Whitaker Bayou Condition Report for 2020

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: 4,967 acres
  • Location: North Sarasota County, south Manatee County
  • Discharges into: Sarasota Bay

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

View county-wide water quality trends »

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Whitaker Bayou

Whitaker Bayou
Visit the Whitaker Bayou 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:
  • 1936A
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: ug/l Year
2020		 Historical
period of record
High 10.40 59.50
Mean 1.1122 1.5689 5.68702
Low 0.237 0.00
No. of Samples 12 561

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2020		 Historical
period of record
High 1.605 15.76
Mean 0.9038 0.8959 1.27042079
Low 0.534 0.0019
No. of Samples 12 524

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2020		 Historical
period of record
High 0.579 2.38
Mean 0.3284 0.2935 0.2083223
Low 0.19 0.082
No. of Samples 12 553

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 125.991 492.60
Mean 96.65 75.16 42.95045
Low 65.9407 2.20
No. of Samples 12 587

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2020		 Historical
period of record
High 2.42 175.00
Mean 1.13 0.92 17.96486
Low 1.00 0.50
No. of Samples 12 492

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2020		 Historical
period of record
High 160.00 330.00
Mean 81.32 69.21 29.80425
Low 55.00 20.00
No. of Samples 12 634

Five-year Rolling Average

  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2020		 Historical
period of record
High 14136.00 15531.00
Mean 1707.83 2911.63 3387.46051
Low 602.00 97.00
No. of Samples 12 122

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2020		 Historical
period of record
High 0.105 30.06
Mean 0.02 0.02 2.2189588
Low 0.008 0.00
No. of Samples 12 628

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2020		 Historical
period of record
High 1.55 15.36
Mean 0.78 0.78 1.15097214
Low 0.361 0.20
No. of Samples 12 596

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2020		 Historical
period of record
High 0.306 1.02
Mean 0.09 0.08 0.15552304
Low 0.019 0.00
No. of Samples 12 568

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2020		 Historical
period of record
High 8.25 11.77
Mean 7.8 7.65 0.3625
Low 7.2799 6.10
No. of Samples 12 878

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2020		 Historical
period of record
High 0.3904 23.40
Mean 0.29 0.39 1.66459
Low 0.1938 0.00
No. of Samples 12 774

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2020		 Historical
period of record
High 788.952 49645.00
Mean 596.57 701.51 5310.83152
Low 401.155 0.524
No. of Samples 12 889

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2020		 Historical
period of record
High 91.40
Mean 69.65 9.33554
Low 14.018
No. of Samples 0 844

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2020		 Historical
period of record
High 56.40
Mean 2.88 5.01445
Low 0.50
No. of Samples 0 566

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:
  • 1936
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Caution

Chlorophyll a

Score: Caution
Units: ug/l Year
2020		 Historical
period of record
High 101.0 196.0
Mean 22.0875 12.2416 31.28733
Low 1.70 0.38
No. of Samples 18 236

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
2020		 Historical
period of record
High 1.9 7.0
Mean 0.9247 0.9498 1.17506702
Low 0.557 0.0018
No. of Samples 15 239

Five-year Rolling Average

  • Annual Mean
×

Nitrogen, Total

Pass

Phosphorus, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/L Year
2020		 Historical
period of record
High 0.4 2.0
Mean 0.2246 0.215 0.36610104
Low 0.112 0.008
No. of Samples 15 280

Five-year Rolling Average

  • Annual Mean
×

Phosphorus, Total

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 214.5 827.0
Mean 80.41 63.32 43.27844
Low 19.70 0.00
No. of Samples 19 629

Five-year Rolling Average

  • Annual Mean
×

Dissolved Oxygen Saturation

BOD, Biochemical oxygen demand

Units: mg/l Year
2020		 Historical
period of record
High 13.7 13.7
Mean 4.2 2.51 2.35135
Low 1.49 0.543
No. of Samples 12 218

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2020		 Historical
period of record
High 90.0 200.0
Mean 43.81 39.92 28.22279
Low 15.00 5.00
No. of Samples 12 335

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2020		 Historical
period of record
High 12,033.0 17,000.0
Mean 385.12 315.2 3364.69886
Low 10.00 10.00
No. of Samples 18 119

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2020		 Historical
period of record
High 1.2 1.9
Mean 0.09 0.02 0.20067858
Low 0.007 0.00
No. of Samples 15 336

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2020		 Historical
period of record
High 1.8 6.3
Mean 0.78 0.88 0.87599458
Low 0.318 0.05
No. of Samples 15 323

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2020		 Historical
period of record
High 0.5 3.3
Mean 0.06 0.06 0.32857637
Low 0.004 0.004
No. of Samples 15 286

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2020		 Historical
period of record
High 8.1 9.6
Mean 7.83 7.62 0.40985
Low 7.34 4.90
No. of Samples 19 2,931

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2020		 Historical
period of record
High 34.3 45.0
Mean 30.34 6.34 15.31202
Low 20.6592 0.00
No. of Samples 26 2,988

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2020		 Historical
period of record
High 52,330.0 55,760.0
Mean 46053.8 7481.33 22727.87275
Low 32648.80 320.00
No. of Samples 19 2,745

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2020		 Historical
period of record
High 90.7 95.5
Mean 84.57 74.66 6.18856
Low 72.32 49.10
No. of Samples 7 3,104

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2020		 Historical
period of record
High 12.0 31.3
Mean 4.33 3.79 3.29384
Low 2.50 0.62
No. of Samples 3 537

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...

Impervious Features

Whitaker Bayou is located within the Sarasota Bay Watershed. View details about the 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.

27% of the land area within the Whitaker Bayou Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Whitaker Bayou is located within the Sarasota Bay Watershed. View details about the 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 Whitaker Bayou Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 Trend
Urban & Built-up 3,83077.1% 3,83477.2% 3,83177.1% 3,90378.6% 3,95279.6% 3,92179% 3,95179.6% 3,97079.9% Land Use Trend Sparkline
Agriculture 2144.3% 1823.7% 1883.8% 1813.6% 1813.6% 1813.6% 1783.6% 1683.4% Land Use Trend Sparkline
Rangeland 40.1% 40.1% 40.1% 40.1% 40.1% 40.1% 40.1% 40.1% Land Use Trend Sparkline
Upland Forests 2354.7% 2495% 2495% 1953.9% 1643.3% 1953.9% 1643.3% 1583.2% Land Use Trend Sparkline
Water 1302.6% 1372.7% 1402.8% 1262.5% 881.8% 881.8% 891.8% 911.8% Land Use Trend Sparkline
Wetlands 3156.4% 2324.7% 2274.6% 2294.6% 2224.5% 2224.5% 2224.5% 2214.4% Land Use Trend Sparkline
Barren Land 00% 00% 00% 00% 00% 00% 30.1% 00% Land Use Trend Sparkline
Transportation and Utilities 2384.8% 3296.6% 3296.6% 3286.6% 3567.2% 3567.2% 3557.2% 3567.2% Land Use Trend Sparkline
Land Use Chart