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F

Knaus Lake

Stearns County, MinnesotaEutrophic

Knaus Lake earns an F: 126 µg/L of phosphorus and clarity at 2.5 ft signal heavy nutrient loading from the surrounding watershed. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. Knaus Lake reaches 20 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 216 acres, Knaus Lake fits the Minnesota median for monitored lakes, with 4.5 miles of shoreline. Within the 55 graded lakes of Stearns County, Knaus Lake sits at rank 52, near the bottom of the county list.

Knaus Lake is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Walleye are documented at Knaus Lake, one of 17 fish species on record for the lake. No formal public access is documented at Knaus Lake — most use is by shoreline residents and their guests. 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 2024-10-17. Grade methodology: LakeGrade methodology.

Reviewed by LakeQuality Editorial Team · Updated

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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 2.5 ft of visibility. Phosphorus level: 126 µg/L. Trophic State Index: 69.

MetricValueGrade
Water Clarity (Secchi Depth)2.5 ftF
Phosphorus126 µg/LF
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)69Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Maximum Depth20 ft
Average Depth6.4 ft
Surface Area215.95 acres
Shoreline Length4.5 mi
Littoral Zone94%
Public AccessNo

Fish Species

black bullhead,black crappie,bluegill,channel catfish,common carp,greater redhorse,hybrid sunfish,largemouth bass,northern pike,pumpkinseed,shorthead redhorse,silver redhorse,smallmouth bass,walleye,white sucker,yellow bullhead,yellow perch

Click a species to see all Minnesota and Wisconsin lakes where it is found.

→ Best fishing times for Knaus Lake (14-day solunar calendar)

→ Is it safe to eat fish from Knaus Lake? (mercury & PFAS guide)

Knaus Lake fishing regulations (limits, seasons, special rules)

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

Eurasian watermilfoilzebra mussel

Water Quality Trend: Improving

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.413 m/yr5
Phosphorus Improving-3.5 µg/L/yr2
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (9 observations).

Typical Ice-Out
Apr 9
Typical Ice-In
Nov 24

Estimated open water season: 229 days

EarliestLatest
Ice-Out2004-04-03 (2004)2008-04-21 (2008)
Ice-In2007-11-01 (2007)2004-11-25 (2004)

Most recent ice-out: 2008-04-21

Location

Loading map…

County Ranking

Ranked #52 of 55 lakes in Stearns County

Cleaner Lakes Within 30 Miles

Knaus Lake holds Grade F. 4 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Stearns County

DNR Fisheries Survey Summary

8 surveys on file from MN DNR Fisheries. Most recent: 2024-07-31 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Black Crappie33.500.35 lb
Largemouth Bass18.280.62 lb
Channel Catfish14.062.25 lb
GRR12.502.59 lb
Yellow Perch11.780.19 lb
Bluegill10.250.29 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.

Black Crappie

3 fish · 911 in · 2024-07-31
10trophy 1091011

Largemouth Bass

44 fish · 518 in · 2024-07-31
126056789101112131415161718

Channel Catfish

21 fish · 1728 in · 2024-07-31
320171819202122232425262728

GRR

25 fish · 1420 in · 2024-07-31
105014151617181920

From the 2024-07-31 survey

The Sauk River Chain of Lakes (SRCL) is located in south-central Stearns County, near the city of Richmond. A dam built in the early 1900's on the Sauk River in Cold Spring created the SRCL a reservoir consisting of nine lakes and approximately 3,200 acres of water. The Sauk River drains a large portion of central…

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 Knaus Lake. 1 report on file.

EPA Impairment Status

Knaus 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 MN73-0086-00 · 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

Ice data from Minnesota DNR Climate

Most recent sample: 2024-10-17

Monitoring stations: 3