Tujunga Wash Spreading Grounds Enhancement Project

Project Description: The goal of the project was to transport 1.76 million tons of native soil using a 4,975-foot-long Zipline transfer conveyor belt. As part of the contract, W.A. Rasic constructed the conveyor system to move soil through and around existing and newly installed reinforced concrete pipe (RCP) interconnections. The soil was transported from a 150-acre site that consisted of 20 small retention basins to Vulcan’s Boulevard Pit in Sun Valley. The 20 small retention basins were consolidated into nine larger and deeper basins to improve local water supplies and reduce reliance on imported water. We also installed rubber-gasket reinforced concrete pipe (RGRCP) that ranged in size from 12 to 96 inches and was placed at depths of up to 20 feet. W.A. Rasic installed approximately 2,752 linear feet of RGRCP using the jack and bore method at seven locations. RGRCP was also installed via open cut outside of the jack and bore sections to construct cast-in-place concrete weir intake and outlet structures to control the anticipated flow of 8,000-acre-feet of water per year. Other elements of work included installing geotechnical instruments; sound monitoring; installing temporary and permanent electrical power, asphalt paving, levee, and down drains; and finishing grading the basins and roadways.