Lake Mexia
Limestone County, Texas1,009 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- #2 of 2 in the county
- 31 ft max depth
- Limited data
Lake Mexia in Limestone County, Texas has a water quality grade of F (Algae-prone). Water clarity: 1.1 ft visibility. Phosphorus: 170 µg/L. Chlorophyll-a (algae): 50.7 µg/L. Surface area: 1009 acres.
- Clarity
- 1.1 ft
- Max depth
- ~31 ft est.
- Area
- 1,009 acres
- Type
- Hypereutrophic
- Phosphorus
- 170 µg/L
- Chlorophyll-a
- 50.7 µg/L
- Trend
- → Stable
Stays via Stay22
Stays near Lake Mexia
Compare lakeside cabins, hotels, and vacation rentals near Lake Mexia in Limestone 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Lake Mexia are listed below.
Top-rated places to stay near Lake Mexia
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Watch Lake Mexia’s letter
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Lake Mexia is a 1,009-acre highly nutrient-loaded hypereutrophic lake in Limestone County, Texas with an estimated average depth of about 31 feet. Water quality is graded F based on 2 sampling years through 2026. Water clarity is declining over recent sampling years. Compared to the 1 other monitored lakes in Limestone County, Lake Mexia ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled 2026-01-13. Grade methodology: LakeQuality methodology.
What Lake Mexia is good for
From access and monitoring records, not editorial picks.
- Big water1,009 acres
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The F is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.1 ft of visibility. Phosphorus 170 µg/L. Chlorophyll-a 50.7 µg/L. TSI 74. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.1 ft | Not graded |
| Phosphorus | 170 µg/L | Poor |
| Chlorophyll-a (Algae) | 50.7 µg/L | Poor |
| Trophic State Index (TSI) | 74 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Current Conditions
USGS snapshot Sep 7, 2026, 4:00 PM from gauge 08110300 (Lk Mexia nr Mexia, TX). Station page ↗ — a live reading replaces this snapshot when the gauge responds. Missing live data is not an all-clear.
→ Lake Mexia water level: the live USGS gauge reading
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~31 ft est. |
| Average Depth | ~11 ft est. |
| Surface Area | 1,009 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Texas has not published bathymetry for Lake Mexia.
Lake Size & Watershed
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.
Fishing Lake Mexia
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.08 m/yr | 5 |
| Phosphorus | → Stable | +0.93 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -2.83 µg/L/yr | 4 |
Reservoir Info (USACE NID)
Lake Mexia is a man-made reservoir impounded by the Bistone Dam (completed 1961), built primarily for water supply on the Navasota River; earth-type dam, 50 ft tall and 1,645 ft long.
- Surface area
- 1,009 ac
- Normal storage
- 4,687 ac-ft
- Max storage
- 44,321 ac-ft
- Drainage area
- 198 sq mi
- Hazard class
- High
- Owner
- BISTONE MWS DISTRICT
All listed purposes: Water Supply;Other;Recreation.
Source: USACE National Inventory of Dams, NID ID TX01061 · Operator website · Matched by proximity (0.34 km)
County Ranking
Ranked #2 of 2 lakes in Limestone County
Nearby Lakes in Limestone County
Frequently asked questions about Lake Mexia
Where is Lake Mexia?
- Lake Mexia is a lake in Limestone County, Texas. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Mexia?
- Lake Mexia in Limestone County, Texas has a water quality grade of F (Algae-prone). Water clarity: 1.1 ft visibility. Phosphorus: 170 µg/L. Chlorophyll-a (algae): 50.7 µg/L. Surface area: 1009 acres.
Is Lake Mexia safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
How deep is Lake Mexia?
- No published bathymetric survey covers Lake Mexia, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 31 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 1009 acres.
What is the water level at Lake Mexia?
- The USGS snapshot on this page for Lake Mexia is 446.83 ft of water-surface elevation, recorded Sep 7, 2026, 4:00 PM at gauge 08110300. Current Conditions hydrates a live NWIS reading from that same station when the gauge responds. A missed live fetch is not an all-clear.
Explore Lake Mexia across LakeQuality
More Texas Lake Rankings
Other Grade F Lakes in Texas
Hypereutrophic Lakes in Texas
Where this data comes from
61 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Texas Commission on Environmental Quality
TCEQMAIN61 samples · 2020–2026
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)