Whaletail Lake
Whaletail Lake in Hennepin County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.3 ft visibility. Phosphorus: 45.8 µg/L. Chlorophyll-a (algae): 19.4 µg/L. Maximum depth: 22 ft. Surface area: 510.03 acres.
- Clarity
- 3.3 ft
- Typical in August
- 71°F
- Max depth
- 22 ft
- Area
- 510 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 8
- Open water
- 236 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Whaletail Lake →
Next lake in Hennepin County
Whaletail Lake is a 510-acre productive, nutrient-rich eutrophic lake in Hennepin County, Minnesota with a maximum depth of 22 feet. Water quality is graded D based on 3 sampling years through 2024. 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 2 public boat landings. Compared to the 80 other monitored lakes in Hennepin County, Whaletail Lake ranks #29 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-07. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyAlgae 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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 3.3 ft of visibility. Phosphorus level: 45.8 µg/L. Chlorophyll-a: 19.4 µg/L. Trophic State Index: 60.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | 45.8 µg/L | Poor |
| Chlorophyll-a (Algae) | 19.4 µg/L | Poor |
| Trophic State Index (TSI) | 60 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Whaletail Lake
Compare lakeside cabins, hotels, and vacation rentals near Whaletail 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 Whaletail Lake are listed below.
Top-rated places to stay near Whaletail Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Whaletail Lake typically sits around 71°F at the surface in August. Summer average is about 70°F. Usually warmest in Jul (about 72°F) and coldest in Apr (about 48°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 1,382 field readings (2010–2024) via the EPA Water Quality Portal. See the full Whaletail Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 22 ft |
| Surface Area | 510 acres |
| Shoreline Length | 6.9 mi |
| Littoral Zone | 92% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Whaletail LakePublic
- Halsted BayPublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Whaletail 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.
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2021-07-26 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Crappie | 45.96 | 0.16 lb |
| Bluegill | 20.04 | 0.15 lb |
| White Crappie | 12.45 | 0.21 lb |
| Yellow Perch | 8.26 | 0.11 lb |
| Yellow Bass | 4.84 | 0.78 lb |
| Brown Bullhead | 3.37 | 0.83 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.
Black Crappie
Bluegill
White Crappie
Yellow Perch
From the 2021-07-26 survey
Whaletail Lake is 510-acres (469 littoral acres) with a maximum depth of 22 feet. Whaletail is located northeast of St. Bonifacious in southwestern Hennepin County. Public water access is provided by DNR Parks and Trails on the northwest side of the lake off of County road 92 and West Highland road (up to 16…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Whaletail Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — WhaletailFisheries Lake Survey · MN DNR LakeFinder
- —Public Water Access Sites — WhaletailPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.217 m/yr | 5 |
| Phosphorus | ↑ Improving | -1.52 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -1.98 µg/L/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (13 observations).
Estimated open water season: 236 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-03 (2024) | 2018-05-01 (2018) |
| Ice-In | 1997-11-15 (1997) | 1999-12-14 (1999) |
Most recent ice-out: 2024-03-03
EPA Impairment Status
Whaletail Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN27-0184-02 · Official waterbody report · Matched by proximity (0.51 km)
County Ranking
Ranked #29 of 81 lakes in Hennepin County
Nearby Lakes With Higher Grades
Whaletail Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Hennepin County
Frequently asked questions about Whaletail Lake
What is the water quality grade for Whaletail Lake?
- Whaletail Lake in Hennepin County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.3 ft visibility. Phosphorus: 45.8 µg/L. Chlorophyll-a (algae): 19.4 µg/L. Maximum depth: 22 ft. Surface area: 510.03 acres.
Is Whaletail Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Whaletail Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 19.4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Whaletail Lake?
- Whaletail Lake typically sits around 71°F at the surface in August, from 1,382 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Whaletail Lake?
- Whaletail Lake has a maximum depth of 22 feet. The lake covers 510.03 acres.
What fish are in Whaletail Lake?
- Fish species found in Whaletail Lake include black bullhead, black crappie, bluegill, brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, white crappie, yellow bullhead, yellow perch. Whaletail Lake is located in Hennepin County, Minnesota.
When does Whaletail Lake thaw?
- Whaletail Lake typically has ice-out around Apr 8. Ice typically forms around Nov 30. The open water season is approximately 236 days.
Are there boat ramps on Whaletail Lake?
- Whaletail Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Whaletail Lake, Halsted Bay. Public access is listed as yes.
Explore Whaletail Lake across LakeGrade
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Where this data comes from
514 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA514 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 4500 N C ~ Persufate Method for Total Nitrogen
- Phosphorus by Colorimetry
- 2120 B ~ Color in Water by Visual Comparison
Monitoring station identifiers (2)
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
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