O'Farrell Dam No. 2

TR-N. FORK WHETSTONE· Grant, South Dakota· Built 2006· Earth· 20 ft tall

Key Takeaway

O'Farrell Dam No. 2 is classified as low hazard in South Dakota. It was completed in 2006 and is 20 years old. Its primary use is recreation.

Physical Details

Dam Height 20 ft (taller than 33.7% in SD)
Dam Length400 ft
Dam TypeEarth
Max Storage65 acre-ft
Normal Storage32 acre-ft
Surface Area6 acres
Drainage Area1 sq mi
Max Discharge2,026 cfs
Year Completed2006 (20 years old)
NID IDSD02587

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

MARIE O'FARRELL

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of O'Farrell Dam No. 2?

O'Farrell Dam No. 2 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 O'Farrell Dam No. 2?

O'Farrell Dam No. 2 is owned by MARIE O'FARRELL (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was O'Farrell Dam No. 2 built?

O'Farrell Dam No. 2 was completed in 2006, making it 20 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 O'Farrell Dam No. 2?

O'Farrell Dam No. 2 serves the following purposes: Recreation, Fire Protection, Stock, Or Small Fish Pond, Fish And Wildlife Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is O'Farrell Dam No. 2?

O'Farrell Dam No. 2 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.

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.