The work consisted of construction of a concrete intake structure equipped with hydraulic vertical traveling screens, hydraulic slide gates, various wash down piping assemblies, a concrete wet well, a 3,600 horsepower pump station and associated piping and appurtenances. This phase of the project also included approximately 3,200 LF (650 LF of 36” D.I., 100 LF of 30” D.I., 100 LF of 24” D.I., 2,280 LF of 20” D.I.) high pressure irrigation lines installed on steep slopes in solid rock conditions. This project was given a short in water work window of July 15th – Oct 15th 2009 which Emery & Sons finished two full days ahead of schedule. This project was constructed in a highly sensitive area that included wetlands, and a historic Native American camp site. The project was constantly monitored by tribal members to ensure that the historic site was not damaged in any way, and to look for any artifacts that may have been unearthed during excavation. Access to this site was very limited, and was only accessible by a ¼ mile long narrow gravel road. A slope stabilization fence was required to keep rocks from falling into the new structure. The intake structure and wet well were constructed with the use of a 10’ high x 355’ long Portadam system to hold back the Yakima River. During construction the water levels of the Yakima River were in excess of 12’ above the finished floors of both of these structures. Infiltration was dealt with using 6” & 8” submersible pumps and sediment laden water was treated to acceptable turbidity levels prior to being discharged back into the river.
Owner: Benton Irrigation District
Engineer: Anderson-Perry & Associates
Location: Benton City, Washington
Completion Date: 2010