Alder
Alder is a dam located in Owyhee County, Idaho, built in 1909. It carries a Low hazard potential classification and has a poor condition assessment.
About Alder
The primary purpose of Alder is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is private-owned. It impounds the Otter Creek Marys Creek near Riddle.
The dam stands 21 feet tall and stretches 1,020 feet across, creates a reservoir covering 120 acres, has a storage capacity of 960 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1909, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 06/07/2018.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Idaho |
| County | Owyhee |
| Nearest City | Riddle |
| River/Stream | Otter Creek Marys Creek |
| Coordinates | 42.15860, -116.00620 |
Physical Characteristics
| NID Height | 21 ft |
| Dam Height | 21 ft |
| Dam Length | 1,020 ft |
| Year Completed | 1909 (117 years old) |
Storage & Hydraulics
| NID Storage | 960 acre-ft |
| Normal Storage | 960 acre-ft |
| Surface Area | 120 acres |
| Drainage Area | 1 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 06/07/2018 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | ID00082 |
| Federal ID | ID00082 |
| More Info | State Dam Safety Program |