1
ABlack Hawk Lake
Iowa County, Wisconsin · 11.1 mi from Ludden Lake
- +Two grade letters higher (D → A)
- ++12.3 ft water clarity
- +Lower phosphorus (19.9 vs 172 µg/L)
Cleaner Lakes Than Ludden Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Ludden Lake carries a Grade D (Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Black Hawk Lake (Iowa County, Grade A, 11.1 mi away) is the closest meaningful upgrade.
2
BHidden Valley Lake
Lafayette County, Wisconsin · 15.6 mi from Ludden Lake
- +Two grade letters higher (D → B)
- ++11.5 ft water clarity
- +Lower phosphorus (44.7 vs 172 µg/L)
3
BLong Lake
Sauk County, Wisconsin · 20.5 mi from Ludden Lake
- +Two grade letters higher (D → B)
- ++8.6 ft water clarity
- +Lower phosphorus (27.9 vs 172 µg/L)
4
BHill Slough Lake
Sauk County, Wisconsin · 20.7 mi from Ludden Lake
- +Two grade letters higher (D → B)
- ++9.5 ft water clarity
- +Lower phosphorus (42.7 vs 172 µg/L)
5
BBakkens Pond
Sauk County, Wisconsin · 21.1 mi from Ludden Lake
- +Two grade letters higher (D → B)
- ++3.3 ft water clarity
- +Lower phosphorus (23.3 vs 172 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.