Jones Slough Lake
Grant County, WisconsinMesotrophic
Jones Slough Lake comes in at a B on the grading rubric — a respectable showing for a Wisconsin lake of its size and depth. Of the three parameters, phosphorus is the worst — at 31 µg/L of phosphorus, it keeps the lake susceptible to algal blooms in warm years.
The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. 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. Among the 3 graded lakes in Grant County, Jones Slough Lake sits at rank 1, above the county median.
Jones Slough Lake has no invasive species recorded in Wisconsin state databases as of 2023, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Jones Slough Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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 2023-10-30. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Crystal clear, you can see 16.1 ft down. Phosphorus level: 31 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 16.1 ft | A |
| Phosphorus | 31 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.3 m/yr | 2 |
| Phosphorus | ↓ Declining | +35.6 µg/L/yr | 2 |
Location
County Ranking
Ranked #1 of 3 lakes in Grant County
Cleaner Lakes Within 30 Miles
Jones Slough Lake holds Grade B. 2 nearby lakes hold higher grades.
- AGoodwiler LakeIowa County · 6.5 mi · Higher grade (B → A)
- ACruson Slough LakeRichland County · 15.6 mi · Higher grade (B → A)
Nearby Lakes in Grant County
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
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: 2023-10-30
Monitoring stations: 1