1
AAnn Lake
Sherburne County, Minnesota · 3.7 mi from Birch Lake
- +Two grade letters higher (C → A)
- ++5.8 ft water clarity
- +Lower phosphorus (15.5 vs 21 µg/L)
Cleaner Lakes Than Birch Lake
3 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Birch Lake carries a Grade C (Fair) water quality score. Within 30 miles, 3 lakes hold a higher grade. Ann Lake (Sherburne County, Grade A, 3.7 mi away) is the closest meaningful upgrade.
2
AMitchell Lake
Sherburne County, Minnesota · 4.7 mi from Birch Lake
- +Two grade letters higher (C → A)
- ++4.2 ft water clarity
- +Lower phosphorus (14.5 vs 21 µg/L)
3
ABig Lake
Sherburne County, Minnesota · 4.7 mi from Birch Lake
- +Two grade letters higher (C → A)
- ++7.7 ft water clarity
- +Lower phosphorus (10.5 vs 21 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.