Mattson Lake
Chisago County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Mattson Lake. Here is what has been measured.
- Mesotrophic
- 35 ft max depth
Mattson Lake in Chisago County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 1 µg/L.
Mattson Lake is a mesotrophic lake in Chisago County, Minnesota with an estimated average depth of about 35 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 29 other monitored lakes in Chisago County, Mattson Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-17. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLow algae
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 Mattson 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 Mattson Lake
These are the measurements Minnesota PCA publishes for Mattson 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 3.9 ft. Phosphorus 12 µg/L. Chlorophyll-a 1 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 12µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Mattson Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Mattson Lake typically sits around 51°F at the surface in October. Summer average is about 76°F. Usually warmest in Jul (about 79°F) and coldest in Oct (about 51°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (51°F) to its warmest (79°F).
Typical surface water temperature by month, from 66 field readings (2017–2025) via the EPA Water Quality Portal. See the full Mattson Lake water temperature breakdown →
Lake Details
Max depth
~35 ft est.
Public access
No
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 Mattson Lake.
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Surface area
54 acres
HydroLAKES / HydroSHEDS
Shoreline
1.6 mi
HydroLAKES / HydroSHEDS
Elevation
873 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 Mattson Lake
Compare lakeside cabins, hotels, and vacation rentals near Mattson Lake in Chisago 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 Mattson 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 Mattson Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Mattson Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Improving-14.27 µg/L/yr6 years
Chlorophyll-a
Improving-8.81 µg/L/yr6 years
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Mattson Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Chisago Lakes Joint StcChisago City · 1.3 mi away · NPDES MN0055808MajorRecent violation
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.
Nearby Lakes in Chisago County
Frequently asked questions about Mattson Lake
Where is Mattson Lake?
- Mattson Lake is a lake in Chisago County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Mattson Lake?
- Mattson Lake in Chisago County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 1 µg/L.
Is Mattson 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 Mattson Lake?
- Mattson Lake typically sits around 51°F at the surface in October, from 66 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is Mattson Lake?
- No published bathymetric survey covers Mattson Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 35 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 Mattson Lake?
- Public access to Mattson Lake is listed as no on the lake record, so confirm before you make the trip. 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 Mattson Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Chisago County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the St. Croix Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Mattson Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
47 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
MNPCA47 samples · 2022–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder