Hennepin Lake
Hennepin Lake in Hubbard County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 4.8 µg/L. Maximum depth: 14 ft. Surface area: 417.61 acres.
- Clarity
- 10 ft
- Typical in August
- 71°F
- Max depth
- 14 ft
- Area
- 418 acres
- Type
- Mesotrophic
- Public access
- Yes
Next lake in Hubbard County
Hennepin Lake is a 418-acre mesotrophic lake in Hubbard County, Minnesota with a maximum depth of 14 feet. Water quality is graded A based on 2 sampling years through 2024. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 67 other monitored lakes in Hubbard County, Hennepin Lake ranks #53 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 10 ft. Phosphorus level: 15 µg/L. Chlorophyll-a: 4.8 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10 ft | Not graded |
| Phosphorus | 15 µg/L | Good |
| Chlorophyll-a (Algae) | 4.8 µg/L | Good |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Hennepin Lake
Compare lakeside cabins, hotels, and vacation rentals near Hennepin Lake in Hubbard 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.
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Water Temperature
Hennepin Lake typically sits around 71°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 76°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 28 field readings (2024–2024) via the EPA Water Quality Portal. See the full Hennepin Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 14 ft |
| Surface Area | 418 acres |
| Shoreline Length | 5.5 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Evergreen LakePublic
- Hennepin LakePublic
- Frontenac LakePublic
Fishing Hennepin Lake
DNR Fisheries Survey Summary
6 surveys on file from MN DNR Fisheries. Most recent: 2013-05-29 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Brown Bullhead | 19.54 | 0.26 lb |
| Bluegill | 17.29 | 0.15 lb |
| Yellow Perch | 8.84 | 0.23 lb |
| Northern Pike | 7.08 | 1.59 lb |
| Pumpkinseed | 6.84 | 0.14 lb |
| Black Crappie | 3.93 | 0.3 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.
Brown Bullhead
Bluegill
Yellow Perch
Northern Pike
From the 2013-05-29 survey
Hennepin Lake is located 2 miles southeast of Becida in northwestern Hubbard County. Hennepin has a surface area of 418 acres and a maximum depth of 14 feet. A public access is located on the western shore of the lake, off of 470th street. The Minnesota Department of Natural Resources (DNR) has classified Minnesota's…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Hennepin Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HennepinFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Hennepin (1280)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — HennepinFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — HennepinPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Hennepin 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 MN29-0246-00 · Official waterbody report
County Ranking
Ranked #53 of 68 lakes in Hubbard County
Nearby Lakes in Hubbard County
Frequently asked questions about Hennepin Lake
What is the water quality grade for Hennepin Lake?
- Hennepin Lake in Hubbard County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 4.8 µg/L. Maximum depth: 14 ft. Surface area: 417.61 acres.
Is Hennepin Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Hennepin Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Hennepin Lake?
- Hennepin Lake typically sits around 71°F at the surface in August, from 28 EPA Water Quality Portal field readings (2024–2024). That is a typical value for the month, not a live reading.
How deep is Hennepin Lake?
- Hennepin Lake has a maximum depth of 14 feet. The lake covers 417.61 acres.
Are there boat ramps on Hennepin Lake?
- Hennepin Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Evergreen Lake, Hennepin Lake, Frontenac Lake. Public access is listed as yes.
Explore Hennepin Lake across LakeGrade
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Where this data comes from
38 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA38 samples · 2024
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory