Carmichael Underground Cable Reliability Project

Carmichael Underground Cable Reliability Project

The project alignment is located in the Carmichael neighborhood in unincorporated eastern Sacramento County. The project alignment extends from a connection point starting at SMUD’s Carmichael substation heading south onto Manzanita Avenue and then east onto Lincoln Avenue for approximately 800 feet. Between these points, the project is generally located within road right of way along Manzanita Avenue and Lincoln Avenue. The area surrounding the proposed project is primarily commercial and urban residential. The project involves the installation of new underground concrete encased conduit duct bank and 69kV cable to replace approximately 2,000 feet of existing direct buried underground 69kV cable installed in the 1970s within existing right-of-way. The project also involves installation of up to 6 new precast concrete manholes along the route to allow electric cable pulling, splicing and maintenance. The following provides a more detailed description of proposed improvements along the project alignment. From the northern terminus of the project alignment, the existing direct buried 69kV cable extends 400 feet east out to the road and southward from within the Carmichael substation. From this location, the replacement 69kV underground duct bank would be located along the eastern side (generally, the number one eastbound lane of Manzanita Avenue). For the portion of the project continuing along Lincoln Avenue, the replacement 69kV underground conduit duct bank would continue to be located along the northern edge of Lincoln Avenue approximately 800 feet east to Salmaan Street, before turning right and rising above ground at two existing riser poles. The proposed manholes would consist of pre-cast concrete, measuring 8’ x 14’ x 8’ inside, requiring an excavation area of approximately 15’ x 20’ x 15’, and would generally be installed in pairs spaced evenly throughout the alignment to allow for cable pulling, splicing, and maintenance of the 69kV cable. In general, manholes would be located in the street. In the open trenches, cable would be placed in a duct bank, a series of conduits encased in concrete. The trenches would then be backfilled with a cementitious slurry mixture or compacted aggregate base to the roadway subgrade elevation followed by replacement of the required aggregate base and pavement section. Most construction would include open trenching to a maximum depth of 7 feet, though some deeper excavation may be necessary to avoid conflicts with existing utility lines. As noted above, construction activities would generally be conducted in roadway rights-of-way and would include the temporary closure of roads and sidewalks. Following construction activities each day, the open trenches would be covered. K-rails would be utilized to provide a buffer around excavations where manholes would be installed, or the excavations will be plated over. Where K-rails are used, then extended lane closures would be required. Equipment will be removed to allow reopening of the lanes as trenching and excavation activities are completed. In residential areas, there may be slight delays but no prolonged inaccessibility for residents. Construction activities would likely take 3 months and are expected to begin as early as February 2021. While construction activities may not be continuous, they are expected to be completed by mid-2021.

Sacramento

Sacramento