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LakeQuality
C

White Ash Lake

Polk County, WisconsinEutrophic

The LakeGrade rubric puts White Ash Lake at a C: clarity at 9.8 ft, 68 µg/L of phosphorus, and a TSI of 55 signal an intermediate trophic state. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of just 9 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. White Ash Lake covers 147 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 77 graded lakes of Polk County, White Ash Lake sits at rank 70, near the bottom of the county list.

An invasive species record — Chinese Mystery Snail — has been logged at White Ash Lake; Wisconsin DNR maintains the official infested-waters list. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-29. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Moderate clarity, visible to about 9.8 ft. Phosphorus level: 68.2 µg/L. Trophic State Index: 55.

MetricValueGrade
Water Clarity (Secchi Depth)9.8 ftC
Phosphorus68.2 µg/LD
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)55Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Maximum Depth9 ft
Surface Area147 acres
Public AccessYes

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for White Ash Lake (14-day solunar calendar)

→ Is it safe to eat fish from White Ash Lake? (mercury & PFAS guide)

White Ash Lake fishing regulations (limits, seasons, special rules)

Invasive Species

Chinese Mystery SnailCurly-Leaf PondweedPurple Loosestrife

Water Quality Trend: Declining

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.264 m/yr7
Phosphorus Declining+3.15 µg/L/yr6
See year-by-year chart →

Recreation & Access

2
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #70 of 77 lakes in Polk County

Cleaner Lakes Within 30 Miles

White Ash Lake holds Grade C. 5 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Polk County

Eutrophic Lakes in Wisconsin

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1993. 2 stations on file (most recent sample 2025).

DNR Assessment
Fair · Shallow Lowland lake
Trophic State Index 68 (eutrophic) · 5-year average

Fish Species (DNR-rated)

Panfish(Common)Largemouth Bass(Common)Northern Pike(Common)

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2025-09-29

Monitoring stations: 2