1
ALower Birch Lake
Isanti County, Minnesota · 0.6 mi from Twin Lake
- +Two grade letters higher (D → A)
- ++8.2 ft water clarity
- +Lower phosphorus (15 vs 110 µg/L)
Cleaner Lakes Than Twin Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Twin Lake carries a Grade D (Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Lower Birch Lake (Isanti County, Grade A, 0.6 mi away) is the closest meaningful upgrade.
2
AUpper Birch Lake
Isanti County, Minnesota · 0.7 mi from Twin Lake
- +Two grade letters higher (D → A)
- ++8.2 ft water clarity
- +Lower phosphorus (9.5 vs 110 µg/L)
3
BHorseshoe Lake
Isanti County, Minnesota · 1.1 mi from Twin Lake
- +Two grade letters higher (D → B)
- +Lower phosphorus (12 vs 110 µg/L)
4
BHoffman Lake
Isanti County, Minnesota · 1.2 mi from Twin Lake
- +Two grade letters higher (D → B)
- ++1.5 ft water clarity
- +Lower phosphorus (15 vs 110 µg/L)
5
BHorseleg Lake
Isanti County, Minnesota · 1.6 mi from Twin Lake
- +Two grade letters higher (D → B)
- ++1.1 ft water clarity
- +Lower phosphorus (17 vs 110 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.