Evans Konnowac Dam

Evans Konnowac Dam is an earth dam located in Yakima County, Washington, built in 1990. It carries a High hazard potential classification and has a poor condition assessment.

About Evans Konnowac Dam

The primary purpose of Evans Konnowac Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Evans Fruit Co Inc (private). It impounds the Offstream.

The dam stands 33 feet tall and stretches 320 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 28 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1990, the structure is 36 years old.

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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 04/16/2015. That was 10 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.

At 33 feet, this dam is taller than 78% of dams nationwide.

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 HazardPoor ConditionEmergency Action Plan: Yes

Location

StateWashington
CountyYakima
River/StreamOffstream
Coordinates46.53299, -120.36071

Physical Characteristics

Dam TypeEarth
NID Height33 ft
Dam Length320 ft
Year Completed1990 (36 years old)

Storage & Hydraulics

NID Storage28 acre-ft
Max Storage28 acre-ft
Normal Storage21 acre-ft
Surface Area2 acres
Drainage Area0 sq mi
Max Discharge50 cfs

Ownership & Safety

PurposeIrrigation
OwnerEvans Fruit Co Inc
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentPoor
Last Inspection04/16/2015
Emergency Action PlanYes

Identifiers

NID IDWA01933
Federal IDWA01933
More InfoState Dam Safety Program

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