Long Lake
Sunflower County, MississippiView mapDirections
MDEQ publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Hypereutrophic
Long Lake in Sunflower County, Mississippi has water-quality measurements published by MDEQ, shown here as reported. Water clarity: 1.5 ft visibility. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 46.8 µg/L.
Long Lake is a highly nutrient-loaded hypereutrophic lake in Sunflower County, Mississippi.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2021-10-19. Methodology: how these readings are compared.
Swimming conditions
Readings onlyAlgae risk
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. Check local advisories before you swim.
Whether Long Lake is safe to swim in today is a call for the Mississippi Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Long Lake
These are the measurements MDEQ publishes for Long Lake, 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 1.5 ft of visibility. Phosphorus 55 µg/L. Chlorophyll-a 46.8 µg/L. TSI 67.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 55µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 46.8µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 67 | 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.
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Stays near Long Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Lake in Sunflower County, Mississippi — 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 Long Lake are listed below.
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Fishing Long Lake
Nearby Lakes in Sunflower County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Sunflower County, Mississippi. Its water-quality measurements are published by MDEQ and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Sunflower County, Mississippi has water-quality measurements published by MDEQ, shown here as reported. Water clarity: 1.5 ft visibility. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 46.8 µg/L.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Long Lake across LakeQuality
More lakes in Mississippi
Other Lakes in Mississippi
Hypereutrophic Lakes in Mississippi
Where this data comes from
53 measurements from 1 monitoring station, 2020–2021. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- MISSISSIPPI DEPARTMENT OF ENVIRONMENTAL QUALITY
21MSWQ_WQX53 samples · 2020–2021
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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.