The St. Marys watershed, located in southeastern Michigan, covers an area of approximately 1,035 square miles. The hydrology of the watershed is influenced by the nearby Great Lakes, with surface water flowing into the St. Clair River and eventually into Lake St. Clair. The watershed receives an average of 32 inches of precipitation per year, with snowfall accounting for a significant portion of this amount during the winter months. The watershed contains several reservoirs, including the St. Clair Lake Reservoir and the Upper and Lower Fish Lake Reservoirs. These reservoirs are used for water supply, flood control, and recreational purposes. The watershed has experienced several significant weather events in recent years, including severe flooding in 2014 and a record-breaking rainfall in 2018. Climate change is expected to continue to impact the watershed, potentially leading to more frequent and intense weather events.