Cowlitz Falls is a concrete dam located in Lewis County, Washington, built in 1994. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 145 ft145 ft tall and 700 ft long, taller than 99% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Cowlitz Falls
The primary purpose of Cowlitz Falls 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 PUD #1 of Lewis County, Wa (public utility). It impounds the Cowlitz River.
The dam stands 145 feet tall and stretches 700 feet across, creates a reservoir covering 700 acres, has a storage capacity of 11,000 acre-feet, and collects water from a drainage area of 1,000 square miles. Completed in 1994, the structure is 32 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in 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 09/07/2022.
At 145 feet, this dam is taller than 99% of all dams in the United States.
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Location
| State | Washington |
| County | Lewis |
| Nearest City | None |
| River/Stream | Cowlitz River |
| Coordinates | 46.46630, -122.10960 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 145 ft |
| Dam Height | 120 ft |
| Dam Length | 700 ft |
| Year Completed | 1994 (32 years old) |
Storage & Hydraulics
| NID Storage | 11,000 acre-ft |
| Normal Storage | 11,000 acre-ft |
| Surface Area | 700 acres |
| Drainage Area | 1,000 sq mi |
| Max Discharge | 360,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | PUD #1 of Lewis County, Wa |
| Owner Type | Public Utility |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/07/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00581 |
| Federal ID | WA00581 |
| More Info | State Dam Safety Program |