Turtle-Flambeau Flowage Lake
Turtle-Flambeau Flowage Lake in Iron County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4 ft visibility. Maximum depth: 50 ft. Surface area: 12942 acres.
Wisconsin DNR rates Northern Pike and Walleye as abundant on Turtle-Flambeau Flowage Lake. DNR survey details →
- Clarity
- 4 ft
- Max depth
- 50 ft
- Area
- 12,942 acres
- Trend
- ↓ Declining
- Public access
- Yes
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Why Turtle-Flambeau Flowage Lake has no grade
We grade a lake only when the monitoring record supports a letter: 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 Turtle-Flambeau Flowage Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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 WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Turtle-Flambeau Flowage Lake is a 12,942-acre lake in Iron County, Wisconsin with a maximum depth of 50 feet. Overall water quality is declining over recent sampling years. The lake supports 7 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-05-07. Grade methodology: LakeQuality 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 Turtle-Flambeau Flowage Lake
These readings exist but are not enough for an A–F grade — see why.
Murky, only visible to about 4 ft. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Turtle-Flambeau Flowage Lake
Compare lakeside cabins, hotels, and vacation rentals near Turtle-Flambeau 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.
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Wisconsin DNR rates Northern Pike and Walleye as abundant on Turtle-Flambeau Flowage Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Turtle-Flambeau Flowage Lake — official chemistry is on file, not a letter, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1998. 11 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 50 ft |
| Surface Area | 12,942 acres |
| Public Access | Yes |
Recreation & Access
- SpringsteadPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Turtle-Flambeau Flowage 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.
Water Quality Trend: ↓ Declining
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.103 m/yr | 6 |
| Phosphorus | → Stable | +0.3 µg/L/yr | 7 |
Reservoir Info (USACE NID)
Turtle-Flambeau Flowage Lake is a man-made reservoir impounded by the Turtle-Flambeau (completed 1926), built primarily for hydroelectric on the North Fork Flambeau; concrete-type dam, 26 ft tall and 9,150 ft long.
- Surface area
- 13,798 ac
- Normal storage
- 135,000 ac-ft
- Max storage
- 239,000 ac-ft
- Drainage area
- 666 sq mi
- Hazard class
- High
- Owner
- Chippewa and Flambeau Improvement Company
Source: USACE National Inventory of Dams, NID ID WI00041 · Operator website
EPA Impairment Status
Turtle-Flambeau 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 WI10026777 · Official waterbody report
Graded lakes near Turtle-Flambeau Flowage Lake
Turtle-Flambeau Flowage Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Iron County
Frequently asked questions about Turtle-Flambeau Flowage Lake
Where is Turtle-Flambeau Flowage Lake?
- Turtle-Flambeau Flowage Lake is a lake in Iron County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Turtle-Flambeau Flowage Lake?
- Turtle-Flambeau Flowage Lake in Iron County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4 ft visibility. Maximum depth: 50 ft. Surface area: 12942 acres.
Is Turtle-Flambeau Flowage Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Turtle-Flambeau 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.
How deep is Turtle-Flambeau Flowage Lake?
- Turtle-Flambeau Flowage Lake has a maximum depth of 50 feet. The lake covers 12942 acres.
What fish are in Turtle-Flambeau Flowage Lake?
- Fish species found in Turtle-Flambeau Flowage Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye, Sturgeon. Turtle-Flambeau Flowage Lake is located in Iron County, Wisconsin.
What did the DNR fisheries survey find at Turtle-Flambeau Flowage Lake?
- Wisconsin DNR rates Northern Pike and Walleye as abundant on Turtle-Flambeau Flowage Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Turtle-Flambeau Flowage Lake — official chemistry is on file, not a letter, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Turtle-Flambeau Flowage Lake?
- Turtle-Flambeau Flowage Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Springstead. Public access is listed as yes.
Explore Turtle-Flambeau Flowage Lake across LakeQuality
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Where this data comes from
2 measurements from 1 monitoring station, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX2 samples · 2022–2023
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)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory