Lebanon Reservoir #1 (Upper) in Arizona, completed in 1910, serves as a vital water resource for irrigation purposes in the region. With a dam height of 40 feet and a storage capacity of 147 acre-feet, this earth dam structure spans 570 feet in length and covers a surface area of 9 acres. Located in Safford, Graham County, this reservoir is regulated by the Arizona Department of Water Resources and undergoes regular inspections to ensure its fair condition and significant hazard potential.

The reservoir is situated on Marijilda Wash - OS and is owned jointly by private and state entities. It features an uncontrolled spillway with a width of 10 feet and a maximum discharge capacity of 210 cubic feet per second. Despite its fair condition, the Lebanon Reservoir #1 (Upper) poses a moderate risk, prompting the need for risk management measures to be implemented. Overall, this reservoir plays a crucial role in supporting the local agricultural community by providing essential water resources for irrigation.

As a key component of the water infrastructure in the area, Lebanon Reservoir #1 (Upper) not only facilitates irrigation activities but also contributes to the overall water management efforts in Arizona. Its historical significance, dating back over a century, underscores its importance in sustaining agricultural operations and ensuring water availability for the region. With a focus on maintaining its structural integrity and addressing any potential risks, this reservoir remains a vital resource for water and climate enthusiasts interested in sustainable water resource management practices.