Mallard Lake
Becker County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Mallard Lake. Here is what has been measured.
- Eutrophic
- 50 ft max depth
- Public access
Mallard Lake in Becker County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.6 ft visibility. Phosphorus: 43 µg/L. Chlorophyll-a (algae): 13.4 µg/L.
Mallard Lake is a productive, nutrient-rich eutrophic lake in Becker County, Minnesota with an estimated average depth of about 50 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 83 other monitored lakes in Becker County, Mallard Lake ranks #79 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-26. Methodology: how these readings are compared.
Swimming conditions
Readings onlyElevated nutrients
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Mallard Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Mallard Lake
These are the measurements Minnesota PCA publishes for Mallard Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.6 ft. Phosphorus 43 µg/L. Chlorophyll-a 13.4 µg/L. TSI 58.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 43µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 13.4µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 58 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Mallard Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Mallard Lake typically sits around 62°F at the surface in September. Summer average is about 69°F. Usually warmest in Jul (about 75°F) and coldest in Sep (about 62°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (62°F) to its warmest (75°F).
Typical surface water temperature by month, from 32 field readings (2010–2025) via the EPA Water Quality Portal. See the full Mallard Lake water temperature breakdown →
Lake Details
Max depth
~50 ft est.
Public access
Yes
Listed by Minnesota PCA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Mallard Lake.
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Surface area
121 acres
HydroLAKES / HydroSHEDS
Shoreline
2.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,509 ft
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.
Stays via Stay22
Stays near Mallard Lake
Compare lakeside cabins, hotels, and vacation rentals near Mallard Lake in Becker 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Mallard Lake are listed below.
Top-rated places to stay near Mallard Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
Follow Mallard Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Mallard Lake
Water Quality Trend: Worsening
Based on 4 years of monitoring (2022–2025).
Water clarity
Worsening4 years
Phosphorus
Worsening+4 µg/L/yr4 years
Chlorophyll-a
Worsening+3.35 µg/L/yr4 years
Nearby Lakes in Becker County
Frequently asked questions about Mallard Lake
Where is Mallard Lake?
- Mallard Lake is a lake in Becker County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Mallard Lake?
- Mallard Lake in Becker County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.6 ft visibility. Phosphorus: 43 µg/L. Chlorophyll-a (algae): 13.4 µg/L.
Is Mallard Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Mallard Lake?
- Mallard Lake typically sits around 62°F at the surface in September, from 32 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Mallard Lake?
- No published bathymetric survey covers Mallard Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 50 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Can I fish at Mallard Lake?
- Public access to Mallard Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Mallard Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Becker County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Detroit Lakes Area area
Top lakes and where to stay in the Park Rapids Area area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Red River of the North Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Mallard Lake
Other Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
56 measurements from 1 monitoring station, 2022–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA56 samples · 2022–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity, Nephelometric Method
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder