Theodore Roosevelt Dam - Later Expansion

Later Expansion

In 1989, an ambitious expansion and renovation project was begun at Roosevelt Dam. The dam was resurfaced with concrete by J.A. Jones Construction Company, and its height was raised 77 feet (23 m) to 357 feet (107 m), which had the effect of increasing the storage capacity of Roosevelt Lake by roughly 20%. This project was completed in 1996 at a cost of $430 million. The $430 million in costs included three other major construction contracts associated with the dam. These included the realignment of Highway 188 over the new Theodore Roosevelt Bridge upstream of the dam, renovations to the hydroelectric power plant, and a tunneling contract known as the "Lake Tap". The Lake Tap contract would provide locations where the penstocks would be located to bring water into the hydroelectric power plant. Shortly after completion, however, the area entered into a prolonged period of drought, and it would be some time before the newly increased capacity was put to use, with the lake finally reaching historic levels of 100% capacity in February 2009.

As a result of the reconstruction, the dam has a completely altered appearance from when it was originally listed as a National Historic Landmark. The original rubble-masonry dam was completely encased in concrete, and the structural height was extended from 280 feet (85 m) to 357 feet (109 m). Since the dam no longer had the integrity of the design, materials, workmanship, feeling, or association that it had when it was originally listed, the National Historic Landmark designation was withdrawn on March 10, 1999. The Theodore Roosevelt Dam National Register District contains other resources that are listed on the National Register of Historic Places, but the dam itself is no longer a contributing property to the district.