Lower Mission Creek Flood Control Project (Streambed Alteration Agreement No. 1600-2016-0078-R5 (SAA))

Lower Mission Creek Flood Control Project (Streambed Alteration Agreement No. 1600-2016-0078-R5 (SAA))

CDFW is intending to execute a Lake and Streambed Alteration Agreement pursuant to Section 1602 of the Fish and Game Code (# 1600-2015-0078-R5), to the Project applicant, Santa Barbara County Flood Control District. The project is a restoration project designed to increase flood capacity to a 20-year event level. The banks will be redesigned from a concrete trapezoidal shape to a combination of vertical concrete walls for the lower half of the banks, sloped with un-grouted rock, and rip-rap added for the upper half of the banks. The final configuration will have a width range from 60 to 70 feet at the top, and an average depth of 8 to 12 feet throughout the project site. A natural bottom will be maintained or restored to natural sediments where hardened concrete is now present. The rock rip-rap will be covered with top soil and pipes will be placed through the rip-rap to allow the planting of native creek. New culverts will be constructed between Gutierrez and Chapala Street Bridges to bypass an oxbow. A weir will be constructed at the inlet of the culvert. Five small parcels of open land will be left along the banks, ranging in size from 0.03 to 0.14 acres; these parcels will be planted with native vegetation expanding the riparian habitat and providing open spaces for residences. The area between Canon Perdido Street and Cabrillo Blvd Bridge will be excavated (82,000 cubic yards) to increase creek capacity. Material to be removed includes burlap bag concrete walls, masonry walls, shot-crete walls, gabions, wooden pilings, and other various bank materials. All materials will be recycled if possible. A pilot channel will be scored into the bottom, approx. 1 foot deep and 10 to 12 feet wide, and will be allowed to collect rock, cobbles and boulders. mitigation for fish consists of providing resting places for migrating steelhead by constructing artificial overhangs projecting from the walls, placing double rows of coarse boulders between the overhangs along the creek walls, and providing rock energy dissipaters. Mitigation for tidewater goby consists of coarse surface relief of the walls.

Santa Barbara

Santa Barbara