Harriet Lake

Oak Grove River· Clackamas, Oregon· Built 1923· Arch· 68 ft tall
Low Hazard Hydroelectric Recreation Private

Key Takeaway

Harriet Lake is classified as low hazard in Oregon. It was completed in 1923 and is 103 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 68 ft (taller than 90.7% in OR)
Dam Length186 ft
Dam TypeArch
Max Storage400 acre-ft
Normal Storage152 acre-ft
Surface Area22 acres
Drainage Area131 sq mi
Max Discharge11,200 cfs
Year Completed1923 (103 years old)
NID IDOR00546

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: Yes
Last Inspection: September 20, 2022
State Regulated: No

Ownership

Portland General Electric Company

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Harriet Lake?

Harriet 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 Harriet Lake?

Harriet Lake is owned by Portland General Electric Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Harriet Lake built?

Harriet Lake was completed in 1923, making it 103 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 Harriet Lake?

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

How tall is Harriet Lake?

Harriet Lake has a dam height of 68 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 Harriet Lake last inspected?

Harriet Lake was last inspected on September 20, 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.