Austin Lake is a natural inland lake situated in Portage, Michigan. The lake was formed during the last ice age and has evolved over time to become a popular recreational spot. The lake is fed by three primary surface flow providers, including Portage Creek, which enters the lake through Austin Lake Park. The hydrology of the lake is also impacted by the surrounding snowpack, which can lead to increased runoff during the winter months. The lake is used for recreational activities, such as boating, swimming, and fishing. Additionally, the lake provides water for agricultural use, such as irrigation for nearby farms. In recent years, efforts have been made to control water quality through a variety of measures, including the implementation of a watershed protection plan.