TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

Appendix B-17: FDEP’s Stream Benchmark Summaries 

(Appendix 7-A from USEPA. 2009. Proposed Methods and Approaches for Developing Numeric 

Nutrient Criteria for Florida’s Inland Waters. United States Environmental Protection Agency, 

Office of Water, Office of Science and Technology, Health and Ecological Criteria Division, 

Washington, DC.) 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-1 

BONE VALLEY NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Deer Prairie Creek 

 STORET Station 27051558216422 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.57, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of agriculture and residential land use observed beyond an extensive forested riparian buffer zone. The 

majority of the watershed lies within conservation lands. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Deer Prairie Creek (Station 27051558216422) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Deer Prairie Creek (Station 27051558216422) showing close-up of sampling site. 

Photograph of Deer Prairie Creek 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-2 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 117 

Hydrologic Score 2 

LDI Score 1.57 

SCI Score 74 A 

Total Phosphorus Geometric Mean (mg/L) 0.285 

Total Nitrogen Geometric Mean (mg/L) 1.14 

The habitat assessment scored in the high end of the “Suboptimal” range due to the low water levels. The Stream 

Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive 

invertebrates, fully supporting the Class III designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 89.00 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 10.67 

Number of Taxa 51 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 51 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Deer Prairie Creek. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-3 

BONE VALLEY NUTRIENT REGION

Nutrient Benchmark Site Summary 

East Fork Manatee River 

 STORET Station 273116508208152 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 2.22, suggesting relatively benign human influences in the watershed. During the site visit, aerial 

photographs were examined and direct observations confirmed that the majority of the watershed land use was 

forest/natural, with field/pasture located beyond a riparian buffer zone. Although there is phosphate mining in the 

area, no phosphate process water is discharged to the East fork of the Manatee River. The site is located within 

protected conservation lands. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of East Fork Manatee River (Station 273116508208152) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of East Fork Manatee River (Station 273116508208152) showing close-up of 

sampling site. 

Photograph of East Fork Manatee River 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-4 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 128 

Hydrologic Score 2 

LDI Score 2.22 

SCI Score 71 A 

Total Phosphorus Geometric Mean (mg/L) 0.417 

Total Nitrogen Geometric Mean (mg/L) 1.04 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Exceptional” 

category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III 

designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 76.00 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 23.67 

Number of Taxa 57 

Of the 57 algal taxa observed, the majority of the periphyton community was composed of diatoms. Algal growth 

was very sparse throughout the stream, and no nuisance algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at East Fork Manatee River. Based on our analyses, 

the Department concluded that the site was influenced only by low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-5 

BONE VALLEY NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Manatee River @ SR 64 

 STORET Station 24010002 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.46, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

some field/pasture beyond an extensive riparian buffer zone. There are no point source discharges upstream of the 

site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Manatee River at SR 64 (Station 24010002) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Manatee River at SR 64 (Station 24010002) showing close-up of sampling site. 

Photograph of Manatee River at SR 64 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-6 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 109 

Hydrologic Score 2 

LDI Score 1.46 

SCI Score 64 A 

Total Phosphorus Geometric Mean (mg/L) 0.560 

Total Nitrogen Geometric Mean (mg/L) 0.67 

The habitat assessment scored in the “Suboptimal” range, mostly due to limited in-stream substrate diversity and 

availability. Despite this, the Stream Condition Index scored in the “Healthy” category, indicating a diverse 

assemblage of sensitive invertebrates, fully supporting the Class III designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 90.00 

% Chlorophycota 0 

% Cryptophycophyta 0 

% Cyanophycota 9.33 

Number of Taxa 34 

Of the 34 algal taxa observed, the majority of the periphyton community was composed of diatoms. This site has 

been a DEP reference stream for 17 years, and local DEP biologists have sampled this site many times during that 

period. However, during the December, 17, 2008 sampling event, a significant amount of filamentous algal growth 

was observed. Peggy Morgan (personal communication) stated that while these types of blooms are common in 

the region during low water events, algal growth is routinely sparse at this location. There have been no additional 

adverse human activities or changes in watershed land use during the past 17 year period, therefore it is likely that 

this type of algal growth is an infrequent natural condition, and that the magnitude, frequency and duration of the 

growth events are limited, as evidenced by the healthy invertebrate community. Ms. Morgan returned to this area 

of the Manatee River on March 2, 2009, and reported that the algae observed in December was significantly 

reduced, and that algal coverage had returned to typical (low coverage) levels. This suggests that even in 

minimally disturbed streams with naturally elevated phosphorus levels, sporadic algal growth occurs, however the 

magnitude, frequency and duration of the growth events are limited. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Manatee River at SR 64. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally 

disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-7 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Alapaha River @ CR 150 

 STORET Station 21010008 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.81, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the watershed land use was predominately forest/natural, with some agricultural activities occurring beyond an 

extensive riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Alapaha River (Station 21020008) showing watershed vicinity and land use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Alapaha River at CR 150 showing close-up of sampling site 

Photograph of the Alapaha River at CR 150 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-8 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 138 

Hydrologic Score 1 

LDI Score 1.81 

SCI Score 59 A 

Total Phosphorus Geometric Mean (mg/L) 0.309 

Total Nitrogen Geometric Mean (mg/L) 2.07 

The Habitat Assessment score was in the “Optimal” range. The SCI scored in the “Healthy” range, indicating a 

diverse community of aquatic invertebrates, and demonstrating that this stream is meeting its Class III designated 

use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 83.44 

% Chlorophycota 2.92 

% Cryptophycophyta 0 

% Cyanophycota 13.31 

Number of Taxa 62 

Minimal to moderate periphyton growth was observed at this site, and there were no nuisance filamentous algae. Of 

the 62 algal taxa observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and macroinvertebrate and algal communities) at the Alapaha River at CR 150. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-9 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Suwannee River @ White Springs, FL (US 41) 

 STORET Station 21010040 / SUW040C1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.27, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with silviculture beyond an extensive forested riparian buffer zone. The 

majority of the water emanates from the Okeefenokee National Wildlife Refuge. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Suwannee River @ US 41 showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Suwannee River @ US 41 showing close-up of sampling site. 

Photograph of the Suwannee River at US Hwy 41
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-10 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 145 

Hydrologic Score 2 

LDI Score 1.27 

SCI Score 69 A 

Total Phosphorus Geometric Mean (mg/L) 0.154 

Total Nitrogen Geometric Mean (mg/L) 1.24 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting a diverse assemblage of sensitive aquatic invertebrates and indicating the site is definitively meeting the 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 54.43 

% Chlorophycota 8.20 

% Cryptophycophyta 0 

% Cyanophycota 37.38 

Number of Taxa 66 

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 66 algal taxa 

observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Suwannee River at US Highway 41. Based on 

our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully 

supportive of the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-11 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Deep Creek @ US 441 

 STORET Station DEP010C1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.34, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some minimal silviculture. There are no point 

source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Deep Creek @ US 441 (Station DEP010C1) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Deep Creek @ US 441 (Station DEP010C1) showing close-up of sampling site. 

Photograph of Deep Creek @ US 441 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-12 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 97 

Hydrologic Score 3 

LDI Score 1.34 

SCI Score 80 A 

Total Phosphorus Geometric Mean (mg/L) 0.112 

Total Nitrogen Geometric Mean (mg/L) 1.04 

The Habitat Assessment score was in the “Suboptimal” range, predominantly due to low water velocity (drought 

conditions) and the presence of naturally eroding sandy banks. The SCI score was in the “Exceptional” category, 

exhibiting an unusually diverse assemblage of sensitive invertebrates and indicating the site is definitely meeting its 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 93.33 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 6.33 

Number of Taxa 58 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 58 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Deep Creek @ US 441. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-13 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Falling Creek @ C-131 

 STORET Station FAL020C1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.36, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and field/pasture located 

beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Falling Creek @ C-131 (Station FAL020C1) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Falling Creek @ C-131 (Station FAL020C1) showing close-up of sampling site. 

Photograph of Falling Creek @ C-131 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-14 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 142 

Hydrologic Score 3 

LDI Score 1.36 

SCI Score 55 A 

Total Phosphorus Geometric Mean (mg/L) 0.236 

Total Nitrogen Geometric Mean (mg/L) 1.22 

The Habitat Assessment score was in the “Optimal” range with 142 points. The SCI score (55) was in the 

“Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting its 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 98.33 

% Chlorophycota 1.33 

% Cryptophycophyta 0 

% Cyanophycota 0.33 

Number of Taxa 48 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 48 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Falling Creek @ C-131. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-15 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Little Creek @ US 441 

 STORET Station 21010033 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little Creek @ US 441 (Station 21010033) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little Creek @ US 441 (Station 21010033) showing close-up of sampling site. 

