Franklin County Lake Quality
Massachusetts, 5 lakes, average grade A (Excellent)
Only 5 lakes in Franklin County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. The county's average grade is A — among the cleanest in {{stateName}}. 4 lakes pull an A on their own, and almost none fall into the D or F brackets.
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. Sherman Reservoir (A) is the cleanest in the county.
Quick Answers for Franklin County
Planning a trip? Check special fishing regulations for Sherman Reservoir — or check the official Massachusetts fishing regulations.
All Lakes in Franklin County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Sherman Reservoir | A | - | 9.7 µg/L |
| 2 | Roaring Brook Lake | A | - | - |
| 3 | Atkins Reservoir | A | - | - |
| 4 | Hallockville Pond | A | - | - |
| 5 | Tully Pond | B | - | - |
Other Counties in Massachusetts
See how Franklin County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 36 states.
Where to stay near Franklin County
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Source: EPA National Aquatic Resource Surveys, 2026.