Backbone Dam

MAQUOKETA RIVER· Delaware, Iowa· Built 1938· Gravity· 33 ft tall
Significant Hazard Recreation State Government

Key Takeaway

Backbone Dam is classified as significant hazard in Iowa. It was completed in 1938 and is 88 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 33 ft (taller than 63.3% in IA)
Dam Length908 ft
Dam TypeGravity
Max Storage1.0K acre-ft
Normal Storage600 acre-ft
Surface Area125 acres
Drainage Area120 sq mi
Max Discharge0 cfs
Year Completed1938 (88 years old)
NID IDIA01965

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: June 10, 2019
State Regulated: Yes
Regulatory Agency: IOWA DNR

Ownership

Iowa Department of Natural Resources

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Backbone Dam?

Backbone Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Backbone Dam?

Backbone Dam is owned by Iowa Department of Natural Resources (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Backbone Dam built?

Backbone Dam was completed in 1938, making it 88 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 Backbone Dam?

Backbone 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 Backbone Dam?

Backbone Dam has a dam height of 33 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 Backbone Dam last inspected?

Backbone Dam was last inspected on June 10, 2019. 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.