French Lake
Wright County, MinnesotaEutrophic
French Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
At a TSI of 58, French Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. French Lake is unusually deep for Minnesota at 50 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. French Lake covers 346 acres alongside 3.8 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Wright County's 64 graded lakes, French Lake ranks 34 — below the local median, though not at the bottom.
Eurasian watermilfoil is established at French Lake, which can dampen recreational access and pressure the native plant community. Walleye are documented at French Lake, one of 15 fish species on record for the lake. A documented public access point at French Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 24 observed ice-outs, centered near Apr 2. 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, Minnesota DNR LakeFinder, last sampled 2024-09-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Murky, only visible to about 4.3 ft. Phosphorus level: 47 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.3 ft | D |
| Phosphorus | 47 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 50 ft |
| Average Depth | 16.6 ft |
| Surface Area | 346.37 acres |
| Shoreline Length | 3.8 mi |
| Littoral Zone | 45% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for French Lake (14-day solunar calendar)
→ Is it safe to eat fish from French Lake? (mercury & PFAS guide)
→ French Lake 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: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.166 m/yr | 5 |
| Phosphorus | ↓ Declining | +3.55 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (36 observations).
Estimated open water season: 244 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-07 (2024) | 2013-05-02 (2013) |
| Ice-In | 2018-11-13 (2018) | 2015-12-19 (2015) |
Most recent ice-out: 2025-03-24
Location
County Ranking
Ranked #34 of 64 lakes in Wright County
Cleaner Lakes Within 30 Miles
French Lake holds Grade C. 5 nearby lakes hold higher grades.
- AEast Sylvia LakeWright County · mi · Two grade letters higher (C → A)
- AWest Sylvia LakeWright County · mi · Two grade letters higher (C → A)
- AMoose LakeWright County · mi · Two grade letters higher (C → A)
- BJohn LakeWright County · mi · Higher grade (C → B)
- CMud LakeWright County · mi · Higher overall water quality score
Nearby Lakes in Wright County
More Minnesota Lake Rankings
State Parks Near French Lake
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2025-07-07 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 53.71 | 0.19 lb |
| Largemouth Bass | 36.82 | 1.18 lb |
| Black Crappie | 17.56 | 0.26 lb |
| Bluntnose Minnow | 13.12 | — |
| Yellow Perch | 11.28 | 0.1 lb |
| White Crappie | 10.08 | 0.26 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Largemouth Bass
Black Crappie
Yellow Perch
From the 2025-07-07 survey
French Lake is a 346-acre lake located three miles southwest of the City of Annandale. The lake is highly productive and has a maximum depth of 50 feet. The watershed is large, and land use is primarily cultivated crops (47%). Summer water clarity is relatively poor and was 1.5 feet in July. Additionally, the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for French Lake. 3 reports on file.
- —Fisheries Lake Survey — FrenchFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — FrenchFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — FrenchPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
French Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN86-0273-00 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate
Most recent sample: 2024-09-23
Monitoring stations: 1