Pass
Rating icon - Chlorophyll a Rating icon - Total Nitrogen Rating icon - Total Phosphorous Rating icon - Dissolved Oxygen Saturation

4 out of 4 primary indicators were rated as PASS.

"Primary" are nutrient related (Chl, N, P) and bacteria (B) parameters.

All four indicators must pass for the creek to be rated as PASS.

Greyed out values indicate no data for the report year.

  • Size: 12,630 acres
  • Location: Central Sarasota County
  • Discharges into: Blackburn Bay

For more information, please see: Little Sarasota Bay Water Quality Management Plan (2012)

View county-wide water quality trends »

South Creek

Water Chemistry Ratings

Monitoring data is analyzed to determine stream health based on State water quality standards. Official determination of impairment or attainment of the water quality standards is performed by FDEP and is based on at least three years and up to seven and a half years of data. Information on approximately 17 different parameters are collected at stream sites, but only total nitrogen, total phosphorus, chlorophyll a, dissolved oxygen (percent saturation), and bacteria are assessed according to established water quality criteria mandated by the Clean Water Act. Additionally, the floral and faunal communities (SCI) are assessed at some sites to determine whether waters support a healthy aquatic community.

The "pass/fail" conditions presented here do not indicate impairment as determined by the official Florida Department of Environmental Protection Impaired Waters Rule assessment but, rather, give an indication of stream condition in a particular year in relation to the set regulatory numeric limits. Streams receive an annual "PASS" rating for each parameter if the mean value is below the regulatory value and a "FAIL" rating if the mean value exceeds the regulatory value. Not all water quality parameters have an established numeric criterion, so only some of the graphs below show the regulatory limit, represented by a horizontal red line.

Chart Legend
  • Monthly Average
  • Threshold
  • Annual Mean

The graphs here illustrate results over the past five years. Data from sites monitored within a single waterbody identification basin (WBID) are combined to determine water quality status for each WBID, and the annual geometric mean of sample results is indicated on the graph for the most recent year. The table to the left of the graph gives the annual and historic range of values for the indicator.

Click the graph to view a larger image and to download the full dataset.

Freshwater Portion of the Creek

Data for the following WBIDs is averaged when compiling the data below:
  • 1982
  • 1982B
  • 1985

Chlorophyll a

Units: µg/l Year
2025
Historical
period of record
High 30.70 41.60
Mean 12.3228 4.6522 6.85467
Low 3.62 0.25
No. of Samples 12 390
  • Monthly Average
  • NNC 20.00 µg/l
  • Annual Mean

Nitrogen, Total

Units: mg/L Year
2025
Historical
period of record
High 2.479 3.60
Mean 1.4665 1.2124 0.51768458
Low 0.927 0.0022
No. of Samples 28 364
  • Monthly Average
  • NNC 1.65 mg/L
  • Annual Mean

Phosphorus, Total

Units: mg/L Year
2025
Historical
period of record
High 0.276 1.308
Mean 0.1241 0.1418 0.16114643
Low 0.055 0.01
No. of Samples 12 405
  • Monthly Average
  • NNC 0.49 mg/L
  • Annual Mean

Dissolved Oxygen Saturation

Note: Dissolved oxygen saturation percentages above the regulatory threshold meet established water quality targets.
Units: percent (%) Year
2025
Historical
period of record
High 67.75 135.60
Mean 44.11 48.06 21.6465
Low 24.03 1.80
No. of Samples 12 456
  • Monthly Average
  • NNC 38.00 percent (%)
  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2025
Historical
period of record
High 5.13 8.49
Mean 2.39 1.21 0.97052
Low 1.00 0.50
No. of Samples 12 341
  • Monthly Average
  • Annual Mean

Color

Units: PCU Year
2025
Historical
period of record
High 220.00 450.00
Mean 106.46 100.62 69.61884
Low 60.00 10.00
No. of Samples 12 448
  • Monthly Average
  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2025
Historical
period of record
High 1515.00 8164.00
Mean 209.85 111.93 807.34276
Low 30.00 9.10
No. of Samples 12 178
  • Monthly Average
  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2025
Historical
period of record
High 0.351 0.741
Mean 0.06 0.03 0.10360789
Low 0.011 0.00
No. of Samples 24 497
  • Monthly Average
  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2025
Historical
period of record
High 2.25 3.11
Mean 1.34 1.15 0.46734687
Low 0.694 0.129
No. of Samples 18 469
  • Monthly Average
  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2025
Historical
period of record
High 0.327 1.81
Mean 0.07 0.07 0.17867423
Low 0.012 0.00
No. of Samples 18 419
  • Monthly Average
  • Annual Mean

pH

Units: None Year
2025
Historical
period of record
High 7.38 8.9237
Mean 6.99 7.48 0.29575
Low 6.61 3.00
No. of Samples 12 2,062
  • Monthly Average
  • Annual Mean

Salinity

Units: PSS Year
2025
Historical
period of record
High 1.21 38.60
Mean 0.59 7.6 12.68009
Low 0.28 0.00
No. of Samples 12 1,957
  • Monthly Average
  • Annual Mean

Specific conductance

Units: µmho Year
2025
Historical
period of record
High 2325.51 55148.00
Mean 1171.73 9386.25 15563.63706
Low 581.24 0.00
No. of Samples 12 2,065
  • Monthly Average
  • Annual Mean

Temperature, water

Units: °F Year
2025
Historical
period of record
High 187.5776 187.5776
Mean 167.43 79.7 18.26374
Low 146.5916 34.574
No. of Samples 12 1,940
  • Monthly Average
  • Annual Mean

Turbidity

Units: NTU Year
2025
Historical
period of record
High 280.00
Mean 4.06 14.89747
Low 0.42
No. of Samples 0 366
  • Monthly Average
  • Annual Mean
Other Measures of Creek Health:

Tidal Portion of the Creek

Data for the following WBIDs is averaged when compiling the data below:
  • 1982A
  • 1992

Chlorophyll a

Units: µg/l Year
2025
Historical
period of record
High 136.1
Mean 8.3181 17.21423
Low 0.06
No. of Samples 0 195
  • Monthly Average
  • NNC 11.00 ug/l
  • Annual Mean

Nitrogen, Total

Units: mg/L Year
2025
Historical
period of record
High 2.6
Mean 1.1008 0.41548598
Low 0.049
No. of Samples 0 226
  • Monthly Average
  • Annual Mean

Phosphorus, Total

Units: mg/L Year
2025
Historical
period of record
High 1.6
Mean 0.0912 0.21578032
Low 0.015
No. of Samples 0 258
  • Monthly Average
  • Annual Mean

Dissolved Oxygen Saturation

Note: Dissolved oxygen saturation percentages above the regulatory threshold meet established water quality targets.
Units: percent (%) Year
2025
Historical
period of record
High 136.1
Mean 59.41 22.25479
Low 3.9474
No. of Samples 0 297
  • Monthly Average
  • NNC 56.00 percent (%)
  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2025
Historical
period of record
High 8.3
Mean 2.81 2.004
Low 0.78
No. of Samples 0 23
  • Monthly Average
  • Annual Mean

Color

Units: PCU Year
2025
Historical
period of record
High 280.0
Mean 40.35 58.51692
Low 0.00
No. of Samples 0 225
  • Monthly Average
  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2025
Historical
period of record
High 15.0
Mean 15.0
Low 15.00
No. of Samples 0 1
  • Monthly Average
  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2025
Historical
period of record
High 2.2
Mean 0.0 0.1564174
Low 0.00
No. of Samples 0 211
  • Monthly Average
  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2025
Historical
period of record
High 4.7
Mean 0.87 0.55729386
Low 0.00
No. of Samples 0 210
  • Monthly Average
  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2025
Historical
period of record
High 0.4
Mean 0.03 0.08073186
Low 0.00
No. of Samples 0 141
  • Monthly Average
  • Annual Mean

pH

Units: None Year
2025
Historical
period of record
High 9.1
Mean 7.77 0.42566
Low 5.80
No. of Samples 0 315
  • Monthly Average
  • Annual Mean

Salinity

Units: PSS Year
2025
Historical
period of record
High 35.0
Mean 19.03 9.87822
Low 0.00
No. of Samples 0 210
  • Monthly Average
  • Annual Mean

Specific conductance

Units: µmho Year
2025
Historical
period of record
High 56,200.0
Mean 22023.79 16909.72363
Low 230.00
No. of Samples 0 459
  • Monthly Average
  • Annual Mean

