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: 5,863 acres
  • Location: South Sarasota County
  • Discharges into: Lemon Bay

Historically, the Forked Creek Basin consisted of a series of contiguous wetlands and mesic hammocks that extended from the creek’s headwaters to its outfall. The entirety of Forked Creek is predominantly marine. There are three branches within this basin: the eastern, main branch which extends from State Road 776 north and east to the headwaters; the central branch which extends from the main confluence at SR776 north into the Dale Lakes area; and the western branch which extends north of Overbrook Road to Manasota Beach Road. The eastern branch traverses mainly undeveloped range land and sparsely populated land, while the central branch traverses through two urban subdivisions and one sparsely populated section. The flow characteristics of the creek have been greatly diminished because of the invasion of a variety of exotics, debris and storm-damaged trees. Sarasota County has designated the Forked Creek basin as a regional stormwater facility requiring immediate attention. For basin details see: Forked Creek Drainage Improvements, Preliminary Report Phase I (2000)

Forked Creek

Forked 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 »

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

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:
  • 2039
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Caution

Chlorophyll a

Score: Caution
Units: mg/l Year
2016
Historical
period of record
High 0.2 0.2
Mean 0.0129 0.0147 0.03077708
Low 0.0014 0.0003
No. of Samples 64 1,040

Five-year Rolling Average

  • Annual Mean

Nitrogen, Total

We were unable to determine a trend for the data available.
Units: mg/l Year
2016
Historical
period of record
High 3.0 8.1
Mean 1.1201 1.0834 0.70565143
Low 0.744 0.00
No. of Samples 32 626

Five-year Rolling Average

  • Annual Mean

Phosphorus, Total

We were unable to determine a trend for the data available.
Units: mg/l Year
2016
Historical
period of record
High 0.6 3.8
Mean 0.2143 0.3005 0.4606269
Low 0.12 0.03
No. of Samples 64 1,149

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
2016
Historical
period of record
High 81.4 169.7
Mean 39.59 65.82 29.50621
Low 12.50 7.40
No. of Samples 13 938

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2016
Historical
period of record
High 3.9 16.7
Mean 1.32 2.3 2.11894
Low 0.508 0.50
No. of Samples 12 430

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2016
Historical
period of record
High 120.0 250.0
Mean 51.51 41.51 46.53509
Low 20.00 10.00
No. of Samples 11 189

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: cfu/100ml Year
2016
Historical
period of record
High 670.0 670.0
Mean 85.5 97.94 145.75111
Low 10.00 10.00
No. of Samples 13 28

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: ug/l Year
2016
Historical
period of record
High 234.0 587.0
Mean 122.85 22.36 94.88044
Low 41.00 0.00
No. of Samples 6 579

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: ug/l Year
2016
Historical
period of record
High 3,000.0 4,340.0
Mean 1122.08 1072.13 535.2888
Low 730.00 50.00
No. of Samples 63 1,211

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: ug/l Year
2016
Historical
period of record
High 67.0 882.0
Mean 22.61 15.62 51.39088
Low 5.00 0.00
No. of Samples 40 928

Five-year Rolling Average

  • Annual Mean

Oysters

Units: Year
2016
Historical
period of record
High 977.0
Mean 76.63
Low 0.00
No. of Samples 311 6,658

Five-year Rolling Average

pH

Units: None Year
2016
Historical
period of record
High 8.5 9.3
Mean 7.45 7.75 0.42621
Low 6.94 4.90
No. of Samples 85 1,787

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2016
Historical
period of record
High 35.2 40.5
Mean 18.78 17.31 10.61335
Low 3.10 0.00
No. of Samples 80 1,694

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2016
Historical
period of record
High 45,021.0 55,192.0
Mean 28015.55 16784.65 17488.15374
Low 8849.00 0.941
No. of Samples 13 780

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2016
Historical
period of record
High 89.8 93.9
Mean 78.17 76.14 8.49571
Low 62.69 50.00
No. of Samples 59 1,456

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2016
Historical
period of record
High 31.0 402.0
Mean 3.61 3.28 15.44154
Low 0.88 0.34
No. of Samples 64 1,570

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 FRK1 2016 12 55 67 82
2 FRK1A 2013 96 76 172 44
3 FRK2 2016 31 213 244 87

Impervious Features

Forked Creek is located within the Lemon Bay Watershed. View details about the Lemon 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.

7% of the land area within the Forked Creek Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Forked Creek is located within the Lemon Bay Watershed. View details about the Lemon 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 Forked Creek Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 Trend
Urban & Built-up 1,39423.8% 1,57026.8% 1,88832.2% 1,85931.7% 2,15436.7% 2,15436.7% Land Use Trend Sparkline
Agriculture 1,05518% 1,08118.4% 1,06418.2% 98816.8% 61910.6% 61910.6% Land Use Trend Sparkline
Rangeland 2324% 68811.7% 3956.7% 5529.4% 72612.4% 72612.4% Land Use Trend Sparkline
Upland Forests 2,05935.1% 1,32222.5% 1,31322.4% 1,18720.3% 1,03117.6% 1,03117.6% Land Use Trend Sparkline
Water 1392.4% 3906.7% 2374% 2293.9% 2764.7% 2764.7% Land Use Trend Sparkline
Wetlands 90515.4% 74312.7% 90415.4% 94416.1% 94816.2% 94816.2% Land Use Trend Sparkline
Barren Land 10% 00% 00% 00% 00% 00% Land Use Trend Sparkline
Transportation and Utilities 781.3% 681.2% 611% 1031.8% 1071.8% 1071.8% Land Use Trend Sparkline
Land Use Chart