Lake St. Joseph
Tensas Parish County, LouisianaView mapDirections
LDEQ publishes the water-quality measurements for Lake St. Joseph. Here is what has been measured.
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
Lake St. Joseph in Tensas Parish County, Louisiana has water-quality measurements published by LDEQ, shown here as reported. Phosphorus: 737 µg/L.
Lake St. Joseph is a highly nutrient-loaded hypereutrophic lake in Tensas Parish County, Louisiana. Compared to the 4 other monitored lakes in Tensas Parish County, Lake St. Joseph ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-12-17. Methodology: how these readings are compared.
Swimming conditions
Readings onlyBacteria advisory
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 St. Joseph is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pathogens (E. coli, fecal), turbidity. Check local advisories before you swim.
Whether Lake St. Joseph is safe to swim in today is a call for the Louisiana Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake St. Joseph
These are the measurements LDEQ publishes for Lake St. Joseph, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 737 µg/L. TSI 99.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 737µg/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. | 99 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lake St. Joseph
Answers come straight from the public measurements and survey records on this page.
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Stays near Lake St. Joseph
Compare lakeside cabins, hotels, and vacation rentals near Lake St. Joseph in Tensas Parish County, Louisiana — 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 St. Joseph are listed below.
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Fishing Lake St. Joseph
EPA Impairment Status
Lake St. Joseph is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit LA081202_00 · Official waterbody report
Nearby Lakes in Tensas Parish County
Frequently asked questions about Lake St. Joseph
Where is Lake St. Joseph?
- Lake St. Joseph is a lake in Tensas Parish County, Louisiana. Its water-quality measurements are published by LDEQ and shown on this page as reported.
What is the water quality of Lake St. Joseph?
- Lake St. Joseph in Tensas Parish County, Louisiana has water-quality measurements published by LDEQ, shown here as reported. Phosphorus: 737 µg/L.
Is Lake St. Joseph safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake St. Joseph is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pathogens (E. coli, fecal), turbidity. Check local advisories before you swim.
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Where this data comes from
75 measurements from 2 monitoring stations, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- LDEQ319
LDEQ31958 samples · 2023–2025 - LDEQ/Water Planning and Assessment (Louisiana)
LADEQWPD_WQX17 samples · 2021–2022
Analytical methods
- Total Phosphorus After Block Digestion
- 2130 B ~ Nephelometric Method
- Phosphorus by Two Reagent Colorimetry
- Turbidity by Nephelometry
Monitoring station identifiers (2)
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