Ossum Wash Repair Project

Victor Valley Wastewater Reclamation Authority (VVWRA) owns two existing gravity trunk sewer pipelines (36-in Reinforced Concrete Pipe [RCP] and 42-in Vitrified Clay Pipe [VCP]) that cross Ossum Wash. These large diameter sewer pipelines transport around 1-MG of the City of Victorville’s daily sewage. After recent heavy rain events, the existing grade above these pipelines has eroded substantially. VVWRA is concerned that future rain events might expose the two pipelines, making them susceptible to a pipe break and sewage spill from bedload or debris travelling down the wash during a rain event. The two existing pipelines are estimated to have approximately 4 feet of cover remaining above them. VVWRA is proposing to construct emergency improvements to the wash to mitigate the risk of pipe exposure and damage. To address the critical erosion issues within the wash described above, VVWRA hired Dudek to design emergency improvements to protect the sewer lines. The proposed improvements include the following: • Installing grouted riprap on the channel side slope along the easterly side of the existing grouted riprap channel. • Installing an extension of the grouted riprap channel from the downstream end of the existing grouted riprap to the northerly extent of the VVWRA pipeline easement. • Installing loose riprap lined channel downstream of the proposed grouted riprap.