Photograph of Little Creek @ US 441
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-16 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 127 

Hydrologic Score 1 

LDI Score 1.18 

SCI Score 89 A 

Total Phosphorus Geometric Mean (mg/L) 0.373 

Total Nitrogen Geometric Mean (mg/L) 0.72 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

indicating an exceedingly diverse assemblage of sensitive macroinvertebrates, and demonstrating that the site is 

clearly meeting its designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 89.00 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 10.67 

Number of Taxa 53 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 53 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and macroinvertebrate and algal communities) at Little Creek @ US 441. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-17 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

New River @ SR 18 

 STORET Station 21030049 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.28, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and pasture located beyond a 

forested buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of New River @ SR 18 (Station 21030049) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of New River @ SR 18 (Station 21030049) showing close-up of sampling site. 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-18 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 130 

Hydrologic Score 2 

LDI Score 1.28 

SCI Score 76 

Total Phosphorus Geometric Mean (mg/L) 0.229 

Total Nitrogen Geometric Mean (mg/L) 1.04 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

indicating an unusually diverse community of macroinvertebrates, and demonstrating that the water body is 

definitively meeting its designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 75.62 

% Chlorophycota 0.50 

% Cryptophycophyta 0 

% Cyanophycota 23.88 

Number of Taxa 72 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 72 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at New River @ SR 18. Based on our analyses, the Department concluded 

that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy 

biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, 

they are associated with biota which demonstrate full support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-19 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Olustee Creek @ SR 100 

 STORET Station UNI234LV 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.32, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and pasture located well 

beyond a forested buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Olustee Creek @ SR 100 (Station UNI234LV) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Olustee Creek @ SR 100 (Station UNI234LV) showing close-up of sampling 

site. 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-20 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 118 

Hydrologic Score 2 

LDI Score 1.32 

SCI Score 44 A 

Total Phosphorus Geometric Mean (mg/L) 0.119 

Total Nitrogen Geometric Mean (mg/L) 2.05 

The Habitat Assessment score was in the high end of the “Suboptimal” range, predominantly due to low water 

velocity. The SCI score was in the “Healthy” category, indicating a diverse community of sensitive invertebrates, 

and demonstrating that the water body is meeting its designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 95.77 

% Chlorophycota 2.82 

% Cryptophycophyta 0 

% Cyanophycota 1.41 

Number of Taxa 57 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 57 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and macroinvertebrate and algal communities) at Olustee Creek @ SR 100. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-21 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Sampson River @ SW 106 Ave 

 STORET Station 3598-B 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.68, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silvicultural activities and pasture beyond a 

forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Sampson River @ SW 106 Ave (Station 3598-B) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Sampson River @ SW 106 Ave (Station 3598-B) showing close-up of sampling 

site. 

Photograph of Sampson River @ SW 106 Ave 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-22 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 131 

Hydrologic Score 4 

LDI Score 1.68 

SCI Score 65 A 

Total Phosphorus Geometric Mean (mg/L) 0.342 

Total Nitrogen Geometric Mean (mg/L) 0.68 

The Habitat Assessment score was in the “Optimal” range. The hydrologic score was somewhat elevated due to 

presence of a control structure at outlet of Lake Sampson, however, local residents indicated that this structure had 

not been operational for at least 6 months, meaning the contemporaneous biological community had recovered from 

any potential hydrologic modification. The SCI score was in the “Healthy” category, exhibiting a diverse 

assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 58.33 

% Chlorophycota 1.33 

% Cryptophycophyta 0 

% Cyanophycota 40.33 

Number of Taxa 63 

Minimal periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 63 algal taxa observed, the majority of the periphyton community was 

composed of diatoms, with a large proportion of blue-green algae. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Sampson River @ SW 106 Ave. Based on our 

analyses, the Department concluded that the site was influenced only by low levels of anthropogenic stressors and 

that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective 

of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most 

sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-23 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Santa Fe River @ Worthington Springs 

 STORET Station SFR030C1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.88, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silvicultural activities and pasture beyond 

an extensive forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Santa Fe River @ Worthington Springs (Station SFR030C1) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Santa Fe River @ Worthington Springs (Station SFR030C1) showing close-up of 

sampling site. 

Photograph of Santa Fe River @ Worthington Springs 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-24 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 132 

Hydrologic Score 2 

LDI Score 1.88 

SCI Score 64 A 

Total Phosphorus Geometric Mean (mg/L) 0.235 

Total Nitrogen Geometric Mean (mg/L) 1.15 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Healthy” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated 

use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 61.33 

% Chlorophycota 3.00 

% Euglenophycota 0.33 

% Cyanophycota 35.33 

Number of Taxa 64 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 64 algal taxa observed, the majority of the periphyton community was 

composed of diatoms, with a large proportion of blue-green algae. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Santa Fe River @ Worthington Springs. Based on 

our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full 

support of the most sensitive designated use (propagation and maintenance of a healthy, well-balanced population 

of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-25 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Suwannee River @ CR 6 

 STORET Station 3535 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.22, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with some silvicultural activities and pasture beyond an extensive forested 

riparian buffer zone. The vast majority of the basin lies within the Okeefenokee National Wildlife Refuge, an area 

of pristine water quality conditions. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Suwannee River @CR 6 (Station 3535) showing watershed vicinity and land 

use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Suwannee River @ CR 6 (Station 3535) showing close-up of sampling site 

Photograph of the Suwannee River @ CR 6
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-26 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 115 

Hydrologic Score 1 

LDI Score 1.22 

SCI Score 52 A 

Total Phosphorus Geometric Mean (mg/L) 0.078 

Total Nitrogen Geometric Mean (mg/L) 1.34 

The Habitat Assessment score was in high end of the “Suboptimal” range. The SCI was not conducted due to a 

limited amount of habitat in very shallow water. Water levels had recently increased, and the habitat was not 

inundated for a sufficient period to comply with the Standard Operating Procedure. However, this site was sampled 

for SCI on 10/10/2006 and 12/12/2007 and received a 53 and 51, respectively, both in the “Healthy” SCI category. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 91.48 

% Chlorophycota 6.89 

% Cryptophycophyta 0 

% Cyanophycota 1.64 

Number of Taxa 45 

Extensive periphyton growth was observed at this site, which is thought to be a natural phenomenon associated 

with the limerock substrate and very low water conditions. Of the 45 algal taxa observed, the majority of the 

periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at the Suwannee River at CR 6. Based on our analyses, the Department 

concluded that the site was influenced only by very low levels of anthropogenic stressors and that the algal growth 

observed was a natural phenomenon. Thus, not only are the nutrient concentrations reflective of minimally 

disturbed conditions, they are associated with biota which suggest support of the most sensitive designated use 

(propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-27 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Swift Creek @ CR 239 

 STORET Station 21030088 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.26, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with silvicultural activities beyond a forested buffer 

zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Swift Creek @ CR 239 (Station 21030088) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Swift Creek @ CR 239 (Station 21030088) showing close-up of sampling site. 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-28 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 105 

Hydrologic Score 2 

LDI Score 1.26 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.083 

Total Nitrogen Geometric Mean (mg/L) 2.06 

The Habitat Assessment score was in the “Suboptimal” range. There was no water flow at the time of sampling, 

therefore the SCI was not conducted, according to the SCI Standard Operating Procedure. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 99.67 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 0 

Number of Taxa 32 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 32 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at Swift Creek @ CR 239. Based on our analyses, the Department 

concluded that the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal 

or aquatic plant issues were present. Thus, not only are the nutrient concentrations reflective of minimally 

disturbed conditions, they are associated with biota which suggest support of the most sensitive designated use 

(propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-29 

NORTH CENTRAL NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Robinson Branch @ C-246 

 STORET Station ROB01C1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.36, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silvicultural activities and unimproved 

pasture beyond a forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Robinson Branch @ C-246 (Station ROB01C1) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Robinson Branch @ C-246 (Station ROB01C1) showing close-up of sampling 

site. 

Photograph of Robinson Branch @ C-246 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-30 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 128 

Hydrologic Score 2 

LDI Score 1.36 

SCI Score 81 A 

Total Phosphorus Geometric Mean (mg/L) 0.158 

Total Nitrogen Geometric Mean (mg/L) 0.95 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting an unusually diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting 

the Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 97.33 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 2.33 

Number of Taxa 58 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 58 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Robinson Branch @ C-246. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the 

most sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and 

wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-31 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Alligator Creek @ US 301 & SR115 

 STORET Station 19020052 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.74, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and unimproved pasture 

generally beyond a 100 m forested riparian zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Alligator Creek @ US 301 & SR 115 (Station 19020052) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Alligator Creek @ US 301 & SR 115 (Station 19020052) showing close-up of 

sampling site. 

