Sam Rayburn Reservoir
San Augustine County, TexasView mapDirections
TCEQ publishes the water-quality measurements for Sam Rayburn Reservoir. Here is what has been measured.
- Eutrophic
- Impaired · Algal growth
- Public access
Sam Rayburn Reservoir in San Augustine County, Texas has water-quality measurements published by TCEQ, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 27.5 µg/L. Chlorophyll-a (algae): 18.6 µg/L.
Sam Rayburn Reservoir is a productive, nutrient-rich eutrophic lake in San Augustine County, Texas. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 12 public boat landings. Compared to the 2 other monitored lakes in San Augustine County, Sam Rayburn Reservoir ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled 2025-12-10. Methodology: how these readings are compared.
Sam Rayburn Reservoir has 12 public boat landings, so a lakefront rental is not the only way to get a boat on the water. If you are planning to stay, you can search lake houses and cabins around Sam Rayburn Reservoir on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Sam Rayburn Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch12 documented ramps
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. Sam Rayburn Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, dioxins, mercury. Check local advisories before you swim.
Whether Sam Rayburn Reservoir 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 Sam Rayburn Reservoir
These are the measurements TCEQ publishes for Sam Rayburn Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.9 ft. Phosphorus 27.5 µg/L. Chlorophyll-a 18.6 µg/L. TSI 56.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 27.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 18.6µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 56 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Sam Rayburn Reservoir
Answers come straight from the public measurements and survey records on this page.
→ Sam Rayburn Reservoir water level: the live USGS gauge reading
Recreation & Access
- Cassells-Boykin Park (East)Public
- Boat Ramp RoadPublic
- Caney Creek ParkPublic
- Hanks Creek Park (North)Public
- Hanks Creek Park (South)Public
- Monterrey ParkPublic
Showing 6 of 12 documented landings from the USGS National Boat Ramps inventory.
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Sam Rayburn Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Sam Rayburn Reservoir in San Augustine 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 Sam Rayburn Reservoir
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Fishing Sam Rayburn Reservoir
Water Quality Trend: Worsening
Based on 5 years of monitoring (2021–2025).
Water clarity
Worsening5 years
Phosphorus
Worsening+4.02 µg/L/yr4 years
Chlorophyll-a
Improving-1.17 µg/L/yr5 years
EPA Impairment Status
Sam Rayburn Reservoir 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: Fish consumption, Other.
Source: EPA ATTAINS assessment unit TX-0610_03 · Official waterbody report
Nearby Lakes in San Augustine County
Frequently asked questions about Sam Rayburn Reservoir
Where is Sam Rayburn Reservoir?
- Sam Rayburn Reservoir is a lake in San Augustine County, Texas. Its water-quality measurements are published by TCEQ and shown on this page as reported.
What is the water quality of Sam Rayburn Reservoir?
- Sam Rayburn Reservoir in San Augustine County, Texas has water-quality measurements published by TCEQ, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 27.5 µg/L. Chlorophyll-a (algae): 18.6 µg/L.
Is Sam Rayburn Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Sam Rayburn Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, dioxins, mercury. Check local advisories before you swim.
Are there boat ramps on Sam Rayburn Reservoir?
- Sam Rayburn Reservoir has 12 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Cassells-Boykin Park (East), Boat Ramp Road, Caney Creek Park, Hanks Creek Park (North), among others. Public access is listed as yes.
Can I fish at Sam Rayburn Reservoir?
- Sam Rayburn Reservoir has 12 documented boat landings in the USGS National Boat Ramps inventory. 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.
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Where this data comes from
53 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
TCEQMAIN53 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
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory