Tri County Lake
Calhoun County, Arkansas289 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from D at the last regrade
- Hypereutrophic
- #1 of 1 in the county
- 29 ft max depth
- Limited data
Tri County Lake in Calhoun County, Arkansas has a water quality grade of F (Algae-prone). Phosphorus: 80 µg/L. Chlorophyll-a (algae): 32.3 µg/L. Surface area: 288.9 acres.
- Max depth
- ~29 ft est.
- Area
- 289 acres
- Type
- Hypereutrophic
- Phosphorus
- 80 µg/L
- Chlorophyll-a
- 32.3 µg/L
- Trend
- ↑ Improving
Stays via Stay22
Stays near Tri County Lake
Compare lakeside cabins, hotels, and vacation rentals near Tri County Lake in Calhoun County, Arkansas — 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 Tri County Lake are listed below.
Top-rated places to stay near Tri County Lake
Prices for Sep 11–13, 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 Arkansas’s top lakes →
Watch Tri County Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Tri County Lake is a 289-acre highly nutrient-loaded hypereutrophic lake in Calhoun County, Arkansas with an estimated average depth of about 29 feet. Water quality is graded F based on 1 sampling years through 2026. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, ADEQ, last sampled 2026-02-10. Grade methodology: LakeQuality methodology.
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)
No clarity data. Phosphorus 80 µg/L. Chlorophyll-a 32.3 µg/L. TSI 66. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 80 µg/L | Not graded |
| Chlorophyll-a (Algae) | 32.3 µg/L | Poor |
| Trophic State Index (TSI) | 66 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~29 ft est. |
| Average Depth | ~10 ft est. |
| Surface Area | 289 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Arkansas has not published bathymetry for Tri County Lake.
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 Tri County Lake
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Chlorophyll-a | ↑ Improving | -12.3 µg/L/yr | 3 |
Reservoir Info (USACE NID)
Tri County Lake is a man-made reservoir impounded by the Tri-County Lake Dam (completed 1962), built primarily for recreation on the Caney Creek; earth-type dam, 16 ft tall and 3,000 ft long.
- Surface area
- 288.9 ac
- Normal storage
- 1,230 ac-ft
- Max storage
- 2,910 ac-ft
- Drainage area
- 14.48 sq mi
- Hazard class
- Low
- Owner
- Arkansas Game and Fish Commission
Source: USACE National Inventory of Dams, NID ID AR00957 · Operator website
County Ranking
Ranked #1 of 1 lakes in Calhoun County
Nearby Lakes in Calhoun County
Frequently asked questions about Tri County Lake
Where is Tri County Lake?
- Tri County Lake is a lake in Calhoun County, Arkansas. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Tri County Lake?
- Tri County Lake in Calhoun County, Arkansas has a water quality grade of F (Algae-prone). Phosphorus: 80 µg/L. Chlorophyll-a (algae): 32.3 µg/L. Surface area: 288.9 acres.
Is Tri County Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
How deep is Tri County Lake?
- No published bathymetric survey covers Tri County Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 29 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 288.9 acres.
Explore Tri County Lake across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Arkansas's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
Arkansas's cleanest and most-polluted lakes, ranked
More Arkansas Lake Rankings
Other Grade F Lakes in Arkansas
Hypereutrophic Lakes in Arkansas
Where this data comes from
31 measurements from 1 monitoring station, 2023–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Arkansas Department of Environmental Quality
ARDEQH2O_WQX31 samples · 2023–2026
Analytical methods
- 4500 P J ~ Persulfate Method for Simultaneous Determination of Total Nitrogen and Total Phosphorus
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- Turbidity by Nephelometry
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)