CSU Chico Bridge Replacements (Streambed Alteration Agreement No. 1600-2014-0303-R2).

CSU Chico Bridge Replacements (Streambed Alteration Agreement No. 1600-2014-0303-R2).

The California Department of Fish and Wildlife (CDFW) has executed Lake and Streambed Alteration Agreement number 1600-2014-0303-R2, pursuant to section 1602 of the Fish and Game Code to the project Applicant, California State University, Chico. The proposed project consists of the replacement of two bridges within approximately 300 feet (ft) of one another. Project 1: The Physical Science pedestrian footbridge will be replaced with a new 22ft wide bridge to allow access for emergency response vehicles. The new bridge is designed as a single-span. Removal of the existing bridge will include the removal of a one-foot wide pier which exists within the channel but outside the ordinary high water mark (OHWM). Supporting bridge abutments for the new structure will be placed outside the existing bridge abutments and near the top of the existing channel. The abutments foundation will include a concrete abutment cap atop 5 - 30 inch (in) cast-in-drilled-hole (CIDH) concrete piles at a depth of 35ft below the existing grade. The proposed bridge is an arched steel truss structure with 16in tall fllor beams and a concrete deck that is 9in thick for a total structure depth of 25in. Approximately nine trees within the channel prism will be removed as a result of the bridge installation/removal activities. The proposed location for the replacement of these trees is proposed at the top of the channel prism and out of the effective hydraulic flow area. Re-vegetation of disturbed (cut) areas is proposed with low profile, flow resistant plantings, such as sedge grasses and other appropriate species. In order to secure the section of bridge structure and install electrical conduit along the new structure's side, temporary scaffolding will be placed within the OHWM as well as the adjacent bank areas under the bridge. All scaffolding will be removed at the completion of the project and bank areas will be restored to pre-construction conditions. Project 2: The Gus Manolis Bridge received irreparable damage from a falling ree during a recent storm event. The existing damaged structure (6.5ft x 60ft) will be removed, and replaced with a new 72ft x 7ft single-span stell truss with concrete deck pedestrian bridge. The proposed replacement bridge is longer than the existing which will result in the new abutments being further away from the creek centerline. The increased length of the proposed structure will eliminate permanent impacts to the stream and associated banks. The foundation will consist of two 30in CIDH conrete piles at a depth of approximately 35 feet below the existing grade. Two trees within the stream prism have been identified for removal. Replacement trees will be placed in the ineffective flow areas of the channel. In oder to facilitate the connection of the two bridge sections, temporary scaffolding will be placed within the OHWM as well as the adjacent bank areas under the bridge. All scaffolding will be removed at the completion of the project and bank areas will be restored to pre-construction conditions.

Chico

Butte