Photograph of Alligator Creek @ US 301 & SR 115
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-32 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 137 

Hydrologic Score 2 

LDI Score 1.74 

SCI Score 63 A 

Total Phosphorus Geometric Mean (mg/L) 0.190 

Total Nitrogen Geometric Mean (mg/L) 1.12 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Healthy” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated 

use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 83.02 

% Chlorophycota 1.89 

% Cryptophycophyta 0 

% Cyanophycota 15.09 

Number of Taxa 64 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 64 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Alligator Creek @ US 301 & SR 115. Based on 

our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full 

support of the most sensitive designated use (propagation and maintenance of a healthy, well-balanced population 

of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-33 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Ates Creek @ CR 315 

 STORET Station CLA243LV 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Ates Creek @ CR 315 (Station CLA243LV) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Ates Creek @ CR 315 (Station CLA243LV) showing close-up of sampling site. 

Photograph of Ates Creek @ CR 315 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-34 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 144 

Hydrologic Score 2 

LDI Score 1.18 

SCI Score 91 A 

Total Phosphorus Geometric Mean (mg/L) 0.198 

Total Nitrogen Geometric Mean (mg/L) 0.71 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting an exceedingly diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting the 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 98.00 

% Chlorophycota 1.00 

% Cryptophycophyta 0 

% Cyanophycota 0.33 

Number of Taxa 41 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 41 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Ates Creek @ CR 315. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-35 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Black Creek @ SR 16 

 STORET Station CLA254LR 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.21, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Black Creek @ SR 16 (Station CLA254LR) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Black Creek @ SR 16 (Station CLA254LR) showing close-up of sampling site. 

Photograph of Black Creek @ SR 16 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-36 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 133 

Hydrologic Score 2 

LDI Score 1.21 

SCI Score 91 A 

Total Phosphorus Geometric Mean (mg/L) 0.116 

Total Nitrogen Geometric Mean (mg/L) 0.55 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting an unusually diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting its 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 94.67 

% Chlorophycota 1.33 

% Cryptophycophyta 0 

% Cyanophycota 4.00 

Number of Taxa 54 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 54 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Black Creek @ SR 16. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-37 

 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Greens Creek @ CR 315 

 STORET Station GC315 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.33, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Greens Creek @ CR 315 (Station GC315) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Greens Creek @ CR 315 (Station GC315) showing close-up of sampling site. 

Photograph of Greens Creek @ CR 315 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-38 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 114 

Hydrologic Score 2 

LDI Score 1.33 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.020 

Total Nitrogen Geometric Mean (mg/L) 0.57 

The Habitat Assessment score was in the high “Suboptimal” range, mostly because of the lack of water velocity. 

Stream Condition Index sampling was not performed at the time of sampling due to the stagnant water conditions. 

An adjacent station was sampled for SCI in 2005 and 2006, and both times scored in the “Healthy” category based 

on SCI_2007 thresholds. This suggests that the site is meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 98.05 

% Chlorophycota 0.65 

% Cryptophycophyta 0 

% Cyanophycota 1.30 

Number of Taxa 42 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 42 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at Greens Creek @ CR 315. Based on our analyses, the Department 

concluded that the site was influenced only by very low levels of anthropogenic stressors with no algae related 

issues. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are 

associated with plants and algae which suggest support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-39 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Little St. Marys River@ CR 121 A 

 STORET Station 19010046 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with silvicultural activities beyond a forested riparian 

zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little St. Marys River @ CR 121 A (Station 19010046) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little St. Marys River @ CR 121 A (Station 19010046) showing close-up of 

sampling site. 

Photograph of Little St. Marys River @ CR 121 A
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-40 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 117 

Hydrologic Score 2 

LDI Score 1.18 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.048 

Total Nitrogen Geometric Mean (mg/L) 1.15 

The Habitat Assessment score was in the high end of the “Suboptimal” category, predominantly sue to low water 

velocity. Due to the swamp-like nature of this system, SCI sampling was not appropriate and was not conducted. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 61.64 

% Chlorophycota 5.90 

% Euglenophycota 1.97 

% Cyanophycota 29.84 

Number of Taxa 75 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 75 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at Little St. Marys River @ CR 121 A. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-41 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Middle Prong St. Marys River @ CR 125 

 STORET Station 19010041 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.16, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and pasture located beyond a 

100 m forested buffer. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 125 (Station 19010041) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 125 (Station 19010041) showing close-up of 

sampling site. 

Photograph of Middle Prong St. Marys @ CR 125
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-42 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 137 

Hydrologic Score 2 

LDI Score 1.16 

SCI Score 78 A 

Total Phosphorus Geometric Mean (mg/L) 0.029 

Total Nitrogen Geometric Mean (mg/L) 1.10 

The Habitat Assessment score was in the “Optimal” range. Despite the naturally low dissolved oxygen measured 

during sampling (2.7 mg/L) the SCI score was in the “Exceptional” category, exhibiting an unusually diverse 

assemblage of sensitive invertebrates and indicating the site is clearly meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 81.40 

% Chlorophycota 1.33 

% Cryptophycophyta 0 

% Cyanophycota 17.28 

Number of Taxa 55 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 55 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Middle Prong St. Marys @ CR 125. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the 

most sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and 

wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-43 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Middle Prong St. Marys River @ CR 127 

 STORET Station MPS 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.34, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 127 (Station MPS) showing watershed vicinity 

and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 127 (Station MPS) showing close-up of sampling 

site. 

Photograph of Middle Prong St. Marys @ CR 127
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-44 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 131 

Hydrologic Score 2 

LDI Score 1.34 

SCI Score 71 A 

Total Phosphorus Geometric Mean (mg/L) 1.09 

Total Nitrogen Geometric Mean (mg/L) 0.026 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting an unusually diverse assemblage of sensitive invertebrates and indicating the site is certainly meeting its 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 97.33 

% Chlorophycota 0.67 

% Cryptophycophyta 0 

% Cyanophycota 2.00 

Number of Taxa 42 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 42 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Middle Prong St. Marys @ CR 127. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the 

most sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and 

wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-45 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

North Fork Black Creek @ Jennings Landing 

 STORET Station 14264 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.62, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and pasture located beyond an 

extensive forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of North Fork Black Creek @ Jennings Landing (Station 14264) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of North Fork Black Creek @ Jennings Landing (Station 14264) showing close-up 

of sampling site. 

Photograph of North Fork Black Creek @ Jennings Landing 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-46 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 137 

Hydrologic Score 2 

LDI Score 1.62 

SCI Score 73 A 

Total Phosphorus Geometric Mean (mg/L) 0.038 

Total Nitrogen Geometric Mean (mg/L) 0.51 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting an unusually diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting 

the Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 69.33 

% Chlorophycota 1.33 

% Cryptophycophyta 0 

% Cyanophycota 29.33 

Number of Taxa 48 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 48 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at North Fork Black Creek @ Jennings Landing. 

Based on our analyses, the Department concluded that the site was influenced only by very low levels of 

anthropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the 

nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which 

demonstrate full support of the most sensitive designated use (propagation and maintenance of a healthy, wellbalanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-47 

 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Peters Creek @ CR 315 A 

 STORET Station CLA246GS 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.21, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and pasture located beyond a 

forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Peters Creek @ CR315A (Station CLA246GS) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Peters Creek @ CR315A (Station CLA246GS) showing close-up of sampling 

site. 

Photograph of Peters Creek @ CR315A
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-48 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 148 

Hydrologic Score 2 

LDI Score 1.21 

SCI Score 73 A 

Total Phosphorus Geometric Mean (mg/L) 0.019 

Total Nitrogen Geometric Mean (mg/L) 0.40 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 94.00 

% Chlorophycota 2.67 

% Euglenophycota 0.67 

% Cyanophycota 2.67 

Number of Taxa 64 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 64 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Peters Creek @ CR 315 A. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-49 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

South Fork Black Creek @ SR 21 

 STORET Station 20030481 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.35, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silvicultural activities beyond an extensive 

forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of South Fork Black Creek @ SR 21 (Station 20030481) showing watershed 

vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of South Fork Black Creek @ SR 21 (Station 20030481) showing close-up of 

sampling site. 

Photograph of South Fork Black Creek @ SR 21 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-50 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 144 

Hydrologic Score 1 

LDI Score 1.35 

SCI Score 83 A 

Total Phosphorus Geometric Mean (mg/L) 0.093 

Total Nitrogen Geometric Mean (mg/L) 0.50 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting an exceedingly diverse assemblage of sensitive invertebrates and indicating the site is definitively 

meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 72.61 

% Chlorophycota 0.99 

% Cryptophycophyta 0 

% Cyanophycota 26.40 

Number of Taxa 67 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 67 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at South Fork Black Creek @ SR 21. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the 

most sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and 

wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-51 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

St. Marys River @ SR 2 

 STORET Station 19010006 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.09, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silvicultural activities and unimproved 

pasture beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the 

site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of St. Marys at SR 2 (Station 19010006) showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of St. Marys at SR 2 (Station 19010006) showing close-up of sampling site. 

