Owner: Glenn-Colusa Irrigation District
Contract value: $3,518,020
There were four different site locations spread out from just north of Maxwell, CA to south of Artois, CA. Shimmick worked closely with the designers, CH2MHill, to provide GCID with an improved water distribution system. The timing and sequence of construction were critical to the success of the project.
Among the four work locations, two were canal bypass structures. Shimmick built a reinforced concrete box culvert to transport the water in Bondurant Slough from the north side under GCID's main canal to the south side without entering the main canal. On top of the box culvert, there was a concrete check structure to control flow in the main canal. A sheet pile cofferdam to enclose the area of the box culvert and a bypass cofferdam to divert the flow of the existing canal were constructed in just a few weeks.
The other canal bypass structure allowed Hunters Creek to bypass underneath the main canal via a 120-in diameter reinforced concrete pressure pipe. Construction of this pipe bypass involved building inlet and outlet concrete structures, excavating in the main canal to install the 120-in pipe, and realignment of the Hunters Creek channel erosion resistance.
There were two other work sites which consisted of 6,800 ft of earth-lined drainage channel excavation, demolition of various existing concrete structures, temporary and permanent storm water diversion channels, minor concrete check structures, and civil work to restore each of the work sites to pre-construction condition.