Temperature, water

Units: °F Year
2025
Historical
period of record
High 3.2 89.8
Mean 0.13 33.47 34.43148
Low 0.00 0.00
No. of Samples 119 436
  • Monthly Average
  • Annual Mean

Turbidity

Units: NTU Year
2025
Historical
period of record
High 23.0
Mean 3.36 3.1481
Low 0.65
No. of Samples 0 242
  • Monthly Average
  • Annual Mean
Other Measures of Creek Health:

Oysters

Because they are immobile and will tolerate a fairly wide salinity range, eastern oysters (Crassostrea virginica) are valuable as an indicator of the relative health of aquatic ecosystems in the tidally-influenced portions of coastal creeks. Sarasota County has established an oyster monitoring program to track the location, types, and status of oyster reefs. Data from this monitoring program is shown below. Learn more about Oysters »

Loading oyster site map...
Most Recent Sarasota County Oyster Monitoring Program Data
Icon Site ID Year Dead Live Total % Live
1 SC1 2025 40 112 152 73
2 SC2 2025 187 372 559 66

Impervious Features

South Creek is located within the Little Sarasota Bay Watershed. View details about the Little Sarasota Bay Watershed »

Rain that falls on land that is in a natural state is absorbed and filtered by soils and vegetation as it makes it way into underground aquifers. However, in developed areas, "impervious surfaces" impede this process and contribute to polluted urban runoff entering surface waters. These surfaces include human infrastructure like roads, sidewalks, driveways and parking lots that are covered by impenetrable materials such as asphalt, concrete, brick and stone, as well as buildings and other permanent structures. Soils that have been disturbed and compacted by urban development are often impervious as well. Learn more about Impervious Features »

The Sarasota County Stormwater Environmental Utility (SEU) mapped impervious surfaces in the County in 2013. A map showing impervious surfaces can be viewed using the Water Atlas Map Viewer tool.

6% of the land area within the South Creek Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

South Creek is located within the Little Sarasota Bay Watershed. View details about the Little Sarasota Bay Watershed »

Land use within a creek's watershed has a major effect on its water quality. In general, less development means better water quality. Land Cover/Land Use classifications categorize land in terms of its observed physical surface characteristics (e.g. upland or wetland), and also reflect the types of activity that are taking place on it (agriculture, urban/built-up, utilities, etc.). Florida uses as its standard a set of statewide classifications which were developed by the Florida Department of Transportation. Learn more about Land Use and Land Cover »

Acreage and Percentage within each Land Use / Land Cover Category for South Creek Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 2023 Trend
Urban & Built-up 1,1298.9% 1,36910.8% 1,74513.8% 2,34118.5% 2,54620.2% 2,75621.8% 2,99523.7% 3,52527.9% 3,85830.5% Land Use Trend Sparkline
Agriculture 2,79022.1% 3,03524% 3,10424.6% 3,03124% 3,08824.5% 3,79330% 2,97923.6% 2,71921.5% 2,52920% Land Use Trend Sparkline
Rangeland 6495.1% 1,45211.5% 1,72313.6% 1,56512.4% 1,1819.4% 4843.8% 1,0408.2% 7155.7% 5574.4% Land Use Trend Sparkline
Upland Forests 4,91638.9% 3,58528.4% 2,78922.1% 2,39819% 2,40919.1% 2,15517.1% 2,21617.5% 2,14417% 2,08016.5% Land Use Trend Sparkline
Water 2261.8% 5414.3% 4383.5% 6054.8% 6275% 6545.2% 6835.4% 7836.2% 8656.8% Land Use Trend Sparkline
Wetlands 2,55320.2% 2,22517.6% 2,40319% 2,29018.1% 2,32018.4% 2,32118.4% 2,26417.9% 2,24317.8% 2,23817.7% Land Use Trend Sparkline
Barren Land 00% 110.1% 130.1% 100.1% 180.1% 200.2% 60% 60% 60% Land Use Trend Sparkline
Transportation and Utilities 3672.9% 4123.3% 4153.3% 3903.1% 4403.5% 4453.5% 4483.5% 4963.9% 4983.9% Land Use Trend Sparkline
Land Use Chart