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LakeQuality

Rush Lake

F
Grade F — Algae-prone
Algae-prone · #26 of 30 lakes in the county · 3 ft clear · Eutrophic · 1,494 acres · from D
Eutrophic

Rush Lake in Chisago County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3 ft visibility. Phosphorus: 55.5 µg/L. Chlorophyll-a (algae): 31.4 µg/L. Maximum depth: 24 ft. Surface area: 1493.93 acres.

Clarity
3 ft
Typical in August
74°F
Max depth
24 ft
Area
1,494 acres
Type
Eutrophic
Trend
Improving
Public access
Yes
Ice-out
Apr 8

Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Rush Lake

Next lake in Chisago County

CGoose Lake4.5 ft clear · Chisago CountyView →
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Rush Lake is a 1,494-acre productive, nutrient-rich eutrophic lake in Chisago County, Minnesota with a maximum depth of 24 feet. Water quality is graded F based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 16 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 2 public boat landings. Compared to the 29 other monitored lakes in Chisago County, Rush Lake ranks #26 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-30. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Algae risk

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.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Compare the safest swimming lakes near Minneapolis

Get alerts for Rush Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 3 ft of visibility. Phosphorus level: 55.5 µg/L. Chlorophyll-a: 31.4 µg/L. Trophic State Index: 63.

MetricValueGrade
Water Clarity (Secchi Depth)3 ftNot graded
Phosphorus55.5 µg/LPoor
Chlorophyll-a (Algae)31.4 µg/LPoor
Trophic State Index (TSI)63Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Rush Lake

Compare lakeside cabins, hotels, and vacation rentals near Rush Lake in Chisago 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 Rush Lake are listed below.

Top-rated places to stay near Rush 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

Rush Lake typically sits around 74°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 80°F) and coldest in May (about 65°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
65°
Jun
73°
Jul
80°
Aug
74°
Sep
66°
Oct
Nov
Dec

Typical surface water temperature by month, from 39 field readings (20172025) via the EPA Water Quality Portal. See the full Rush Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth24 ft
Surface Area1,494 acres
Shoreline Length11 mi
Littoral Zone69%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
60 sq mi
Elevation
896 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

2
Boat Landings
Yes
Public Access
  • West Rush LakePublic
  • East Rush LakePublic

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Rush 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.

Eurasian watermilfoil

DNR Fisheries Survey Summary

15 surveys on file from MN DNR Fisheries. Most recent: 2024-04-09 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Yellow Perch20.490.16 lb
CNM19.74
White Crappie15.030.28 lb
Black Crappie13.160.27 lb
Bluegill9.810.19 lb
BKF8.29

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.

Yellow Perch

261 fish · 411 in · 2023-08-21
121610trophy 124567891011

Black Crappie

138 fish · 211 in · 2024-04-09
27140trophy 10234567891011

Bluegill

150 fish · 29 in · 2023-08-21
40200trophy 1023456789

From the 2024-04-09 survey

East Rush Lake is a 1,481-acre lake in northern Chisago County located four miles west of Rush City, MN, and is within the Lower St. Croix River Watershed. The lake has a maximum depth of 24 feet, an average depth of 8 feet, and 70% of the lake is 15 feet or less (1,033 acres). East Rush has four inlets, three small…

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 Rush Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.059 m/yr6
Phosphorus Improving-2.9 µg/L/yr6
Chlorophyll-a Improving-5.89 µg/L/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (5 observations).

Typical Ice-Out
Apr 8
EarliestLatest
Ice-Out2025-03-28 (2025)2007-04-13 (2007)
Ice-In2006-12-01 (2006)2004-12-02 (2004)

Most recent ice-out: 2025-03-28

EPA Impairment Status

Rush Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Impaired biota (cause unknown)MercuryNutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN13-0069-02 · Official waterbody report · Matched by proximity (1.66 km)

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Rush Lake under Clean Water Act (NPDES) discharge permits.

  • Shorewood Park Sanitary Distr
    Rush City · 1.8 mi away · NPDES MN0051390

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 #26 of 30 lakes in Chisago County

Nearby Lakes With Higher Grades

Rush Lake holds Grade F. 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 Chisago County

Frequently asked questions about Rush Lake

What is the water quality grade for Rush Lake?

Rush Lake in Chisago County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3 ft visibility. Phosphorus: 55.5 µg/L. Chlorophyll-a (algae): 31.4 µg/L. Maximum depth: 24 ft. Surface area: 1493.93 acres.

Is Rush Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Rush Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 31.4 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Rush Lake?

Rush Lake typically sits around 74°F at the surface in August, from 39 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.

How deep is Rush Lake?

Rush Lake has a maximum depth of 24 feet. The lake covers 1493.93 acres.

What fish are in Rush Lake?

Fish species found in Rush Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, freshwater drum, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Rush Lake is located in Chisago County, Minnesota.

When does Rush Lake thaw?

Rush Lake typically has ice-out around Apr 8.

Are there boat ramps on Rush Lake?

Rush Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include West Rush Lake, East Rush Lake. Public access is listed as yes.

Where this data comes from

190 measurements from 3 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 WaterMNPCA190 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • 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
Monitoring station identifiers (3)

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

Named boat-access points from the USGS National Boat Ramps inventory

Ice data from Minnesota DNR Climate