Harper Lake

COAL CREEK-TR· Boulder, Colorado· Built 1985· Earth· 11 ft tall
High Hazard Water Supply Local Government

Key Takeaway

Harper Lake is classified as high hazard in Colorado. It was completed in 1985 and is 41 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 11 ft (taller than 8.7% in CO)
Dam Length2,200 ft
Dam TypeEarth
Max Storage843 acre-ft
Normal Storage715 acre-ft
Surface Area31 acres
Drainage Area0 sq mi
Max Discharge460 cfs
Year Completed1985 (41 years old)
NID IDCO02674

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: October 11, 2022
State Regulated: Yes
Regulatory Agency: DWR

Ownership

CITY OF LOUISVILLE (KOWAR, KURT)

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Harper Lake?

Harper Lake 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 Harper Lake?

Harper Lake is owned by CITY OF LOUISVILLE (KOWAR, KURT) (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Harper Lake built?

Harper Lake was completed in 1985, making it 41 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 Harper Lake?

Harper Lake 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 Harper Lake?

Harper Lake has a dam height of 11 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 Harper Lake last inspected?

Harper Lake was last inspected on October 11, 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.