Larsen Dam

DRY DRAW· Lyman, South Dakota· Built 1937· Earth· 26 ft tall
Low Hazard Recreation State Government

Key Takeaway

Larsen Dam is classified as low hazard in South Dakota. It was completed in 1937 and is 89 years old. Its primary use is recreation.

Physical Details

Dam Height 26 ft (taller than 65.2% in SD)
Dam Length350 ft
Dam TypeEarth
Max Storage280 acre-ft
Normal Storage183 acre-ft
Surface Area31 acres
Drainage Area3 sq mi
Max Discharge600 cfs
Year Completed1937 (89 years old)
NID IDSD02171

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: October 19, 2017
State Regulated: Yes
Regulatory Agency: DANR

Ownership

S&PL

State Government

Nearby Dams

Thompson Dam

Lyman, SD

Low Hazard 23 ft

Reliance Dam

Lyman, SD

Significant Hazard 16 ft

Schindler Dam

Lyman, SD

Low Hazard 16 ft

John Bunker

Lyman, SD

Low Hazard 26 ft

Orl Walcott #1

Lyman, SD

Significant Hazard 53 ft

Oscar Diess

Lyman, SD

Low Hazard 22 ft

Larsen Irrigation Dam

Lyman, SD

Low Hazard 25 ft

Merrill Karlen #1

Lyman, SD

Low Hazard 28 ft

Frequently Asked Questions

What is the hazard classification of Larsen Dam?

Larsen Dam 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 Larsen Dam?

Larsen Dam is owned by S&PL (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Larsen Dam built?

Larsen Dam was completed in 1937, making it 89 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 Larsen Dam?

Larsen Dam serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Larsen Dam?

Larsen Dam has a dam height of 26 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 Larsen Dam last inspected?

Larsen Dam was last inspected on October 19, 2017. 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.