Condit Dam Removal Condit Dam Removal - Access Washington

Condit Dam Hydroelectric Project
Final Supplemental EIS
4.11 PUBLIC SAFETY
This section evaluates public safety, which could be affected as a result of the Proposed
Action. A related section, Public Services (Section 4.12), also includes relevant public safety
discussions.
4.11.1 Affected Environment
The Proposed Action extends over an area including Northwestern Lake (reservoir) to the
Condit Dam and along the White Salmon River from the dam to the Underwood (in-lieu) site
adjacent to the Columbia River (see Figures 3-1 through 3-6 in Section 3). This would
include not only the area, but all points of access (state and local roads).
In addition to PacifiCorp, the public service providers to the area would be involved in
coordination of proposed safety plans and measures. The providers include the Klickitat and
Skamania County Sheriff’s departments, Fire District No. 3 (Klickitat County side), the
Underwood Fire Department (Skamania County side), and the Washington State Patrol (state
roads). Emergency service providers include ambulances (Stevenson) and other emergency
service operations (Skyline Hospital in White Salmon).
4.11.2 Impacts
Pre-Dam Removal Activities
Limited blasting may occur in association with access road building and road widening
operations. Because of the locations, this would not have an impact on access to the
proposed action area for the service providers and the public.
Dam Breaching and Removal
Drain Tunnel and Dam
Lake tap tunneling is considered among the most dangerous tunneling operations for
workers. Blasting operations would be dangerous for members of the public if they were
allowed to be too close to the drain tunnel. Water levels in the river would rise rapidly as the
reservoir drains, quickly engulfing the river floodplain between the dam and the Underwood
site. Water would be drained rapidly through the tunnel and a vortex with strong currents
would likely form in the reservoir during the first six hours as the reservoir drains. Dam
removal will involve blasting the concrete and hauling it to a disposal site. Blasting will be
conducted according to a blasting plan by highly experienced contract specialists.
Sediment Transport
Water would drain out of the reservoir over the first six hours after the dam was breached.
The White Salmon River would quickly cut a new course through the reservoir sediments,
and the river edge would be unstable and fall into the river, creating a hazard to any person or
animal near the river. People will, of course, be excluded. In addition, access to the
proposed action area by the service providers could be affected.
4.11-1