The local Lake Winnebago Watershed

The Lake Winnebago Watershed covers over 581 square miles with over 200 square miles of the watershed being lakes, the largest of which is Lake Winnebago. The watershed is located between Upper and Lower Fox Rivers in Wisconsin, and includes the cities of Menasha, Oshkosh, and Fond du Lac as the primary urbanized areas. The watershed also includes the High Cliff State Park, a 1,145 acre state park, located in Calumet County.
The watershed is above a sandstone aquifer and is primarily a glacial plain. The Niagara Escarpment, a bedrock ridge, forms the eastern boundary of the Lake Winnebago Watershed.
A Glacial Habitat Restoration Area (GHRA) is located in the watershed in Winnebago and Fond du Lac counties. The GHRA is an area where the state is restoring a patchwork of grasslands and wetlands over a large rural landscape enabling wildlife to coexist side-by-side with agriculture. The basin hosts resident and migratory neo-tropical songbirds in its open grassland/agricultural habitat.
There are several water quality issues associated with the watershed. Several urban stormwater outfalls discharge to Lake Winnebago from portions of the Cities of Oshkosh, Neenah, and Menasha. Runoff from peak storm events from commercial, industrial, and residential construction sites, and from plat developments in rapidly developing sections of these cities have been identified as sources of nonpoint source pollution problems. Water quality modeling done by Northeast Wisconsin Waters of Tomorrow (NEWWT) have indicated this watershed to be a major contributor of phosphorus and suspended solids to Lake Winnebago. Critical animal waste and soil erosion problems have been intensified by the steep slopes along the Niagra Escarpment. Average soil loss in Calumet County is estimated to be 2.7 tons per acre.  Both the Winnebago Comprehensive Management Plan and the Lower Green Bay Remedial Action Plan have identified this watershed as a high priority for the control of non point sources of pollution. The eastern portion of the watershed was selected as a nonpoint source priority watershed project in 1989. The primary goals of the watershed project were to reduce phosphorus and sediment loading to Lake Winnebago and decrease the loading of heavy metals from urban nonpoint sources.

Lake Winnebago Harbors

An important objective of Army Corps of Engineer lake operations is to reduce downstream flooding during spring snowmelt and heavy rains. The lake is drawn down in the winter in anticipation of spring rains and snowmelt. The lake’s storage capacity allows it to be used to reduce the incidence of downstream floods. After the threat of spring flooding has passed, the lake level is gradually raised during the spring season to its summer target for navigation and recreational boating.

Through regulation of the lake level, the Corps attempts to minimize therisk of ice damage by keeping the level as low as possible when the ice layer is weak.

The Lower Fox River is part of the most important industrialized region in the basin. Wisconsin’s pulp and paper industry makes extensive use of the river within this area. The river also provides water for navigation, hydropower, municipalities and  other industries along the Lower Fox River. Each user affects the quantity and quality of water available as a resource.

The Lower Fox River from Lake Winnebago to De Pere has a fall of 168 feet in a distance of 39 miles, making it a valuable source of hydropower. Currently, there are nine hydropower generating stations along the Lower Fox River. They utilize the power to operate numerous paper mills, factories and municipalities in the immediate vicinity of the Lower Fox River.

Winds typically blow stronger over the lake during fall. When the water is warmer than the air, the lower 500 to 1,500 feet of the atmosphere over the lake becomes unstable. Higher momentum air aloft becomes mixed down to the surface resulting in stronger winds being observed on the lake.  During the early spring when air temperatures begin to rise, the lake waters remain cold.  The colder lake waters actually produce a stable layer of air in the lower levels, inhibiting the turbulent mixing process, resulting in lighter winds in the spring.