Cottage Grove Dam, also known as Cottage Grove Lake, is a federally owned structure located on the Coast Fork Willamette River in Oregon. Built in 1942, this earth dam stands at 81 feet tall and serves multiple purposes including flood risk reduction, irrigation, navigation, and recreation. With a storage capacity of 33,000 acre-feet, the dam covers a surface area of 1,158 acres and has a maximum discharge of 40,800 cubic feet per second.

A routine risk assessment conducted in 2012 identified Cottage Grove Dam's risk level as moderate, particularly in the event of an extreme earthquake causing settlement and cracking that could lead to flooding downstream. To address potential risks, the US Army Corps of Engineers (USACE) has implemented risk management measures such as soil sampling, groundwater monitoring, and ongoing inspections. Plans for an advanced risk assessment in 2022, along with the development of an updated Emergency Action Plan, aim to enhance the dam's resilience and reduce risks associated with extreme events.

USACE's commitment to conducting regular risk assessments, implementing interim risk reduction measures, and enhancing community awareness of flood risks underscores its dedication to ensuring the safety and functionality of Cottage Grove Dam. By staying proactive in risk management strategies and engaging with local stakeholders, USACE aims to mitigate potential threats and maintain the dam's critical role in flood risk reduction for the region.