1
ALower Hamlin Lake North Central Basin South of the Narrows
Mason County, Wisconsin · 19.7 mi from Pentwater Lake Northwest Basin; Pentwater Township
- +Higher grade (B → A)
- ++6.5 ft water clarity
Cleaner Lakes Than Pentwater Lake Northwest Basin; Pentwater Township
1 higher-graded lake within 30 miles, ranked by grade improvement and proximity.
Pentwater Lake Northwest Basin; Pentwater Township carries a Grade B (Good) water quality score. Within 30 miles, 1 lake holds a higher grade. Lower Hamlin Lake North Central Basin South of the Narrows (Mason County, Grade A, 19.7 mi away) is the closest meaningful upgrade.
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.