Blackwelder, also known as Upper Blackwelder Lake, is a federally owned dam located in Yuba County, California. Built in 1955 by the USAF, this rockfill dam stands at a height of 19 feet and serves primarily for flood risk reduction. With a storage capacity of 330 acre-feet and a surface area of 35 acres, Blackwelder plays a crucial role in managing water resources in the area.

Situated on Hutchinson Creek, Blackwelder has a significant hazard potential and is classified as having a moderate risk level. Despite its age, the dam has not undergone a recent condition assessment and lacks an emergency action plan. With no outlet gates and an uncontrolled spillway, the dam poses challenges for emergency response and water release during high flow events. However, the dam's inspection frequency of every 5 years helps to ensure its structural integrity and safety.

While primarily designed for flood risk reduction, Blackwelder also offers recreational opportunities for visitors. As part of the US Air Force infrastructure, the dam is a key component of the region's water management system. Its location at Beale AFB makes it a notable landmark in the area, attracting both water resource and climate enthusiasts interested in its engineering and environmental impact.