Little Onion Dam is an earth dam located in Humboldt County, Nevada. It carries a Significant hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 35 ft35 ft tall and 710 ft long, taller than 80% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Little Onion Dam
The primary purpose of Little Onion Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Alder Creek Ranch LLC (private). It impounds the Alder Creek.
The dam stands 35 feet tall and stretches 710 feet across, creates a reservoir covering 30 acres, and has a maximum storage capacity of 325 acre-feet.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 07/18/2022.
At 35 feet, this dam is taller than 80% of dams nationwide.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Nevada |
| County | Humboldt |
| Nearest City | None |
| River/Stream | Alder Creek |
| Coordinates | 41.68290, -118.75550 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 35 ft |
| Dam Height | 31 ft |
| Dam Length | 710 ft |
Storage & Hydraulics
| NID Storage | 325 acre-ft |
| Max Storage | 325 acre-ft |
| Normal Storage | 50 acre-ft |
| Surface Area | 30 acres |
| Max Discharge | 4,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Alder Creek Ranch LLC |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 07/18/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NV00006 |
| Federal ID | NV00006 |
| More Info | State Dam Safety Program |