From a Valley Transportation Authority press release, Dec. 10, 2012:
The BART Silicon Valley Project has reached a significant marker with the completion of the Upper Penitencia Creek Improvement Project at the future Berryessa BART Station in San Jose.
This biological restoration effort lessens the environmental impact of construction and improves the highly degraded condition of the banks of Upper Penitencia Creek.
The new channel includes repurposed tree root structures and boulders to protect the banks, and a widened and realigned portion of the creek creates a more natural floodplain. The benefits of the UPC Improvement Project are already evident as ducks and fish move into the widened, meandering creek channel. In addition, the UPC Improvement Project removed non-native vegetation and is replacing it with native wetland and riparian plantings, which will shade the channel and help to enhance fish passage for the federal and state protected Central California Coast steelhead. The creek's distance from commercial buildings and residential homes is now increased, reducing potential impacts of possible creek overflow in the future.
Completion of the UPC Improvement Project occurred on October 31, 2012. Based on weather conditions, native wetland vegetation will be planted throughout December 2012 and January 2013.
The BART Silicon Valley Project is a 16-mile extension of the existing Bay Area Rapid Transit system to San Jose, Milpitas and Santa Clara. The first phase, the Berryessa Extension, is a 10-mile, two-station extension, beginning in Fremont south of the future BART Warm Springs Station and proceeding in the former Union Pacific Railroad right-of-way through Milpitas, the location of the first station, and then to the Berryessa area of north San Jose.