Monterey, located in Waukesha, Wisconsin, is a gravity dam built in 1848 primarily for recreational purposes on the Ashippun River. With a dam height of 16 feet and a capacity of 200 acre-feet, this structure covers a surface area of 28 acres and has a drainage area of 40.7 square miles. The dam is regulated by the Wisconsin Department of Natural Resources (WIDNR) and has state permitting, inspection, and enforcement in place, ensuring its safety and compliance with regulations.

Despite being classified as having a low hazard potential and a satisfactory condition assessment, Monterey poses a very high risk due to its age and the surrounding area's vulnerability. The dam has undergone modifications in 1898, and its last inspection was conducted in August 2013, with an inspection frequency of 10 years. Additionally, the emergency action plan (EAP) for the dam might not meet current guidelines, raising concerns about the readiness to address potential risks and emergencies.

Managed by the local government, Monterey stands as a historic site with a controlled spillway and a maximum discharge capacity of 706 cubic feet per second. The dam's location in S8, T8N, R17E offers a tranquil recreational spot for visitors while also highlighting the importance of maintaining and updating infrastructure to ensure public safety and environmental preservation in the face of changing climate conditions.