Fish Lake
Chisago County, Minnesota319 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Fish Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- Eurasian watermilfoil
- 57 ft max depth
- Public access
Fish Lake in Chisago County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 9.4 ft visibility. Phosphorus: 14.5 µg/L. Chlorophyll-a (algae): 3 µg/L. Maximum depth: 57 ft. Surface area: 318.82 acres.
Minnesota DNR's Targeted Survey on July 27, 2020 caught 0.88 northern pike per trap net at Fish Lake. DNR survey details →
Fish Lake is a 319-acre mesotrophic lake in Chisago County, Minnesota with a maximum depth of 57 feet (16-foot average). Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 29 other monitored lakes in Chisago County, Fish Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Methodology: how these readings are compared.
What Fish Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing13 species recorded
- Ice seasonIce-out around Apr 13
- Deep water57 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Fish Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Fish Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Fish Lake
These are the measurements Minnesota PCA publishes for Fish Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.4 ft. Phosphorus 14.5 µg/L. Chlorophyll-a 3 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 14.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 3µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Fish Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Fish Lake typically sits around 66°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 79°F) and coldest in May (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (79°F).
Typical surface water temperature by month, from 45 field readings (2017–2025) via the EPA Water Quality Portal. See the full Fish Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Fish Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (97,275 cells/mL) on November 13, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Targeted Survey on July 27, 2020 caught 0.88 northern pike per trap net at Fish Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Fish Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2020-07-27 (Targeted Survey).
8 surveys on file · most recent 2020-07-27 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 30.08 | 2–8 in 2020-07-27 | 0.17 lb |
| Bluntnose Minnow | 27.09 | ||
| Largemouth Bass | 18.29 | 4–14 in 2020-07-27 | 0.86 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Largemouth Bass
From the 2020-07-27 survey
A targeted survey of the nearshore fish community in Fish Lake was conducted by Fisheries Index of Biological Integrity (IBI) Program Staff starting on July 27, 2020. Ten sampling sites were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 15-foot or 50-foot seine, where…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Fish Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — FishFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — FishFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — FishPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
57 ft
Average depth
16 ft
Surface area
319 acres
Shoreline
3.3 mi
Littoral zone
44%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
3 sq mi
HydroLAKES / HydroSHEDS
Elevation
896 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Fish LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Fish Lake
Compare lakeside cabins, hotels, and vacation rentals near Fish 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.
Top-rated places to stay near Fish Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Fish Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Fish 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.
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Improving-1.22 µg/L/yr6 years
Chlorophyll-a
Improving-0.74 µg/L/yr6 years
Ice season
Typical ice-out
Apr 13
Earliest Mar 20, 2012 · Latest May 6, 2013
Most recent ice-out
Apr 2
2026
54 observations · Minnesota PCA ice records
EPA Impairment Status
Fish Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN13-0068-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Fish Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Harris WwtpHarris · 2.8 mi away · NPDES MN0050130Recent 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.
Nearby Lakes in Chisago County
Frequently asked questions about Fish Lake
Where is Fish Lake?
- Fish Lake is a lake in Chisago County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Fish Lake?
- Fish Lake in Chisago County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 9.4 ft visibility. Phosphorus: 14.5 µg/L. Chlorophyll-a (algae): 3 µg/L. Maximum depth: 57 ft. Surface area: 318.82 acres.
Is Fish Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Fish Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Fish Lake?
- Fish Lake typically sits around 66°F at the surface in September, from 45 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is Fish Lake?
- Fish Lake has a maximum depth of 57 feet and an average depth of 16 feet. The lake covers 318.82 acres.
What fish are in Fish Lake?
- Fish species found in Fish Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead, yellow perch. Fish Lake is located in Chisago County, Minnesota.
What did the DNR fisheries survey find at Fish Lake?
- Minnesota DNR's Targeted Survey on July 27, 2020 caught 0.88 northern pike per trap net at Fish Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Fish Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Fish Lake thaw?
- Fish Lake typically has ice-out around Apr 13.
Does Fish Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Fish Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (97,275 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Fish Lake?
- Fish Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Fish Lake. Public access is listed as yes.
Can I fish at Fish Lake?
- Fish Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Fish Lake across LakeQuality
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Fish species and best lakes in Chisago County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the St. Croix Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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Mesotrophic Lakes in Minnesota
Where this data comes from
96 measurements from 2 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 Water
MNPCA96 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 (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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