Upper Stehly is a privately owned earth dam located in Valley Center, California, along Tr Keys Creek. Completed in 1999, this dam serves primarily for water supply purposes, including irrigation. With a height of 29 feet and a length of 420 feet, Upper Stehly has a storage capacity of 229 acre-feet and covers a surface area of 9 acres. The dam is regulated by the California Department of Water Resources (DWR) under the Safety of Dams jurisdiction, with regular inspections ensuring its satisfactory condition.

Despite its modest size, Upper Stehly poses a high hazard potential due to its location and the volume of water it can hold. However, recent condition assessments have deemed it to be in satisfactory shape as of September 2017. The dam is subject to state regulations, permitting, inspection, and enforcement, highlighting the importance of proper maintenance and monitoring to mitigate any potential risks associated with its operation. As a key component of the local water infrastructure, Upper Stehly plays a crucial role in supporting agricultural activities and ensuring a reliable water supply for the surrounding community.