Webb Lake
Cass County, Minnesota720 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Webb Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- 84 ft max depth
- Public access
Webb Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 18 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.9 µg/L. Maximum depth: 84 ft. Surface area: 720.03 acres.
Minnesota DNR's Standard Survey on July 14, 2025 caught 1.92 walleye per gill net at Webb Lake. DNR survey details →
Webb Lake is a 720-acre cold, clear oligotrophic lake in Cass County, Minnesota with a maximum depth of 84 feet (21-foot average). Overall water quality is declining over recent sampling years. The lake supports 12 documented fish species including black crappie, bluegill, and hybrid sunfish. Public access is available with 1 public boat landing. Compared to the 103 other monitored lakes in Cass County, Webb Lake ranks #31 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Methodology: how these readings are compared.
Webb Lake covers about 720 acres in Cass County. It has one public boat landing. The median ice-out date is April 22, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Webb Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Webb Lake is good for
From access and monitoring records, not editorial picks.
- Clear water18 ft of visibility
- Boat launch1 documented ramp
- Fishing12 species recorded
- Ice seasonIce-out around Apr 22
- Deep water84 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. Webb Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Webb 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 Webb Lake
These are the measurements Minnesota PCA publishes for Webb Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 18 ft down. Phosphorus 9.5 µg/L. Chlorophyll-a 2.9 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 18ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 9.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.9µg/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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Webb Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Webb Lake typically sits around 68°F at the surface in September. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in May (about 58°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (58°F) to its warmest (75°F).
Typical surface water temperature by month, from 62 field readings (2011–2025) via the EPA Water Quality Portal. See the full Webb Lake water temperature breakdown →
Minnesota DNR's Standard Survey on July 14, 2025 caught 1.92 walleye per gill net at Webb Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Webb 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: 2025-07-14 (Standard Survey).
12 surveys on file · most recent 2025-07-14 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 58.39 | ||
| Bluegill | 28.65 | 2–8 in 2025-07-14 | 0.13 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
From the 2025-07-14 survey
Webb Lake (DOW# 11-0311; Lake Class 27) is a 720-acre lake with 278 littoral acres, 7.1 miles of shoreline and a maximum depth of 84 feet located northeast of Hackensack, MN. There is a Minnesota Department of Natural Resources (MNDNR) owned public access on the south shore. The lake is primarily managed for…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Webb Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — WebbFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Webb (1545)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — WebbFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — WebbPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
84 ft
Average depth
20.9 ft
Surface area
720 acres
Shoreline
7.1 mi
Littoral zone
39%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
13 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,339 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Webb 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 Webb Lake
Compare lakeside cabins, hotels, and vacation rentals near Webb 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 Webb Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
Follow Webb Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Webb Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Worsening+0.39 µg/L/yr6 years
Chlorophyll-a
Worsening+0.15 µg/L/yr6 years
Ice season
Typical ice-out
Apr 22
Earliest Apr 2, 2010 · Latest May 13, 2013
Typical ice-in
Nov 25
Earliest Oct 22, 1977 · Latest Dec 21, 1998
Most recent ice-out
May 7
2022
91 observations · Minnesota PCA ice records
EPA Impairment Status
Webb 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 MN11-0311-00 · Official waterbody report
Nearby Lakes in Cass County
Frequently asked questions about Webb Lake
Where is Webb Lake?
- Webb 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 Webb Lake?
- Webb Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 18 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.9 µg/L. Maximum depth: 84 ft. Surface area: 720.03 acres.
Is Webb Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Webb 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 Webb Lake?
- Webb Lake typically sits around 68°F at the surface in September, from 62 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Webb Lake?
- Webb Lake has a maximum depth of 84 feet and an average depth of 20.9 feet. The lake covers 720.03 acres.
What fish are in Webb Lake?
- Fish species found in Webb Lake include black crappie, bluegill, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Webb Lake is located in Cass County, Minnesota.
What did the DNR fisheries survey find at Webb Lake?
- Minnesota DNR's Standard Survey on July 14, 2025 caught 1.92 walleye per gill net at Webb Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Webb 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 Webb Lake thaw?
- Webb Lake typically has ice-out around Apr 22. Ice typically forms around Nov 25. The open water season is approximately 217 days.
Are there boat ramps on Webb Lake?
- Webb Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Webb Lake. Public access is listed as yes.
Can I fish at Webb Lake?
- Webb 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 Webb Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Cass County
Species activity outlook by water temperature and season
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Where to stay at Minnesota's top lakes, each with its readings
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Minnesota's cleanest lakes, ranked on agency measurements
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Where this data comes from
130 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
MNPCA130 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 (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
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