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.
Dam profile
NID height · 16 ft16 ft tall and 718 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
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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Location
| State | Washington |
| County | Lewis |
| Nearest City | Toledo, Wa |
| River/Stream | Cowlitz River |
| Coordinates | 46.50680, -122.60220 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 16 ft |
| Dam Height | 12 ft |
| Dam Length | 718 ft |
| Year Completed | 1968 (58 years old) |
Storage & Hydraulics
| NID Storage | 600 acre-ft |
| Max Storage | 600 acre-ft |
| Normal Storage | 455 acre-ft |
| Surface Area | 23 acres |
| Drainage Area | 1,402 sq mi |
| Max Discharge | 68,350 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | City of Tacoma |
| Owner Type | Public Utility |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/21/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00555 |
| Federal ID | WA00555 |
| More Info | State Dam Safety Program |