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LakeQuality

Curtis Lake

NR
Not yet rated
4 ft clear · Eutrophic · 382 acres
Limited DataEutrophic

Curtis Lake in Yellow Medicine County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4 ft visibility. Maximum depth: 8 ft. Surface area: 381.54 acres.

Clarity
4 ft
Max depth
8 ft
Area
382 acres
Trend
Improving
Public access
Yes

Next lake in Yellow Medicine County

DWood Lake3 ft clear · Yellow Medicine CountyView →
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Why Curtis Lake has no grade

We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Curtis Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Curtis Lake is a 382-acre lake in Yellow Medicine County, Minnesota with a maximum depth of 8 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-01. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Willmar

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Water quality measurements for Curtis Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Murky, only visible to about 4 ft. Trophic State Index: 57.

MetricValueGrade
Water Clarity (Secchi Depth)4 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)57Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Curtis Lake

Compare lakeside cabins, hotels, and vacation rentals near Curtis Lake in Yellow Medicine 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 Curtis Lake

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 →

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for Curtis Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,047,129 cells/mL) on July 18, 2026.

Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗

Lake Details

CharacteristicValue
Maximum Depth8 ft
Surface Area382 acres
Shoreline Length5.5 mi
Littoral Zone114%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
19 sq mi
Elevation
1,047 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Curtis LakePublic

Fishing Curtis Lake

DNR Fisheries Survey Summary

1 survey on file from MN DNR Fisheries. Most recent: 1987-09-22 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Black Bullhead134.580.15 lb
Green Sunfish27.340.17 lb
Common Carp19.001.13 lb
White Sucker0.420.41 lb

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.

From the 1987-09-22 survey

CARP, BULLHEAD AND GREEN SUNFISH.

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Curtis Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.234 m/yr4
See year-by-year chart →

Reservoir Info (USACE NID)

Curtis Lake is a man-made reservoir impounded by the Curtis Lake (completed 2009), built primarily for fish and wildlife pond on the Boiling Spring Creek; other-type dam, 8 ft tall and 400 ft long.

Surface area
440 ac
Normal storage
1,595 ac-ft
Max storage
3,000 ac-ft
Drainage area
9 sq mi
Hazard class
Low
Owner
MNDNR-Wildlife

Source: USACE National Inventory of Dams, NID ID MN01564 · Operator website

EPA Impairment Status

Curtis Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN87-0016-00 · Official waterbody report

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Curtis Lake under Clean Water Act (NPDES) discharge permits.

  • Meier Ranch Llc
    Belview · 4.6 mi away · NPDES MN0071480

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.

Graded lakes near Curtis Lake

Curtis Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Yellow Medicine County

Frequently asked questions about Curtis Lake

What is the water quality grade for Curtis Lake?

Curtis Lake in Yellow Medicine County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4 ft visibility. Maximum depth: 8 ft. Surface area: 381.54 acres.

Is Curtis Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Curtis Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

How deep is Curtis Lake?

Curtis Lake has a maximum depth of 8 feet. The lake covers 381.54 acres.

Does Curtis Lake have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for Curtis Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,047,129 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.

Are there boat ramps on Curtis Lake?

Curtis Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Curtis Lake. Public access is listed as yes.

Where this data comes from

26 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA26 samples · 2020–2024

Analytical methods

  • Field measurement/observation, generic method
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory