Eleven Mile Canyon

SOUTH PLATTE RIVER· Park, Colorado· Built 1932· Concrete· 128 ft tall
High Hazard Water Supply Public Utility

Key Takeaway

Eleven Mile Canyon is classified as high hazard in Colorado. It was completed in 1932 and is 94 years old. Its primary use is water supply. 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 128 ft (taller than 97.5% in CO)
Dam Length375 ft
Dam TypeConcrete
Max Storage128.0K acre-ft
Normal Storage97.8K acre-ft
Surface Area3,500 acres
Drainage Area963 sq mi
Max Discharge3,500 cfs
Year Completed1932 (94 years old)
NID IDCO00359

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: August 24, 2022
State Regulated: Yes
Regulatory Agency: DWR

Ownership

DENVER BOARD OF WATER COMMISSIONERS

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Eleven Mile Canyon?

Eleven Mile Canyon 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 Eleven Mile Canyon?

Eleven Mile Canyon is owned by DENVER BOARD OF WATER COMMISSIONERS (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Eleven Mile Canyon built?

Eleven Mile Canyon was completed in 1932, making it 94 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 Eleven Mile Canyon?

Eleven Mile Canyon serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Eleven Mile Canyon?

Eleven Mile Canyon has a dam height of 128 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 Eleven Mile Canyon last inspected?

Eleven Mile Canyon was last inspected on August 24, 2022. 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.