Flowage Lake
Flowage Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.5 ft visibility. Maximum depth: 15 ft. Surface area: 111.57 acres.
- Clarity
- 8.5 ft
- Typical in August
- 73°F
- Max depth
- 15 ft
- Area
- 112 acres
- Trend
- → Stable
- Public access
- Yes
- Ice-out
- Apr 22
- Open water
- 209 days
Next lake in St. Louis County
Why Flowage Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Flowage Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Flowage Lake is a 112-acre lake in St. Louis County, Minnesota with a maximum depth of 15 feet. The lake supports 7 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-11-02. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Flowage Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 8.5 ft. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Flowage Lake
Compare lakeside cabins, hotels, and vacation rentals near Flowage Lake in St. Louis 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 Flowage Lake
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Water Temperature
Flowage Lake typically sits around 73°F at the surface in August. Summer average is about 71°F. Usually warmest in Jul (about 74°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 101 field readings (2010–2011) via the EPA Water Quality Portal. See the full Flowage Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 15 ft |
| Surface Area | 112 acres |
| Shoreline Length | 3.1 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Dam SitePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Flowage Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1991-08-16 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 4.00 | 0.18 lb |
| White Sucker | 3.63 | 1.36 lb |
| Northern Pike | 3.50 | 4.96 lb |
| Pumpkinseed | 2.88 | 0.15 lb |
| Black Crappie | 2.88 | 0.29 lb |
| Walleye | 2.00 | 1.65 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1991-08-16 survey
ALL FISH POPULATIONS SAMPLED IN FLOWAGE LAKE ARE NATURALLY REPRODUCING. NOP GILLNET CATCH RATE OF 3.5 PER LIFT IS BELOW THE SCHUPP MEDIAN OF 6.2 PER LIFT FOR THIS CLASS LAKE. NOP SIZE STRUCTURE IS GOOD WITH 64% OF THE FISH SAMPLED LONGER THAN 21 INCHES. NOP GROWTH RATES ARE FASTER THAN AREA MEAN, WITH FISH REACHING 21…
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).
- —Fisheries Lake Survey — FlowageFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Flowage (0460)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: → Stable
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.045 m/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (40 observations).
Estimated open water season: 209 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-24 (2012) | 2013-05-13 (2013) |
| Ice-In | 2003-11-06 (2003) | 2001-12-01 (2001) |
Most recent ice-out: 2021-04-07
EPA Impairment Status
Flowage 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 MN69-0372-01 · Official waterbody report · Matched by proximity (2.97 km)
Nearby Lakes in St. Louis County
Frequently asked questions about Flowage Lake
What is the water quality grade for Flowage Lake?
- Flowage Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.5 ft visibility. Maximum depth: 15 ft. Surface area: 111.57 acres.
Is Flowage Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Flowage Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Flowage Lake?
- Flowage Lake typically sits around 73°F at the surface in August, from 101 EPA Water Quality Portal field readings (2010–2011). That is a typical value for the month, not a live reading.
How deep is Flowage Lake?
- Flowage Lake has a maximum depth of 15 feet. The lake covers 111.57 acres.
What fish are in Flowage Lake?
- Fish species found in Flowage Lake include black bullhead, black crappie, bluegill, northern pike, smallmouth bass, white sucker, yellow perch. Flowage Lake is located in St. Louis County, Minnesota.
When does Flowage Lake thaw?
- Flowage Lake typically has ice-out around Apr 22. Ice typically forms around Nov 17. The open water season is approximately 209 days.
Are there boat ramps on Flowage Lake?
- Flowage Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Dam Site. Public access is listed as yes.
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Where this data comes from
42 measurements from 2 monitoring stations, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA42 samples · 2020–2023
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (2)
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate