Thelma #1
Key Takeaway
Thelma #1 is classified as low hazard in Montana. It was completed in 1962 and is 64 years old. Its primary use is irrigation.
Physical Details
| Dam Height | 19 ft (taller than 42.9% in MT) |
| Dam Length | 211 ft |
| Dam Type | Earth |
| Max Storage | 106 acre-ft |
| Normal Storage | 63 acre-ft |
| Max Discharge | 120 cfs |
| Year Completed | 1962 (64 years old) |
| NID ID | MT00338 |
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
THELMA D. GRAY
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Thelma #1?
Thelma #1 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 Thelma #1?
Thelma #1 is owned by THELMA D. GRAY (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Thelma #1 built?
Thelma #1 was completed in 1962, making it 64 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 Thelma #1?
Thelma #1 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 Thelma #1?
Thelma #1 has a dam height of 19 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.