Barrier Dam

Barrier Dam is a concrete dam located in Lewis County, Washington, built in 1968. It carries a Low hazard potential classification and has a satisfactory condition assessment.

About Barrier Dam

The primary purpose of Barrier Dam is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by City Of Tacoma (public utility). It impounds the Cowlitz River near Toledo, Wa.

The dam stands 16 feet tall and stretches 718 feet across, creates a reservoir covering 23 acres, has a maximum storage capacity of 600 acre-feet, and collects water from a drainage area of 1,402 square miles. Completed in 1968, the structure is well into its service life at over 50 years old.

This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/21/2025.

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Low HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateWashington
CountyLewis
Nearest CityToledo, Wa
River/StreamCowlitz River
Coordinates46.50680, -122.60220

Physical Characteristics

Dam TypeConcrete
NID Height16 ft
Dam Height12 ft
Dam Length718 ft
Year Completed1968 (58 years old)

Storage & Hydraulics

NID Storage600 acre-ft
Max Storage600 acre-ft
Normal Storage455 acre-ft
Surface Area23 acres
Drainage Area1,402 sq mi
Max Discharge68,350 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeHydroelectric
OwnerCity of Tacoma
Owner TypePublic Utility
Hazard ClassificationLow
Condition AssessmentSatisfactory
Last Inspection08/21/2025
Emergency Action PlanYes

Identifiers

NID IDWA00555
Federal IDWA00555
More InfoState Dam Safety Program

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