Photograph of St. Marys at SR 2 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-52 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 124 

Hydrologic Score 1 

LDI Score 1.09 

SCI Score 100 A 

Total Phosphorus Geometric Mean (mg/L) 0.017 

Total Nitrogen Geometric Mean (mg/L) 1.27 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

indicating an exceedingly diverse community of sensitive invertebrates, and demonstrating that the site is 

definitively meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 93.33 

% Chlorophycota 4.00 

% Euglenophycota 0.33 

% Cyanophycota 2.33 

Number of Taxa 54 

No nuisance algal growth was found. Of the 54 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at St. Marys River at SR 2. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-53 

NORTHEAST NUTRIENT REGION 

Nutrient Benchmark Site Summary 

St. Marys River @ Tompkins Landing 

 STORET Station 19010077 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.22, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silvicultural activities and pasture beyond 

an extensive forested riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of St. Marys at Tompkins Landing (Station 19010077) showing watershed vicinity 

and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of St. Marys at Tompkins Landing (Station 19010077) showing close-up of 

sampling site. 

Photograph of St. Marys at Tompkins Landing 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-54 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 114 

Hydrologic Score 2 

LDI Score 1.22 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.043 

Total Nitrogen Geometric Mean (mg/L) 0.87 

The Habitat Assessment score was in the high end of the “Suboptimal” range (mostly due to limited substrate 

availability associated with low water conditions). Since very little habitat was submerged due to the 

unrepresentative low water level, SCI sampling was determined to be inappropriate (according to the Standard 

Operating Procedure) and was not conducted. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 75.50 

% Chlorophycota 8.94 

% Cryptophycophyta 0 

% Cyanophycota 15.56 

Number of Taxa 73 

No visual evidence of algal growth or adverse aquatic growth was observed at this site. Of the 73 algal taxa found, 

the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at St. Marys River at Tompkins Landing. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that no 

adverse algal or aquatic plant issues were present. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-55 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Aucilla River @ Highway 90 

 STORET Station 22040004 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.06, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some field/pasture located well beyond the 

extensive riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Aucilla River (Station 22040004) showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Aucilla River (Station 22040004) showing close-up of sampling site. 

Photograph of the Aucilla River at Highway 90
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-56 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 126 

Hydrologic Score 2 

LDI Score 1.06 

SCI Score 61 A 

Total Phosphorus Geometric Mean (mg/L) 0.090 

Total Nitrogen Geometric Mean (mg/L) 3.10 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Healthy” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting the Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 96.67 

% Chlorophycota 1.33 

% Cryptophycophyta 0 

% Cyanophycota 2.00 

Number of Taxa 30 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 30 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Aucilla River at Highway 90. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-57 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Blackwater River @ Highway 4 NW of Baker 

 STORET Station 3545 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.04, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Blackwater River (Station 21FLGW_3545) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Blackwater River (Station 21FLGW_3545) showing close-up of sampling 

site. 

Photograph of the Blackwater River (Station 21FLGW_3545)
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-58 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 128 

Hydrologic Score 1 

LDI Score 1.04 

SCI Score 70 A 

Total Phosphorus Geometric Mean (mg/L) 0.009 

Total Nitrogen Geometric Mean (mg/L) 0.40 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 88.45 

% Chlorophycota 2.31 

% Cryptophycophyta 0 

% Cyanophycota 2.31 

% Euglenophycota 0.33 

Number of Taxa 39 

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 39 algal taxa 

observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Blackwater River at Highway 4 NW of Baker. 

Based on our analyses, the Department concluded that the site was influenced only by very low levels of 

anthropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the 

nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to 

be fully supportive of the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-59 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Econfina Creek @ Scott Road 

 STORET Station 32030023 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.57, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with silvicultural activities beyond the extensive riparian buffer zone. 

There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Econfina Creek (Station 32030023) showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Econfina Creek (Station 32030023) showing close-up of sampling site. 

Photograph of Econfina Creek at Scott Rd.
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-60 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 130 

Hydrologic Score 1 

LDI Score 1.57 

SCI Score 81 A 

Total Phosphorus Geometric Mean (mg/L) 0.010 

Total Nitrogen Geometric Mean (mg/L) 0.26 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 89.70 

% Chlorophycota 5.65 

% Cryptophycophyta 0 

% Cyanophycota 3.65 

% Euglenophycota 1.00 

Number of Taxa 48 

Minimal periphyton growth was observed at this site, which would allow for optimal substrate use by 

macroinvertebrates. There was no nuisance algal growth. Of the 48 algal taxa observed, the majority of the 

periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Econfina Creek at Scott Road. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-61 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Econfina River @ Highway 98 

 STORET Station TAY170LR 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.14, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture beyond an extensive riparian 

buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Econfina River (Station TAY170LR) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Econfina River (Station TAY170LR) showing close-up of sampling site. 

Photograph of the Econfina River at Hwy 98
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-62 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 99 

Hydrologic Score 1 

LDI Score 1.14 

SCI Score 41A 

Total Phosphorus Geometric Mean (mg/L) 0.066 

Total Nitrogen Geometric Mean (mg/L) 1.21 

The Habitat Assessment score was in the “Suboptimal” range due mostly to low water velocity (<0.05 m/s) and 

limited availability of wetted habitat, making natural drought the most influential stressor during the most recent 

site visit. Prior to this event, the two most recent SCI samples for this site, which were collected during normal 

water levels on 2/23/06 and 8/2/05, scored 40 and 42, respectively. Both of these score were in the “Healthy” 

category, and the average of these scores is shown in the table. From 1996 to 1998, a total of 18 SCIs were 

performed at a site located approximately 3000 m above Highway 98 as part of a study to evaluate the effectiveness 

of forestry best management practices. All 18 of these SCIs scored in the category referred to as “excellent” in that 

version of the index, indicating that this site has a long demonstrated history of healthy biota. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 86.67 

% Chlorophycota 7.0 

% Cryptophycophyta 0 

% Cyanophycota 6.33 

Number of Taxa 36 

Filamentous algal growth was observed on the shallow, rocky substrate in the first 20 m of the site, but very little 

periphyton was observed in the rest of the stretch. This patch of filamentous algae was likely favored by the low 

water conditions. Of the 36 algal taxa observed, the majority of the periphyton community was composed of 

diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Econfina River at Hwy 98. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-63 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Escambia River @ Highway 4 

 STORET Station 3549 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.27, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and field/pasture beyond an 

extensive riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Escambia River (Station 21FLGW_3549) showing watershed vicinity and 

land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Escambia River (Station 21FLGW_3549) showing close-up of sampling site. 

An extensive forested buffer is present on both sides of the river. 

Photograph of the Escambia River (Station 21FLGW_3549)
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-64 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 120 

Hydrologic Score 2 

LDI Score 1.27 

SCI Score 51 A 

Total Phosphorus Geometric Mean (mg/L) 0.041 

Total Nitrogen Geometric Mean (mg/L) 0.55 

The Habitat Assessment score was in the “Optimal” range, although substrate availability was somewhat limited 

due to the overall large size of the river. The SCI score was in the “Healthy” category, exhibiting a diverse 

assemblage of sensitive invertebrates and indicating the site is clearly meeting the Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 84.72 

% Chlorophycota 5.98 

% Cryptophycophyta 0 

% Cyanophycota 9.30 

Number of Taxa 43 

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 43 algal taxa 

observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Escambia River at Highway 4. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-65 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Escambia River @ Highway 184 

 STORET Station 33020007 / 3541 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed 

that the majority of the watershed land use was forest/natural with some silviculture and agricultural activities well 

beyond an extensive riparian buffer zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Escambia River @ 184 showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Escambia River @ 184 showing close-up of sampling site. An extensive 

forested buffer is present on both sides of the river. 

