North Creek Condition Report for 2024

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

2 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: 2,327 acres
  • Location: Central Sarasota County
  • Discharges into: Little Sarasota Bay

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

View county-wide water quality trends »

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North Creek

North Creek
Visit the North Creek water resource page »

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:
  • 1984AB
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold

Chlorophyll a

Units: ug/l Year
2024		 Historical
period of record
High 32.00
Mean 3.1997 7.42842
Low 0.73
No. of Samples 0 43

Five-year Rolling Average

  • Annual Mean

Nitrogen, Total

Units: mg/L Year
2024		 Historical
period of record
High 3.71
Mean 1.4619 0.57251886
Low 1.08
No. of Samples 0 26

Five-year Rolling Average

  • Annual Mean

Phosphorus, Total

Units: mg/L Year
2024		 Historical
period of record
High 2.70
Mean 0.1655 0.48260276
Low 0.041
No. of Samples 0 30

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 117.00
Mean 44.19 19.22071
Low 10.70
No. of Samples 0 62

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2024		 Historical
period of record
High 1.70
Mean 1.54 0.21213
Low 1.40
No. of Samples 0 2

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2024		 Historical
period of record
High 250.00
Mean 84.57 49.16482
Low 38.00
No. of Samples 0 27

Five-year Rolling Average

  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2024		 Historical
period of record
High 1439.00
Mean 218.1 326.0278
Low 74.00
No. of Samples 0 19

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2024		 Historical
period of record
High 0.46
Mean 0.07 0.08232951
Low 0.018
No. of Samples 0 27

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2024		 Historical
period of record
High 27.00
Mean 1.36 4.98012583
Low 0.89
No. of Samples 0 27

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2024		 Historical
period of record
High 0.52
Mean 0.11 0.17175027
Low 0.004
No. of Samples 0 27

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2024		 Historical
period of record
High 7.72
Mean 7.31 0.19276
Low 6.80
No. of Samples 0 62

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2024		 Historical
period of record
High 14.86
Mean 0.67 2.21695
Low 0.16
No. of Samples 0 70

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2024		 Historical
period of record
High 24590.00
Mean 1340.62 3868.34665
Low 328.00
No. of Samples 0 62

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2024		 Historical
period of record
High 85.028
Mean 74.87 7.27197
Low 55.94
No. of Samples 0 62

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2024		 Historical
period of record
High 39.00
Mean 4.25 9.34828
Low 1.30
No. of Samples 0 27

Five-year Rolling Average

  • Annual Mean
Other Measures of Creek Health:

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:
  • 1984A
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Caution

Chlorophyll a

Score: Caution
Units: ug/l Year
2024		 Historical
period of record
High 24.2 163.0
Mean 11.398 11.9521 20.58164
Low 4.75 0.90
No. of Samples 12 423

Five-year Rolling Average

  • Annual Mean
×

Chlorophyll a

The rating for Chlorophyll a is determined by comparing the annual arithmetic mean of its sampled values to fixed target and threshold values. The annual arithmetic mean is shown in the graph at left, as compared to its established target and threshold values.

An arithmetic mean is used for Chlorophyll a for consistency with the Surface Water Quality Standards, Florida Administrative Code 62-302.532, Estuary-Specific Numeric Interpretations of the Narrative Nutrient Criterion.

Pass

Nitrogen, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/L Year
2024		 Historical
period of record
High 2.2 4.0
Mean 1.4784 1.3639 0.43256386
Low 0.91 0.002
No. of Samples 12 343

Five-year Rolling Average

  • Annual Mean
×

Nitrogen, Total

Pass

Phosphorus, Total

Trend analysis shows a weak decreasing trend.
Score: Pass
Units: mg/L Year
2024		 Historical
period of record
High 0.3 0.9
Mean 0.2586 0.2843 0.14353292
Low 0.163 0.08
No. of Samples 12 461

Five-year Rolling Average

  • Annual Mean
×

Phosphorus, Total

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 46.5 157.4
Mean 14.16 25.82 23.39517
Low 3.03 0.70
No. of Samples 12 469

Five-year Rolling Average

  • Annual Mean
×

Dissolved Oxygen Saturation

BOD, Biochemical oxygen demand

Units: mg/l Year
2024		 Historical
period of record
High 4.6 14.5
Mean 2.0 1.72 1.52533
Low 1.00 0.50
No. of Samples 12 393

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2024		 Historical
period of record
High 150.0 300.0
Mean 86.73 84.32 34.4902
Low 60.00 5.00
No. of Samples 12 517

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2024		 Historical
period of record
High 4,106.0 31,000.0
Mean 864.3 952.56 3830.73591
Low 209.00 40.00
No. of Samples 12 231

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2024		 Historical
period of record
High 0.2 0.6
Mean 0.12 0.03 0.09524936
Low 0.038 0.00
No. of Samples 12 515

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2024		 Historical
period of record
High 2.1 2.9
Mean 1.42 1.24 0.373181
Low 0.894 0.05
No. of Samples 12 509

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2024		 Historical
period of record
High 0.1 2.4
Mean 0.05 0.1 0.20657502
Low 0.016 0.00
No. of Samples 12 475

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2024		 Historical
period of record
High 7.5 8.8
Mean 7.2 7.37 0.31944
Low 6.92 5.40
No. of Samples 12 600

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2024		 Historical
period of record
High 33.4 33.4
Mean 3.64 6.44 8.63868
Low 0.46 0.00
No. of Samples 12 503

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2024		 Historical
period of record
High 50,091.1 650,900.0
Mean 6467.55 11811.18 30182.03027
Low 927.92 25.058
No. of Samples 12 555

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2024		 Historical
period of record
High 192.1 194.2
Mean 170.96 86.76 34.53208
Low 145.6358 48.56
No. of Samples 12 420

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2024		 Historical
period of record
High 30.0
Mean 4.98 3.34514
Low 1.20
No. of Samples 0 415

Five-year Rolling 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 NO1 2023 80

Impervious Features

North 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.

15% of the land area within the North Creek Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

North 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 North Creek Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 Trend
Urban & Built-up 1,07446.2% 1,58468.1% 1,65271% 1,70273.2% 1,69973% 1,67972.2% 1,79577.1% 1,80977.8% Land Use Trend Sparkline
Agriculture 793.4% 863.7% 180.8% 90.4% 40.2% 1225.2% 40.2% 40.2% Land Use Trend Sparkline
Rangeland 00% 00% 00% 753.2% 743.2% 200.9% 301.3% 00% Land Use Trend Sparkline
Upland Forests 84536.3% 27511.8% 27711.9% 1426.1% 1416.1% 974.2% 944.1% 903.9% Land Use Trend Sparkline
Water 773.3% 1616.9% 1807.8% 1807.7% 1777.6% 1777.6% 1827.8% 1978.5% Land Use Trend Sparkline
Wetlands 2169.3% 2018.6% 1797.7% 1787.7% 1918.2% 1918.2% 1827.8% 1847.9% Land Use Trend Sparkline
Barren Land 170.7% 00% 00% 00% 10% 00% 00% 00% Land Use Trend Sparkline
Transportation and Utilities 180.8% 200.8% 200.8% 401.7% 401.7% 401.7% 401.7% 431.8% Land Use Trend Sparkline
Land Use Chart