Onion Dam

EAST FORK ALDER CREEK· Humboldt, Nevada· Earth· 48 ft tall
Significant Hazard Irrigation Recreation Private

Key Takeaway

Onion Dam is classified as significant hazard in Nevada. Its primary use is irrigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 48 ft (taller than 79.7% in NV)
Dam Length320 ft
Dam TypeEarth
Max Storage1.5K acre-ft
Normal Storage1.5K acre-ft
Surface Area101 acres
Drainage Area1 sq mi
Max Discharge3,700 cfs
NID IDNV00005

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: July 18, 2022
State Regulated: Yes
Regulatory Agency: NEVADA DWR

Ownership

ALDER CREEK RANCH LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Onion Dam?

Onion Dam 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 Onion Dam?

Onion Dam is owned by ALDER CREEK RANCH LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Onion Dam?

Onion Dam serves the following purposes: Irrigation, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Onion Dam?

Onion Dam has a dam height of 48 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 Onion Dam last inspected?

Onion Dam was last inspected on July 18, 2022. 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.