The Lewis River Hydroelectric Projects - PacifiCorp

Crews began preparing the site of Merwin Dam in 1929. The dam, a
concrete arch, was poured in sections, within a huge wooden framework
that was shifted across the river as each section cured. A bypass tunnel
carried water around the site.
In 1930, workers shut off the bypass tunnel, allowing water to begin
building up behind the dam. Slowly, over the course of many days, the
water covered the homesteads and forests of the valley.
Sidebar
Caption:
Photos of architectural elements
Merwin Dam and its adjacent powerhouse are on the National Register of
Historic Places. Both the dam and the powerhouse were built with Art
Deco-style architectural elements.
Photo of dam construction workers
Many locals, as well as outsiders, found work with the dam construction
crews, which included engineers, laborers, supervisors, clerks, and health
care workers.
Hydro-stats: Hydroelectric power icon
Merwin Dam: Year completed—1932; Crest length—1300 feet; Maximum
height—314 feet; Annual power generation: 517,812Mwh (enough to
power over 68,000 homes).
Images:
Historic photos of dam construction. Photos/illustrations of Edison with
lightbulb, period images of electrical equipment from the early 20 th
century. Map showing “relocated” town of Ariel. Photos of Art Deco
architectural elements on power house and dam.
Appendix 1: panel profiles Lewis River Draft I&E Plan page 12