Cox Hollow Number Two

Mill Creek· Iowa, Wisconsin· Built 1965· Earth· 55 ft tall
High Hazard Recreation State Government

Key Takeaway

Cox Hollow Number Two is classified as high hazard in Wisconsin. It was completed in 1965 and is 61 years old. Its primary use is recreation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 55 ft (taller than 98.1% in WI)
Dam Length630 ft
Dam TypeEarth
Max Storage5.4K acre-ft
Normal Storage1.9K acre-ft
Surface Area152 acres
Drainage Area14 sq mi
Max Discharge606 cfs
Year Completed1965 (61 years old)
NID IDWI00013

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes
Last Inspection: November 9, 2021
State Regulated: Yes
Regulatory Agency: WIDNR

Ownership

Wisconsin Department of Natural Resources

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Cox Hollow Number Two?

Cox Hollow Number Two is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Cox Hollow Number Two?

Cox Hollow Number Two is owned by Wisconsin Department of Natural Resources (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Cox Hollow Number Two built?

Cox Hollow Number Two was completed in 1965, making it 61 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 Cox Hollow Number Two?

Cox Hollow Number Two 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 Cox Hollow Number Two?

Cox Hollow Number Two has a dam height of 55 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 Cox Hollow Number Two last inspected?

Cox Hollow Number Two was last inspected on November 9, 2021. 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.