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

3 out of 4 indicators were rated as PASS.

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

Learn more about how this report is created

  • 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

South Creek

Water Chemistry Ratings | Freshwater Portion of the Creek

Creek Conditions Ratings are based on comparing nitrogen, phosphorus, chlorophyll and dissolved oxygen to water quality guidelines or regulations. Florida law defines a maximum allowable concentration of nitrogen, phosphorus, and chlorophyll a, and a minimum allowable concentration of dissolved oxygen in these streams. Learn more about these ratings and how they are calculated »

Data for the following WBIDs is averaged when compiling the data below:
  • 1982
  • 1982B
  • 1985
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: ug/l Year
2024
Historical
period of record
High 15.80 41.60
Mean 3.4556 4.5368 6.47839
Low 0.495 0.25
No. of Samples 11 440

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2024
Historical
period of record
High 2.039 3.60
Mean 1.4911 1.1916 0.52523955
Low 1.028 0.0022
No. of Samples 11 370

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2024
Historical
period of record
High 0.177 1.308
Mean 0.088 0.1383 0.15512667
Low 0.039 0.01
No. of Samples 11 462

Five-year Rolling Average

  • Annual Mean
Caution

Dissolved Oxygen Saturation

Note: Low DO saturation also may be naturally influenced by inflows from nearby wetlands or groundwater sources.
Score: Caution
Units: percent (%) Year
2024
Historical
period of record
High 60.9345 135.60
Mean 33.22 47.91 21.7747
Low 8.20 0.80
No. of Samples 11 469

Five-year Rolling Average

  • Annual Mean
Other Measures of Creek Health:

BOD, Biochemical oxygen demand

Units: mg/l Year
2024
Historical
period of record
High 3.47 8.49
Mean 1.37 1.19 0.90419
Low 1.00 0.50
No. of Samples 11 390

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2024
Historical
period of record
High 80.00 450.00
Mean 60.78 102.89 70.94704
Low 30.00 10.00
No. of Samples 11 543

Five-year Rolling Average

  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2024
Historical
period of record
High 397.00 8164.00
Mean 86.63 107.07 821.12363
Low 31.00 9.10
No. of Samples 11 233

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2024
Historical
period of record
High 0.059 0.741
Mean 0.03 0.03 0.10298755
Low 0.024 0.00
No. of Samples 11 526

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2024
Historical
period of record
High 1.92 3.11
Mean 1.34 1.16 0.46716921
Low 0.904 0.129
No. of Samples 11 518

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2024
Historical
period of record
High 0.208 1.81
Mean 0.14 0.08 0.16949228
Low 0.094 0.00
No. of Samples 11 476

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2024
Historical
period of record
High 7.42 8.9237
Mean 7.1 7.47 0.30484
Low 6.62 3.00
No. of Samples 11 2,149

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2024
Historical
period of record
High 0.72 38.60
Mean 0.5 6.89 12.79843
Low 0.25 0.00
No. of Samples 11 2,020

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2024
Historical
period of record
High 1420.24 55148.00
Mean 1000.17 9105.57 15610.01082
Low 514.04 0.00
No. of Samples 11 2,085

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2024
Historical
period of record
High 184.4348 185.1029
Mean 165.41 79.25 16.88011
Low 145.7016 34.574
No. of Samples 11 1,953

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2024
Historical
period of record
High 280.00
Mean 4.14 13.94438
Low 0.42
No. of Samples 0 422

Five-year Rolling Average

  • Annual Mean

Water Chemistry Ratings | Tidal Portion of the Creek

Creek Conditions Ratings are based on comparing nitrogen, phosphorus, chlorophyll and dissolved oxygen to water quality guidelines or regulations. Florida law defines a maximum allowable concentration of chlorophyll a and a minimum allowable concentration of dissolved oxygen in these streams. Florida has no regulatory thresholds for nitrogen or phosphorus in tidal creeks so trends are used to rate the creeks. Learn more about these ratings and how they are calculated »

Data for the following WBIDs is averaged when compiling the data below:
  • 1982A
  • 1992
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold

Chlorophyll a

Units: ug/l Year
2024
Historical
period of record
High 136.1
Mean 8.9616 17.85495
Low 0.06
No. of Samples 0 176

Five-year Rolling Average

  • Annual Mean

Nitrogen, Total

We were unable to determine a trend for the data available.
Units: mg/L Year
2024
Historical
period of record
High 2.6
Mean 1.1079 0.41180712
Low 0.049
No. of Samples 0 225

Five-year Rolling Average

  • Annual Mean

Phosphorus, Total

We were unable to determine a trend for the data available.
Units: mg/L Year
2024
Historical
period of record
High 1.6
Mean 0.0911 0.22204468
Low 0.015
No. of Samples 0 241

Five-year Rolling Average

  • Annual Mean

Dissolved Oxygen Saturation

Note: Low DO saturation also may be naturally influenced by inflows from nearby wetlands or groundwater sources
Units: percent (%) Year
2024
Historical
period of record
High 135.9
Mean 56.54 21.08039
Low 3.90
No. of Samples 0 272

Five-year Rolling Average

  • Annual Mean
Other Measures of Creek Health:

BOD, Biochemical oxygen demand

Units: mg/l Year
2024
Historical
period of record
High 8.3
Mean 2.81 2.004
Low 0.78
No. of Samples 0 23

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2024
Historical
period of record
High 280.0
Mean 43.23 59.5616
Low 0.00
No. of Samples 0 209

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2024
Historical
period of record
High 15.0
Mean 15.0
Low 15.00
No. of Samples 0 1

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2024
Historical
period of record
High 0.4
Mean 0.0 0.04353386
Low 0.00
No. of Samples 0 195

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2024
Historical
period of record
High 4.7
Mean 0.94 0.55353871
Low 0.00
No. of Samples 0 191

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2024
Historical
period of record
High 0.4
Mean 0.04 0.0849911
Low 0.00
No. of Samples 0 124

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2024
Historical
period of record
High 9.1
Mean 7.64 0.49879
Low 5.80
No. of Samples 0 376

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2024
Historical
period of record
High 35.0
Mean 17.65 9.90896
Low 0.00
No. of Samples 0 183

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2024
Historical
period of record
High 56,200.0
Mean 16677.44 18585.94354
Low 230.00
No. of Samples 0 506

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2024
Historical
period of record
High 90.0
Mean 76.0 8.18761
Low 52.70
No. of Samples 0 353

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2024
Historical
period of record
High 60.0
Mean 3.36 4.92101
Low 0.65
No. of Samples 0 227

Five-year Rolling Average

  • Annual Mean

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 »

Most Recent Sarasota County Oyster Monitoring Program Data
Icon Site ID Year Dead Live Total % Live
1 SC1 2024 39 75 114 65
2 SC2 2024 100 214 314 68

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 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% 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% 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% 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% Land Use Trend Sparkline
Water 2261.8% 5414.3% 4383.5% 6054.8% 6275% 6545.2% 6835.4% 7836.2% 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% Land Use Trend Sparkline
Barren Land 00% 110.1% 130.1% 100.1% 180.1% 200.2% 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% Land Use Trend Sparkline
Land Use Chart