Gile Flowage Lake
Gile Flowage Lake in Iron County, Wisconsin has a water quality grade of C (Fair). Water clarity: 4.6 ft visibility. Phosphorus: 30.2 µg/L. Surface area: 3317 acres.
- Clarity
- 4.6 ft
- Max depth
- ~72 ft est.
- Area
- 3,317 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
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Gile Flowage Lake is a 3,317-acre productive, nutrient-rich eutrophic lake in Iron County, Wisconsin with an estimated average depth of about 72 feet. Water quality is graded C based on 1 sampling years through 2026. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 4 public boat landings. Compared to the 15 other monitored lakes in Iron County, Gile Flowage Lake ranks #16 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-14. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 4.6 ft. Phosphorus level: 30.2 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.6 ft | Not graded |
| Phosphorus | 30.2 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Gile Flowage Lake
Compare lakeside cabins, hotels, and vacation rentals near Gile Flowage Lake in Iron County, Wisconsin — 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 Gile Flowage Lake
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Planning a trip? Cabins and lodging at Gile Flowage Lake → · more Wisconsin lake trips
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Gile Flowage Lake covering fish populations, stocking, water quality, and management. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2024Gile Flowage late spring shocking and netting survey, 2024Spring Shocking Survey · WI DNR · 2024 (PDF)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~72 ft est. |
| Average Depth | ~17 ft est. |
| Surface Area | 3,317 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wisconsin has not published bathymetry for Gile 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
- Gile Flowage - NorthPublic
- Highway CPublic
- 4-HPublic
- Gile Flowage - SouthPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Gile Flowage Lake
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.305 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.6 µg/L/yr | 6 |
Reservoir Info (USACE NID)
Gile Flowage Lake is a man-made reservoir impounded by the Gile (completed 1941), built primarily for other on the West Fork, Montreal Rive; earth-type dam, 30 ft tall and 899 ft long.
- Surface area
- 3,317 ac
- Normal storage
- 37,064 ac-ft
- Max storage
- 38,000 ac-ft
- Hazard class
- High
Source: USACE National Inventory of Dams, NID ID WI00042 · Operator website
County Ranking
Ranked #16 of 16 lakes in Iron County
Nearby Lakes With Higher Grades
Gile Flowage Lake holds Grade C. 2 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 Iron County
Frequently asked questions about Gile Flowage Lake
Where is Gile Flowage Lake?
- Gile Flowage Lake is a lake in Iron County, Wisconsin. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Gile Flowage Lake?
- Gile Flowage Lake in Iron County, Wisconsin has a water quality grade of C (Fair). Water clarity: 4.6 ft visibility. Phosphorus: 30.2 µg/L. Surface area: 3317 acres.
Is Gile Flowage Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Gile Flowage Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
How deep is Gile Flowage Lake?
- No published bathymetric survey covers Gile Flowage Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 72 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 3317 acres.
Are there boat ramps on Gile Flowage Lake?
- Gile Flowage Lake has 4 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Gile Flowage - North, Highway C, 4-H, Gile Flowage - South. Public access is listed as yes.
Explore Gile Flowage Lake across LakeQuality
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Where this data comes from
39 measurements from 2 monitoring stations, 2021–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX39 samples · 2021–2026
Analytical methods
- Phosphorus by Colorimetry
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory