1
BMilan Lake North
Sullivan County, Wisconsin · 21.1 mi from Unionville Lake
- +Two grade letters higher (F → B)
- +Lower phosphorus (51.8 vs 129.5 µg/L)
Cleaner Lakes Than Unionville Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Unionville Lake carries a Grade F (Very Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Milan Lake North (Sullivan County, Grade B, 21.1 mi away) is the closest meaningful upgrade.
2
CHazel Creek Lk. Lake
Adair County, Wisconsin · 25.2 mi from Unionville Lake
- +Two grade letters higher (F → C)
- ++2 ft water clarity
- +Lower phosphorus (24.5 vs 129.5 µg/L)
3
CHazel Creek Lk. Lake
Adair County, Wisconsin · 25.1 mi from Unionville Lake
- +Two grade letters higher (F → C)
- ++1.2 ft water clarity
- +Lower phosphorus (22 vs 129.5 µg/L)
4
DHazel Creek Lk. East Fork Lake
Adair County, Wisconsin · 26.8 mi from Unionville Lake
- +Higher grade (F → D)
- +Lower phosphorus (31.5 vs 129.5 µg/L)
5
FElmwood Lake
Sullivan County, Wisconsin · 19.6 mi from Unionville Lake
- +Higher overall water quality score
- ++1.1 ft water clarity
- +Lower phosphorus (70.8 vs 129.5 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.