Johnson (Oscar) Dam

Trib to Elk Creek· Harrison, Iowa· Built 2011· Earth· 49 ft tall

Key Takeaway

Johnson (Oscar) Dam is classified as low hazard in Iowa. It was completed in 2011 and is 15 years old. Its primary use is flood risk reduction.

Physical Details

Dam Height 49 ft (taller than 94.6% in IA)
Dam Length530 ft
Dam TypeEarth
Max Storage187 acre-ft
Normal Storage53 acre-ft
Surface Area6 acres
Drainage Area1 sq mi
Max Discharge150 cfs
Year Completed2011 (15 years old)
NID IDIA04188

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: IOWA DNR

Ownership

Oscar Johnson

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Johnson (Oscar) Dam?

Johnson (Oscar) 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 Johnson (Oscar) Dam?

Johnson (Oscar) Dam is owned by Oscar Johnson (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Johnson (Oscar) Dam built?

Johnson (Oscar) Dam was completed in 2011, making it 15 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 Johnson (Oscar) Dam?

Johnson (Oscar) Dam serves the following purposes: Flood Risk Reduction, Grade Stabilization, Fish And Wildlife Pond, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Johnson (Oscar) Dam?

Johnson (Oscar) Dam has a dam height of 49 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.