Cox Lake
Calhoun County, TexasView mapDirections
TCEQ publishes the water-quality measurements for Cox Lake. Here is what has been measured.
- 40 ft max depth
- Public access
- Limited data
Cox Lake in Calhoun County, Texas has water-quality measurements published by TCEQ, shown here as reported. Water clarity: 0.7 ft visibility. Phosphorus: 303 µg/L. Chlorophyll-a (algae): 15.8 µg/L.
Cox Lake is a lake in Calhoun County, Texas with an estimated average depth of about 40 feet. Phosphorus level is declining over recent sampling years. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled 2025-11-20. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Cox Lake is safe to swim in today is a call for the Texas Commission on Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Cox Lake
These are the measurements TCEQ publishes for Cox 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 0.7 ft of visibility. Phosphorus 303 µg/L. Chlorophyll-a 15.8 µg/L. TSI 76.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 303µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 15.8µg/L | Measured, not scored 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. | 76 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Cox Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~40 ft est.
Public access
Yes
Listed by TCEQ
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Texas has not published bathymetry for Cox Lake.
Lake Size & Watershed
Watershed (drainage) area
9 sq mi
HydroLAKES / HydroSHEDS
Surface area
267 acres
HydroLAKES / HydroSHEDS
Shoreline
5.8 mi
HydroLAKES / HydroSHEDS
Elevation
20 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Stays via Stay22
Stays near Cox Lake
Compare lakeside cabins, hotels, and vacation rentals near Cox Lake in Calhoun County, Texas — 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.
Top-rated places to stay near Cox Lake
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Texas’s top lakes →
Follow Cox Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Cox Lake
Water quality readings over time
2 seasons of samples on record (2023–2025). Calling a direction takes at least 4 years of the same measurement.
Phosphorus
Worsening+17 µg/L/yr2 years
Chlorophyll-a
Improving-6.75 µg/L/yr2 years
Nearby Lakes in Calhoun County
Frequently asked questions about Cox Lake
Where is Cox Lake?
- Cox Lake is a lake in Calhoun County, Texas. Its water-quality measurements are published by TCEQ and shown on this page as reported.
What is the water quality of Cox Lake?
- Cox Lake in Calhoun County, Texas has water-quality measurements published by TCEQ, shown here as reported. Water clarity: 0.7 ft visibility. Phosphorus: 303 µg/L. Chlorophyll-a (algae): 15.8 µg/L.
Is Cox Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Cox Lake?
- No published bathymetric survey covers Cox Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 40 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Can I fish at Cox Lake?
- Public access to Cox Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Texas's fish and wildlife agency, so check its current regulations before you go.
Explore Cox Lake across LakeQuality
More lakes in Texas
Other Lakes in Texas
Hypereutrophic Lakes in Texas
Where this data comes from
31 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Texas Commission on Environmental Quality
TCEQMAIN31 samples · 2020–2025
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
Lake size & watershed from HydroLAKES (HydroSHEDS)