Lower Mission Creek Flood Control Project

Lower Mission Creek Flood Control Project

A proposal by the U.S. Army Corps of Engineers and the Santa Barbara County Flood Control and Water Conservation District, in cooperation with the City of Santa Barbara, to construct a flood control project on Lower Mission Creek between Canon Perdido Street and Cabrillo Boulevard. The project would increase channel capacity from as little as 1500 cfs (5-year storm) to 3400 cubic feet per second (cfs), providing approximately a 20-year level of protection. The natural bottom would be retained and some existing concrete channel bottom would br removed. Creek banks upstream from U.S. Highway 101 would consist mostly of a combination of short (two to four and one half feet) vertical walls at the bottom and vegetated 15-inch thick riprap side slopes at a 1.5:1 (horizontal: vertical) or flatter slope above. The riprap slopes would be covered with topsoil with unreinforced cocrete pipes in varying sizes up to three feet in diameter strategically placed between the riprap to allow planting of larger native trees and shrubs. The topsoil would also be seeded with native seed mix to promote a healthy understory. The toe wall-riprap sideslope would be the pre-dominant treatment upstream from U.S. Highway 101, except in two short reaches upstream of the Haley-De la Vina and De la Guerra Street bridges. Downstream of U.S. Highway 101, vertical walls would be the predominant treatment, with the tow wall-riprap combination found on the easterly bank just above and below the Mason Street bridge and between State Street and Cabrillo Boulevard. The existing channel ranges in width (at the top of bank) from 25 to 70 feet. The final width would range from 53 to 71 feet. The changes to the creek would include creek widening, bridge replacement, bedslope streamlining, creek bank protection and stabilization, and installation of an overflow culvert to bypass the oxbow between U.S. 101 and the Chapala Street Bridge.

Santa Barbara

Santa Barbara