Due to damage caused by sediment as well as security concerns, the City is relocating water conveyance conduits below ground. Kiewit Pacific Co., a subsidiary of Kiewit Corporation, is constructing the Sandy River Conduit Relocation project. This design-build project involves taking the two existing above ground conduits and placing them in a 441-linear-foot tunnel under the Sandy River.
Bull Run watershed provides water to the City of Portland. Water is transferred through a two pin-truss steel pipeline bridge, which was constructed in 1893. Due to damage caused by sediment as well as security concerns, the City is relocating water conveyance conduits below ground. Kiewit Pacific Co., a subsidiary of Kiewit Corporation, is constructing the Sandy River Conduit Relocation project. This design-build project involves taking the two existing above ground conduits and placing them in a 441-linear-foot tunnel under the Sandy River.
The scope of work includes a 30-foot-diameter construction shaft to a depth of 85 feet; two drilled 9-foot-diameter shafts to a depth of 110 feet and a 13-foot-diameter modified horseshoe tunnel running diagonally under the girth of the Sandy River. Before completion of all shafts, the tunnel will be backfilled with cell grout and the site will be restored. A series of trenches will be placed at the surface, connecting the existing pipes to new underground conduits.
Once the conduits have been diverted to the new underground tunnel, the current pipe bridge will be dismantled and hauled off-site.