Mandall Lake
Mandall Lake in Chisago County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 57 µg/L. Chlorophyll-a (algae): 26.4 µg/L. Maximum depth: 26 ft. Surface area: 47.01 acres.
- Clarity
- 3 ft
- Typical in August
- 74°F
- Max depth
- 26 ft
- Area
- 47 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- No
- Ice-out
- Apr 7
- Open water
- 229 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Mandall Lake →
Next lake in Chisago County
Mandall Lake is a 47-acre productive, nutrient-rich eutrophic lake in Chisago County, Minnesota with a maximum depth of 26 feet. Water quality is graded D based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 5 documented fish species including black crappie, bluegill, and largemouth bass. No public access — the lake is private or restricted. Compared to the 29 other monitored lakes in Chisago County, Mandall Lake ranks #22 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-18. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyAlgae risk
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)
Very murky, less than 3 ft of visibility. Phosphorus level: 57 µg/L. Chlorophyll-a: 26.4 µg/L. Trophic State Index: 62.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | Not graded |
| Phosphorus | 57 µg/L | Poor |
| Chlorophyll-a (Algae) | 26.4 µg/L | Poor |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Mandall Lake
Compare lakeside cabins, hotels, and vacation rentals near Mandall 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Mandall Lake are listed below.
Top-rated places to stay near Mandall Lake
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 →
Water Temperature
Mandall Lake typically sits around 74°F at the surface in August. Summer average is about 75°F. Usually warmest in Jul (about 80°F) and coldest in May (about 64°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 43 field readings (2017–2025) via the EPA Water Quality Portal. See the full Mandall Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 26 ft |
| Surface Area | 47 acres |
| Shoreline Length | 1.2 mi |
| Littoral Zone | 53% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Mandall Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2016-05-03 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Crappie | 19.97 | 0.2 lb |
| Bluegill | 18.57 | 0.29 lb |
| Black Bullhead | 16.13 | 0.32 lb |
| Largemouth Bass | 11.49 | 1.91 lb |
| Pumpkinseed | 7.30 | 0.18 lb |
| Yellow Perch | 6.69 | 0.13 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Black Crappie
Bluegill
Black Bullhead
Largemouth Bass
From the 2016-05-03 survey
In May 2016, spring trap netting was conducted to assess Bluegill and Black Crappie populations and night electrofishing was used to assess that of Largemouth Bass. Both Bluegill and Black Crappie catch rates were lower than in connected Rabour Lake to the south but similar to Goose Lake to the north. Catch rates were…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mandall Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MandallFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.006 m/yr | 6 |
| Phosphorus | ↑ Improving | -3.1 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -6.53 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (52 observations).
Estimated open water season: 229 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2000-03-09 (2000) | 1996-04-22 (1996) |
| Ice-In | 1991-11-04 (1991) | 2001-12-20 (2001) |
Most recent ice-out: 2026-04-02
EPA Impairment Status
Mandall 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 MN13-0074-00 · Official waterbody report
County Ranking
Ranked #22 of 30 lakes in Chisago County
Nearby Lakes With Higher Grades
Mandall 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 Chisago County
Frequently asked questions about Mandall Lake
What is the water quality grade for Mandall Lake?
- Mandall Lake in Chisago County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 57 µg/L. Chlorophyll-a (algae): 26.4 µg/L. Maximum depth: 26 ft. Surface area: 47.01 acres.
Is Mandall 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. Mandall Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 26.4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Mandall Lake?
- Mandall Lake typically sits around 74°F at the surface in August, from 43 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is Mandall Lake?
- Mandall Lake has a maximum depth of 26 feet. The lake covers 47.01 acres.
What fish are in Mandall Lake?
- Fish species found in Mandall Lake include black crappie, bluegill, largemouth bass, northern pike, walleye. Mandall Lake is located in Chisago County, Minnesota.
When does Mandall Lake thaw?
- Mandall Lake typically has ice-out around Apr 7. Ice typically forms around Nov 22. The open water season is approximately 229 days.
Explore Mandall Lake across LakeGrade
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Where this data comes from
124 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA124 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
- 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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate