Mallard Marsh Dam No 1

TR-WINNEBAGO RIVER· Cerro Gordo, Iowa· Built 1967· Earth· 8 ft tall
Low Hazard Recreation Local Government

Key Takeaway

Mallard Marsh Dam No 1 is classified as low hazard in Iowa. It was completed in 1967 and is 59 years old. Its primary use is recreation.

Physical Details

Dam Height 8 ft (taller than 0.7% in IA)
Dam Length650 ft
Dam TypeEarth
Max Storage156 acre-ft
Normal Storage52 acre-ft
Surface Area26 acres
Drainage Area3 sq mi
Max Discharge0 cfs
Year Completed1967 (59 years old)
NID IDIA00177

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

Cerro Gordo County Conservation Board

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Mallard Marsh Dam No 1?

Mallard Marsh Dam No 1 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 Mallard Marsh Dam No 1?

Mallard Marsh Dam No 1 is owned by Cerro Gordo County Conservation Board (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mallard Marsh Dam No 1 built?

Mallard Marsh Dam No 1 was completed in 1967, making it 59 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 Mallard Marsh Dam No 1?

Mallard Marsh Dam No 1 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 Mallard Marsh Dam No 1?

Mallard Marsh Dam No 1 has a dam height of 8 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.