Johnson Pond Dam

Johnson Pond Dam is an earth dam located in King County, Washington, built in 2011. It carries a High hazard potential classification and has a fair condition assessment.

About Johnson Pond Dam

The primary purpose of Johnson Pond Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by King County Natural Resources And Parks (local government). It impounds the Offstream - Rutherford Creek.

The dam stands 18 feet tall and stretches 130 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 43 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 2011, the structure is relatively new.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 07/21/2021.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Washington dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateWashington
CountyKing
River/StreamOffstream - Rutherford Creek
Coordinates47.66287, -122.05003

Physical Characteristics

Dam TypeEarth
NID Height18 ft
Dam Length130 ft
Year Completed2011 (15 years old)

Storage & Hydraulics

NID Storage43 acre-ft
Max Storage43 acre-ft
Normal Storage17 acre-ft
Surface Area2 acres
Drainage Area0 sq mi
Max Discharge10 cfs

Ownership & Safety

PurposeFlood Risk Reduction
OwnerKing County Natural Resources and Parks
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection07/21/2021
Emergency Action PlanYes

Identifiers

NID IDWA01999
Federal IDWA01999
More InfoState Dam Safety Program

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