Harriet Lake
Harriet Lake in Hennepin County, Minnesota has a water quality grade of C (Fair). Water clarity: 9.7 ft visibility. Phosphorus: 189.5 µg/L. Chlorophyll-a (algae): 5.4 µg/L. Maximum depth: 87 ft. Surface area: 341.22 acres.
- Clarity
- 9.7 ft
- Typical in August
- 56°F
- Max depth
- 87 ft
- Area
- 341 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 7
- Open water
- 247 days
Next lake in Hennepin County
Harriet Lake is a 341-acre productive, nutrient-rich eutrophic lake in Hennepin County, Minnesota with a maximum depth of 87 feet (29-foot average). Water quality is graded C based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 15 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 80 other monitored lakes in Hennepin County, Harriet Lake ranks #13 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-24. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyBacteria A
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.
Based on E. coli testing, Harriet Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 6 samples across 6 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Minnesota’s current beach and health-department advisories before swimming.
Water Quality Grade: C (Fair)
Moderate clarity, visible to about 9.7 ft. Phosphorus level: 189.5 µg/L. Chlorophyll-a: 5.4 µg/L. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9.7 ft | Not graded |
| Phosphorus | 189.5 µg/L | Poor |
| Chlorophyll-a (Algae) | 5.4 µg/L | Good |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Harriet Lake
Compare lakeside cabins, hotels, and vacation rentals near Harriet 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.
Top-rated places to stay near Harriet Lake
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Water Temperature
Harriet Lake typically sits around 56°F at the surface in August. Summer average is about 55°F. Usually warmest in Aug (about 56°F) and coldest in Jan (about 36°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 3,238 field readings (2010–2025) via the EPA Water Quality Portal. See the full Harriet Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 87 ft |
| Average Depth | 29 ft |
| Surface Area | 341 acres |
| Shoreline Length | 2.7 mi |
| Littoral Zone | 25% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Lake HarrietPublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Harriet 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.
Source: USGS Nonindigenous Aquatic Species (NAS) Database. Hover a chip to see scientific name, ecological context, status, and first-observed year.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2024-07-08 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 97.07 | 0.14 lb |
| Yellow Perch | 18.14 | 0.12 lb |
| Black Crappie | 10.67 | 0.23 lb |
| Pumpkinseed | 4.91 | 0.1 lb |
| Walleye | 2.59 | 1.9 lb |
| Hybrid Sunfish | 2.57 | 0.12 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.
Bluegill
Yellow Perch
Black Crappie
Pumpkinseed
From the 2024-07-08 survey
Harriet is a 341-acre (85 littoral acres) lake with a maximum depth of 82 feet. Harriet is located in south Minneapolis in eastern Hennepin County. Harriet is primarily managed for Walleye (fingerling stocked annually) and Muskellunge (fingerling stocked during even-numbered years), but includes catchable populations…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Harriet Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HarrietFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — HarrietFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — HarrietPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.179 m/yr | 6 |
| Phosphorus | ↑ Improving | -5.39 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.65 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (160 observations).
Estimated open water season: 247 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2017-03-07 (2017) | 2018-05-02 (2018) |
| Ice-In | 1996-11-25 (1996) | 2024-01-14 (2024) |
Most recent ice-out: 2026-04-01
EPA Impairment Status
Harriet Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN27-0016-00 · Official waterbody report
County Ranking
Ranked #13 of 81 lakes in Hennepin County
Nearby Lakes in Hennepin County
Frequently asked questions about Harriet Lake
What is the water quality grade for Harriet Lake?
- Harriet Lake in Hennepin County, Minnesota has a water quality grade of C (Fair). Water clarity: 9.7 ft visibility. Phosphorus: 189.5 µg/L. Chlorophyll-a (algae): 5.4 µg/L. Maximum depth: 87 ft. Surface area: 341.22 acres.
Is Harriet Lake safe to swim in?
- Based on E. coli testing, Harriet Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 6 samples across 6 seasons. That works out to a bacteria swim-safety grade of A — a historical summary of past testing, not a current reading. Harriet Lake has a water quality grade of C (Fair). Bacteria levels can spike quickly after heavy rain, so always check Minnesota's current beach and health-department advisories before you swim.
What is the water temperature of Harriet Lake?
- Harriet Lake typically sits around 56°F at the surface in August, from 3,238 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Harriet Lake?
- Harriet Lake has a maximum depth of 87 feet and an average depth of 29 feet. The lake covers 341.22 acres.
What fish are in Harriet Lake?
- Fish species found in Harriet Lake include black bullhead, black crappie, bluegill, brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Harriet Lake is located in Hennepin County, Minnesota.
When does Harriet Lake thaw?
- Harriet Lake typically has ice-out around Apr 7. Ice typically forms around Dec 10. The open water season is approximately 247 days.
Are there boat ramps on Harriet Lake?
- Harriet Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Harriet. Public access is listed as yes.
Explore Harriet Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Hennepin County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Crow River Watershed, ranked by water quality
High nutrients, frequent algae, reduced clarity
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State Parks Near Harriet Lake
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
1,650 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
MNPCA1,650 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity, Nephelometric Method
- Turbidity, Probe Method
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