Lake Ripley
Jefferson County, WisconsinMesotrophic
Lake Ripley carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.
Mesotrophic conditions dominate at Lake Ripley: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake bottoms out at 44 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Lake Ripley covers 420 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Lake Ripley ranks 2 of 8 in Jefferson County, putting it in the upper tier of locally monitored lakes.
Zebra mussel presence at Lake Ripley means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Walleye are documented at Lake Ripley, one of 4 fish species on record for the 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 2025-08-27. Grade methodology: LakeGrade methodology.
Track Lake Ripley
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 8.8 ft. Phosphorus level: 22.3 µg/L. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.8 ft | C |
| Phosphorus | 22.3 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 44 ft |
| Surface Area | 420 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Lake Ripley (14-day solunar calendar)
→ Is it safe to eat fish from Lake Ripley? (mercury & PFAS guide)
→ Lake Ripley fishing regulations (limits, seasons, special rules)
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.112 m/yr | 5 |
| Phosphorus | ↑ Improving | -1.71 µg/L/yr | 6 |
Location
County Ranking
Ranked #2 of 8 lakes in Jefferson County
Cleaner Lakes Within 30 Miles
Lake Ripley holds Grade B. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Jefferson County
More Wisconsin Lake Rankings
State Parks Near Lake Ripley
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1989. 5 stations on file (most recent sample 2026).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Lake Ripley covering fish populations, stocking, water quality, and management. 1 report on file.
- 2023Lake Ripley comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-08-27
Monitoring stations: 1