Markgrafs Lake
Markgrafs Lake in Washington County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 4.8 ft visibility. Phosphorus: 60 µg/L. Chlorophyll-a (algae): 15 µg/L.
- Clarity
- 4.8 ft
- Typical in August
- 75°F
- Max depth
- ~29 ft est.
- Type
- Eutrophic
- Public access
- No
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Markgrafs Lake →
Next lake in Washington County
Markgrafs Lake is a productive, nutrient-rich eutrophic lake in Washington County, Minnesota with an estimated average depth of about 29 feet. Water quality is graded D based on 2 sampling years through 2024. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 74 other monitored lakes in Washington County, Markgrafs Lake ranks #59 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-23. Grade methodology: LakeGrade methodology.
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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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 4.8 ft. Phosphorus level: 60 µg/L. Chlorophyll-a: 15 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | Not graded |
| Phosphorus | 60 µg/L | Poor |
| Chlorophyll-a (Algae) | 15 µg/L | Poor |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Markgrafs Lake
Compare lakeside cabins, hotels, and vacation rentals near Markgrafs Lake in Washington 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 Markgrafs Lake are listed below.
Top-rated places to stay near Markgrafs Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Markgrafs Lake typically sits around 75°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in Apr (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 81 field readings (2010–2024) via the EPA Water Quality Portal. See the full Markgrafs Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~29 ft est. |
| Average Depth | ~7 ft est. |
| Public Access | No |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Markgrafs 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 Markgrafs Lake
EPA Impairment Status
Markgrafs Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN82-0089-00 · Official waterbody report
County Ranking
Ranked #59 of 75 lakes in Washington County
Nearby Lakes in Washington County
Frequently asked questions about Markgrafs Lake
What is the water quality grade for Markgrafs Lake?
- Markgrafs Lake in Washington County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 4.8 ft visibility. Phosphorus: 60 µg/L. Chlorophyll-a (algae): 15 µg/L.
Is Markgrafs Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Markgrafs Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 15 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Markgrafs Lake?
- Markgrafs Lake typically sits around 75°F at the surface in August, from 81 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Markgrafs Lake?
- No published bathymetric survey covers Markgrafs Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 29 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Markgrafs Lake across LakeGrade
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
56 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA56 samples · 2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder