The 4-S Ranch Reclamation Reservoir, located in Rancho Bernardo, California, is a vital water supply structure designed to serve the community's irrigation and water supply needs. Completed in 2000, this earth dam stands at a height of 22 feet, with a storage capacity of 410 acre-feet and a surface area of 13 acres. The reservoir is situated along the Artesian Creek and is regulated by the Department of Water Resources, ensuring its safety and compliance with state regulations.

With a high hazard potential but a satisfactory condition assessment as of September 2017, the 4-S Ranch Reclamation Reservoir plays a crucial role in water management in San Diego County. Its primary purpose is to provide a reliable water source for agricultural irrigation and domestic use. The dam's inspection frequency, emergency action plan preparedness, and risk management measures are all in place to safeguard the surrounding community in the event of any unforeseen emergencies. The reservoir's strategic location and design make it an essential asset for water resource and climate enthusiasts interested in sustainable water supply infrastructure.