Lebanon Reservoir #1 (Upper)

MARIJILDA WASH - OS· Graham, Arizona· Built 1910· Earth· 40 ft tall
Significant Hazard Irrigation Private

Key Takeaway

Lebanon Reservoir #1 (Upper) is classified as significant hazard in Arizona. It was completed in 1910 and is 116 years old. Its primary use is irrigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 40 ft (taller than 68.4% in AZ)
Dam Length570 ft
Dam TypeEarth
Max Storage147 acre-ft
Normal Storage115 acre-ft
Surface Area9 acres
Drainage Area1 sq mi
Max Discharge210 cfs
Year Completed1910 (116 years old)
NID IDAZ00054

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes
Last Inspection: December 17, 2019
State Regulated: Yes
Regulatory Agency: ARIZONA DEPARTMENT OF WATER RESOURCES

Ownership

ARIZONA STATE LAND DEPARTMENT;LEBANON RESERVOIR & DITCH CO.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lebanon Reservoir #1 (Upper)?

Lebanon Reservoir #1 (Upper) is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Lebanon Reservoir #1 (Upper)?

Lebanon Reservoir #1 (Upper) is owned by ARIZONA STATE LAND DEPARTMENT;LEBANON RESERVOIR & DITCH CO. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lebanon Reservoir #1 (Upper) built?

Lebanon Reservoir #1 (Upper) was completed in 1910, making it 116 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Lebanon Reservoir #1 (Upper)?

Lebanon Reservoir #1 (Upper) serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Lebanon Reservoir #1 (Upper)?

Lebanon Reservoir #1 (Upper) has a dam height of 40 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Lebanon Reservoir #1 (Upper) last inspected?

Lebanon Reservoir #1 (Upper) was last inspected on December 17, 2019. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.