Harrison County Roadgrade Dam 18-79-43

TR-WILLOW CREEK· Harrison, Iowa· Built 1959· Earth· 66 ft tall
Significant Hazard Other Fire Protection Stock Or Small Fish Pond Local Government

Key Takeaway

Harrison County Roadgrade Dam 18-79-43 is classified as significant hazard in Iowa. It was completed in 1959 and is 67 years old. Its primary use is other. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 66 ft (taller than 99.3% in IA)
Dam Length395 ft
Dam TypeEarth
Max Storage486 acre-ft
Normal Storage246 acre-ft
Surface Area14 acres
Drainage Area2 sq mi
Max Discharge0 cfs
Year Completed1959 (67 years old)
Year Modified1969
NID IDIA00475

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: July 24, 2018
State Regulated: Yes
Regulatory Agency: IOWA DNR

Ownership

Harrison County Board of Supervisors

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Harrison County Roadgrade Dam 18-79-43?

Harrison County Roadgrade Dam 18-79-43 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 Harrison County Roadgrade Dam 18-79-43?

Harrison County Roadgrade Dam 18-79-43 is owned by Harrison County Board of Supervisors (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Harrison County Roadgrade Dam 18-79-43 built?

Harrison County Roadgrade Dam 18-79-43 was completed in 1959, making it 67 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 Harrison County Roadgrade Dam 18-79-43?

Harrison County Roadgrade Dam 18-79-43 serves the following purposes: Other, Fire Protection, Stock, Or Small Fish Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Harrison County Roadgrade Dam 18-79-43?

Harrison County Roadgrade Dam 18-79-43 has a dam height of 66 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 Harrison County Roadgrade Dam 18-79-43 last inspected?

Harrison County Roadgrade Dam 18-79-43 was last inspected on July 24, 2018. 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.