B. Oleary

TR MOREAU· Dewey, South Dakota· Built 1945· Earth· 18 ft tall
Low Hazard Fire Protection Stock Or Small Fish Pond Private

Key Takeaway

B. Oleary is classified as low hazard in South Dakota. It was completed in 1945 and is 81 years old. Its primary use is fire protection.

Physical Details

Dam Height 18 ft (taller than 24.1% in SD)
Dam Length500 ft
Dam TypeEarth
Max Storage54 acre-ft
Normal Storage12 acre-ft
Max Discharge1,320 cfs
Year Completed1945 (81 years old)
NID IDSD01675

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: DANR

Ownership

BEN OLEARY ESTATE

Private

Nearby Dams

Oleary

Dewey, SD

Low Hazard 15 ft

Oleary Ranch 1

Dewey, SD

Low Hazard 31 ft

Oleary Ranch 2

Dewey, SD

Low Hazard 23 ft

Thorstensen 1

Dewey, SD

Low Hazard 26 ft

Thorstensen 2

Dewey, SD

Low Hazard 28 ft

Fred Joens

Dewey, SD

Low Hazard 16 ft

A. Lee

Dewey, SD

Low Hazard 20 ft

Vern Long

Dewey, SD

Low Hazard 27 ft

Frequently Asked Questions

What is the hazard classification of B. Oleary?

B. Oleary 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 B. Oleary?

B. Oleary is owned by BEN OLEARY ESTATE (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was B. Oleary built?

B. Oleary was completed in 1945, making it 81 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 B. Oleary?

B. Oleary serves the following purposes: Fire Protection, Stock, Or Small Fish Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is B. Oleary?

B. Oleary has a dam height of 18 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.