Twin Granite
Key Takeaway
Twin Granite is classified as low hazard in Idaho. It was completed in 1920 and is 106 years old. Its primary use is irrigation.
Physical Details
| Dam Height | 25 ft (taller than 43.7% in ID) |
| Dam Length | 620 ft |
| Normal Storage | 600 acre-ft |
| Surface Area | 40 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 64 cfs |
| Year Completed | 1920 (106 years old) |
| NID ID | ID00260 |
Safety Information
No probable loss of human life and low economic/environmental losses expected.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Twin Granite?
Twin Granite is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Twin Granite?
Twin Granite is owned by information not available (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Twin Granite built?
Twin Granite was completed in 1920, making it 106 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 Twin Granite?
Twin Granite 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 Twin Granite?
Twin Granite has a dam height of 25 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 Twin Granite last inspected?
Twin Granite was last inspected on July 25, 2019. Inspection dates indicate when a formal review occurred, not the results of that inspection.