Photograph of the Escambia River at Highway 184 (Station 21FLGW_3541)
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-66 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 115 

Hydrologic Score 2 

LDI Score 1.18 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.035 

Total Nitrogen Geometric Mean (mg/L) 0.53 

The Habitat Assessment score was in the high end of the “Suboptimal” range, predominantly due to lack of water 

velocity and limited substrate availability, related to the overall large size of the system. SCI sampling was not 

conducted because of the “lake-like” conditions present, and lack of water velocity in areas where accessible 

habitats were located, in accordance with the Standard Operating Procedures. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 83.72 

% Chlorophycota 1.66 

% Cryptophycophyta 0 

% Cyanophycota 14.62 

Number of Taxa 52 

Minimal periphyton growth was observed at this site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 52 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

algal community, and local land use) at the Escambia River at Highway 184. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that no 

adverse algal or aquatic plant issues were present. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-67 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Mule Creek @ SR 12 

 STORET Station LIB104LV 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.31, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the watershed 

land use was predominately forest/natural with some silviculture. There are no point source discharges upstream of 

the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Mule Creek (Station LIB104LV) showing watershed vicinity and land use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Mule Creek (Station LIB104LV) showing close-up of sampling site 

Photograph of Mule Creek 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-68 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 132 

Hydrologic Score 2 

LDI Score 1.31 

SCI Score 67 A 

Total Phosphorus Geometric Mean (mg/L) 0.033 

Total Nitrogen Geometric Mean (mg/L) 0.50 

The Habitat Assessment score was in the “Optimal” range. The SCI scored in the “Exceptional” category, therefore 

Mule Creek hosts a diverse community of sensitive aquatic macroinvertebrates. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 99.0 

% Chlorophycota 0 

% Cryptophycophyta 0 

% Cyanophycota 1.0 

Number of Taxa 22 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 22 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Mule Creek. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-69 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Quincy Creek above 267 

STORET Station 22020093 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.34, suggesting benign human influences in the watershed. Direct observations during the site visit 

confirmed that the majority of the watershed land use was forest/natural with silviculture, agriculture, and 

field/pasture located beyond an adequate riparian buffer zone. There are no direct point source discharges upstream 

of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Quincy Creek (Station 22020093) showing watershed vicinity and land use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Quincy Creek near 267 (Station 22020093) showing close-up of sampling site 

Photograph of Quincy Creek upstream of 267 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-70 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 122 

Hydrologic Score 3 

LDI Score 1.34 

SCI Score 57 A 

Total Phosphorus Geometric Mean (mg/L) 0.110 

Total Nitrogen Geometric Mean (mg/L) 0.58 

The Habitat Assessment score was in the “Optimal” range. Extensive deposits of “pipe clay” (Attapulgite) were 

noted throughout the stream, a natural geologic feature which would be expected to contribute total phosphorus to 

the water. The Stream Condition Index scored in the “Healthy” category, indicating a diverse assemblage of 

macroinvertebrates, and demonstrating that the site is meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 93.0 

% Chlorophycota 2.0 

% Cryptophycophyta 0 

% Cyanophycota 5.0 

Number of Taxa 53 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 53 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Quincy Creek, upstream of 267. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms).
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-71 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Sopchoppy River 

 STORET Station WAK158LR 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.13, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural, with some limited silviculture beyond an extensive riparian buffer zone. 

The watershed lies within the Apalachicola National Forest. There are no point source discharges upstream of the 

site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Sopchoppy River (Station WAK158LR) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Sopchoppy River (Station WAK158LR) showing close-up of sampling site. 

An extensive riparian forested buffer is present on both sides of the system. 

Photograph of the Sopchoppy River (Station WAK158LR)
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-72 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 128 

Hydrologic Score 1 

LDI Score 1.13 

SCI Score 64 A 

Total Phosphorus Geometric Mean (mg/L) 0.026 

Total Nitrogen Geometric Mean (mg/L) 0.60 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Healthy” category, 

indicating that the site contains a diverse assemblage of sensitive invertebrates and is meeting its Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 73.05 

% Chlorophycota 4.55 

% Cryptophycophyta 0 

% Cyanophycota 22.40 

Number of Taxa 54 

While a small amount of filamentous algae was found, the majority of the site had minimal periphyton growth. Of 

the 54 algal taxa observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Sopchoppy River. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-73 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

St. Marks River 

 STORET Station WAK168LR 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.40, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the watershed 

land use was predominately forest/natural with some silviculture beyond a forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Saint Marks River (Station WAK168LR) showing watershed vicinity and 

land use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Saint Marks River (Station WAK168LR) showing close-up of sampling site 

Photograph of the Saint Marks River 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-74 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 155 

Hydrologic Score 2 

LDI Score 1.40 

SCI Score 45 A 

Total Phosphorus Geometric Mean (mg/L) 0.040 

Total Nitrogen Geometric Mean (mg/L) 0.25 

The Habitat Assessment score was in the “Optimal” range. The SCI scored in the “Healthy” category, which 

indicates a diverse assemblage of aquatic invertebrates, and demonstrated that the stream is meeting its Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 91.36 

% Chlorophycota 0.66 

% Cryptophycophyta 1.00 

% Cyanophycota 6.98 

Number of Taxa 43 

Nuisance algal growth was not an issue at this site, although moderate periphyton growth was observed in isolated 

areas of the sampling reach, thought to be a natural condition. There was no habitat smothering (this element scored 

in the optimal range). Of the 43 algal taxa observed, the majority of the periphyton community was composed of 

diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and aquatic invertebrate communities) at the Saint Marks River. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-75 

PANHANDLE NUTRIENT REGION

 Nutrient Benchmark Site Summary 

Swamp Creek at SR 159 

STORET Station S232 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.51, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

minimal areas of silviculture and field/pasture located beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Swamp Creek @ SR 159 (Station S232) showing watershed vicinity and land use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Swamp Creek @ SR 159 (Station S232) showing close-up of sampling site 

Photograph of Swamp Creek at SR 159 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-76 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 112 

Hydrologic Score 2 

LDI Score 1.51 

SCI Score 49 A 

Total Phosphorus Geometric Mean (mg/L) 0.170 

Total Nitrogen Geometric Mean (mg/L) 0.75 

The Habitat Assessment score was in the high end of the “Suboptimal” range. The Stream Condition Index scored 

in the “Healthy” category, indicating a diverse assemblage of macroinvertebrates, and demonstrating that the site is 

meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 67.43 

% Chlorophycota 5.92 

% Cryptophycophyta 0 

% Cyanophycota 25.99 

% Euglenophycota 0.66 

Number of Taxa 65 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 65 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Swamp Creek at SR 159. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms).
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-77 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Telogia Creek @ CR 1641 

 STORET Station NUTREF001 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.24, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with some silviculture beyond an extensive forested riparian buffer zone. 

There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Telogia Creek (Station NUTREF001) showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Telogia Creek (Station NUTREF001) showing close-up of sampling site. 

Photograph of Telogia Creek at CR 1641
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-78 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 131 

Hydrologic Score 1 

LDI Score 1.24 

SCI Score 78 A 

Total Phosphorus Geometric Mean (mg/L) 0.067 

Total Nitrogen Geometric Mean (mg/L) 0.47 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

indicating an unusually diverse assemblage of sensitive aquatic invertebrates, definitively supporting the Class III 

designation. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 85.0 

% Chlorophycota 0.33 

% Cryptophycophyta 0 

% Cyanophycota 14.67 

Number of Taxa 40 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 40 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Telogia Creek at CR 1641. Based on our analyses, 

the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-79 

PANHANDLE NUTRIENT REGION

Nutrient Reference Site Summary 

Wacissa River near Big Blue Spring 

 STORET Station 22040009 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.03, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with silvicultural activities beyond and extensive forested riparian buffer 

zone. There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Wacissa River (Station 22040009) showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Wacissa River (Station 22040009) showing close-up of sampling site. 

Photograph of the Wacissa River near the headwaters.
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-80 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 138 

Hydrologic Score 1 

LDI Score 1.03 

SCI Score 40 A 

Total Phosphorus Geometric Mean (mg/L) 0.046 

Total Nitrogen Geometric Mean (mg/L) 0.29 

The Habitat Assessment score was in the high end of the “Suboptimal” range. The SCI score was in the “Healthy” 

category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting the 

Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 85.43 

% Chlorophycota 2.65 

% Cryptophycophyta 0 

% Cyanophycota 11.92 

Number of Taxa 50 

There was a minimal amount of periphyton at this site, with no nuisance algal growth. Of the 50 algal taxa 

observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Wacissa River near Big Blue Spring. Based on 

our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully 

supportive of the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-81 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Yellow River at Highway 2 

 STORET Station 3546 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.24, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with some silviculture beyond an extensive forested riparian buffer zone. 

There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Yellow River at Hwy 2 (Station 21FLGW_ 3546) showing watershed vicinity 

and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Yellow River (Station 21FLGW_ 3546) showing close-up of sampling site. 

An extensive riparian forested buffer is present on both sides of the system. 

Photograph of the Yellow River near Hwy 2
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-82 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 137 

Hydrologic Score 1 

LDI Score 1.24 

SCI Score 79 A 

Total Phosphorus Geometric Mean (mg/L) 0.024 

Total Nitrogen Geometric Mean (mg/L) 0.40 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III 

designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 90.07 

% Chlorophycota 1.99 

% Cryptophycophyta 0 

% Cyanophycota 7.95 

Number of Taxa 50 

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 50 algal taxa 

observed, the majority of the periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Yellow River at Highway 2. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-83 

PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

Yon Creek @ SR 12 

 STORET Station GAD106GS 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.26, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with some silviculture and field/pasture located beyond an extensive 

forested riparian buffer zone. There are no known point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Yon Creek (Station GAD106GS) showing watershed vicinity and land use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Yon Creek (Station GAD106GS) showing close-up of sampling site. 

Photograph of Yon Creek @ SR 12
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-84 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 137 

Hydrologic Score 2 

LDI Score 1.26 

SCI Score 81 A 

Total Phosphorus Geometric Mean (mg/L) 0.083 

Total Nitrogen Geometric Mean (mg/L) 0.86 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Exceptional” category, 

indicating an unusually diverse community of sensitive aquatic invertebrates, and demonstrating that the stream is 

definitively meeting its Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 98.00 

% Chlorophycota 0 

% Cryptophycophyta 0 

% Cyanophycota 2.00 

Number of Taxa 23 

Minimal periphyton growth was observed at this site, which would allow for optimal substrate use by 

macroinvertebrates. There was no nuisance algal growth. Of the 23 algal taxa observed, the majority of the 

periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Yon Creek @ SR 12. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-85 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Bee Branch 

 STORET Station 28020299FTM 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.64, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of citrus and field/pasture observed beyond the forested buffer zone. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Bee Branch (Station 28020299FTM) showing watershed vicinity and land use. 

The headwaters drain an area dominated by pine flatwoods, prairie, and wetlands. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial l photograph of Bee Branch (Station 28020299FTM) showing close-up of sampling site. An 

extensive forested riparian zone was evident of both sides of the system. 

Photographs of Bee Branch (Station 28020299FTM). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-86 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 147 

Hydrologic Score 3 

LDI Score 1.64 

SCI Score 49 A 

Total Phosphorus Geometric Mean (mg/L) 0.080 

Total Nitrogen Geometric Mean (mg/L) 1.13 

The habitat assessment scored in the “Optimal” range. The Stream Condition Index scored in the “Healthy” 

category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting the 

Class III designated use. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 91.33 

% Chlorophycota 2.67 

% Euglenophycota 0.67 

% Cyanophycota 4.67 

Number of Taxa 60 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 60 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal community) at Bee Branch. Based on our analyses, the Department concluded that the site 

was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological 

assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are 

associated with biota which demonstrate full support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-87 

PENINSULA NUTRIENT REGION 

Nutrient Reference Site Summary 

Blackwater Creek at State Road 44A 

STORET Station ALT_BWC44 (20010455) 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.09, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Blackwater Creek at State Road 44A (Station BWC44 or 20010455) showing 

watershed vicinity and land use. The system originates in Lake Norris, an undeveloped lake surrounded by 

wetland. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Blackwater Creek at State Road 44A (Station BWC44 or 20010455) showing 

close-up of sampling site. An extensive forested riparian zone was evident on both sides of the system. 

Photographs of Blackwater Creek at State Road 44A 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-88 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 125 

Hydrologic Score 2 

LDI Score 1.09 

SCI Score 77 A 

Total Phosphorus Geometric Mean (mg/L) 0.050 

Total Nitrogen Geometric Mean (mg/L) 1.60 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Exceptional” 

category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III 

designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 93.0 

% Chlorophycota 0 

% Cryptophycophyta 0 

% Cyanophycota 7.0 

Number of Taxa 45 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 45 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (hydrology, habitat assessment, 

local land use, algal and macroinvertebrate communities) at Blackwater Creek at State Road 44A. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the 

most sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and 

wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-89 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Blackwater Creek upstream of Carter Prop Bridge 

STORET Station BWCCPB / 20010536 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.31, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Blackwater Creek upstream of Carter Prop Bridge (Station BWCCPB) showing 

watershed vicinity and land use. The system originates in Lake Norris, an undeveloped lake surrounding by 

wetland. 

Image Removed Due to Copyright. 

DOQQ aerial photograph of Blackwater Creek upstream of Carter Prop Bridge (Station BWCCPB) showing closeup of sampling site. An extensive forested riparian zone was evident of both sides of the system. 

Photographs of Blackwater Creek upstream of Carter Prop Bridge 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-90 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 130 

Hydrologic Score 2 

LDI Score 1.31 

Total Phosphorus Geometric Mean (mg/L) 0.054 

Total Nitrogen Geometric Mean (mg/L) 1.28 

The habitat assessment scored in the “Optimal” range. High water caused by recent rains made Stream Condition 

Index sampling inappropriate according to DEP standard operating procedures. Results from a Biorecon that was 

performed 2/7/2007 demonstrated that this site scored in the “healthy” range, indicating that the Class III 

designation is being fully supported. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 72.43 

% Chlorophycota 15.28 

% Cryptophycophyta 0.33 

% Cyanophycota 7.31 

% Euglenophycota 2.99 

Number of Taxa 72 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 72 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (hydrology, local land use, and 

algal communities) at Blackwater Creek, upstream of Carter Prop Bridge. Based on our analyses, the Department 

concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly 

maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally 

disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-91 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Cow Creek @ CR 138 

STORET Station 21030086 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.61, suggesting benign human influences in the watershed. Before and during the site visit, aerial 

photographs were examined and direct observations confirmed that the majority of the watershed land use was 

forest/natural with some silvicultural activities and field/pasture beyond an extensive forested riparian buffer zone. 

There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Cow Creek @ CR 138 showing watershed vicinity and land use 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Cow Creek @ CR 138 showing close-up of sampling site 

Photograph of Cow Creek near CR 138 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-92 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 134 

Hydrologic Score 2 

LDI Score 1.61 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.114 

Total Nitrogen Geometric Mean (mg/L) 0.39 

The Habitat Assessment score was in the “Optimal” range. Stream Condition Index sampling was not performed at 

this site due to the low water level and the possibility of recent desiccation, in accordance with the Standard 

Operating Procedure. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 72.61 

% Chlorophycota 1.32 

% Cryptophycophyta 0 

% Cyanophycota 25.74 

Number of Taxa 64 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 64 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at Cow Creek @ CR 138. Based on our analyses, the Department concluded 

that the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal or aquatic 

plant issues were present. Thus, not only are the nutrient concentrations reflective of minimally disturbed 

conditions, they are associated with biota which suggest support of the most sensitive designated use (propagation 

and maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-93 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Cypress Branch above 78 

STORET Station 28020239 / GLA630GS 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.21 suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

areas of citrus and field/pasture observed beyond an extensive forested riparian buffer zone. There are no point 

source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Cypress Branch (Station GLA630GS) showing watershed vicinity and land use. 

The stream originates in an area of prairie, flatwoods, and swamp. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Cypress Branch (Station GLA630GS) showing close-up of sampling site. An 

extensive riparian forested zone is generally present on both sides of the system throughout the watershed, with a 

minimum of a 75-100 m buffer. 

Photograph of Cypress Branch (Station GLA630GS). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-94 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 134 

Hydrologic Score 2 

LDI Score 1.21 

SCI Score 63 A 

Total Phosphorus Geometric Mean (mg/L) 0.131 

Total Nitrogen Geometric Mean (mg/L) 1.97 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Healthy” 

category, indicating a diverse assemblage of sensitive invertebrates, and fully supporting the Class III designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 91.33 

% Chlorophycota 0 

% Cryptophycophyta 0 

% Cyanophycota 8.67 

Number of Taxa 48 

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No 

nuisance algal growth was found. Of the 48 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

and local land use) at Cypress Branch. Based on our analyses, the Department concluded that the site was 

influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological 

assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are 

associated with biota which demonstrate full support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-95 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Econlockhatchee River at Snowhill Road 

 STORET Station ECH 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.14, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond the forested buffer zone. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Econlockhatchee River at Snowhill Road (Station ECH) showing watershed 

vicinity and land use. The system originates in the Econlockhatchee River Swamp, an extensive wetland area. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Econlockhatchee River at Snowhill Road (Station ECH) showing close-up of 

sampling site. An extensive forested riparian zone was evident of both sides of the system. 

Photographs of Econlockhatchee River at Snowhill Road 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-96 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 106 

Hydrologic Score 2 

LDI Score 1.14 

SCI Score 52 A 

Total Phosphorus Geometric Mean (mg/L) 0.098 

Total Nitrogen Geometric Mean (mg/L) 0.93 

The habitat assessment score of 106 placed this site in the high “Suboptimal” range. The Stream Condition Index 

score of 52 was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating 

the site is clearly meeting the Class III designated use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 90.31 

% Chlorophycota 1.38 

% Cryptophycophyta 0 

% Cyanophycota 8.3 

Number of Taxa 53 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 53 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Econlockhatchee River at Snowhill Road. Based 

on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full 

support of the most sensitive designated use (propagation and maintenance of a healthy, well-balanced population 

of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-97 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Little Orange Creek 

STORET Station PUT308GS 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 2.01, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little Orange Creek (Station PUT308GS) showing watershed vicinity and land 

use. The stream originates from Little Orange Lake, an undeveloped system surrounded by forest and swamp. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little Orange Creek (Station PUT308GS) showing close-up of sampling site. An 

extensive riparian forested buffer is generally present on both sides of the system throughout the watershed, with 

one small clear-cut area approaching within 75 m of the stream. 

