Medicine Lake
Medicine Lake in Hennepin County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 7.9 ft visibility. Phosphorus: 73.9 µg/L. Chlorophyll-a (algae): 9.6 µg/L. Maximum depth: 49 ft. Surface area: 924.36 acres.
- Clarity
- 7.9 ft
- Typical in August
- 66°F
- Max depth
- 49 ft
- Area
- 924 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 10
- Open water
- 234 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Medicine Lake →
Next lake in Hennepin County
Free interactive depth-contour map of Medicine Lake, reaching a maximum surveyed depth of 40 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Medicine Lake is a 924-acre productive, nutrient-rich eutrophic lake in Hennepin County, Minnesota with a maximum depth of 49 feet. Water quality is graded D based on 3 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 15 documented fish species including black bullhead, black crappie, and bluegill. Public access is available. Compared to the 80 other monitored lakes in Hennepin County, Medicine Lake ranks #27 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-26. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyElevated nutrients
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Moderate clarity, visible to about 7.9 ft. Phosphorus level: 73.9 µg/L. Chlorophyll-a: 9.6 µg/L. Trophic State Index: 55.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.9 ft | Not graded |
| Phosphorus | 73.9 µg/L | Poor |
| Chlorophyll-a (Algae) | 9.6 µg/L | Fair |
| Trophic State Index (TSI) | 55 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Medicine Lake
Compare lakeside cabins, hotels, and vacation rentals near Medicine Lake in Hennepin 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 grade measures nutrients and algae, not lodging — cabins and rentals around Medicine Lake are listed below.
Top-rated places to stay near Medicine 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 →
Water Temperature
Medicine Lake typically sits around 66°F at the surface in August. Summer average is about 64°F. Usually warmest in Aug (about 66°F) and coldest in Jan (about 36°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 2,653 field readings (2010–2025) via the EPA Water Quality Portal. See the full Medicine Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Medicine Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (205,116 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
| Characteristic | Value |
|---|---|
| Maximum Depth | 49 ft |
| Surface Area | 924 acres |
| Shoreline Length | 8.8 mi |
| Littoral Zone | 43% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Medicine 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.
DNR Fisheries Survey Summary
15 surveys on file from MN DNR Fisheries. Most recent: 2023-07-05 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 24.96 | 0.18 lb |
| BKF | 18.21 | — |
| Bluntnose Minnow | 9.80 | — |
| Black Crappie | 8.40 | 0.17 lb |
| Yellow Bass | 6.30 | 0.82 lb |
| Northern Pike | 5.92 | 2.53 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
Black Crappie
Yellow Bass
Northern Pike
From the 2023-07-05 survey
Medicine Lake is a 924-acre lake surrounded by the cities of Plymouth and Medicine Lake. Clifton E. French Regional Park (a Three Rivers Parks District property) borders the northwest portion of the lake and provides the only public boat launch during the open-water season; a fee is charged for parking boat…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Medicine Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MedicineFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — MedicineFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MedicinePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.238 m/yr | 6 |
| Phosphorus | ↓ Declining | +3.68 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +1.64 µg/L/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (257 observations).
Estimated open water season: 234 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-07 (2024) | 2018-05-02 (2018) |
| Ice-In | 1991-11-07 (1991) | 1998-12-21 (1998) |
Most recent ice-out: 2025-03-23
EPA Impairment Status
Medicine 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 MN27-0104-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Medicine Lake under Clean Water Act (NPDES) discharge permits.
- Honeywell-Plymouth OperationsPlymouth · 1.4 mi away · NPDES MN0063266
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.
County Ranking
Ranked #27 of 81 lakes in Hennepin County
Nearby Lakes With Higher Grades
Medicine Lake holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Hennepin County
Frequently asked questions about Medicine Lake
What is the water quality grade for Medicine Lake?
- Medicine Lake in Hennepin County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 7.9 ft visibility. Phosphorus: 73.9 µg/L. Chlorophyll-a (algae): 9.6 µg/L. Maximum depth: 49 ft. Surface area: 924.36 acres.
Is Medicine Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Medicine Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 9.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Medicine Lake?
- Medicine Lake typically sits around 66°F at the surface in August, from 2,653 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Medicine Lake?
- Medicine Lake has a maximum depth of 49 feet. The lake covers 924.36 acres.
What fish are in Medicine Lake?
- Fish species found in Medicine Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Medicine Lake is located in Hennepin County, Minnesota.
When does Medicine Lake thaw?
- Medicine Lake typically has ice-out around Apr 10. Ice typically forms around Nov 30. The open water season is approximately 234 days.
Does Medicine Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Medicine Lake (clouds, ice, or an off-season gap). The most recent reading was high (205,116 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Medicine Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Hennepin County
Species activity outlook by water temperature and season
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Where this data comes from
553 measurements from 4 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
MNPCA553 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 4500 N C ~ Persufate Method for Total Nitrogen
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
Monitoring station identifiers (4)
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
Ice data from Minnesota DNR Climate