Rahn Lake Dam

Keya Paha River-TR· Tripp, South Dakota· Built 1936· Earth· 22 ft tall
Low Hazard Recreation State Government

Key Takeaway

Rahn Lake Dam is classified as low hazard in South Dakota. It was completed in 1936 and is 90 years old. Its primary use is recreation.

Physical Details

Dam Height 22 ft (taller than 45.6% in SD)
Dam Length570 ft
Dam TypeEarth
Max Storage891 acre-ft
Normal Storage320 acre-ft
Max Discharge2,000 cfs
Year Completed1936 (90 years old)
NID IDSD00539

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 12, 2017
State Regulated: Yes
Regulatory Agency: DANR

Ownership

GF&P

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Rahn Lake Dam?

Rahn Lake 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 Rahn Lake Dam?

Rahn Lake Dam is owned by GF&P (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Rahn Lake Dam built?

Rahn Lake Dam was completed in 1936, making it 90 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 Rahn Lake Dam?

Rahn Lake 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 Rahn Lake Dam?

Rahn Lake Dam has a dam height of 22 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 Rahn Lake Dam last inspected?

Rahn Lake Dam was last inspected on October 12, 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.