Green Castle Dam

TR- BRUSH CREEK· Marshall, Iowa· Built 1954· Earth· 30 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

Green Castle Dam is classified as significant hazard in Iowa. It was completed in 1954 and is 72 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 30 ft (taller than 48.2% in IA)
Dam Length650 ft
Dam TypeEarth
Max Storage263 acre-ft
Normal Storage150 acre-ft
Surface Area17 acres
Drainage Area0 sq mi
Max Discharge0 cfs
Year Completed1954 (72 years old)
Year Modified1988
NID IDIA02418

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 5, 2020
State Regulated: Yes
Regulatory Agency: IOWA DNR

Ownership

Marshall County Conservation Board

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Green Castle Dam?

Green Castle 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 Green Castle Dam?

Green Castle Dam is owned by Marshall County Conservation Board (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Green Castle Dam built?

Green Castle Dam was completed in 1954, making it 72 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 Green Castle Dam?

Green Castle 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 Green Castle Dam?

Green Castle Dam has a dam height of 30 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 Green Castle Dam last inspected?

Green Castle Dam was last inspected on June 5, 2020. 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.