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
2011
Historical
period of record
High 0.1 0.2
Mean 0.0175 0.016 0.02826813
Low 0.0017 0.0008
No. of Samples 127 625

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/l Year
2011
Historical
period of record
High 2.4 8.1
Mean 1.0947 1.0825 0.79608904
Low 0.452 0.00
No. of Samples 57 426

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/l Year
2011
Historical
period of record
High 3.6 3.8
Mean 0.4295 0.3308 0.54027765
Low 0.12 0.03
No. of Samples 127 734

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
2011
Historical
period of record
High 114.9 169.7
Mean 54.44 68.26 29.06881
Low 7.90 7.40
No. of Samples 96 776

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2011
Historical
period of record
High 6.1 16.7
Mean 2.99 2.83 2.15968
Low 0.99 0.50
No. of Samples 72 266

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2011
Historical
period of record
High 250.0
Mean 40.97 47.46825
Low 10.00
No. of Samples 0 178

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: cfu/100ml Year
2011
Historical
period of record
High 270.0
Mean 270.0
Low 270.00
No. of Samples 0 1

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: ug/l Year
2011
Historical
period of record
High 442.0 587.0
Mean 39.86 19.82 100.95806
Low 8.00 0.00
No. of Samples 72 408

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: ug/l Year
2011
Historical
period of record
High 2,260.0 4,340.0
Mean 1108.87 1068.56 565.32645
Low 443.00 50.00
No. of Samples 127 797

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: ug/l Year
2011
Historical
period of record
High 125.0 739.0
Mean 15.12 14.64 51.40685
Low 4.00 0.00
No. of Samples 107 581

Five-year Rolling Average

  • Annual Mean

Oysters

Units: Year
2011
Historical
period of record
High 977.0
Mean 76.63
Low 0.00
No. of Samples 667 6,658

Five-year Rolling Average

pH

Units: None Year
2011
Historical
period of record
High 8.4 9.3
Mean 7.55 7.84 0.40396
Low 5.10 5.10
No. of Samples 97 1,357

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2011
Historical
period of record
High 36.4 39.4
Mean 14.61 17.34 10.76566
Low 1.31 0.00
No. of Samples 106 1,250

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2011
Historical
period of record
High 47,725.0 54,900.0
Mean 10561.77 15381.46 17922.11146
Low 2534.00 0.941
No. of Samples 33 631

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2011
Historical
period of record
High 89.4 92.3
Mean 75.94 75.95 8.62642
Low 60.296 50.00
No. of Samples 71 1,156

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2011
Historical
period of record
High 69.0 402.0
Mean 4.31 3.22 17.8337
Low 0.80 0.34
No. of Samples 136 1,152

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 2011 4 1 5 20
2 FRK2 2011 96 566 662 85

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