SCH Number 2015112002

Project Info

Title

Tower Bridge Fender Replacement Project

Description

The project is limited to the removal of an existing timber fender system on the Tower Bridge that surrounds the in-water piers 6 and 7 of the bridge within the Sacramento River. The timber system will be replaced with modern plastic wales and sheathing supported by steel piles. All removal and construction activity will be performed via barge. The existing timber fender system will be removed via barge by mechanically cutting or breaking the existing pile off at or near the mudline. A total of 200 16-inch timber piles will be removed employing this method, 100 piles per pier. All piles will be placed in a containment basin along with any attached sediment or debris after removal and disposed of at an off-site facility. The new fender system will be installed via barge. A total of 104 new piles will be installed at Pier 6 and 7 via barge mounted cranes with vibratory hammers. Eight 36-inch diameter steel piles and ninety six 24-inch diameter steel piles will replace the existing 200 cresote 16-inch timber piles. The eight new 36-inch steel piers and the ninety six 24 inch steel piers will create a permanent loss of aquatic habitat of approx. 5,105 sq. ft. over 0.12 acres. The previously existing fender structure had an area of 4,266 sq. ft. over 0.10 acres. The completion of the new fender structure shall result in the net permanent impact of 839 sq. ft. over 0.02 acres. The Biological Study Area (BSA) consists of 84.53 acres of which consists of in-water areas upstream and downstream of the Tower Bridge site as well as the surfaces of the bridge, surfaces of the freeway and adjacent street surfaces. The eight new 36-inch steel piers and the ninety-six 24-inch steel piers will create a permanent loss of aquatic habitat of approx.. 5,105 sq. ft. over 0.12 acres. The previously existing fender structure had an area of 4,266 sq. ft. over 0.10 acres. The completion of the new fender structure shall result in the net permanent impact of 839 sq. ft. over 0.02 acres. The project is expected to result in incidental take of Chinook Salmon - Central Valley Spring Run, which are designated as a threatened species under CESA and the incidental take of Chinook Salmon - Sacramento River Winter Run and Delta Smelt, both designated as an endangered species under CESA. The ITP referenced above as issued by CDFW authorizes incidental take of species listed under CESA that may occur as a result of Project implementation.

9 documents in project