Blanchard-Offner, also known as Lake Rodney, is a private dam located in Napa, California, specifically in the city of Aetna Springs. This earth dam was completed in 1963 and stands at a height of 47 feet, with a hydraulic height of 43 feet. It serves multiple purposes including flood risk reduction, irrigation, recreation, and water supply, with a storage capacity of 274 acre-feet.

Managed by the Natural Resources Conservation Service, Blanchard-Offner has a high hazard potential and is considered to be in satisfactory condition as of the last assessment in September 2017. The dam spans a length of 785 feet and has an associated surface area of 19 acres, with its primary function being flood risk reduction. The dam is regulated and permitted by the California Department of Water Resources, ensuring its safety and compliance with state standards.

Located near Tr Pope Creek, Blanchard-Offner plays a crucial role in managing water resources in the region. Its strategic placement and multiple functions make it a vital infrastructure for the community, safeguarding against floods while providing essential water for irrigation and recreation activities. Enthusiasts of water resources and climate management will find Blanchard-Offner to be a noteworthy example of sustainable infrastructure design and management in California.