Deadfish Lake
Carlton County, MinnesotaEutrophic
Deadfish Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. Secchi readings are the weakest of the scored parameters, suggesting suspended sediment or algal biomass dominates the optical signal.
Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Within Carlton County's 33 graded lakes, Deadfish Lake ranks 21 — below the local median, though not at the bottom.
No invasive species are currently listed at Deadfish Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Deadfish Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. The grade is supported by multiple sampling years from Minnesota PCA volunteers and partner agencies, giving the letter a reasonably stable foundation.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-16. Grade methodology: LakeGrade methodology.
Track Deadfish Lake
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Very murky, less than 1.6 ft of visibility. Phosphorus level: 48.5 µg/L. Chlorophyll-a: 3.6 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | F |
| Phosphorus | 48.5 µg/L | C |
| Chlorophyll-a (Algae) | 3.6 µg/L | A |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.963 m/yr | 5 |
| Phosphorus | ↓ Declining | +25 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -0.88 µg/L/yr | 5 |
Location
County Ranking
Ranked #21 of 33 lakes in Carlton County
Cleaner Lakes Within 30 Miles
Deadfish Lake holds Grade C. 5 nearby lakes hold higher grades.
- BLac LakeCarlton County · mi · Higher grade (C → B)
- BLost LakeSt. Louis County · mi · Higher grade (C → B)
- CHardwood LakeCarlton County · mi · Higher overall water quality score
- CRice Portage LakeCarlton County · mi · Higher overall water quality score
- CSpruce LakeCarlton County · mi · Higher overall water quality score
Nearby Lakes in Carlton County
More Minnesota Lake Rankings
State Parks Near Deadfish Lake
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Deadfish Lake. 1 report on file.
- —Aquatic Plant Report — Lac (0262)Aquatic Plant Report · MN DNR LakeFinder
Reservoir Info (USACE NID)
Deadfish Lake is a man-made reservoir impounded by the Deadfish Lake, 10 ft tall.
- Normal storage
- 321 ac-ft
- Hazard class
- Undetermined
Source: USACE National Inventory of Dams, NID ID MN01827 · Operator website
EPA Impairment Status
Deadfish 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_104 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-10-16
Monitoring stations: 1