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: 35,771 acres
  • Location: North Sarasota County, south Manatee County
  • Discharges into: Sarasota Bay

For more information, please see: Phillippi Creek Flood Study Update (2001)

View county-wide water quality trends »

Phillippi 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:
  • 1937
  • 1941
  • 1966
  • 1971
  • 1971A

Chlorophyll a

Units: µg/l Year
2025
Historical
period of record
High 348.00 1573.00
Mean 11.831 6.1585 47.50017
Low 0.36 0.00
No. of Samples 223 5,132
  • Monthly Average
  • NNC 20.00 µg/l
  • Annual Mean

Nitrogen, Total

Units: mg/L Year
2025
Historical
period of record
High 11.972 21.845
Mean 1.0397 1.2393 1.74213382
Low 0.05 0.05
No. of Samples 247 4,420
  • Monthly Average
  • NNC 1.65 mg/L
  • Annual Mean

Phosphorus, Total

Units: mg/L Year
2025
Historical
period of record
High 1.35 4.25
Mean 0.3344 0.3126 0.33230127
Low 0.045 0.008
No. of Samples 172 4,783
  • 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 174.78 876.00
Mean 65.36 61.39 34.03897
Low 0.00 0.00
No. of Samples 163 4,546
  • Monthly Average
  • NNC 38.00 percent (%)
  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2025
Historical
period of record
High 9.31 21.30
Mean 2.53 1.41 1.95046
Low 1.00 0.071
No. of Samples 155 3,273
  • Monthly Average
  • Annual Mean

Color

Units: PCU Year
2025
Historical
period of record
High 280.00 936.00
Mean 93.46 73.19 49.27654
Low 28.00 2.50
No. of Samples 148 4,081
  • Monthly Average
  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2025
Historical
period of record
High 24196.00 24196.00
Mean 1188.38 822.55 4333.59291
Low 10.00 10.00
No. of Samples 151 2,100
  • Monthly Average
  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2025
Historical
period of record
High 9.77 19.60
Mean 0.08 0.03 1.30473209
Low 0.008 0.00
No. of Samples 239 4,617
  • Monthly Average
  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2025
Historical
period of record
High 11.90 21.70
Mean 1.03 1.02 1.73148685
Low 0.242 0.002
No. of Samples 201 4,591
  • Monthly Average
  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2025
Historical
period of record
High 16.00 16.00
Mean 0.09 0.14 0.57128868
Low 0.008 0.00
No. of Samples 201 4,205
  • Monthly Average
  • Annual Mean

pH

Units: None Year
2025
Historical
period of record
High 8.98 12.00
Mean 7.47 7.4 0.55453
Low 6.56 0.40
No. of Samples 163 5,417
  • Monthly Average
  • Annual Mean

Salinity

Units: PSS Year
2025
Historical
period of record
High 2.36 430.00
Mean 0.33 0.31 6.87985
Low 0.00 0.00
No. of Samples 161 4,040
  • Monthly Average
  • Annual Mean

Specific conductance

Units: µmho Year
2025
Historical
period of record
High 4380.32 51500.00
Mean 679.39 610.37 2072.65401
Low 209.65 0.369
No. of Samples 166 5,613
  • Monthly Average
  • Annual Mean

Temperature, water

Units: °F Year
2025
Historical
period of record
High 194.5436 412.8548
Mean 29.3 83.96 45.49553
Low 0.00 0.00
No. of Samples 282 4,671
  • Monthly Average
  • Annual Mean

Turbidity

Units: NTU Year
2025
Historical
period of record
High 10.00 240.00
Mean 7.35 4.4 10.00935
Low 5.40 0.091
No. of Samples 2 3,300
  • 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:
  • 1947
  • 1968D
Pass

Chlorophyll a

Score: Pass
Units: µg/l Year
2025
Historical
period of record
High 32.4 99.1
Mean 5.5569 5.7491 8.18713
Low 1.39 0.10
No. of Samples 72 2,475
  • Monthly Average
  • NNC 11.00 ug/l
  • Annual Mean
Pass

Nitrogen, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/L Year
2025
Historical
period of record
High 2.1 3.7
Mean 0.519 0.5145 0.34456423
Low 0.305 0.065
No. of Samples 72 2,611
  • Monthly Average
  • Annual Mean
Pass

Phosphorus, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/L Year
2025
Historical
period of record
High 0.3 2.2
Mean 0.1162 0.1247 0.13645348
Low 0.05 0.0001
No. of Samples 72 2,737
  • Monthly Average
  • Annual Mean
Pass

Dissolved Oxygen Saturation

Note: Dissolved oxygen saturation percentages above the regulatory threshold meet established water quality targets.
Score: Pass
Units: percent (%) Year
2025
Historical
period of record
High 160.0 530.0
Mean 98.72 86.6 20.09616
Low 44.16 0.0001
No. of Samples 192 7,865
  • Monthly Average
  • NNC 56.00 percent (%)
  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2025
Historical
period of record
High 4.0 7.5
Mean 1.09 1.23 0.82478
Low 0.50 0.20
No. of Samples 72 2,220
  • Monthly Average
  • Annual Mean

Color

Units: PCU Year
2025
Historical
period of record
High 60.0 280.0
Mean 11.28 20.32 26.3626
Low 4.00 0.00
No. of Samples 72 2,721
  • Monthly Average
  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2025
Historical
period of record
High 24,196.0 41,000.0
Mean 552.58 444.93 4223.54182
Low 75.00 10.00
No. of Samples 12 160
  • Monthly Average
  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2025
Historical
period of record
High 1.4 1.4
Mean 0.18 0.01 0.08594041
Low 0.075 0.00
No. of Samples 12 1,694
  • Monthly Average
  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2025
Historical
period of record
High 2.1 3.6
Mean 0.51 0.52 0.31995328
Low 0.30 0.00
No. of Samples 72 3,015
  • Monthly Average
  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2025
Historical
period of record
High 0.1 5.7
Mean 0.01 0.0 0.13647037
Low 0.005 0.00
No. of Samples 72 2,868
  • Monthly Average
  • Annual Mean

pH

Units: None Year
2025
Historical
period of record
High 8.2 9.2
Mean 7.85 7.84 0.26706
Low 7.35 5.00
No. of Samples 192 8,906
  • Monthly Average
  • Annual Mean

Salinity

Units: PSS Year
2025
Historical
period of record
High 36.5 38.8
Mean 31.31 24.15 8.64026
Low 0.68 0.00
No. of Samples 192 9,479
  • Monthly Average
  • Annual Mean

Specific conductance

Units: µmho Year
2025
Historical
period of record
High 55,000.0 69,000.0
Mean 47854.24 37545.27 12228.08042
Low 1351.76 5.70
No. of Samples 192 9,928
  • Monthly Average
  • Annual Mean

Temperature, water

Units: °F Year
2025
Historical
period of record
High 193.0 412.9
Mean 83.2 77.08 13.49799
Low 59.36 37.49
No. of Samples 192 9,440
  • Monthly Average
  • Annual Mean

Turbidity

Units: NTU Year
2025
Historical
period of record
High 19.0 24.0
Mean 3.48 3.41 2.09916
Low 1.40 0.20
No. of Samples 60 3,032
  • 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 PH3 2025 30 37 67 55

Impervious Features

Phillippi Creek 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.

20% of the land area within the Phillippi Creek Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Phillippi Creek 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 Phillippi Creek Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 2023 Trend
Urban & Built-up 20,77358.1% 22,10961.8% 23,05164.4% 25,70071.8% 26,06672.9% 25,76872% 26,46074% 27,12475.8% 27,35676.5% Land Use Trend Sparkline
Agriculture 6,39817.9% 6,01816.8% 4,65713% 2,4987% 2,2166.2% 2,3096.5% 1,8225.1% 1,3183.7% 9902.8% Land Use Trend Sparkline
Rangeland 5231.5% 3080.9% 2620.7% 1420.4% 1470.4% 3300.9% 1290.4% 1290.4% 1380.4% Land Use Trend Sparkline
Upland Forests 3,3729.4% 2,6197.3% 2,3636.6% 1,9055.3% 1,7244.8% 1,7715% 1,6184.5% 1,4394% 1,3883.9% Land Use Trend Sparkline
Water 1,1713.3% 1,3673.8% 1,6064.5% 1,8585.2% 2,0275.7% 1,8835.3% 1,9975.6% 2,0635.8% 2,1386% Land Use Trend Sparkline
Wetlands 2,2736.4% 1,7624.9% 1,7354.8% 1,7154.8% 1,7274.8% 1,8605.2% 1,8195.1% 1,8105.1% 1,8375.1% Land Use Trend Sparkline
Barren Land 190.1% 1060.3% 6341.8% 90% 990.3% 950.3% 1000.3% 650.2% 620.2% Land Use Trend Sparkline
Transportation and Utilities 1,2443.5% 1,4814.1% 1,4644.1% 1,9435.4% 1,7674.9% 1,7554.9% 1,8265.1% 1,8235.1% 1,8655.2% Land Use Trend Sparkline
Land Use Chart