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LakeQuality

Crystal Lake

F
Grade F — Algae-prone
Algae-prone · #65 of 81 lakes in the county · 3.5 ft clear · Eutrophic · 79 acres · from C
Eutrophic

Crystal Lake in Hennepin County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3.5 ft visibility. Phosphorus: 58 µg/L. Chlorophyll-a (algae): 34.9 µg/L. Maximum depth: 39 ft. Surface area: 79.12 acres.

Clarity
3.5 ft
Typical in August
66°F
Max depth
39 ft
Area
79 acres
Type
Eutrophic
Trend
Declining
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 Crystal Lake

Next lake in Hennepin County

DTwin Lake5.9 ft clear · Hennepin CountyView →
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Crystal Lake is a 79-acre productive, nutrient-rich eutrophic lake in Hennepin County, Minnesota with a maximum depth of 39 feet (10-foot average). Water quality is graded F based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 12 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 80 other monitored lakes in Hennepin County, Crystal Lake ranks #65 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. 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 Crystal Lake

Water Quality Grade: F (Algae-prone)

Murky, only visible to about 3.5 ft. Phosphorus level: 58 µg/L. Chlorophyll-a: 34.9 µg/L. Trophic State Index: 62.

MetricValueGrade
Water Clarity (Secchi Depth)3.5 ftNot graded
Phosphorus58 µg/LPoor
Chlorophyll-a (Algae)34.9 µg/LPoor
Trophic State Index (TSI)62Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Crystal Lake

Compare lakeside cabins, hotels, and vacation rentals near Crystal Lake in Hennepin 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 Crystal Lake are listed below.

Top-rated places to stay near Crystal 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

Crystal Lake typically sits around 66°F at the surface in August. Summer average is about 65°F. Usually warmest in Jul (about 66°F) and coldest in Feb (about 35°F). These are typical values by month — not a live reading.

Jan
Feb
35°
Mar
Apr
May
57°
Jun
63°
Jul
66°
Aug
66°
Sep
65°
Oct
54°
Nov
44°
Dec

Typical surface water temperature by month, from 378 field readings (20102025) via the EPA Water Quality Portal. See the full Crystal Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth39 ft
Average Depth9.8 ft
Surface Area79 acres
Shoreline Length1.6 mi
Littoral Zone67%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Elevation
843 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Lakeview TerracePublic

Fish Species

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

Fishing Crystal Lake

DNR Fisheries Survey Summary

8 surveys on file from MN DNR Fisheries. Most recent: 2022-08-17 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluegill67.880.11 lb
Black Crappie55.270.14 lb
GOS19.010.09 lb
Yellow Perch13.760.14 lb
Black Bullhead12.060.35 lb
Northern Pike3.303.79 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.

Bluegill

129 fish · 36 in · 2022-08-17
693503456

Black Crappie

129 fish · 59 in · 2022-08-17
68340trophy 1056789

GOS

18 fish · 56 in · 2022-08-17
116056

Yellow Perch

109 fish · 46 in · 2022-08-17
86430456

From the 2022-08-17 survey

Crystal Lake is a 78-acre lake located in Robbinsdale. City parks are situated to the north and south of the lake, and both provide shore fishing access. The park to the north includes a fishing pier (Installed in 2019), and the park to the south includes a boat access with trailer parking. Crystal Lake is primarily a…

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 Crystal Lake. 3 reports on file.

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

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

MetricTrendChange/YearYears
Water Clarity Declining-0.029 m/yr5
Phosphorus Declining+2.5 µg/L/yr3
Chlorophyll-a Improving-1.5 µg/L/yr3
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (6 observations).

Typical Ice-Out
Apr 8
EarliestLatest
Ice-Out2007-03-29 (2007)2022-04-10 (2022)
Ice-In2006-12-01 (2006)2007-12-04 (2007)

Most recent ice-out: 2022-04-10

EPA Impairment Status

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

Causes of impairment

Nutrients (phosphorus, nitrogen)PFAS

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

Source: EPA ATTAINS assessment unit MN27-0034-00 · Official waterbody report

Regulated Pollution Sources Nearby

2 EPA-permitted facilities operate within about 5 miles of Crystal Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.

  • Xcel - Riverside Generating Plant
    Minneapolis · 2.7 mi away · NPDES MN0000892
    Major
  • Crystal Lake Flocculation Treatment Facility
    Robbinsdale · 0.4 mi away · NPDES MN0069957
    Recent violation

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 #65 of 81 lakes in Hennepin County

Nearby Lakes With Higher Grades

Crystal 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 Hennepin County

Frequently asked questions about Crystal Lake

What is the water quality grade for Crystal Lake?

Crystal Lake in Hennepin County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3.5 ft visibility. Phosphorus: 58 µg/L. Chlorophyll-a (algae): 34.9 µg/L. Maximum depth: 39 ft. Surface area: 79.12 acres.

Is Crystal 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. Crystal Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 34.9 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Crystal Lake?

Crystal Lake typically sits around 66°F at the surface in August, from 378 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.

How deep is Crystal Lake?

Crystal Lake has a maximum depth of 39 feet and an average depth of 9.8 feet. The lake covers 79.12 acres.

What fish are in Crystal Lake?

Fish species found in Crystal Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), common carp, green sunfish, hybrid sunfish, pumpkinseed, tiger muskellunge, white sucker, yellow bullhead, yellow perch. Crystal Lake is located in Hennepin County, Minnesota.

When does Crystal Lake thaw?

Crystal Lake typically has ice-out around Apr 8.

Are there boat ramps on Crystal Lake?

Crystal Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lakeview Terrace. Public access is listed as yes.

Eutrophic Lakes in Minnesota

Where this data comes from

127 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA127 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)

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