[3] The flowage was constructed as a reservoir to augment river flows and sustain hydroelectric plants operated downstream by electric utilities and paper mills.
[11] Discharge from the dam is monitored by Xcel Energy, which operates several power stations on the Flambeau River downstream of the flowage.
The dam's average discharge is 20 cubic meters per second; however, it varies greatly based on lake water levels and the energy company's hydroelectric needs.
Four water access points on the flowage also serve as fish stocking sites, with a fifth at the nearby Lake of the Falls impoundment.
[24] The Turtle-Flambeau Flowage is also prime habitat for loons and features the largest concentration of eagle and osprey breeding pairs in Wisconsin.
[4][25][26] Mammal species found living in and around the flowage include river otter, beaver, black bear, and white-tailed deer.
[22] Significant levels of methylmercury have been found in walleye tissue in both the Turtle-Flambeau Flowage and other reservoirs in Oneida, Sawyer, and Vilas counties.
Walleye are harvested as a traditional food source for the Lake Superior Chippewa, and the bioaccumulation of mercury in these fish increases the risk of harmful exposure to humans.
[27] The Turtle-Flambeau Flowage was declared impaired due to mercury contamination by the Wisconsin Department of Natural Resources in 2002,[15] and a fish consumption warning has been in effect since 2009.
[5] However, tannin-stained runoff from surrounding wetlands decreases light penetration in the flowage, reducing the potential impact of harmful algal blooms in comparison to other area lakes.
[30] Purple loosestrife, native to Asia, Europe, northwest Africa, and southeastern Australia, is an invasive species in Wisconsin.
[36] Additionally, the Iron County Land and Water Conservation Department[37] monitors, reports, and takes action against invasive species.
At the flowage, the department has performed biological control of purple loosestrife with Galerucella calmariensis beetles and conducted surveys of boating practices at landings.
[3] In the Treaty of 1854 the Ojibwe officially ceded several territories in modern day Minnesota and Wisconsin including Iron County.
[45][3] While the Turtle-Flambeau flowage post-dates the ceding of Ojibwe lands to the state of Wisconsin, it and the surrounding waterways have been the source of many treaty disputes.
While the 1854 treaty allowed the Ojibwe to hunt and fish on ceded territory, the state of Wisconsin attempted to regulate these activities both on and off reservations.
[48] Additionally, then-governor Tommy Thompson attempted to roll back the Ojibwe treaty rights, first through the court system and then by offering payments to different bands to suspend their harvest.
Rep. Jim Sensenbrenner also introduced (unsuccessful) legislation in the U.S. House of representatives to ban tribal hunting and fishing on non-reservation lands.
[53] While most individuals are only allowed to use rod and reel for fishing, members of Ojibwe people have the right to spearfish walleye (see above).