John Orr is a privately owned dam located in Ione, California, specifically on the Tr Jackson Cr river. Completed in 1959, this earth dam stands at 20 feet high with a hydraulic height of 16 feet and a length of 590 feet. Its primary purpose is for water supply, serving irrigation, recreation, and water supply needs in the area.

Managed by the California Department of Water Resources, John Orr is regulated, permitted, inspected, and enforced under state jurisdiction. With a storage capacity of 152 acre-feet and a drainage area of 0.85 square miles, this dam has a low hazard potential and is assessed to be in satisfactory condition as of September 2017. Despite its age, John Orr remains a vital infrastructure for water resource management in Amador County, California.

The dam's last inspection was conducted in October 2020, with a regular inspection frequency of once per year. While no emergency action plan (EAP) or risk assessment information is currently available, the dam's condition and hazard potential are continuously monitored to ensure the safety and reliability of its operations. As a key component in the water supply infrastructure of the region, John Orr plays a crucial role in sustaining water resources and adapting to the challenges of a changing climate.