Hawthorne Lake Dam

PLEASANT CREEK· Mahaska, Iowa· Built 1979· Earth· 45 ft tall
Significant Hazard Recreation State Government

Key Takeaway

Hawthorne Lake Dam is classified as significant hazard in Iowa. It was completed in 1979 and is 47 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 45 ft (taller than 91.4% in IA)
Dam Length900 ft
Dam TypeEarth
Max Storage4.1K acre-ft
Normal Storage1.9K acre-ft
Surface Area160 acres
Drainage Area5 sq mi
Max Discharge0 cfs
Year Completed1979 (47 years old)
NID IDIA01874

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 14, 2017
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 Hawthorne Lake Dam?

Hawthorne Lake 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 Hawthorne Lake Dam?

Hawthorne Lake 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 Hawthorne Lake Dam built?

Hawthorne Lake Dam was completed in 1979, making it 47 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 Hawthorne Lake Dam?

Hawthorne Lake 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 Hawthorne Lake Dam?

Hawthorne Lake Dam has a dam height of 45 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 Hawthorne Lake Dam last inspected?

Hawthorne Lake Dam was last inspected on June 14, 2017. 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.