The Shiawassee Watershed (HUC 04080203) covers approximately 1,389 square miles in central Michigan. It is drained by the Shiawassee River, which flows into the Saginaw River and eventually into Lake Huron. The watershed has a humid continental climate with four distinct seasons. The area receives an average of 30 inches of precipitation annually, mostly in the form of rain. Snowpack varies from year to year, but the watershed typically receives around 40 inches of snowfall annually. Surface water and reservoirs in the watershed are used for recreation, irrigation, and drinking water supply. Water quality in the watershed is monitored and managed by several organizations. Interesting climatic trends include an increase in average annual temperature and more frequent extreme weather events in recent years. Over the past few decades, there has also been a shift from agricultural land use to urban and suburban development in parts of the watershed.