Prairie Oaks Pond
Dane County, WisconsinLimited DataHypereutrophic
On the LakeGrade rubric Prairie Oaks Pond fails the cutoffs — a TSI of 89 and persistent algal pressure put it in the bottom tier. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
A TSI above 70 puts Prairie Oaks Pond in hypereutrophic territory: visible blooms are common, and clarity rarely climbs even in early summer. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Prairie Oaks Pond ranks 20 of 23 in Dane County — at the lower end of the locally monitored distribution.
No invasive species are currently listed at Prairie Oaks Pond — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Prairie Oaks Pond, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2021-10-05. Grade methodology: LakeGrade methodology.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
No clarity data. Phosphorus level: 350.5 µg/L. Trophic State Index: 89.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 350.5 µg/L | F |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 89 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↑ Improving | -132 µg/L/yr | 2 |
Location
County Ranking
Ranked #20 of 23 lakes in Dane County
Nearby Lakes in Dane County
More Wisconsin Lake Rankings
State Parks Near Prairie Oaks Pond
Other Grade F Lakes in Wisconsin
Hypereutrophic Lakes in Wisconsin
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2021-10-05
Monitoring stations: 1