Prunedale Drainage Improvements Project

ongoing

Caltrans proposes multiple drainage improvements within a 1.5-mile-long section of U.S. Route 101 in Monterey County from just north of the Crazy Horse Canyon Road/Echo Valley Road overcrossing (at post mile 98.8) to the northernmost intersection with Dunbarton Road (at post mile 100.3). Improvements will be implemented through various ways, including joint repair and/or a complete replacement, depending on the conditions at each location. Existing culverts proposed for removal will be replaced with reinforced concrete pipes. For most of the project culvert locations, the scope of work includes upgrading the size of the culverts to a minimum of 24 inches in diameter to increase the discharge capacity and reduce the velocity of water flow. One 24-inch-diameter culvert will be replaced with a 30-inch-diameter culvert, and two others will be replaced with 36-inch-diameter culverts. Culvert replacements will use either the cut and cover method or the trenchless pipe jacking method. Existing drainage inlets will be replaced with new drainage inlets that meet current design standards. New flared end sections will be installed on the inlets and outlets of culverts as needed throughout the project limits to prevent erosion. Concrete headwalls will be removed and replaced as needed. Concrete spall repair will occur at the reinforced concrete box joints in one culvert (post mile 99.732). The repair of shoulder embankment slopes that have been damaged by erosion will occur at the outlets of two culverts (at post miles 99.06 and 99.21). Two drainage channels will be graded to remove excess silt and vegetation at post miles 99.42 and 99.73.