Grand River Marsh is a state-owned dam located in Marquette, Wisconsin, along the Grand River. Built in 1969, this earth dam stands at a height of 16 feet and has a storage capacity of 22,000 acre-feet. The dam serves multiple purposes, including flood control, water storage, and recreational activities, with a surface area of 2,500 acres and a drainage area of 184 square miles.

Despite being classified as having a low hazard potential, Grand River Marsh is considered to be in fair condition, with a very high risk assessment rating of 1. The dam features a controlled spillway with a width of 185 feet and a maximum discharge capacity of 9,580 cubic feet per second. The dam is regulated by the Wisconsin Department of Natural Resources and undergoes regular inspections and maintenance to ensure its integrity and safety for nearby communities and the environment.

With its scenic location and essential role in managing water resources in the region, Grand River Marsh is a vital structure for both the local ecosystem and surrounding communities. Climate and water resource enthusiasts can appreciate the dam's history, design, and ongoing efforts to mitigate risks and ensure its continued functionality in the face of changing environmental conditions.