detention system surface area shall consistofa littoral zone. The percentage of littoral zoneisbased on the ratioofvegetated littoral zonetosurface areaofthe pondatthe control elevation . b.The treatment volume should not cause the pond leveltorise more than18inches above the control elevation unless the applicant affirmatively demonstrates that the littoral zone vegetationcansurvive at greater depths.c.Eighty percent coverage of the littoral zone by suitable aquatic plantsisrequired within the first twentyfour monthsofcompletionofthe system orasspecifiedbypermit conditions.d.To meet the 80% coverage requirement, planting of the littoral zone isrecommended.Asanalternative, portionsofthe littoral zone maybeestablished by placementofwetlandtopsoils (at least a four inch depth) containing a seed sourceofdesirable native plants. When utilizing this alternative, the littoral zone mustbestabilized by mulching or other means and at least the portionofthe littoral zone within25feetoftheinlet and outlet structures must be planted.2.In lieuofthe requirements of subparagraph 1.,above, the applicant may provide either ofthefollOWing:a.At least fifty percent additional permanent pool volume over that specified in paragraph(c),above;orb.Treatmentofthe stormwater pursuanttosubparagraphs40C-42.024(2) (b)2., 3., 4., or 6., F.A.C., prior to the stormwater entering the wet detention pond.(e)Be designed so thatthemean depthofthe permanent poolisbetween 2 and 8 feet andthemaximum depth does not exceed12feet below the invertofthe bleed down device, unless the applicant affirmatively demonstrates that alternative depths willnotinhibit the physical, chemical, and biological treatment processes or cause the resuspensionofpollutants into the water columnduetoanaerobic conditions in the water column.14

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(f)Be designedsothe flow path throughthepond has an average lengthtowidth ratioofat least Z:I.Thealignment and locationofinlets and outlets should be desigoedtomaximize flow pathsinthe pond.Ifshort flow paths are unavoidable, the effective flow path shouldbeincreased by adding diversion barriers suchasislands, peninsulas,orbafflestothe pond. Inlet structures shallbedesignedtodissipate the energyofwater entering the pond.(g)Be designed so that bleed down devices incorporating dimensions smaller than three inches minimum width or less thanZOdegrees fornvunotches shall include a devicetoeliminate clogging. Examples include baffles, grates, and pipe elbows.(h)Be designedsothat bleed down structure invert elevations are at or above the estimatedpost-development normal ground water table elevation.Ifthe structureisproposedtobeset below this elevation, ground water inflow mustbeconsidered in the drawdown calculations, calculationofaverage residence time, estimated normal water level in the pond, and pollution removal efficiencyofthe system.(i)Provide. for permanent maintenance easements or other acceptable legal instruments to allow for accesstoand maintenanceofthe system, including the pond, littoral zone, inlets, and outlets. The easement or other acceptable instrument must cover the entire littoral zone. 0) Be designedsothat the average pond side slope measured between the control elevation and two feet below the control elevation is no steeper than3:1(horizontal:vertical).(k)Wet detention systems which have direct dischargetoClass I, ClassIIOutstanding Florida Waters, or Class III waters which are approved, conditionally approved, restricted, or conditionally restricted for shellfish harvesting shall provide eitherofthefollOWingin additiontothe requirementsinparagraphs(b),(d),and(e)0), above:1.Anadditional fifty percentofthe applicable treatment volume specified in paragraph(a),above, and an additional fifty percentofthe applicable permanent pool volumes specified in paragraphs(c)or subparagraph(d)Z.,above; orZ.Treatment pursuanttosubsections(1),(Z),(3)above, or(5)below, priortodischarging into a wet detention pond designed pursuant to paragraphs (a)-0),above.(5)Swale systems shall:(a)Percolate 80%ofthe runoff from the three year,one-hour storm.(b)Percolate the runoff from the three-year, one-hour storm for those swale systems which have direct dischargetoClassI,Class II, Outstanding Florida Waters, or Class III waters which are approved, conditionally approved, restricted, or conditionally restricted for shellfish harvesting.(c)Provide the capacity for the given volumeofstormwater pursuanttoparagraphs(a)or(b),above, and contain no contiguous areas of standing orflOWingwater within 72 hours following the storm event referenced in paragraphs(a)aod(b), above, assuming average antecedent moisture conditions. The storage volume mustbeproVidedby a decreaseofstored water caused only by percolation through soil, evaporation or evapotraospiration.(d)Meet the criteria in subsection 40C-4Z.0Z1(Z9), F.A.C.(6)Drydetention systems shall:(a)Provideoff-line detentionofthe first one inchofrunofforZ.5inchesofrunoff from the impervious area, whicheverisgreater.15


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