Deans Lake
Deans Lake in Scott County, Minnesota has a water quality grade of C (Fair). Phosphorus: 33 µg/L. Chlorophyll-a (algae): 3.4 µg/L.
- Typical in July
- 83°F
- Mean depth
- ~10 ft est.
- Type
- Mesotrophic
- Trend
- → Stable
- Public access
- No
- Ice-out
- Mar 18
- Open water
- 258 days
Next lake in Scott County
Deans Lake is a mesotrophic lake in Scott County, Minnesota with an estimated average depth of about 10 feet. Water quality is graded C based on 2 sampling years through 2025. Phosphorus level is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 20 other monitored lakes in Scott County, Deans Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-01. Grade methodology: LakeGrade methodology.
Watch Deans Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
No clarity data. Phosphorus level: 33 µg/L. Chlorophyll-a: 3.4 µg/L. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 33 µg/L | Fair |
| Chlorophyll-a (Algae) | 3.4 µg/L | Good |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Deans Lake
Compare lakeside cabins, hotels, and vacation rentals near Deans Lake in Scott 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 Deans 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
Deans Lake typically sits around 83°F at the surface in July. Summer average is about 77°F. Usually warmest in Jul (about 83°F) and coldest in May (about 68°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 9 field readings (2010–2024) via the EPA Water Quality Portal. See the full Deans 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 Deans 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 Deans Lake
Water Quality Trend: → Stable
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↓ Declining | +3 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -13.1 µg/L/yr | 2 |
Ice Season
Historical ice data from Minnesota DNR (9 observations).
Estimated open water season: 258 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-01 (2024) | 2020-03-27 (2020) |
| Ice-In | 2014-11-12 (2014) | 2015-12-16 (2015) |
Most recent ice-out: 2024-03-01
EPA Impairment Status
Deans 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 MN70-0076-00 · Official waterbody report · Matched by proximity (2.74 km)
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Deans Lake under Clean Water Act (NPDES) discharge permits.
- Smsc Organics Recycling FacilityShakopee · 1.3 mi away · NPDES MN0075025
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #7 of 21 lakes in Scott County
Nearby Lakes in Scott County
Frequently asked questions about Deans Lake
What is the water quality grade for Deans Lake?
- Deans Lake in Scott County, Minnesota has a water quality grade of C (Fair). Phosphorus: 33 µg/L. Chlorophyll-a (algae): 3.4 µg/L.
Is Deans Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Deans Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 3.4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Deans Lake?
- Deans Lake typically sits around 83°F at the surface in July, from 9 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Deans Lake?
- No published bathymetric survey covers Deans 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.
When does Deans Lake thaw?
- Deans Lake typically has ice-out around Mar 18. Ice typically forms around Dec 1. The open water season is approximately 258 days.
Explore Deans Lake across LakeGrade
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Scott 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
Moderate nutrients, good water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Deans Lake
Other Grade C Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
13 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Shakopee Mdewakanton Sioux Community of Minnesota (Tribal)
SMSCGOV_WQX13 samples · 2024–2025
Analytical methods
- 4500 P F ~ Phosphorus in Water by Colorimetry Automated Ascorbic Acid Method
- 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate