DESCRIPTION: The US Bureau of Reclamation and the Klamath Irrigation District are replacing the ±4,320-foot long C-Flume. The C-Flume is an elevated irrigation flume built in the early 1920’s of pre‑cast concrete panels supported on a series of trusses. The canal has been deemed structurally insufficient and will be replaced with new structures including a concrete lined channel on new embankments, siphon pipe, and a pipe bridge structure. Key elements planned for design include the siphon pipe structure undercrossing at State Highway 39 and the Lost River Diversion Canal Pipe Bridge.
SERVICE: Foundation Engineering is currently providing geotechnical services. The preliminary design work included evaluation for re-using the existing Lost River crossing structure foundations, but staging and seismic stability made a new structure more cost‑effective. Analyses were also completed for shoring and dewatering for the siphon pipe construction below OR 39 and to protect an existing railroad bridge.
Project challenges include demolition of the existing canal and new construction during a 7‑month time span when the canal is normally off-line. Therefore, we worked with the design team to provide constructible designs for the siphon pipe that could be completed while the flume is in service and designs for structures that could be completed in the off‑line period.