Butt Valley, located in Little Haven, California, is a private hydroelectric dam on Butt Creek completed in 1924. With a height of 70 feet and a length of 1520 feet, this earth dam provides a storage capacity of nearly 50,000 acre-feet, serving as a vital water resource in the region. The dam has a high hazard potential and is regulated by the Federal Energy Regulatory Commission, ensuring its safety and compliance with inspection and enforcement measures.

The dam's primary purpose is hydroelectric power generation, with a normal storage capacity of 49,800 acre-feet and a maximum discharge of 30,000 cubic feet per second. Its uncontrolled spillway, with a width of 150 feet, helps manage excess water flow during peak periods. Despite its age, Butt Valley Dam continues to be a significant feature in the region's water infrastructure, supporting both water supply and energy generation needs. Climate and water resource enthusiasts are drawn to the dam's historical significance and its role in sustainable water management practices.