Yellowstone River watershed (SP04)
The Yellowstone River watershed is in northeastern Lafayette County and southern Iowa County. The watershed's land use is dominated by agriculture. A significant portion of publicly owned land exists in the watershed: About 800 acres in Yellowstone Lake State Park and 4,000 acres in the Yellowstone Wildlife Area (Howard, 1994). The addition of 2,200 acres to the wildlife area and, its management for wildlife, have probably reduced the impacts of polluted runoff on Steiner branch, Yellowstone River and Yellowstone Lake.
This watershed was ranked high under the old nonpoint source priority watershed project selection pool (Eagan, 1988). Fieldwork conducted by Southern District staff in the fall of 1994 noted sedimentation in the streams tributary to Yellowstone Creek (Wisconsin DNR, 1994). Potential sources of sedimentation were also noted. This, coupled with the water quality problems noted in Yellowstone Lake, make this watershed a candidate for possible selection as a nonpoint source priority watershed project.
Steiner branch is a class II and class III trout stream (Wisconsin DNR, 1980) tributary to the Yellowstone River at Lake Yellowstone. It had suffered from extreme sedimentation due to agricultural land-use practices in the early 1980s (Wisconsin DNR, 19931). These practices have been altered or eliminated, primarily because of land acquisition for the Yellowstone Wildlife Area. A dam on the headwaters of the creek affects water quality and is probably preventing the creek from meeting its full coldwater fishery potential (Van Dyck, 1994).
Yellowstone Lake is a 455-acre impoundment on the Yellowstone River. The lake has a good warmwater fishery and experiences a high level of public use because it is within a state park. Water quality has been a problem. Excessive sedimentation and nutrient loading resulted in algae blooms and excessive aquatic plant growth in the past (Eagan, 1988). Lack of adequate aquatic plant growth due to sedimentation has been a more recent problem.
Heavy motorboat use and high winds cause excessive wave action resuspending sediment and nutrients and keeping the lake turbid. Carp and bullhead populations in the lake have expanded rapidly (Van Dyck, 1994). Yellowstone Lake is one of the biggest lakes in the Driftless Area of Wisconsin and has a relatively small watershed-to-lake surface area ratio for impoundments in this region. Thus, the lake may have a better chance of responding to improved land use management than other impoundments in the region.