Mcknight Lake
Carver County, MinnesotaHypereutrophic
Mcknight Lake earns an F: 149 µg/L of phosphorus and clarity at 2.3 ft signal heavy nutrient loading from the surrounding watershed. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.
The hypereutrophic status — TSI 71 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake is compact at 31 acres, with partial shoreline records and little volume to buffer nutrient inputs. Mcknight Lake ranks 33 of 40 in Carver County — at the lower end of the locally monitored distribution.
No invasive species are currently listed at Mcknight Lake — the lake remains off the Minnesota infested-waters roster. 3 fish species are on record, with panfish making up the recreational core. The lake lacks a documented public access point, so visitor use is limited. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 2.3 ft of visibility. Phosphorus level: 149 µg/L. Trophic State Index: 71.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.3 ft | F |
| Phosphorus | 149 µg/L | F |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 71 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 31 acres |
| Public Access | No |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Mcknight Lake (14-day solunar calendar)
→ Is it safe to eat fish from Mcknight Lake? (mercury & PFAS guide)
→ Mcknight Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.012 m/yr | 5 |
| Phosphorus | ↓ Declining | +6.15 µg/L/yr | 5 |
Location
County Ranking
Ranked #33 of 40 lakes in Carver County
Cleaner Lakes Within 30 Miles
Mcknight Lake holds Grade F. 3 nearby lakes hold higher grades.
- ABrickyard LakeCarver County · mi · Two grade letters higher (F → A)
- CBavaria LakeCarver County · mi · Two grade letters higher (F → C)
- DGrace LakeCarver County · mi · Higher grade (F → D)
Nearby Lakes in Carver County
More Minnesota Lake Rankings
State Parks Near Mcknight Lake
Other Grade F Lakes in Minnesota
Reservoir Info (USACE NID)
Mcknight Lake is a man-made reservoir impounded by the Mcknight Lake, built primarily for flood risk reduction on the Chaska East Creek; earth-type dam, 8 ft tall.
- Surface area
- 31 ac
- Normal storage
- 82 ac-ft
- Max storage
- 82 ac-ft
- Drainage area
- 5.93 sq mi
- Hazard class
- Low
- Owner
- City of Chaska
Source: USACE National Inventory of Dams, NID ID MN01263 · Operator website
EPA Impairment Status
Mcknight Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN10-0216-00 · 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
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-10-23
Monitoring stations: 2