Sidney Sewage Lagoon

TR-YELLOWSTONE RIVER· Richland, Montana· Built 1960· Earth· 9 ft tall
Low Hazard Other Local Government

Key Takeaway

Sidney Sewage Lagoon is classified as low hazard in Montana. It was completed in 1960 and is 66 years old. Its primary use is other.

Physical Details

Dam Height 9 ft (taller than 2.9% in MT)
Dam Length4,000 ft
Dam TypeEarth
Max Storage340 acre-ft
Normal Storage320 acre-ft
Year Completed1960 (66 years old)
NID IDMT01413

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
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

CITY OF SIDNEY

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Sidney Sewage Lagoon?

Sidney Sewage Lagoon 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 Sidney Sewage Lagoon?

Sidney Sewage Lagoon is owned by CITY OF SIDNEY (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Sidney Sewage Lagoon built?

Sidney Sewage Lagoon was completed in 1960, making it 66 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 Sidney Sewage Lagoon?

Sidney Sewage Lagoon serves the following purposes: Other. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Sidney Sewage Lagoon?

Sidney Sewage Lagoon has a dam height of 9 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.

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.