Crystal is a privately owned dam located in St Helena, California, along the Tr Crystal Crk river/stream. Completed in 1952, this earth dam stands at a height of 51 feet and has a storage capacity of 105 acre-feet. The primary purpose of Crystal Dam is for water supply, with additional uses including irrigation and recreation. It is regulated by the California Department of Water Resources (DWR) and undergoes regular inspections to ensure its safety and compliance with state regulations.

With a high hazard potential, Crystal Dam is deemed to be in satisfactory condition as of the last assessment in September 2017. The dam is subject to annual inspections and has an emergency action plan in place, although details on its compliance with guidelines and the preparation of inundation maps are not specified. Despite these potential risks, Crystal Dam serves as a crucial water resource for the surrounding area, providing essential water supply for agricultural and recreational activities. Enthusiasts of water resources and climate will find interest in the history and operational aspects of this significant structure in Napa, California.

Overall, Crystal Dam is a vital component of the water infrastructure in Napa County, contributing to the region's water supply and supporting various purposes such as irrigation and recreation. Managed by a private entity, the dam is subject to state regulations and inspections to ensure its safety and functionality. As part of the Sacramento District, Crystal Dam plays a key role in the management and distribution of water resources in the area, highlighting the importance of sustainable water management practices in the face of climate challenges.