Holloway Lake

NORTH FORK SWEENEY CREEK· Ravalli, Montana· Built 1900· Concrete· 20 ft tall
Low Hazard Irrigation Private

Key Takeaway

Holloway Lake is classified as low hazard in Montana. It was completed in 1900 and is 126 years old. Its primary use is irrigation.

Physical Details

Dam Height 20 ft (taller than 44.5% in MT)
Dam Length63 ft
Dam TypeConcrete
Normal Storage280 acre-ft
Surface Area25 acres
Drainage Area3 sq mi
Year Completed1900 (126 years old)
NID IDMT00841

Safety Information

Low Hazard

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?

Emergency Action Plan: No
Last Inspection: June 19, 2003
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

SWEENEY CR WATER USERS

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Holloway Lake?

Holloway Lake 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 Holloway Lake?

Holloway Lake is owned by SWEENEY CR WATER USERS (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Holloway Lake built?

Holloway Lake was completed in 1900, making it 126 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 Holloway Lake?

Holloway Lake 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 Holloway Lake?

Holloway Lake has a dam height of 20 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 Holloway Lake last inspected?

Holloway Lake was last inspected on June 19, 2003. 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.