Duvall, also known as Duvall Lake, is a privately owned dam located in Napa, California, along the Tr Pope Creek. Constructed in 1940, this earth dam stands 30 feet tall and spans 1500 feet in length, with a storage capacity of 242 acre-feet. Its primary purpose is flood risk reduction, with additional functions including irrigation and water supply. The dam is regulated by the California Department of Water Resources (DWR) and is subject to state permitting, inspection, and enforcement requirements.

Despite its satisfactory condition assessment as of September 2017, Duvall poses a high hazard potential due to its location and design. Regular inspections are conducted, with the last one taking place in October 2020. While an emergency action plan (EAP) is not currently prepared, the dam meets state guidelines for safety and risk management. The dam's hazard potential underscores the importance of ongoing monitoring and maintenance to ensure the safety of downstream communities and surrounding areas in the event of a flood or other emergency.

With its critical role in flood risk reduction and water management in the region, Duvall serves as a key infrastructure asset for the San Francisco District. Managed by the Natural Resources Conservation Service, the dam contributes to the protection of local communities and agricultural lands from potential flooding events. As water resource and climate enthusiasts, understanding the complexities and responsibilities associated with dams like Duvall highlights the interconnected nature of water management and environmental stewardship in safeguarding our communities and natural resources.