1
AOtter Tail Lake
Otter Tail County, Minnesota · 4.1 mi from Long Lake
- +Two grade letters higher (D → A)
- ++9.1 ft water clarity
- +Lower phosphorus (16 vs 37.5 µg/L)
Cleaner Lakes Than Long Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Long Lake carries a Grade D (Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Otter Tail Lake (Otter Tail County, Grade A, 4.1 mi away) is the closest meaningful upgrade.
2
ABoedigheimer Lake
Otter Tail County, Minnesota · 5.1 mi from Long Lake
- +Two grade letters higher (D → A)
- ++7.2 ft water clarity
- +Lower phosphorus (18.5 vs 37.5 µg/L)
3
AMarion Lake
Otter Tail County, Minnesota · 5.6 mi from Long Lake
- +Two grade letters higher (D → A)
- ++8 ft water clarity
- +Lower phosphorus (18 vs 37.5 µg/L)
4
BWalker Lake
Otter Tail County, Minnesota · 1.8 mi from Long Lake
- +Two grade letters higher (D → B)
- ++4.5 ft water clarity
- +Lower phosphorus (26.5 vs 37.5 µg/L)
5
BRound Lake
Otter Tail County, Minnesota · 3.7 mi from Long Lake
- +Two grade letters higher (D → B)
- ++4.9 ft water clarity
- +Lower phosphorus (22 vs 37.5 µg/L)
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.