Dutchman Lake Deep
Dutchman Lake Deep in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2.3 ft visibility. Phosphorus: 31 µg/L. Chlorophyll-a (algae): 14.7 µg/L.
- Clarity
- 2.3 ft
- Typical in August
- 70°F
- Mean depth
- ~14 ft est.
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in Cook County
Why Dutchman Lake Deep has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Dutchman Lake Deep, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Dutchman Lake Deep is a lake in Cook County, Minnesota with an estimated average depth of about 14 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-10-11. Grade methodology: LakeGrade methodology.
Watch Dutchman Lake Deep water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Dutchman Lake Deep
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 2.3 ft of visibility. Phosphorus level: 31 µg/L. Chlorophyll-a: 14.7 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.3 ft | Not graded |
| Phosphorus | 31 µg/L | Not graded |
| Chlorophyll-a (Algae) | 14.7 µg/L | Not graded |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Dutchman Lake Deep
Compare lakeside cabins, hotels, and vacation rentals near Dutchman Lake Deep in Cook 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 Dutchman Lake Deep
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Water Temperature
Dutchman Lake Deep typically sits around 70°F at the surface in August. Summer average is about 69°F. Usually warmest in Jul (about 72°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 179 field readings (2011–2023) via the EPA Water Quality Portal. See the full Dutchman Lake Deep water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~14 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Dutchman Lake Deep.
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.
Recreation & Access
Fishing Dutchman Lake Deep
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -8.502 m/yr | 4 |
| Phosphorus | ↓ Declining | +1.4 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -0.63 µg/L/yr | 4 |
Graded lakes near Dutchman Lake Deep
Dutchman Lake Deep has no grade, but these lakes within a short drive do.
Nearby Lakes in Cook County
Frequently asked questions about Dutchman Lake Deep
What is the water quality grade for Dutchman Lake Deep?
- Dutchman Lake Deep in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2.3 ft visibility. Phosphorus: 31 µg/L. Chlorophyll-a (algae): 14.7 µg/L.
Is Dutchman Lake Deep safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Dutchman Lake Deep is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 14.7 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Dutchman Lake Deep?
- Dutchman Lake Deep typically sits around 70°F at the surface in August, from 179 EPA Water Quality Portal field readings (2011–2023). That is a typical value for the month, not a live reading.
How deep is Dutchman Lake Deep?
- No published bathymetric survey covers Dutchman Lake Deep, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 14 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Dutchman Lake Deep?
- Dutchman Lake Deep has 1 documented boat landing in the USGS National Boat Ramps inventory. Public access is listed as yes.
Explore Dutchman Lake Deep across LakeGrade
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Where this data comes from
75 measurements from 1 monitoring station, 2021–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Grand Portage Reservation
GPC5_WQX75 samples · 2021–2023
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory