Alva Lake
Oneida County, WisconsinOligotrophic
On the LakeGrade rubric, Alva Lake pulls an A: clarity at 62.8 ft and 12 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
A TSI value of 28 puts Alva Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Alva Lake reaches 43 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 199 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Among the 140 graded lakes in Oneida County, Alva Lake ranks 30 — in the top quartile locally.
An invasive species record — Banded Mystery Snail — has been logged at Alva Lake; Wisconsin DNR maintains the official infested-waters list. Walleye are documented at Alva Lake, one of 5 fish species on record for the lake. A documented public access point at Alva Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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 2025-10-14. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 62.8 ft down. Phosphorus level: 11.5 µg/L. Trophic State Index: 28.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 62.8 ft | A |
| Phosphorus | 11.5 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 28 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 43 ft |
| Surface Area | 199 acres |
| Public Access | Yes |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Alva Lake (14-day solunar calendar)
→ Is it safe to eat fish from Alva Lake? (mercury & PFAS guide)
→ Alva Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.053 m/yr | 7 |
| Phosphorus | ↑ Improving | -0.59 µg/L/yr | 6 |
Recreation & Access
Location
County Ranking
Ranked #30 of 140 lakes in Oneida County
Nearby Lakes in Oneida County
More Wisconsin Lake Rankings
Other Grade A Lakes in Wisconsin
Waukesha County · Clarity: 14.6 ft
Waukesha County · Clarity: 13.8 ft
Walworth County · Clarity: 19 ft
Washington County · Clarity: 12 ft
Kenosha County · Clarity: 10.1 ft
Washington County · Clarity: 12.5 ft
Oligotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1989. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
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: 2025-10-14
Monitoring stations: 1