Courthouse Lake
Carver County, Minnesota12 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Courthouse Lake. Here is what has been measured.
- Oligotrophic
- Eurasian watermilfoil
- 57 ft max depth
Courthouse Lake in Carver County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 18.9 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 57 ft. Surface area: 12.02 acres.
Minnesota DNR's Standard Survey on September 7, 1994 caught 0.50 walleye per gill net at Courthouse Lake. DNR survey details →
Courthouse Lake is a 12-acre cold, clear oligotrophic lake in Carver County, Minnesota with a maximum depth of 57 feet. Overall water quality is declining over recent sampling years. The lake supports 10 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 37 other monitored lakes in Carver County, Courthouse Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-06. Methodology: how these readings are compared.
Courthouse Lake covers about 12 acres in Carver County. Vrbo is where to look for cabins and lake homes around Courthouse Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Courthouse Lake is good for
From access and monitoring records, not editorial picks.
- Clear water18.9 ft of visibility
- Fishing10 species recorded
- Deep water57 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
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.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Courthouse 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 Courthouse Lake
These are the measurements Minnesota PCA publishes for Courthouse Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 18.9 ft down. Phosphorus 14 µg/L. Chlorophyll-a 2.4 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 18.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 14µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.4µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Courthouse Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Courthouse Lake typically sits around 61°F at the surface in October. Summer average is about 56°F. Usually warmest in Sep (about 63°F) and coldest in Jan (about 38°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (38°F) to its warmest (63°F).
Typical surface water temperature by month, from 1,699 field readings (2010–2025) via the EPA Water Quality Portal. See the full Courthouse Lake water temperature breakdown →
Minnesota DNR's Standard Survey on September 7, 1994 caught 0.50 walleye per gill net at Courthouse Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Courthouse Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 1994-09-07 (Standard Survey).
4 surveys on file · most recent 1994-09-07 (Standard Survey)
32 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 8.02 | 6–11 in 1994-09-07 | 0.24 lb |
| Green Sunfish | 4.77 | 0.08 lb | |
| Northern Pike | 4.50 | 13–31 in 1994-09-07 | 1.35 lb |
| White Crappie | 2.96 | 3–9 in 1994-09-07 | 0.17 lb |
| Black Crappie | 2.28 | 3–10 in 1994-09-07 | 0.29 lb |
| Yellow Bullhead | 1.63 | 5–13 in 1994-09-07 | 0.39 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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.
Black Bullhead
Northern Pike
White Crappie
Black Crappie
From the 1994-09-07 survey
The Courthouse Lake fish population has changed significantly in recent years due to flooding. The 1993 flood allowed many species found in the Minnesota River to migrate into the lake, including northern pike. Since Courthouse is a designated trout lake, northern pike are not a desirable species to have present.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Courthouse Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — CourthouseFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — CourthouseFish Stocking History · MN DNR LakeFinder
Lake Details
Max depth
57 ft
Surface area
12 acres
Shoreline
0.7 mi
Littoral zone
25%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Stays via Stay22
Stays near Courthouse Lake
Compare lakeside cabins, hotels, and vacation rentals near Courthouse Lake in Carver 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.
Top-rated places to stay near Courthouse 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 →
Follow Courthouse Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Courthouse 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 Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Worsening+1.14 µg/L/yr6 years
Chlorophyll-a
Stable+0.01 µg/L/yr6 years
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Courthouse Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Gedney, M AChaska · 1.4 mi away · NPDES MN0022446Recent violation
- Anchor Block Co-South PlantShakopee · 2.3 mi away · NPDES MN0069281
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Carver County
Frequently asked questions about Courthouse Lake
Where is Courthouse Lake?
- Courthouse Lake is a lake in Carver County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Courthouse Lake?
- Courthouse Lake in Carver County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 18.9 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 57 ft. Surface area: 12.02 acres.
Is Courthouse Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Courthouse Lake?
- Courthouse Lake typically sits around 61°F at the surface in October, from 1,699 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Courthouse Lake?
- Courthouse Lake has a maximum depth of 57 feet. The lake covers 12.02 acres.
What fish are in Courthouse Lake?
- Fish species found in Courthouse Lake include black bullhead, black crappie, bluegill, common carp, green sunfish, northern pike, walleye, white crappie, white sucker, yellow bullhead. Courthouse Lake is located in Carver County, Minnesota.
What did the DNR fisheries survey find at Courthouse Lake?
- Minnesota DNR's Standard Survey on September 7, 1994 caught 0.50 walleye per gill net at Courthouse Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Courthouse Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Courthouse Lake?
- Public access to Courthouse Lake is listed as no on the lake record, so confirm before you make the trip. 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 Courthouse Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Carver County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Minnesota River Watershed, ranked by water quality
Lakes in the Crow River Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Courthouse Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Where this data comes from
196 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA196 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake details from Minnesota DNR LakeFinder