RES 231363 - Laserfiche WebLink

AUGUSTIN BERNAL MOUNTAIN BIKE TRAIL PROJECT DRAFT INITIAL STUDY 12956 DUDEK 53 April 2022 prone to geological hazards are mapped on their California Earthquake Hazards Zone Application (EQ Zapp) (DOC 2019). As noted in the Setting section above, there are several active faults near the project area, including the Alquist-Priolo designated Calaveras Fault immediately east of the project site and the Hayward Fault approximately 8 miles west of the site. The project would not introduce a new use to the Augustin Bernal Community Park. The project proposes to construct a mountain bike trail to replace an unofficial user-created trail. As discussed further in Section 3.16(a), the proposed project could slightly increase use of the Augustin Bernal Community Park by providing an engineered mountain bike trail that could be used by mountain bikers with a wider range of experience and skill levels than the existing trail supports. However, the project is not expected to substantially increase trail use activity within the park overall because of the existing high volume of trail use at the park, including on the unofficial user-created trail that the proposed project would replace, and the potential to divert a portion of existing downhill mountain bike traffic on the park’s multi-use trails to the new trail. The project does not include any structures or new parking that would be likely to result pose substantial risk associated with seismic activity. Accordingly, risks associated with seismic events, including fault rupture, would be less than significant. ii) Strong seismic ground shaking? Ground shaking can result in structural failure and collapse of structures or cause non- structural building elements to fail, presenting a hazard to building occupants and contents. The project site is located in an area of moderate earthquake hazard. As noted above, the project would construct a mountain bike trail to replace an unofficial user- created trail and trail spurs, and the project would not substantially increase trail use activity within the park. The project would not construct any structures or parking areas. Although trail users could be exposed to strong seismic ground shaking, the project would not substantially increase risks associated with seismic activity because it would not substantially increase use of the park and therefore would not significantly increase the risk of loss, injury, or death involving strong seismic ground shaking. Thus, this impact would be less than significant. iii) Seismic-related ground failure, including liquefaction? Liquefaction generally occurs as a result of strong ground shaking in areas where granular sediment or fill material either contains or is located immediately above high moisture content. The ground shaking transforms the material from a solid state to a temporarily liquid state. Liquefaction is a serious hazard because buildings in areas that experience liquefaction may sink or suffer major structural damage. The project would not construct structures and would not increase the potential for liquefaction to occur within the park. Liquefaction typically occurs during or following heavy precipitation events, during which use of the proposed mountain bike trail would be very low. As the project would not substantially increase use of the park and use of the trail would be low during conditions under which liquefaction risks are highest, the project would not increase the risk of loss, injury, or death due to liquefaction. Thus, this impact would be less than significant.