Williams County Lake Quality
North Dakota, 9 lakes, average grade C (Fair)
Williams County has 9 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. Williams County averages to a C. The distribution behind that average matters more than the letter: a few stressed lakes versus many decent ones can produce the same average as the inverse.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Epping-Springbrook Dam-Littoral Lake (A) is the cleanest in the county.
Quick Answers for Williams County
Planning a trip? Check special fishing regulations for Epping-Springbrook Dam-Littoral Lake, whether the fish are safe to eat, and the best times to fish — or check the official North Dakota fishing regulations.
Fishing in Williams County
All Lakes in Williams County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Epping-Springbrook Dam-Littoral Lake | A | - | 25.4 ft | - |
| 2 | Kota Ray Dam Lake | B | 7.7 ft | 26.2 ft | - |
| 3 | Blacktail Dam Lake | B | 7.2 ft | 36.3 ft | - |
| 4 | Kettle Lake | B | 5.3 ft | 35.8 ft | - |
| 5 | Trenton Lake | C | 1.5 ft | 8.1 ft | - |
| 6 | Epping-Springbrook Dam-S Inlet Lake | C | - | 25.4 ft | - |
| 7 | Mcleod Reservoir | C | 5.4 ft | 34.6 ft | - |
| 8 | Epping-Springbrook Dam-Deepest Lake | D | 4.9 ft | 25.4 ft | - |
| 9 | Tioga Dam Lake | D | 2.2 ft | 28.9 ft | - |
Other Counties in North Dakota
See how Williams County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 15 states.
Where to stay near Williams County
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Source: EPA National Aquatic Resource Surveys, 2026.