Tuesday - December 17, 2013

Focus: Pipeline Route Changes in Lake Oswego

Downtown LO pipeline changes map

Downtown LO pipeline changes

Originally published Dec. 12 - updated Dec. 17, 2013

A pipeline routing change is currently being explored as an alternative to tunneling the pipeline under Oswego Lake, as was previously planned. The Partnership is reviewing a land-based new alignment around the Lake to keep costs controlled since proposals received for tunneling significantly exceeded cost estimates.

The original planned route was to place the pipeline under Oswego Lake by drilling a tunnel for the pipeline using horizontal directional drilling (HDD) from Erickson Street, under the Lake to Cabana Lane, and then trenching pipe along Evergreen Road to Chandler Road. Elimination of the HDD Lake crossing means no months-long disruption for residents on either side of the former HDD route.

Various alignments to connect the pipe between the north and south side of the Lake are currently being reviewed. The Partnership’s goal is to keep impacts to a minimum and find a lower cost alternative before year-end.

Proposals for the planned HDD route under the Willamette River were also too high.  Unfortunately, the Partnership has no practical alternatives to HDD in that location to link the river intake pumping station and pipeline in Gladstone to the water treatment plant in West Linn. Environmental and land use restrictions eliminate all possible alternatives to HDD technology. The Partnership is looking for cost savings for the Willamette River HDD crossing as well. Options include restructuring bid packages, working with interested contractors to find cost savings and examining pipe size and materials.