Stony Lake vs Webb Lake
Water quality, depth, fish species, and recreation comparison.
Stony Lake and Webb Lake both received the same overall water quality grade of A (Excellent). Both are in Cass County, Minnesota.
Both Stony Lake and Webb Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. These two are within a letter of each other on the rubric — Stony Lake (A) versus Webb Lake (A). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Stony Lake
Crystal clear, you can see 23 ft down.
Webb Lake
Crystal clear, you can see 18 ft down.
Side-by-Side Metrics
| Metric | Stony Lake | Webb Lake |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 23 ft | 18 ft |
| Phosphorus | 7 µg/L | 9.5 µg/L |
| Chlorophyll-a (Algae) | 2 µg/L | 2.9 µg/L |
| Maximum Depth | 50 ft | 84 ft |
| Surface Area | 563 acres | 720 acres |
| Public Access | Yes | Yes |
| Fish Species | 12 | 12 |
| Trophic State | oligotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Stony Lake: 23 ft, Webb Lake: 18 ft) and what you want from the lake. Stony Lake matches its peer on species count.
Source: EPA National Aquatic Resource Surveys, 2026.