Condit Dam Removal Condit Dam Removal - Access Washington

Condit Dam Hydroelectric Project
Final Supplemental EIS
activities (Figures 3-1 through 3-6). Although most of the work areas can be accessed using
established roads, some areas would require reestablishing roads that have become
overgrown and others where new segments of road would be built to access specific
facilities.
To access the top of the dam, the access road to the current boat launch area near the dam
(AR-2) would be upgraded. It diverges from Powerhouse Road, passes through the parking
area at the boat launch, and continues to the dam. It would be widened, requiring removal of
adjacent trees.
The proposed concrete disposal area can be accessed via Tamarack Lane, a private road
owned by SDS Lumber Company. However, to reduce the amount of traffic on Tamarack
Lane, a second, direct access road (AR-3) would be established along the eastern banks of
the reservoir in the same alignment as an old road, part of which has become overgrown with
vegetation. This road would connect from the boat-launch parking area near the dam across
a small stream via a temporary culvert, and would follow the old road route to the concrete
disposal site (SA-3). It would require widening and grading, and perhaps some minor
realignment through a mature forested area. This road may branch by ramping down the
tributary canyon to the existing cofferdams and to other reservoir areas that may require
access for reservoir sediment stabilization.
An access road to the lower side of the dam (AR-5) would be required early in the removal
process in order to get the equipment in place to tunnel through the dam. This road would
extend west to near the flowline from Powerhouse Road south of the dam along an existing
small access road that would be upgraded. From that point, the road would be new and
would follow a topographic bench approximately parallel with the flowline to where the
flowline would be bridged. A bridge over the flowline would be necessary to keep the
flowline operating until the dam is breached. The road would extend to the spillway of the
dam, where a large crane would be set up to move equipment and materials to the tunneling
area. The road surface would be cleared, graded, and gravelled.
Additional short segments of new or upgraded access roads would be required for access to
the lower part of the flowline and the surge tank (AR-7 and AR-8), the penstock (AR-9), and
the powerhouse and tailrace (AR-11).
Access roads would be required within the current reservoir footprint to stabilize slopes, for
revegetation, and to help manage woody debris. One such road would be an extension of
Graves Road (AR-14) about halfway up the reservoir extending from SR 141 to the east side
of the reservoir. This road would also access the temporary waterline replacement area.
Other access points would probably be at Northwestern Lake Park at the upper end of the
reservoir, at the waterline on the west side of the reservoir, and off Cabin Road on the lower
west side of the reservoir (AR-15 and AR-16). The needed upgrades on these roads or the
exact locations have not been determined at this time, as the topography that would exist
after reservoir draw-down and the specific needs cannot be known before the reservoir is
drained. Parts of these temporary roads would be built in the remaining reservoir sediment
and would be reinforced using imported materials. When these temporary access roads are
no longer needed, fill material used within the floodplain would be removed and all areas
3-16