Construction is underway as the Placer County Department of Public Works replaces the existing bridge on Walerga Road over Dry Creek, located approximately 3 miles west of the City of Roseville, in an effort to reduce flooding and provide safe access to cyclists and pedestrians. The new bridge will be raised 14 feet and incorporate a longer span to elevate the roadway approaches and bridge above flood waters, thereby alleviating problematic flooding issues on the portions of Walerga Road adjacent to Dry Creek.
The new bridge design also includes a new 12-foot-wide Class 1 bikeway and 8-foot-wide walkway with concrete barriers on each side to separate pedestrians and cyclists from traffic. These new pathways will improve community access to the area and promote alternative modes of transportation by providing easy access on and off the bridge and connections to existing bike trails.
Challenges on this project included complicated staging and design parameters. The existing and proposed sanitary sewer alignments pass under a creek. Our innovative solutions included designing the 16-inch water main to pass through the abutments and bridge components and incorporating articulating joints at the abutments to accommodate seismic design. WRECO also designed a gravity sewer crossing under the Dry Creek channel.
During the PA/ED phase of the project, WRECO performed the Location Hydraulic and Bridge Design Hydraulic studies and worked with Placer County to develop the full build-out hydrologic evaluation of the watershed. WRECO also coordinated closely with the project team, Central Valley Flood Protection Board, California Department of Water Resources, and other environmental regulatory agencies from the outset to ensure that all design criteria were understood before design work and analyses began.
WRECO provided storm drainage, stormwater quality, sanitary sewer, and water main design and analysis services during the PS&E phase of the project as well as geotechnical design services. As part of our work, WRECO used the existing subsurface information obtained from previous studies to prepare a comprehensive, but not overly conservative, subsurface investigation consisting of soil borings and cone penetration test (CPT) soundings to optimize both information gathering and cost. WRECO also prepared the Foundation Report for the bridge replacement, which provides new foundation design and construction recommendations, new approach fill settlement periods, approach work grading recommendations, new pavement recommendations, and associated retaining wall and trail foundation recommendations.
Construction of this project began in the spring of 2019 and is estimated to be completed by the summer of 2021. WRECO is currently providing design services during construction.