Fact Sheet
US Army Corps of Engineers
U.S. Army Engineer Research and Development Center
April 2004
The Dalles General Model
Purpose: To investigate the location of a juvenile fish outfall site to minimize predation and tailrace egress time,
and to evaluate and design spillway modifications that will improve fish passage survival.
Background: The Dalles Dam is located 192
miles upstream from the mouth of the
Columbia River, two miles east of the city of
The Dalles, Oregon. The dam extends 1.5
miles from the Oregon shore to the navigation
lock on the Washington shore. Because the
boundary between the two states follows the
old river channel, The Dalles Dam is almost
entirely in the state of Washington. The Dalles
project consists of a powerhouse with 22
hydropower turbines with a combined
discharge capacity of 2,290,000 cfs, a
spillway, and navigation lock. The spillway at
The Dalles is 1150 ft wide with 23 tainter
gate-controlled bays. There are no spillway
deflectors at The Dalles Dam. The horizontal
apron-type stilling basin at The Dalles is about 190 ft long with an invert elevation of 55 ft. One row of 8-ft-high
baffle blocks and a 12-ft-high end sill provide for energy dissipation in the stilling basin. Training walls, extending
over two-thirds the length of the stilling basin, separate Bays 1 and 2, 2 and 3, and 22 and 23. The tailwater channel
downstream of the stilling basin has a mean elevation of 68 ft with some irregularities, resulting in elevations less
than 68 ft. The shallow shelf down-stream of the stilling basin is about 850 ft long downstream of the north end of
the spillway but only half that long at the south end of the stilling basin. The navigation lock is located north of the
spillway with its approach channel well downstream the spillway.
Facts: At the request of the U.S. Armyy
Points of Contact: For additional information, please contact
Mr. Glenn Davis at 601-634-4183 ( ),
Mr. Dwayne Fuller at 601-634-2668 ( ) or
Mr. Dennis Markle at 601-634-3680 ( )