Cottonwood Creek Upper, also known as Cottonwood Detention Dam #1, is a key water resource infrastructure owned by the local government in Boise, Idaho. This structure plays a vital role in flood risk reduction, serving as a barrier to protect the surrounding areas from potential flooding. Completed in 1961, the dam stands at a height of 18.1 feet and has a hydraulic height of 13.1 feet, with a length of 840 feet and a storage capacity of 17 acre-feet.

Situated on Cottonwood Creek in the Boise River watershed, this earth dam with stone core is regulated by the Idaho Department of Water Resources and undergoes regular state inspection and enforcement to ensure its structural integrity. With a significant hazard potential and fair condition assessment, the dam's risk management measures are crucial to maintaining its functionality in the face of moderate risk levels. The last inspection in September 2018 revealed no major issues, but the structure is monitored closely to prevent any potential emergencies and ensure the safety of the surrounding community.