Photograph of Little Orange Creek 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-98 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 131 

Hydrologic Score 2 

LDI Score 2.01 

SCI Score 75 A 

Total Phosphorus Geometric Mean (mg/L) 0.201 

Total Nitrogen Geometric Mean (mg/L) 1.13 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Exceptional” 

category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III 

designated use. This is one of the few peninsular sites where Plecopterans (stoneflies, known to be extremely 

sensitive to stress) are routinely found. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 86.6 

% Chlorophycota 5.7 

% Cryptophycophyta 0 

% Cyanophycota 7.4 

Number of Taxa 48 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 48 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Little Orange Creek. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive 

designated use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-99 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Little Orange Creek below Cabbage Creek 

 STORET Station LOCBCC 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.54, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little Orange Creek below Cabbage Creek (Station LOCBCC) showing 

watershed vicinity and land use. Little Orange Creek originates from Little Orange Lake, a completely 

undeveloped system surrounded by forest, and associated wetlands. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Little Orange Creek below Cabbage Creek (Station LOCBCC) showing close-up 

of sampling site. An extensive riparian forested wetland buffer is present on both sides of the system. 

Photographs of Little Orange Creek below Cabbage Creek 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-100 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 132 

Hydrologic Score 2 

LDI Score 1.54 

SCI Score 89 A 

Total Phosphorus Geometric Mean (mg/L) 0.067 

Total Nitrogen Geometric Mean (mg/L) 0.70 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Exceptional” 

category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III 

designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 84.52 

% Chlorophycota 5.16 

% Cryptophycophyta 0 

% Cyanophycota 10.32 

Number of Taxa 54 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 54 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Little Orange Creek below Cabbage Creek. Based 

on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full 

support of the most sensitive designated use (propagation and maintenance of a healthy, well-balanced population 

of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-101 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Moses Creek at US 1 

 STORET Station 27010050 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.24, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond the forested buffer zone. There are no point source 

discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Moses Creek at US 1 (Station 27010050) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Moses Creek at US 1 (Station 27010050) showing close-up of sampling site. 

Moses Creek originates in an area of pine flatwoods and swamp. An extensive riparian forested buffer is present on 

both sides of the system. 

Photograph of Moses Creek at US 1 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-102 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 138 

Hydrologic Score 1 

LDI Score 1.24 

SCI Score 60 A 

Total Phosphorus Geometric Mean (mg/L) 0.081 

Total Nitrogen Geometric Mean (mg/L) 1.03 

The habitat assessment scored in the “Optimal” range. The Stream Condition Index score of 60 was in the 

“Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the 

Class III designated use. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 14.33 

% Chlorophycota 1.33 

% Euglenophycota 1.67 

% Cyanophycota 81.67 

Number of Taxa 71 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 71algal taxa observed, including 66 diatom taxa, the majority of the 

periphyton community was composed of blue-green algae. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

and local land use) at Moses Creek at US 1. Based on our analyses, the Department concluded that the site was 

influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological 

assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are 

associated with biota which demonstrate full support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-103 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Orange Creek Upstream of Highway 21 

STORET Station 21202 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.7, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture and field/pasture observed beyond a forested riparian buffer zone. There are no point 

source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Orange Creek upstream of Highway 21 (Station 21202) showing watershed 

vicinity and land use. The stream originates from Orange Lake, an Outstanding Florida Water. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Orange Creek upstream of HWY 21 (Station 21202) showing close-up of 

sampling site. An extensive riparian forested wetland buffer is present on both sides of the system. 

Photograph of Orange Creek upstream of Highway 21 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-104 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 121 

Hydrologic Score 3 

LDI Score 1.74 

SCI Score 74 A 

Total Phosphorus Geometric Mean (mg/L) 0.125 

Total Nitrogen Geometric Mean (mg/L) 1.43 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Exceptional” 

category, indicating an unusually diverse assemblage of sensitive invertebrates. This is one of the few peninsular 

sites where Plecopterans (stoneflies, known to be extremely sensitive to stress) are routinely found. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 90.38 

% Chlorophycota 1.37 

% Cryptophycophyta 0 

% Cyanophycota 8.25 

Number of Taxa 51 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 51 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Orange Creek, upstream of Highway 21. Based on 

our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full 

support of the most sensitive designated use (propagation and maintenance of a healthy, well-balanced population 

of fish and wildlife).
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-105 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

St. Johns River near DeLand 

STORET Station 2236000 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.68, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond the forested buffer zone. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of St. John’s River near DeLand (Station 2236000) showing watershed vicinity and 

land use. The system originates from Blue Cypress Lake, a completely undeveloped system surrounding by forest 

and wetlands. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of St. John’s River near DeLand (Station 2236000) showing close-up of sampling 

site. An extensive riparian forested wetland buffer is present on both sides of the system. 

Photographs of St. John’s River near DeLand 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-106 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 128 

Hydrologic Score 4 

LDI Score 1.68 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.078 

Total Nitrogen Geometric Mean (mg/L) 1.39 

The habitat assessment scored in the “Optimal” range. This system is characterized by very low flow, therefore 

Stream Condition Index sampling was inappropriate according to DEP standard operating procedures. Aquatic 

vegetation present was typical of sluggish, open systems and there were no nuisance plant issues. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 88.2 

% Chlorophycota 2.4 

% Cryptophycophyta 0 

% Cyanophycota 9.5 

Number of Taxa 53 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 53 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal communities) at the St. Johns River near Deland. Based on our analyses, the Department 

concluded that the site was influenced only by very low levels of anthropogenic stressors and based upon 

observations during the site visit, that no adverse algal or aquatic plant issues were present. Thus, not only are the 

nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest 

support of the most sensitive designated use (propagation and maintenance of a healthy, well-balanced population 

of fish and wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-107 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Steinhatchee River @ Canal Road 

 STORET Station 22050083 / STN020C1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.11, suggesting benign human influences in the watershed. Before the site visit, aerial photographs were 

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of 

the watershed land use was forest/natural with silviculture beyond an extensive forested riparian buffer zone. There 

are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Steinhatchee River (Station 22050083) showing watershed vicinity and land 

use. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Steinhatchee River (Station 22050083) showing close-up of sampling site. 

Photograph of Steinhatchee River at Canal Road
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-108 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 151 

Hydrologic Score 2 

LDI Score 1.11 

SCI Score 41 A 

Total Phosphorus Geometric Mean (mg/L) 0.087 

Total Nitrogen Geometric Mean (mg/L) 0.94 

The Habitat Assessment score was in the “Optimal” range. The SCI score was in the “Healthy” category, 

exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated 

use. 

Periphyton Community Composition

Algal Community Structure % Composition 

% Bacillariophyta 60.13 

% Chlorophycota 3.65 

% Cryptophycophyta 0 

% Cyanophycota 36.21 

Number of Taxa 54 

This site had an isolated area of Rhizoclonium sp. mats, where the canopy was open and the water was shallow over 

rocky substrate. Throughout the majority of the site, only small to moderate amounts of algae were present, and this 

did not affect the inhabitability of the substrates by invertebrates. Of the 54 algal taxa observed, the majority of the 

periphyton community was composed of diatoms. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Steinhatchee River at Canal Rd. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-109 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Steven’s Branch off CR 204 

 STORET Station 27010070 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.29, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Steven’s Branch off CR 204 (Station 27010070) showing watershed vicinity and 

land use. Steven’s Branch originates in an area of pine flatwoods, wetlands and prairie. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Steven’s Branch off CR 204 (Station 27010070) showing close-up of sampling 

site. An extensive riparian forested buffer is present on both sides of the system. 

 

Photographs of Steven’s Branch off CR 204 (Station 27010070) 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-110 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 128 

Hydrologic Score 3 

LDI Score 1.29 

SCI Score 76 A 

Total Phosphorus Geometric Mean (mg/L) 0.120 

Total Nitrogen Geometric Mean (mg/L) 1.09 

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Exceptional” 

category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III 

designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 75.14 

% Chlorophycota 3.39 

% Cryptophycophyta 0 

% Cyanophycota 21.47 

Number of Taxa 66 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 66 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Steven’s Branch off CR 204. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the 

most sensitive designated use (propagation and maintenance of a healthy, well-balanced population of fish and 

wildlife). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-111 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Tosohatchee Creek @ WMA 

 STORET Station ORA331LV 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.50, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Tosohatchee Creek (Station ORA331LV) showing watershed vicinity and land 

use. The stream originates in a swampy area adjacent to Tosohatchee Creek State Preserve. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Tosohatchee Creek (Station ORA331LV) showing close-up of sampling site. An 

extensive riparian forested wetland buffer is present on both sides of the system. 

Photograph of Tosohatchee Creek (Station ORA331LV). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-112 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 116 

Hydrologic Score 1 

LDI Score 1.50 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.034 

Total Nitrogen Geometric Mean (mg/L) 0.77 

The habitat assessment scored in the high “Suboptimal” range, with water velocity being the lowest scoring 

parameter. The site was deemed inappropriate for SCI sampling due to the swamp-like nature of the system and 

lack of water flow. Vegetation present was typical of minimally disturbed swamp systems. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 89.00 

% Chlorophycota 0.33 

% Euglenophycota 0.33 

% Cyanophycota 10.33 

Number of Taxa 56 

Of the 56 algal taxa identified, the majority of the periphyton community was composed of diatoms. No 

problematic filamentous algae were observed. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

algal community, and local land use) at Tosohatchee Creek. Based on our analyses, the Department concluded that 

the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal or aquatic plant 

issues were present. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, 

they are associated with biota which suggest support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife).
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-113 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Waccasassa River above SR 24 

 STORET Station LEV502GS 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.23, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, and field/pasture observed beyond the forested riparian buffer zone. There are no point 

source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Waccasassa River (Station LEV502GS) showing watershed vicinity and land 

use. The Wacasassa River originates in an area of hardwood swamp known as Devils Hammock. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of the Waccasassa River (Station LEV502GS) showing close-up of sampling site. 

Although there was some encroachment from a clear cut area near the site, extensive riparian forested wetland 

buffer is present on both sides for the majority of the system. Note that the forested buffer still exceeded 

approximately 75 m at minimum, and was generally several hundred m wide. 

Photographs of the Waccasassa River 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-114 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 138 

Hydrologic Score 1 

LDI Score 1.23 

SCI Score 69 A 

Total Phosphorus Geometric Mean (mg/L) 0.065 

Total Nitrogen Geometric Mean (mg/L) 0.63 

The habitat assessment scored in the high “Optimal” range, and the Stream Condition Index scored in the 

“Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively 

supporting the Class III designation. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 84.24 

% Chlorophycota 0.32 

% Cryptophycophyta 0 

% Cyanophycota 15.43 

Number of Taxa 46 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 46 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. Although some filamentous algal growth was found in a few small areas, it did not affect 

habitat suitability, as evidenced by the very good SCI score. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at the Waccasassa River. Based on our analyses, the 

Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it 

clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of 

minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated 

use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-115 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Withlacoochee River at SR 471 

 STORET Station WITHLACOORVR1 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.45, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture and field/pasture observed beyond an extensive forested riparian buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

Aerial photograph of Withlacoochee River at SR 471 (Station WITHLACOORVR1) showing watershed vicinity 

and land use. The Withlacoochee River originates in the Green Swamp, an extensive wetland with considerable 

areas in public ownership. 

Image Removed Due to Copyright. 

Aerial photograph of Withlacoochee River at SR 471 (Station WITHLACOORVR1) showing close-up of sampling 

site. An extensive riparian forested wetland buffer is present on both sides of the system. 

Photograph of Withlacoochee River at SR 471 (Station WITHLACOORVR1). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-116 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 119 

Hydrologic Score 2 

LDI Score 1.45 

SCI Score 46 A 

Total Phosphorus Geometric Mean (mg/L) 0.080 

Total Nitrogen Geometric Mean (mg/L) 1.68 

The habitat assessment scored in the high “suboptimal” range due to no water velocity. The Stream Condition 

Index was not performed during this site visit due to low water levels and minimal stream velocity. However, sites 

both upstream (station 33449) and downstream (station 34401) of the sampling location and within the same WBID 

received “healthy” SCI designations in 2007, (51 A and 40 A, respectively) indicating that the water quality is fully 

supporting the Class III designated use. These scores were averaged for the above table. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 85.95 

% Chlorophycota 1.3 

% Cryptophycophyta 0 

% Cyanophycota 12.1 

% Euglenophycota 0.7 

Number of Taxa 61 

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic 

invertebrate and fish communities. Of the 61 algal taxa observed, the majority of the periphyton community was 

composed of diatoms. No problematic filamentous algal growth was found. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) Withlacoochee River at SR 471. Based on our 

analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors 

and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations 

reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of 

the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-117 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Withlacoochee River at Stokes Ferry 

 STORET Station 3513 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.82, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, field/pasture, and residential uses observed beyond a forested riparian buffer zone. 

There are no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Withlacoochee River at Stokes Ferry (Station 3513) showing watershed vicinity 

and land use. The Withlacoochee River originates in the Green Swamp, a very large wetland with considerable 

areas in public ownership. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Withlacoochee River at Stokes Ferry (Station 3513) showing close-up of 

sampling site. An extensive riparian forested wetland buffer is present on both sides of the system. 

Photographs of the Withlacoochee River at Stokes Ferry 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-118 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 153 

Hydrologic Score 4 

LDI Score 1.82 

SCI Score 68 A 

Total Phosphorus Geometric Mean (mg/L) 0.043 

Total Nitrogen Geometric Mean (mg/L) 0.86 

The habitat assessment scored in the high “Optimal” range, and the Stream Condition Index scored in the 

“Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively 

supporting the Class III designated use. 

Periphyton Community Composition

Algal Community Stricture % Composition 

% Bacillariophyta 90.24 

% Chlorophycota 0.7 

% Cryptophycophyta 0 

% Cyanophycota 9.06 

Number of Taxa 40 

Moderate periphyton growth was observed at the site; however, substrate availability for benthic invertebrates was 

not problematic, as evidenced by the “exceptional” SCI score. Of the 40 algal taxa observed, the majority of the 

periphyton community was composed of diatoms. No problematic filamentous algal growth was found, despite the 

relatively open, sunny conditions characteristic of the site. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology, 

local land use, and algal and macroinvertebrate communities) at Withlacoochee River at Stokes Ferry. Based on 

our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic 

stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient 

concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully 

supportive of the designated use (healthy, well balanced populations of aquatic organisms). 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-119 

PENINSULA NUTRIENT REGION 

Nutrient Benchmark Site Summary 

Withlacoochee River at Trails End 

 STORET Station FL0052000087500 

Land Use 

This station was considered to be a candidate reference site based on the Landscape Development Intensity Index 

score of 1.34, suggesting benign human influences in the watershed. During the site visit, aerial photographs were 

examined and direct observations confirmed that the majority of the watershed land use was forest/natural, with 

small areas of silviculture, field/pasture, and residential uses observed beyond the forested buffer zone. There are 

no point source discharges upstream of the site. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Withlacoochee River at Trails End (Station FL0052000087500) showing 

watershed vicinity and land use. The Withlacoochee River originates in the Green Swamp, a very large wetland 

with considerable areas in public ownership. 

Image Removed Due to Copyright. 

DOQQ 2004 aerial photograph of Withlacoochee River at Trails End (Station FL0052000087500) showing closeup of sampling site. An extensive riparian forested wetland buffer is present on both sides of the system. 

Photographs of Withlacoochee River at Trails End 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-120 

Habitat, Biological and Water Quality Data

Parameter Value 

Habitat Assessment 118 

Hydrologic Score 2 

LDI Score 1.34 

SCI Score NA 

Total Phosphorus Geometric Mean (mg/L) 0.059 

Total Nitrogen Geometric Mean (mg/L) 1.01 

The habitat assessment scored in the high “Suboptimal” range. The SCI was not performed due to the morphology 

of the system in this area (lake-like), which when coupled with low water levels, resulted in the system having no 

perceptible water velocity. Typical aquatic plants observed at the site included Taxodium distichum, Hydrocotyle 

sp., Panicum hemitomon, Myriophyllum heterophyllum, and Polygonum sp., indicating healthy conditions. 

Qualitative Periphyton Sampling was not performed at this site, however minimal periphyton growth was observed, 

which would allow for optimal substrate use by benthic invertebrate and fish communities. No problematic 

filamentous algal growth was found, despite the relatively open, sunny conditions characteristic of the site. 

Overall Reference Site Conclusion: 

Experienced FDEP scientists conducted a series of observations and measurements (habitat assessment, hydrology 

and local land use) at Withlacoochee River at Trails End. Based on our analyses, the Department concluded that 

the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal or aquatic plant 

issues were present. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, 

they are associated with biota which suggest support of the most sensitive designated use (propagation and 

maintenance of a healthy, well-balanced population of fish and wildlife).