What is the cleanest lake near Portage Lake?

Lake Winnibigoshish in Cass County holds a Grade A water quality score and is 4.5 miles from Portage Lake.

Why is Portage Lake not Grade A?

Portage Lake holds Grade B, with about 7.5 ft of water clarity and 23 µg/L of phosphorus. The grade reflects measured water quality against Metropolitan Council thresholds. Cleaner alternatives nearby score higher on clarity, phosphorus, or chlorophyll-a.

Are these recommendations based on real data?

Yes. Every grade is calculated from EPA Water Quality Portal samples for the lake. Recommendations are limited to lakes within 30 miles of Portage Lake in Minnesota, with strictly higher numeric grade scores and sufficient monitoring data.

Cleaner Lakes Than Portage Lake, Top 4 Within 30 Miles, LakeQuality

Cleaner Lakes Than Portage Lake

4 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.

Portage Lake carries a Grade B (Good) water quality score. Within 30 miles, 4 lakes hold a higher grade. Lake Winnibigoshish (Cass County, Grade A, 4.5 mi away) is the closest meaningful upgrade.

Lake Winnibigoshish

Cass County, Minnesota · 4.5 mi from Portage Lake

+Higher grade (B → A)
++8.5 ft water clarity

Upper Sucker Lake

Cass County, Minnesota · 4 mi from Portage Lake

+Higher overall water quality score
++3.3 ft water clarity
+Lower phosphorus (17 vs 23 µg/L)

Sugar Lake

Itasca County, Minnesota · 7.6 mi from Portage Lake

+Higher overall water quality score
+Lower phosphorus (16 vs 23 µg/L)

Six Mile Lake

Cass County, Minnesota · 9.6 mi from Portage Lake

+Higher overall water quality score
++4 ft water clarity
+Lower phosphorus (16 vs 23 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.