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BACKGROUND The Bernal Avenue Bridge across the ADLL was constructed in 1941. It is a simple span riveted steel Camelback through truss structure. It sits on reinforced concrete abutments, which are built on and supported by concrete spread footings. The bridge spans approximately 131 feet. It is approximately 24-feet wide, and includes two vehicular lanes (one for eastbound and one westbound) and includes a narrow pedestrian sidewalk on the south side of the bridge. The steel truss structure was recently stripped of all paint and corrosion and repainted. The most recent bi-annual inspection performed by the State of California Department of Transportation on September 14, 2017, did not identify any maintenance work as being required. The inspection was carried out in conformance with Title 23 of the Code of Federal Regulations (Federal Highway Act) and NBIS. The Bernal Avenue Bridge is one of three ADLL crossings within the City of Pleasanton, linking the east and west sides of town. The other two crossings are West Las Positas and Stoneridge Drive, both to the north of Bernal Avenue. Only the Stoneridge Drive crossing and the Bernal Avenue crossing are directly accessible from the Interstate 680 on/off ramps. As such, the Bernal Avenue Bridge provides a vital link to the west side of town. Having to take it out of service if damaged would cause a significant issue not only for residents on the west side, but also for fire and police services. DISCUSSION When the capital improvement project budget was developed it was assumed a second parallel bridge could be constructed to the south of the existing bridge. In fact, this concept has been assumed since the late 1990s, but for various reasons has not been accomplished. The most recent consideration ended when significant concerns were raised regarding how a second bridge built to modern standards would aesthetically blend with the existing 1941 steel truss bridge. Nonstructural façade was considered for the second bridge in the attempt to address this issue, but was eventually abandoned due to high cost. It is very important for the reasons stated in the background section that this transportation link across the ADLL remain reliable, and eventually the 1941 bridge will not be serviceable. For that reason it is recommended that the discussions regarding this ADLL crossing be revived. Circumstances have recently changed. The rains during the winter of 2015/16 were significant. The ADLL, which serves as the storm drain for the entire 427 square mile Tri-Valley Area (Pleasanton, Dublin, San Ramon, Livermore, and the incorporated areas of Alameda County) experienced significant water flows. The flows resulted in scour erosion and alteration of the stream banks in various places along the ADLL. A significant amount of soil erosion and stream widening can be observed immediately south of the existing bridge, on the east side. Staff has concerns that this erosion has affected the feasibility of installing a second bridge as has been a consideration for many years. For example, a second bridge may have to span further, which could interfere with the abutments and spread footings of the existing bridge. Another Page 2 of 3