Benton Lake
Benton Lake in Carver County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 1 ft visibility. Phosphorus: 161 µg/L. Chlorophyll-a (algae): 104 µg/L.
- Clarity
- 1 ft
- Typical in August
- 76°F
- Mean depth
- ~10 ft est.
- Type
- Hypereutrophic
- Trend
- ↑ Improving
- Public access
- No
Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Benton Lake →
Next lake in Carver County
Benton Lake is a highly nutrient-loaded hypereutrophic lake in Carver County, Minnesota with an estimated average depth of about 10 feet. Water quality is graded F based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 37 other monitored lakes in Carver County, Benton Lake ranks #26 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-07. Grade methodology: LakeGrade methodology.
Watch Benton Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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.
Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom
Water Quality Grade: F (Algae-prone)
Very murky, less than 1 ft of visibility. Phosphorus level: 161 µg/L. Chlorophyll-a: 104 µg/L. Trophic State Index: 77.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1 ft | Not graded |
| Phosphorus | 161 µg/L | Poor |
| Chlorophyll-a (Algae) | 104 µg/L | Poor |
| Trophic State Index (TSI) | 77 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Benton Lake
Compare lakeside cabins, hotels, and vacation rentals near Benton Lake in Carver 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 Benton Lake are listed below.
Top-rated places to stay near Benton Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Benton Lake typically sits around 76°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 78°F) and coldest in Feb (about 33°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 292 field readings (2010–2025) via the EPA Water Quality Portal. See the full Benton Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~10 ft est. |
| Public Access | No |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Benton Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Benton Lake
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Benton Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fish Stocking History — BentonFish Stocking History · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.041 m/yr | 6 |
| Phosphorus | ↑ Improving | -32.53 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -18.68 µg/L/yr | 6 |
EPA Impairment Status
Benton 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 MN10-0069-00 · Official waterbody report
County Ranking
Ranked #26 of 38 lakes in Carver County
Nearby Lakes With Higher Grades
Benton Lake holds Grade F. 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 Carver County
Frequently asked questions about Benton Lake
What is the water quality grade for Benton Lake?
- Benton Lake in Carver County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 1 ft visibility. Phosphorus: 161 µg/L. Chlorophyll-a (algae): 104 µg/L.
Is Benton Lake safe to swim in?
- Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Benton Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 104 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Benton Lake?
- Benton Lake typically sits around 76°F at the surface in August, from 292 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Benton Lake?
- No published bathymetric survey covers Benton Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 10 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Benton Lake across LakeGrade
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Carver County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Minnesota River Watershed, ranked by water quality
Lakes in the Crow River Watershed, ranked by water quality
Very high nutrients, dense algae, poor clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Benton Lake
Other Grade F Lakes in Minnesota
Hypereutrophic Lakes in Minnesota
Where this data comes from
272 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
MNPCA272 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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