Lake County Water Atlas

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Lake Joanna

Joanna, Lake


located within Ocklawaha River Watershed


Explore general as well as scientific information about the movement, chemistry and biology of area surface water environments.

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Water Quality sampling site
Hydrology sampling site
Closest Rainfall site
Rainfall sampling site
Multi-type sampling site
Other sampling site

Overall Trophic State Index

"Trophic" means "relating to nutrition." The Trophic State Index (TSI) takes into account chlorophyll, nitrogen, and phosphorus, which are nutrients required by plant life. The Florida Department of Environmental Protection (FDEP) uses this information to determine a rating for the waterbody. Learn more about the Trophic State Index »

Latest Value Limiting Nutrient Historic Range Additional Information
NO DATA NO DATA 4 (Good) - 54 (Good)
4/5/1988 - 8/14/2017
739 samples
Water Quality Trophic State Index Trophic State Classification
GOOD0 - 59Oligotrophic through Mid-Eutrophic
FAIR60 - 69Mid-Eutrophic through Eutrophic
POOR70 - 100Hypereutrophic
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    Nutrient Chemistry

    Although present in all surface waters, nutrients are among the leading causes of degradation of Florida water resources. Learn more about nutrient chemistry »

    Parameter Latest Value Historic Range Additional Information
    Total Nitrogen (TN) NO DATA 160.0 - 2,649.0 ug/L
    4/5/1988 - 8/14/2017
    910 samples
    Total Phosphorus (TP) NO DATA 0.3 - 1,010.0 ug/L
    4/5/1988 - 8/14/2017
    831 samples
    Chlorophyll a,
    uncorrected for
    pheophytin help icon
    NO DATA 0.4 - 27.0 ug/L
    4/5/1988 - 8/14/2017
    751 samples
    Chlorophyll a,
    corrected for
    pheophytin help icon
    NO DATA 1.0 - 11.0 ug/L
    1/25/2010 - 8/14/2017
    59 samples

      Water Clarity

      Water clarity or turbidity measures the degree to which light is blocked because the water is cloudy or contains suspended particles, such as algae. Water clarity is one indicator of a waterbody's ability to sustain plants and wildlife. Learn more about water clarity »

      Parameter Latest Value Historic Range Additional Information
      Secchi Depth NO DATA 1.3 ft - 24.5 ft
      4/5/1988 - 9/26/2016
      847 samples
      Turbidity NO DATA 0.0 NTU - 11.0 NTU
      4/5/1988 - 8/14/2017
      292 samples
      Light Attenuation NO DATA NO DATA NO DATA


        The currently used bacterial indicators for recreational waters include total coliform, fecal coliform and enterococcus. Indicator organisms themselves are not necessarily pathogenic but their presence "indicates" or suggests recent contamination by human sewage or other waste which may result in human illness. Sources of contamination include storm water runoff, sewage overflows and feces from wild and domestic animals. Learn more about bacteria »

        Parameter Latest Value Historic Range Additional Information
        Fecal Coliform NO DATA 1 - 250 CFU/100ml
        11/28/2000 - 2/25/2015
        184 samples
        Total Coliform NO DATA 6 - 2,420 CFU/100ml
        11/28/2000 - 9/26/2016
        48 samples
        Enterococcus NO DATA NO DATA NO DATA
        E. coli NO DATA 1 - 56 CFU/100ml
        4/28/2009 - 9/26/2016
        18 samples

          Dissolved Oxygen

          Dissolved Oxygen (DO) is one of the most important indicators of water quality. It is essential for the survival of fish and other aquatic organisms. Learn more about dissolved oxygen »

          Parameter Latest Value Historic Range Additional Information
          Dissolved Oxygen NO DATA 0.6 - 10.6 mg/l
          4/5/1988 - 8/14/2017
          386 samples

            Impaired Waters

            The Impaired Waters Data is the most recent available data from FDEP, but it may not reflect the current FDEP impaired list. These data are updated when and as soon as they are made available from FDEP.

            This waterbody is impaired according to the State of Florida's Impaired Waters Rule (IWR) Chapter 62-303 F.A.C. that governs the Total Maximum Daily Loads (TMDL) Program or according to the U.S. Environmental Protection Agency (EPA). Identification of Impaired Surface Waters (IWR) is a new scientific approach for guiding Florida Department of Environmental Protection process for identifying and prioritizing impaired surface waters in Florida. The rule evaluates whether waters meet their designated uses for a particular analyte, which include aquatic life use support, primary contact and recreation use support, fish and shellfish consumption use support, and drinking water use support. All water resources in this county are designated as Class III waters. Class III waters are considered recreational use waters, which means that the water should be fishable and swimmable. Class II waters are for shellfish propagation and harvesting. Class I waters are considered potable (drinkable) water supplies. As part of the terms of a court order related to the 1998 303(d) list of impaired waters, some waters are listed as impaired by EPA but not listed by the State of Florida. Learn more about impaired waters »


            This waterbody has been associated with the following WBIDs deemed impaired by the Florida Department of Environmental Protection:

            WBID Basin Impairment(s)

            Source(s): Florida Department of Environmental Protection

            This waterbody has been associated with the following WBIDs deemed impaired by the Environmental Protection Agency's 303(d) list:

            WBID Basin Impairment(s) EPA Details
            2821B LAKE JOANNA TROPHIC STATE INDEX (TSI) View additional EPA information »

            Source(s): US Environmental Protection Agency



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