Flowage Lake
Flowage Lake in Aitkin County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 2.1 ft visibility. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 13.5 µg/L.
- Clarity
- 2.1 ft
- Mean depth
- ~11 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 Flowage Lake →
Next lake in Aitkin County
Flowage Lake is a productive, nutrient-rich eutrophic lake in Aitkin County, Minnesota with an estimated average depth of about 11 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 2 public boat landings. Compared to the 17 other monitored lakes in Aitkin County, Flowage Lake ranks #18 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-20. 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)
Very murky, less than 2.1 ft of visibility. Phosphorus level: 55 µg/L. Chlorophyll-a: 13.5 µg/L. Trophic State Index: 61.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.1 ft | Not graded |
| Phosphorus | 55 µg/L | Poor |
| Chlorophyll-a (Algae) | 13.5 µg/L | Fair |
| Trophic State Index (TSI) | 61 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Flowage Lake
Compare lakeside cabins, hotels, and vacation rentals near Flowage Lake in Aitkin 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 Flowage Lake are listed below.
Top-rated places to stay near Flowage Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~11 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Flowage 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
- Highway 65Public
- Flowage LakePublic
Fishing Flowage Lake
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Flowage Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Aquatic Plant Report — Flowage (0140)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — FlowagePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.35 m/yr | 3 |
| Phosphorus | ↑ Improving | -3.5 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +1 µg/L/yr | 5 |
County Ranking
Ranked #18 of 18 lakes in Aitkin County
Nearby Lakes With Higher Grades
Flowage Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Aitkin County
Frequently asked questions about Flowage Lake
What is the water quality grade for Flowage Lake?
- Flowage Lake in Aitkin County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 2.1 ft visibility. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 13.5 µg/L.
Is Flowage 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. Flowage Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 13.5 µg/L. Always check local health department advisories before swimming.
How deep is Flowage Lake?
- No published bathymetric survey covers Flowage Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 11 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 Flowage Lake?
- Flowage Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Highway 65, Flowage Lake. Public access is listed as yes.
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Where this data comes from
28 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA28 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
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