PacifiCorp, a PacifiCorp Company, was required to reroute the Lemolo No. 2 powerhouse discharge to Toketee Reservoir in accordance with the North Umpqua Settlement Agreement Section 5.4. After a seven-year design process, construction of PacifiCorp’s Lemolo No. 2 tailrace re-routing project is almost complete.
Oldcastle Precast provided a 108” diameter concrete pipeline that transitioned into 96” diameter concrete pipe and then back into 108” concrete pipe. The pipe is t-lok lined pipe in portions to meet hydraulic design criteria. The precast concrete pipe was manufactured in 12 foot lay lengths with numerous custom castings. The pipeline makes multiple turns and grade changes. Inlet and outlet pieces were poured with steel rings cast into the pipe to allow connection to a cast in place head wall. In addition, Oldcastle Precast supplied three T-Top manhole pipe sections, each having a 48” manhole cast into the pipe section for access to the pipeline.
The Lemolo No. 2 tailrace re-routing project consists of in-water construction of the cofferdam for the inlet and an outlet structure. To stay on schedule, they built from both ends. The 3000 feet of pipe was buried along the Toketee-Rigdon road and across the Toketee recreation area. The pipe will carry 700 cfs from the Lemolo 2 plant tailrace and eliminate ramping in the Lemolo 2 full flow reach of the North Umpqua River.
Weekly Brothers, Inc. is the general contractor overseeing the construction and McMillen LLC is the project engineer.
The project is scheduled for completion at the end of October, 2011.
