Henry Lake
Henry Lake in Douglas County, Minnesota has a water quality grade of C (Fair). Water clarity: 5.9 ft visibility. Phosphorus: 25 µg/L. Chlorophyll-a (algae): 12.5 µg/L. Maximum depth: 32 ft. Surface area: 152.12 acres.
- Clarity
- 5.9 ft
- Typical in August
- 76°F
- Max depth
- 32 ft
- Area
- 152 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- No
- Ice-out
- Mar 30
Next lake in Douglas County
Henry Lake is a 152-acre productive, nutrient-rich eutrophic lake in Douglas County, Minnesota with a maximum depth of 32 feet (13-foot average). Water quality is graded C based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 11 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 36 other monitored lakes in Douglas County, Henry Lake ranks #30 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-06. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 5.9 ft. Phosphorus level: 25 µg/L. Chlorophyll-a: 12.5 µg/L. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.9 ft | Not graded |
| Phosphorus | 25 µg/L | Fair |
| Chlorophyll-a (Algae) | 12.5 µg/L | Fair |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Henry Lake
Compare lakeside cabins, hotels, and vacation rentals near Henry Lake in Douglas 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
Henry Lake typically sits around 76°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 76°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 79 field readings (2011–2025) via the EPA Water Quality Portal. See the full Henry Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 32 ft |
| Average Depth | 13 ft |
| Surface Area | 152 acres |
| Shoreline Length | 2 mi |
| Littoral Zone | 60% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Henry 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
11 surveys on file from MN DNR Fisheries. Most recent: 2023-06-06 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 78.63 | 0.41 lb |
| Fathead Minnow | 76.77 | — |
| Yellow Perch | 44.79 | 0.2 lb |
| Black Crappie | 37.27 | 0.28 lb |
| Common Carp | 16.35 | 3.3 lb |
| Largemouth Bass | 14.39 | 0.96 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 Bullhead
Yellow Perch
Black Crappie
Common Carp
From the 2023-06-06 survey
Lake Henry is a small (152 acres), productive basin located within the Long Prairie River watershed. Mean and maximum depths are 13 and 32 feet, respectively. Lake Henry, along with lakes Agnes and Winona, comprise a chain of lakes within the city limits of Alexandria. Lakes Henry and Agnes are broadly connected with…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Henry Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HenryFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — HenryFish Stocking History · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.13 m/yr | 4 |
| Phosphorus | ↑ Improving | -4.95 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -0.42 µg/L/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (6 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-10 (2024) | 2022-04-25 (2022) |
Most recent ice-out: 2024-03-10
EPA Impairment Status
Henry Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN21-0051-00 · Official waterbody report
County Ranking
Ranked #30 of 37 lakes in Douglas County
Nearby Lakes With Higher Grades
Henry Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Douglas County
Frequently asked questions about Henry Lake
What is the water quality grade for Henry Lake?
- Henry Lake in Douglas County, Minnesota has a water quality grade of C (Fair). Water clarity: 5.9 ft visibility. Phosphorus: 25 µg/L. Chlorophyll-a (algae): 12.5 µg/L. Maximum depth: 32 ft. Surface area: 152.12 acres.
Is Henry Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Henry Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 12.5 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Henry Lake?
- Henry Lake typically sits around 76°F at the surface in August, from 79 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Henry Lake?
- Henry Lake has a maximum depth of 32 feet and an average depth of 13 feet. The lake covers 152.12 acres.
What fish are in Henry Lake?
- Fish species found in Henry Lake include black bullhead, black crappie, bluegill, common carp, green sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow perch. Henry Lake is located in Douglas County, Minnesota.
When does Henry Lake thaw?
- Henry Lake typically has ice-out around Mar 30.
Explore Henry Lake across LakeGrade
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
124 measurements from 1 monitoring station, 2022–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA124 samples · 2022–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
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
Ice data from Minnesota DNR Climate