Lake Istokpoga
Highlands County, Florida216 acresView mapDirections
Florida DEP publishes the water-quality measurements for Lake Istokpoga. Here is what has been measured.
- Hypereutrophic
- Impaired · Algal growth
- Limited data
Lake Istokpoga in Highlands County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 1 ft visibility. Phosphorus: 62 µg/L. Surface area: 216 acres.
Lake Istokpoga is a 216-acre highly nutrient-loaded hypereutrophic lake in Highlands County, Florida. Water clarity is declining over recent sampling years. Compared to the 72 other monitored lakes in Highlands County, Lake Istokpoga ranks #73 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2023-08-17. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Lake Istokpoga is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, mercury, nutrients (phosphorus, nitrogen), pH / acidity. Check local advisories before you swim.
Whether Lake Istokpoga is safe to swim in today is a call for the Florida Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Istokpoga
These are the measurements Florida DEP publishes for Lake Istokpoga, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 1 ft of visibility. Phosphorus 62 µg/L. TSI 71.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 62µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 71 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
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Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
216 acres
No bathymetric survey has been published for Lake Istokpoga, so its depth is not documented here.
Stays via Stay22
Stays near Lake Istokpoga
Compare lakeside cabins, hotels, and vacation rentals near Lake Istokpoga in Highlands County, Florida — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Lake Istokpoga are listed below.
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Fishing Lake Istokpoga
Water quality readings over time
2 seasons of samples on record (2022–2023). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening2 years
Phosphorus
Improving-35 µg/L/yr2 years
Reservoir Info (USACE NID)
Lake Istokpoga is a man-made reservoir impounded by the Structure 68, built primarily for flood risk reduction on the Canal C-41; earth-type dam, 13 ft tall.
- Surface area
- 216 ac
- Normal storage
- 1,944 ac-ft
- Max storage
- 2,200 ac-ft
- Drainage area
- 0 sq mi
- Hazard class
- Significant
- Owner
- SFWMD
All listed purposes: Flood Risk Reduction;Irrigation.
Source: USACE National Inventory of Dams, NID ID FL00282 · Operator website · Matched by proximity (0.58 km)
EPA Impairment Status
Lake Istokpoga is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Aquatic life, Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit FL1856B · Official waterbody report
Nearby Lakes in Highlands County
Frequently asked questions about Lake Istokpoga
Where is Lake Istokpoga?
- Lake Istokpoga is a lake in Highlands County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Lake Istokpoga?
- Lake Istokpoga in Highlands County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 1 ft visibility. Phosphorus: 62 µg/L. Surface area: 216 acres.
Is Lake Istokpoga safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Istokpoga is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, mercury, nutrients (phosphorus, nitrogen), pH / acidity. Check local advisories before you swim.
Explore Lake Istokpoga across LakeQuality
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Where this data comes from
12 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples12 samples · 2023
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database