French Lake
Rice County, Minnesota876 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for French Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Mercury
- Eurasian watermilfoil
- 56 ft max depth
- Public access
- Limited data
French Lake in Rice County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1.7 ft visibility. Phosphorus: 134 µg/L. Chlorophyll-a (algae): 46.3 µg/L. Maximum depth: 56 ft. Surface area: 875.81 acres.
Free interactive depth-contour map of French Lake, reaching a maximum surveyed depth of 50 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
French Lake is a 876-acre highly nutrient-loaded hypereutrophic lake in Rice County, Minnesota with a maximum depth of 56 feet. Overall water quality is improving over recent sampling years. The lake supports 16 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 1 public boat landing. Compared to the 13 other monitored lakes in Rice County, French Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-16. Methodology: how these readings are compared.
What French Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing16 species recorded
- Ice seasonIce-out around Mar 31
- Deep water56 ft surveyed max depth
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Based on E. coli testing, French Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 6 samples across 2 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Minnesota’s current beach and health-department advisories before swimming.
Whether French Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for French Lake
These are the measurements Minnesota PCA publishes for French Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 1.7 ft of visibility. Phosphorus 134 µg/L. Chlorophyll-a 46.3 µg/L. TSI 71.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 134µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 46.3µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 71 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about French Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
French Lake typically sits around 73°F at the surface in September. Summer average is about 74°F. Usually warmest in Aug (about 80°F) and coldest in May (about 65°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (65°F) to its warmest (80°F).
Typical surface water temperature by month, from 112 field readings (2025–2025) via the EPA Water Quality Portal. See the full French Lake water temperature breakdown →
Lake Details
Max depth
56 ft
Surface area
876 acres
Shoreline
4.8 mi
Littoral zone
45%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
7 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,047 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- French LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near French Lake
Compare lakeside cabins, hotels, and vacation rentals near French Lake in Rice County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around French Lake are listed below.
Top-rated places to stay near French Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
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Fish Species
Click a species to see every lake where it is documented.
Fishing French Lake
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 readings over time
2 seasons of samples on record (2024–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Phosphorus
Improving-105.5 µg/L/yr2 years
Chlorophyll-a
Worsening+44.9 µg/L/yr2 years
Ice season
Typical ice-out
Mar 31
Earliest Mar 2, 2024 · Latest Apr 30, 2018
Typical ice-in
Dec 2
Earliest Nov 19, 1997 · Latest Jan 4, 2024
Most recent ice-out
Mar 26
2026
26 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
French Lake is a man-made reservoir impounded by the French Lake (completed 1960), built primarily for recreation on the Cannon River-TR; other-type dam, 8 ft tall.
- Surface area
- 880 ac
- Normal storage
- 2,300 ac-ft
- Max storage
- 3,500 ac-ft
- Drainage area
- 6.4 sq mi
- Hazard class
- Low
- Owner
- County of Rice
Source: USACE National Inventory of Dams, NID ID MN01611 · Operator website
EPA Impairment Status
French Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN66-0038-00 · Official waterbody report
Nearby Lakes in Rice County
Frequently asked questions about French Lake
Where is French Lake?
- French Lake is a lake in Rice County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of French Lake?
- French Lake in Rice County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1.7 ft visibility. Phosphorus: 134 µg/L. Chlorophyll-a (algae): 46.3 µg/L. Maximum depth: 56 ft. Surface area: 875.81 acres.
Is French Lake safe to swim in?
- Based on E. coli testing, French Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 6 samples across 2 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether French Lake is safe to swim in today is a call for Minnesota's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of French Lake?
- French Lake typically sits around 73°F at the surface in September, from 112 EPA Water Quality Portal field readings (2025–2025). That is a typical value for the month, not a live reading.
How deep is French Lake?
- French Lake has a maximum depth of 56 feet. The lake covers 875.81 acres.
What fish are in French Lake?
- Fish species found in French Lake include black crappie, bluegill, bowfin (dogfish), common carp, freshwater drum, hybrid crappie, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, walleye, white bass, white crappie, yellow bullhead, yellow perch. French Lake is located in Rice County, Minnesota.
When does French Lake thaw?
- French Lake typically has ice-out around Mar 31. Ice typically forms around Dec 2. The open water season is approximately 246 days.
Are there boat ramps on French Lake?
- French Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include French Lake. Public access is listed as yes.
Can I fish at French Lake?
- French Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore French Lake across LakeQuality
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Fish species and best lakes in Rice County
Species activity outlook by water temperature and season
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Where this data comes from
491 measurements from 9 monitoring stations, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA491 samples · 2024–2025
Analytical methods
- Field measurement/observation, generic method
- Turbidity, Nephelometric Method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (9)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate