Mallard Lake
Mallard Lake in Becker County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.6 ft visibility. Phosphorus: 43 µg/L. Chlorophyll-a (algae): 13.4 µg/L.
- Clarity
- 3.6 ft
- Typical in August
- 69°F
- Max depth
- ~50 ft est.
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Mallard Lake →
Next lake in Becker County
Mallard Lake is a productive, nutrient-rich eutrophic lake in Becker County, Minnesota with an estimated average depth of about 50 feet. Water quality is graded D based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyElevated nutrients
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 3.6 ft. Phosphorus level: 43 µg/L. Chlorophyll-a: 13.4 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.6 ft | Not graded |
| Phosphorus | 43 µg/L | Poor |
| Chlorophyll-a (Algae) | 13.4 µg/L | Fair |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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 grade measures nutrients and algae, not lodging — cabins and rentals around Mallard Lake are listed below.
Top-rated places to stay near Mallard Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Mallard Lake typically sits around 69°F at the surface in August. 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.
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
| Characteristic | Value |
|---|---|
| Maximum Depth | ~50 ft est. |
| Average Depth | ~13 ft est. |
| Public Access | Yes |
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
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
- Many Point LakePublic
Fishing Mallard Lake
Water Quality Trend: ↓ Declining
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.295 m/yr | 4 |
| Phosphorus | ↓ Declining | +4 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +3.35 µg/L/yr | 4 |
County Ranking
Ranked #79 of 84 lakes in Becker County
Nearby Lakes With Higher Grades
Mallard Lake holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Becker County
Frequently asked questions about Mallard Lake
What is the water quality grade for Mallard Lake?
- Mallard Lake in Becker County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.6 ft visibility. Phosphorus: 43 µg/L. Chlorophyll-a (algae): 13.4 µg/L.
Is Mallard 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. Mallard Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 13.4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Mallard Lake?
- Mallard Lake typically sits around 69°F at the surface in August, 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.
Are there boat ramps on Mallard Lake?
- Mallard Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Many Point Lake. Public access is listed as yes.
Explore Mallard Lake across LakeGrade
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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)
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