Hill River Lake
Polk County, MinnesotaEutrophic
Hill River Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
At a TSI of 62, Hill River Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. Hill River Lake is unusually deep for Minnesota at 60 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Hill River Lake covers 102 acres alongside 2.7 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 20 graded lakes of Polk County, Hill River Lake sits at rank 18, near the bottom of the county list.
No invasive species are currently listed at Hill River Lake — the lake remains off the Minnesota infested-waters roster. The fishery includes walleye among the lake's 13 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
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
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Murky, only visible to about 4.6 ft. Phosphorus level: 95 µg/L. Trophic State Index: 62.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.6 ft | D |
| Phosphorus | 95 µg/L | F |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 60 ft |
| Surface Area | 102.07 acres |
| Shoreline Length | 2.7 mi |
| Littoral Zone | 66% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Hill River Lake (14-day solunar calendar)
→ Is it safe to eat fish from Hill River Lake? (mercury & PFAS guide)
→ Hill River Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.015 m/yr | 5 |
| Phosphorus | ↑ Improving | -5.45 µg/L/yr | 5 |
Location
County Ranking
Ranked #18 of 20 lakes in Polk County
Cleaner Lakes Within 30 Miles
Hill River Lake holds Grade D. 5 nearby lakes hold higher grades.
- BBadger LakePolk County · mi · Two grade letters higher (D → B)
- CUff LakePolk County · mi · Higher grade (D → C)
- CTurtle LakePolk County · mi · Higher grade (D → C)
- CWhitefish LakePolk County · mi · Higher grade (D → C)
- DStore LakePolk County · mi · Higher overall water quality score
Nearby Lakes in Polk County
More Minnesota Lake Rankings
Other Grade D Lakes in Minnesota
Eutrophic Lakes in Minnesota
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2025-06-24 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 22.23 | 0.39 lb |
| Bluegill | 16.34 | 0.28 lb |
| Yellow Perch | 8.52 | 0.18 lb |
| Brown Bullhead | 7.74 | 0.57 lb |
| Black Crappie | 5.94 | 0.26 lb |
| TPM | 5.16 | 0.03 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
Bluegill
Yellow Perch
Brown Bullhead
From the 2025-06-24 survey
A targeted survey of nearshore fish species in Hill River Lake was conducted on June 24th-25th, 2025, by Lake Biological Monitoring and Assessment (LBMA) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot seine, where possible.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Hill River Lake. 3 reports on file.
- —Fisheries Lake Survey — Hill RiverFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Hill River (1956)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — Hill RiverPublic Water Access Sites · MN DNR LakeFinder
Reservoir Info (USACE NID)
Hill River Lake is a man-made reservoir impounded by the Hill River Lake (completed 1950), built primarily for flood risk reduction on the Hill River; gravity-type dam, 8 ft tall and 42 ft long.
- Surface area
- 88 ac
- Normal storage
- 780 ac-ft
- Max storage
- 940 ac-ft
- Drainage area
- 99 sq mi
- Hazard class
- Low
- Owner
- MNDNR-Fisheries
Source: USACE National Inventory of Dams, NID ID MN00226 · Operator website
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-09-23
Monitoring stations: 1