Cottonwood Lake

Yellow Medicine River-TR· Lyon, Minnesota· Built 1960· Gravity· 9 ft tall
Low Hazard Grade Stabilization Private

Key Takeaway

Cottonwood Lake is classified as low hazard in Minnesota. It was completed in 1960 and is 66 years old. Its primary use is grade stabilization.

Physical Details

Dam Height 9 ft (taller than 25.1% in MN)
Dam TypeGravity
Max Storage3.6K acre-ft
Normal Storage2.8K acre-ft
Surface Area378 acres
Drainage Area21 sq mi
Year Completed1960 (66 years old)
NID IDMN00768

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
Last Inspection: November 14, 2018
State Regulated: Yes
Regulatory Agency: MNDNR EWR

Ownership

County of Lyon

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Cottonwood Lake?

Cottonwood Lake 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 Cottonwood Lake?

Cottonwood Lake is owned by County of Lyon (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Cottonwood Lake built?

Cottonwood Lake was completed in 1960, making it 66 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 Cottonwood Lake?

Cottonwood Lake serves the following purposes: Grade Stabilization. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Cottonwood Lake?

Cottonwood Lake has a dam height of 9 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 Cottonwood Lake last inspected?

Cottonwood Lake was last inspected on November 14, 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.