Matheny Creek Condition Report for 2020

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

4 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: 1,724 acres
  • Location: Central Sarasota County
  • Discharges into: Little Sarasota Bay

For more information, please see: Matheny Creek Basin Master Plan (1994)

View county-wide water quality trends »

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Matheny Creek

Matheny Creek
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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:
  • 1975B
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: mg/L Year
2020		 Historical
period of record
High 0.042 0.10
Mean 0.0034 0.0029 0.00711302
Low 0.0006 0.0005
No. of Samples 24 614

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2020		 Historical
period of record
High 3.154 3.154
Mean 0.9091 0.7505 0.40108386
Low 0.562 0.0017
No. of Samples 24 527

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2020		 Historical
period of record
High 0.714 1.78
Mean 0.2275 0.2143 0.20391571
Low 0.081 0.041
No. of Samples 24 590

Five-year Rolling Average

  • Annual Mean
Pass

Dissolved Oxygen Saturation

Note: Low DO saturation also may be naturally influenced by inflows from nearby wetlands or groundwater sources.
Score: Pass
Units: percent (%) Year
2020		 Historical
period of record
High 121.262 213.70
Mean 53.41 61.62 32.67578
Low 2.5837 2.5837
No. of Samples 24 551

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2020		 Historical
period of record
High 3.87 10.30
Mean 1.17 0.96 1.05944
Low 1.00 0.50
No. of Samples 24 570

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2020		 Historical
period of record
High 100.00 120.00
Mean 56.76 51.43 16.96674
Low 40.00 20.00
No. of Samples 24 592

Five-year Rolling Average

  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2020		 Historical
period of record
High 2613.00 24196.00
Mean 407.4 422.28 2477.58675
Low 31.00 10.00
No. of Samples 24 226

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2020		 Historical
period of record
High 0.113 0.988
Mean 0.02 0.02 0.07092346
Low 0.008 0.00
No. of Samples 24 621

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2020		 Historical
period of record
High 2.97 2.97
Mean 0.77 0.7 0.31238869
Low 0.511 0.207
No. of Samples 24 590

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2020		 Historical
period of record
High 0.57 0.947
Mean 0.07 0.04 0.15607346
Low 0.004 0.004
No. of Samples 24 594

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2020		 Historical
period of record
High 7.6713 8.82
Mean 7.38 7.47 0.2214
Low 6.99 6.46
No. of Samples 24 598

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2020		 Historical
period of record
High 0.5897 21.86
Mean 0.42 0.44 0.99625
Low 0.1931 0.09
No. of Samples 24 610

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2020		 Historical
period of record
High 1172.67 19300.00
Mean 836.78 821.99 1097.59284
Low 399.692 0.667
No. of Samples 24 525

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2020		 Historical
period of record
High 86.936
Mean 73.4 8.35992
Low 36.05
No. of Samples 0 501

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2020		 Historical
period of record
High 54.40
Mean 1.75 3.31707
Low 0.40
No. of Samples 0 482

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 »

Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Water quality data are not available for the tidal portion of this creek.

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 »

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Impervious Features

Matheny 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.

35% of the land area within the Matheny Creek Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Matheny 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 Matheny Creek Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 Trend
Urban & Built-up 1,56690.9% 1,56991.1% 1,55590.2% 1,58792% 1,58892.1% 1,57391.2% 1,59492.5% 1,59492.5% Land Use Trend Sparkline
Agriculture 00% 00% 00% 00% 00% 191.1% 00% 00% Land Use Trend Sparkline
Rangeland 573.3% 342% 342% 150.9% 150.9% 110.6% 90.5% 90.5% Land Use Trend Sparkline
Upland Forests 150.9% 181.1% 241.4% 30.2% 30.2% 30.2% 30.2% 30.2% Land Use Trend Sparkline
Water 362.1% 533.1% 613.5% 563.3% 553.2% 553.2% 573.3% 573.3% Land Use Trend Sparkline
Wetlands 160.9% 130.8% 100.6% 140.8% 140.8% 140.8% 140.8% 140.8% Land Use Trend Sparkline
Transportation and Utilities 331.9% 362.1% 402.3% 492.9% 492.9% 492.9% 462.7% 462.7% Land Use Trend Sparkline
Land Use Chart