Billingsley #4 is a privately owned earth dam located in Yavapai, Arizona, specifically in Congress. Built in 1957 by the USDA NRCS, this dam on the East Fork of Martinez Creek serves multiple purposes and is regulated by the Arizona Department of Water Resources. With a height of 10 feet and a length of 1850 feet, the dam has a storage capacity of 157 acre-feet and a drainage area of 6.6 square miles. The spillway, which is uncontrolled, has a width of 190 feet, and the dam has a low hazard potential and a moderate risk assessment rating.

Despite its age, Billingsley #4 has not been rated for its condition, and the last inspection took place in February 2010. The dam has not had any modifications over the years, and emergency preparedness measures such as an Emergency Action Plan (EAP) have not been prepared or updated. With the risk assessment rating at moderate, there is a need for further evaluation and potential risk management measures to ensure the safety and integrity of the dam. Water resource and climate enthusiasts should keep an eye on developments related to Billingsley #4 to ensure the protection of surrounding communities and ecosystems.