Sediment Removal Along State Route 246 at Postmile 19.36 Project

The culvert conveys water from the unnamed ephemeral tributary to Santa Rosa Creek and has a history of plugging with sediment during storms. Accumulated sediment was excavated out of the culvert inlet, outlet, and interior for several years between 2001 – 2019, and has since clogged, leaving less than 1 foot of freeboard space remaining inside the culvert. Caltrans is proposing to trim two branches of one coast live oak (Quercus agrifolia) tree located within the understory beneath the canopy of the tree and overhanging the culvert outlet to provide sufficient clearance for machinery to access the culvert outlet and interior. A loader and/or excavator will be used to remove accumulated sediment from the streambed within 120 feet upstream of the culvert inlet and 30 feet downstream of the culvert outlet, while a tunnel mucker and/or skid steer will be used to remove accumulated sediment within 133 feet of the culvert interior. No vegetation removal along the banks of the unnamed tributary to Santa Rosa Creek is proposed to occur.