Birch Lake
Cass County, Minnesota1,267 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Birch Lake. Here is what has been measured.
- Mesotrophic
- 45 ft max depth
- Public access
Birch Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 45 ft. Surface area: 1267.19 acres.
Minnesota DNR's Standard Survey on August 7, 2023 caught 1.83 walleye per gill net at Birch Lake. DNR survey details →
Free interactive depth-contour map of Birch Lake, reaching a maximum surveyed depth of 45 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Birch Lake is a 1,267-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 45 feet (10-foot average). Overall water quality is declining over recent sampling years. The lake supports 14 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 103 other monitored lakes in Cass County, Birch Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Methodology: how these readings are compared.
What Birch Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14 ft of visibility
- Boat launch1 documented ramp
- Fishing14 species recorded
- Ice seasonIce-out around Apr 17
- Deep water45 ft surveyed max depth
- Big water1,267 acres
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. Check local advisories before you swim.
Whether Birch 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 Birch Lake
These are the measurements Minnesota PCA publishes for Birch Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14 ft. Phosphorus 12 µg/L. Chlorophyll-a 4 µg/L. TSI 41.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 12µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4µg/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. | 41 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Birch Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Birch Lake typically sits around 66°F at the surface in September. Summer average is about 73°F. Usually warmest in Jul (about 77°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (61°F) to its warmest (77°F).
Typical surface water temperature by month, from 42 field readings (2011–2024) via the EPA Water Quality Portal. See the full Birch Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Birch Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (139,316 cells/mL) on May 11, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on August 7, 2023 caught 1.83 walleye per gill net at Birch Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Birch Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2023-08-07 (Standard Survey).
12 surveys on file · most recent 2023-08-07 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 16.45 | 3–9 in 2023-08-07 | 0.17 lb |
| Bluntnose Minnow | 8.51 | ||
| Northern Pike | 5.53 | 9–30 in 2023-08-07 | 1.15 lb |
| Yellow Bullhead | 4.53 | 6–13 in 2023-08-07 | 0.51 lb |
| Pumpkinseed | 3.97 | 3–7 in 2023-08-07 | 0.15 lb |
| Yellow Perch | 3.56 | 5–9 in 2023-08-07 | 0.17 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
Northern Pike
Yellow Bullhead
Pumpkinseed
From the 2023-08-07 survey
Birch Lake is a 1,267-acre lake with 15 miles of shoreline and a maximum depth of 45 feet located in Hackensack, MN. A City of Hackensack) owned public access is located on the east shore. The DNR has classified Minnesota's lakes into 43 different classes based on physical, chemical, and other characteristics. Birch…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Birch Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — BirchFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Birch (1472)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — BirchFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — BirchPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
45 ft
Average depth
10 ft
Surface area
1,267 acres
Shoreline
15.3 mi
Littoral zone
60%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
41 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,371 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Birch 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 Birch Lake
Compare lakeside cabins, hotels, and vacation rentals near Birch Lake in Cass 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 Birch Lake
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Follow Birch Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Birch Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.39 µg/L/yr6 years
Chlorophyll-a
Stable+0.06 µg/L/yr6 years
Ice season
Typical ice-out
Apr 17
Earliest Apr 8, 2017 · Latest May 2, 2008
Typical ice-in
Nov 18
Earliest Nov 7, 2019 · Latest Dec 8, 2009
Most recent ice-out
Apr 8
2017
14 observations · Minnesota PCA ice records
Nearby Lakes in Cass County
Frequently asked questions about Birch Lake
Where is Birch Lake?
- Birch Lake is a lake in Cass County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Birch Lake?
- Birch Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 45 ft. Surface area: 1267.19 acres.
Is Birch Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Birch Lake?
- Birch Lake typically sits around 66°F at the surface in September, from 42 EPA Water Quality Portal field readings (2011–2024). That is a typical value for the month, not a live reading.
How deep is Birch Lake?
- Birch Lake has a maximum depth of 45 feet and an average depth of 10 feet. The lake covers 1267.19 acres.
What fish are in Birch Lake?
- Fish species found in Birch Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow bullhead, yellow perch. Birch Lake is located in Cass County, Minnesota.
What did the DNR fisheries survey find at Birch Lake?
- Minnesota DNR's Standard Survey on August 7, 2023 caught 1.83 walleye per gill net at Birch Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Birch Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Birch Lake thaw?
- Birch Lake typically has ice-out around Apr 17. Ice typically forms around Nov 18. The open water season is approximately 215 days.
Does Birch Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Birch Lake (clouds, ice, or an off-season gap). The most recent reading was high (139,316 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Birch Lake?
- Birch Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Birch Lake. Public access is listed as yes.
Can I fish at Birch Lake?
- Birch 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 Birch Lake across LakeQuality
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Compare Birch Lake With Nearby Lakes
Cass County · 17.2 ft
Cass County · 9.8 ft
Cass County · 12.1 ft
Cass County · 11.5 ft
Cass County · 15 ft
Cass County · 14.4 ft
Where this data comes from
128 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 Water
MNPCA128 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)
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
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