Hudson Bayou Condition Report for 2024

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: 2,406 acres
  • Location: North Sarasota 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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Hudson Bayou

Hudson Bayou
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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:
  • 1953A
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: ug/l Year
2024		 Historical
period of record
High 8.46 156.80
Mean 2.1395 1.3285 11.51783
Low 0.545 0.237
No. of Samples 24 774

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2024		 Historical
period of record
High 2.047 17.52
Mean 1.3255 0.9687 1.06960951
Low 1.027 0.0018
No. of Samples 24 576

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2024		 Historical
period of record
High 0.947 4.05
Mean 0.3713 0.4152 0.34225206
Low 0.13 0.047
No. of Samples 24 783

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
2024		 Historical
period of record
High 87.84 489.00
Mean 47.61 51.33 32.19466
Low 4.3899 0.3008
No. of Samples 24 656

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2024		 Historical
period of record
High 3.89 13.10
Mean 1.21 1.05 1.51201
Low 1.00 0.50
No. of Samples 24 737

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2024		 Historical
period of record
High 180.00 400.00
Mean 82.53 74.24 35.3398
Low 60.00 20.00
No. of Samples 24 794

Five-year Rolling Average

  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2024		 Historical
period of record
High 11199.00 24196.00
Mean 1425.13 1337.36 2885.83983
Low 173.00 41.00
No. of Samples 23 421

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2024		 Historical
period of record
High 0.129 1.33
Mean 0.04 0.05 0.11184879
Low 0.008 0.00
No. of Samples 24 809

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2024		 Historical
period of record
High 1.77 13.80
Mean 1.22 0.82 0.90640808
Low 0.847 0.00
No. of Samples 24 784

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2024		 Historical
period of record
High 0.277 3.72
Mean 0.07 0.13 0.25872189
Low 0.011 0.004
No. of Samples 24 792

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2024		 Historical
period of record
High 7.72 758.00
Mean 7.35 7.41 25.43545
Low 7.03 6.20
No. of Samples 24 871

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2024		 Historical
period of record
High 0.58 28.633
Mean 0.38 0.37 2.81969
Low 0.1576 0.04
No. of Samples 24 752

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2024		 Historical
period of record
High 1153.49 54000.00
Mean 772.83 833.03 8732.12037
Low 327.198 0.445
No. of Samples 24 654

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2024		 Historical
period of record
High 185.6012 189.1675
Mean 171.28 88.88 40.63498
Low 150.6617 53.87
No. of Samples 24 542

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2024		 Historical
period of record
High 60.00
Mean 3.81 4.43344
Low 1.00
No. of Samples 0 560

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:
  • 1951
  • 1953
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: ug/l Year
2024		 Historical
period of record
High 23.0 97.2
Mean 8.0984 4.3015 11.11696
Low 3.20 0.25
No. of Samples 10 208

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.

Nitrogen, Total

We were unable to determine a trend for the data available.
Units: mg/L Year
2024		 Historical
period of record
High 1.0 3.5
Mean 0.6468 0.8214 0.37011116
Low 0.516 0.18
No. of Samples 5 191

Five-year Rolling Average

  • Annual Mean
×

Nitrogen, Total

Phosphorus, Total

We were unable to determine a trend for the data available.
Units: mg/L Year
2024		 Historical
period of record
High 0.1 1.3
Mean 0.0968 0.2379 0.24681241
Low 0.074 0.007
No. of Samples 5 245

Five-year Rolling Average

  • Annual Mean
×

Phosphorus, Total

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
2024		 Historical
period of record
High 81.8 137.9
Mean 52.85 63.48 25.29843
Low 34.80 0.60
No. of Samples 5 718

Five-year Rolling Average

  • Annual Mean
×

Dissolved Oxygen Saturation

BOD, Biochemical oxygen demand

Units: mg/l Year
2024		 Historical
period of record
High 5.8
Mean 1.74 1.10122
Low 0.46
No. of Samples 0 122

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2024		 Historical
period of record
High 20.0 125.0
Mean 9.07 24.21 21.97464
Low 4.90 0.00
No. of Samples 5 333

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2024		 Historical
period of record
High 10,112.0 10,112.0
Mean 945.98 287.3 2396.02017
Low 195.00 10.00
No. of Samples 5 20

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2024		 Historical
period of record
High 0.1 0.9
Mean 0.04 0.01 0.12098077
Low 0.02 0.00
No. of Samples 5 330

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2024		 Historical
period of record
High 1.0 3.2
Mean 0.61 0.71 0.35559638
Low 0.50 0.05
No. of Samples 5 324

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2024		 Historical
period of record
High 0.1 0.7
Mean 0.02 0.05 0.13984874
Low 0.006 0.00
No. of Samples 5 251

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2024		 Historical
period of record
High 8.0 9.5
Mean 7.83 7.8 0.49891
Low 7.74 4.20
No. of Samples 5 671

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2024		 Historical
period of record
High 33.3 39.9
Mean 30.83 26.89 6.84538
Low 27.60 0.35
No. of Samples 10 628

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2024		 Historical
period of record
High 50,930.0 56,000.0
Mean 47541.38 29714.44 15902.97703
Low 43203.00 46.582
No. of Samples 5 605

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2024		 Historical
period of record
High 91.0 99.7
Mean 83.67 76.65 8.76568
Low 67.64 51.80
No. of Samples 5 813

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2024		 Historical
period of record
High 7.0 42.0
Mean 3.64 3.93 3.5759
Low 2.70 0.20
No. of Samples 5 623

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 HUD2 2024 122 355 477 74

Impervious Features

Hudson 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.

47% of the land area within the Hudson Bayou Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Hudson 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 Hudson Bayou Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 Trend
Urban & Built-up 2,22492.4% 2,24493.3% 2,24393.2% 2,26093.9% 2,26093.9% 2,24993.5% 2,26093.9% 2,25993.9% Land Use Trend Sparkline
Upland Forests 160.7% 90.4% 90.4% 00% 00% 00% 00% 00% Land Use Trend Sparkline
Water 241% 251% 261.1% 261.1% 271.1% 271.1% 271.1% 271.1% Land Use Trend Sparkline
Wetlands 160.7% 130.5% 130.5% 100.4% 100.4% 100.4% 100.4% 100.4% Land Use Trend Sparkline
Transportation and Utilities 1265.2% 1154.8% 1154.8% 1094.6% 1094.6% 1205% 1094.5% 1104.6% Land Use Trend Sparkline
Land Use Chart