The Joint Transmission Main ( JTM) is a 60-inch water pipeline that was constructed in 1961 to convey potable water from a Metropolitan Water District (MWD) connection in Irvine, California to Bradt Reservoir and Schlegel Reservoir in San Clemente, California. Collectively, these facilities comprise the Joint Regional Water Supply System (JRWSS), a section of which is contract operated by South Coast Water District ("District"). The District plans to re-construct Vault C-10 to replace and upgrade the valves, flow meters, and electrical equipment. The vault is within a JTM easement in a vehicle parking area adjacent to Woodbridge Village Association Community Center, 31 Creek Road, Irvine, CA (Figure 1).
JTM Vault CM-10is located beneath three vehicle parking spots and a grass median as illustrated in Figures 1 and 2. Existing surface features include an access manway and meter/electrical cabinet. When completed the surface equipment and access manway would be similar to the existing features. The staging area for construction would occupy several parking spots as illustrated in Figure 1. Construction is expected to take approximately four months. One tree would be removed for construction and landscape features of the parking median would be restored following completion of construction.