Sinl Lake
Lawrence County, AlabamaView mapDirections
Clarity, phosphorus, and algae all sit in the cleanest band for this region.
- Oligotrophic
- #1 of 2 in the county
- 34 ft max depth
- Limited data
Sinl Lake in Lawrence County, Alabama has a water quality grade of A (Excellent). Water clarity: 14.5 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 1.7 µg/L.
- Clarity
- 14.5 ft
- Max depth
- ~34 ft est.
- Type
- Oligotrophic
- Phosphorus
- 13.5 µg/L
- Chlorophyll-a
- 1.7 µg/L
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Watch Sinl Lake’s letter
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Sinl Lake is a cold, clear oligotrophic lake in Lawrence County, Alabama with an estimated average depth of about 34 feet. Water quality is graded A based on 2 sampling years through 2023. Compared to the 1 other monitored lakes in Lawrence County, Sinl Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, ADEM, last sampled 2023-10-18. Grade methodology: LakeQuality methodology.
What Sinl Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.5 ft of visibility
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 A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: A (Excellent)
Good clarity, visible to about 14.5 ft. Phosphorus 13.5 µg/L. Chlorophyll-a 1.7 µg/L. TSI 39. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.5 ft | Not graded |
| Phosphorus | 13.5 µg/L | Good |
| Chlorophyll-a (Algae) | 1.7 µg/L | Good |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water. The letter is not a swimming clearance.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~34 ft est. |
| Average Depth | ~14 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Alabama has not published bathymetry for Sinl 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 Sinl Lake
County Ranking
Ranked #1 of 2 lakes in Lawrence County
Nearby Lakes in Lawrence County
Frequently asked questions about Sinl Lake
Where is Sinl Lake?
- Sinl Lake is a lake in Lawrence County, Alabama. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Sinl Lake?
- Sinl Lake in Lawrence County, Alabama has a water quality grade of A (Excellent). Water clarity: 14.5 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 1.7 µg/L.
Is Sinl Lake safe to swim in?
- The A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
How deep is Sinl Lake?
- No published bathymetric survey covers Sinl Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 34 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Sinl Lake across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Alabama's top lakes, each with its grade
Low nutrients, clear water. The letter is not a swimming clearance.
Alabama's cleanest and most-polluted lakes, ranked
More Alabama Lake Rankings
Other Grade A Lakes in Alabama
Where this data comes from
28 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- ALABAMA DEPT. OF ENVIRONMENTAL MANAGEMENT - WATER QUALITY DATA
21AWIC28 samples · 2023
Analytical methods
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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)