Perch Lake
Perch Lake in Carlton County, Minnesota has a water quality grade of C (Fair). Water clarity: 2.2 ft visibility. Phosphorus: 51 µg/L. Chlorophyll-a (algae): 6.1 µg/L.
- Clarity
- 2.2 ft
- Mean depth
- ~17 ft est.
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Carlton County
Perch Lake is a productive, nutrient-rich eutrophic lake in Carlton County, Minnesota with an estimated average depth of about 17 feet. Water quality is graded C based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 21 other monitored lakes in Carlton County, Perch Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-09. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Very murky, less than 2.2 ft of visibility. Phosphorus level: 51 µg/L. Chlorophyll-a: 6.1 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.2 ft | Not graded |
| Phosphorus | 51 µg/L | Poor |
| Chlorophyll-a (Algae) | 6.1 µg/L | Good |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Perch Lake
Compare lakeside cabins, hotels, and vacation rentals near Perch Lake in Carlton 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 Perch Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~17 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Perch Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Perch LakePublic
Fishing Perch Lake
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Perch Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — PerchPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.023 m/yr | 5 |
| Phosphorus | ↓ Declining | +69.1 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -0.65 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Perch Lake is a man-made reservoir impounded by the Perch Lake, 7 ft tall.
- Normal storage
- 3,801 ac-ft
- Hazard class
- Undetermined
Source: USACE National Inventory of Dams, NID ID MN01283 · Operator website
EPA Impairment Status
Perch Lake is officially listed as impaired under Clean Water Act §303(d) in the 2019 EPA reporting cycle.
Causes of impairment
Source: EPA ATTAINS assessment unit FDL_115 · Official waterbody report · Matched by proximity (1.83 km)
County Ranking
Ranked #7 of 22 lakes in Carlton County
Nearby Lakes With Higher Grades
Perch Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Carlton County
Frequently asked questions about Perch Lake
What is the water quality grade for Perch Lake?
- Perch Lake in Carlton County, Minnesota has a water quality grade of C (Fair). Water clarity: 2.2 ft visibility. Phosphorus: 51 µg/L. Chlorophyll-a (algae): 6.1 µg/L.
Is Perch Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Perch Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 6.1 µg/L. Always check local health department advisories before swimming.
How deep is Perch Lake?
- No published bathymetric survey covers Perch Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 17 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Perch Lake?
- Perch Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Perch Lake. Public access is listed as yes.
Explore Perch Lake across LakeGrade
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Where this data comes from
248 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Fond du Lac Band of Chippewa (MN)
FONDULAC_WQX248 samples · 2020–2024
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
- 10200 H ~ Chlorophyll a-b-c Determination
- Color, APHA Platinum-Cobalt
- For determination of Copper by the Bicinchoninate method.
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory