The Milwaukee Watershed (HUC 04040003) spans 4,488 square miles in Southeastern Wisconsin and Northern Illinois. The hydrology of the watershed is influenced by numerous streams, including the Milwaukee River and its tributaries. The area typically experiences cold winters with significant snowfall, leading to a high volume of snowpack in late winter and early spring. This snowmelt contributes to the surface water supply in the watershed. The watershed includes several reservoirs, including the Menomonee River Reservoir and Pewaukee Lake. These reservoirs are used for recreation and also provide drinking water for nearby communities. In recent years, the Milwaukee Watershed has experienced an increase in heavy precipitation events, which can lead to flooding and erosion. Additionally, there has been a trend towards warmer temperatures and earlier snowmelt, which can impact the timing and volume of surface water flows.