Austin Road Bridge (No. 29C-259) Scour Mitigation (Lake or Streambed Alteration Agreement No. 1600-2014-0280-R2)

Austin Road Bridge (No. 29C-259) Scour Mitigation (Lake or Streambed Alteration Agreement No. 1600-2014-0280-R2)

The California Department of Fish and Wildlife (CDFW) has executed Lake and Streambed Alteration Agreement number 1600-2014-0280-R2, pursuant to section 1602 of the Fish and Game Code to the project Applicant, San Joaquin County Department of Public Works. The project is limited to the placement of rock slope protection (RSP) in the form of riprap beneath the bridge and along the adjacent embankments to address problems with scour along the stream channel that is exposing the bridge footings and bents to potential damage. Because the foundations are relatively shallow, smaller rocks will be placed underneath the bridge deck to avoid undercutting the bridge footings; however, because of the high velocities, concrete baffles will be required to effectively hold the small rocks in place. The proposed concrete baffles will be staggered to allow a nonconcrete path for riparian wildlife. Staging areas and temporary construction easements will be needed along the east and west edges of Austin Road to install the RSP. Access to the work site will be from Austin Road and adjacent San Joaquin County Department of Public Works operational roads; no new access roads will be necessary and no utilities will be relocated. Staging areas will be within easements on graded and graveled surfaces immediately adjacent to the bridge. Construction activities for the project will include subsurface disturbance. Construction equipment used will be a large front-loader on creek banks and multi-size excavators in the channel bottom. The anticipated approximate depth of excavation is 4.5 feet (137 centimeters). All soil excavated during the project is anticipated to have been previously disturbed during bridge construction.

Stockton

San Joaquin