Google has axed one of the two elevated automobile bridges over Stevens Creek proposed to carry shuttles to a planned 42-acre campus at NASA Ames for Google's Planetary Ventures division, according to a letter to city officials.
"To confirm Google's intentions going forward, Google has determined that the proposed new vehicle bridge at Crittenden is not required," wrote Google real estate and construction manager John Igoe in the April 3 letter. A pedestrian bridge at Crittenden Lane would also be "deleted completely," Igoe wrote.
The change in direction was applauded by Shani Klainhaus of the Santa Clara Valley Audubon Society.
"I'm glad Google is no longer considering a vehicular bridge over Crittenden Lane that would have adverse impacts to Stevens Creek and the wetlands," Kleinhaus said. "We are looking forward to a comprehensive and adequate review of the new proposals for bridges at the Charleston site."
A Google spokesperson said Google considered feedback received, which includes over 100 comments from environmental and conservation groups.
"As we said when we initially introduced this plan, working with the city of Mountain View and local community and environmental groups would be an important part of the process," the spokesperson said. "We've taken their feedback and come up with a plan that provides environmentally-friendly transportation alternatives in the North Bayshore area."
The initial environmental study for the two-bridge project had come to the conclusion that "no significant contribution to cumulative impacts would occur," but conservationists disagreed.
Conservationists said a new auto bridge from the end of Crittenden Lane in particular would have been unnecessarily harmful to a long list of animals and birds, including the California clapper rail and salt marsh harvest mouse, two "species of concern" that have habitat nearby or have been seen in the area, said Eric Mruz, refuge manager of Don Edwards National Wildlife Refuge.
Conservationists noted that one bridge was more than adequate for the amount of traffic proposed, but Google's architects said the two-bridge design would improve circulation of the shuttles among Google's campuses on Charleston and Crittenden streets. Private auto traffic would not be allowed over the Google-owned bridges.
"To disrupt the creek with two crossings seems totally gratuitous," writes Gita Dev of the Sierra Club, one of 19 groups and individuals who provided comments on the project's initial environmental study, said Kevin Woodhouse, assistant to the city manager.
"Although the project has the effect of reducing single occupancy trips and providing access to emergency response vehicles and VTA vehicles, it achieves these goals at the cost of sacrificing the preservation of open space, view corridors, and avoiding adverse impacts on the creek and marsh," wrote Alice Kaufman of the Committee for Green Foothills.
Mruz had similar comments.
"Any bridge built as a part of this project should be built no closer to wetlands than the proposed Charleston Road site," Mruz wrote. "No bridges should be placed at Crittenden Lane."
Kaufman proposed one new vehicle bridge and one new pedestrian bridge Charleston Road. Disabled access and safety improvements should be made to an older existing bridge over the creek at Crittenden Lane, Kaufman said, an idea which Google later proposed in its letter.
Large egret colony
While it may be the least problematic bridge, Kleinhaus expressed concern about how the Charleston Road bridge could impact the South Bay's large egret colony in nearby trees. Kleinhaus notes there have recently been 40 nests there for the long-legged, pointy-beaked birds.
"The Charleston Bridge is proposed next to the first in a line of nine city of Mountain View sycamore trees on Shorebird Drive that host an established, thriving egret nesting colony," Kleinhaus wrote in her comments on the study.
Volunteers with the San Francisco Bay Bird Observatory and Santa Clara Valley Audubon Society have been monitoring this colony since 2005, when there were 21 great egret nests, said Kleinhaus. In 2011, there were 40 great egret nests and five snowy egret nests, and it was the largest great egret colony in the South Bay, she said.
"The egret colony is an important natural resource for the City of Mountain View and North Bayshore and, as a source of Great and Snowy Egrets, to the entire region. Intentional or accidental eviction of this colony would not be acceptable to the birding community of our region," Klienhaus wrote.
Wind tunnel impacts
According to its official comments, the U.S. Air Force is also concerned about impacts of the Charleston Road bridge, but not to wildlife.
The Air Force operates the world's largest wind tunnel nearby for testing full scale airplane aerodynamics, and wants assurance that no disruptive turbulence from any structure within a certain range of the tunnel's large mouth, which inhales fresh Bay air from across the wetlands.
"Highly turbulent atmospheric winds can increase the test section turbulence intensity to unacceptable levels," says a 1987 memo about the wind tunnel from NASA official Jim Ross. "Atmospheric turbulence is much larger when the wind blows over buildings than over open fields." He adds that the effect was found by researchers who created a 1/15 scale model of the wind tunnel.
Ross's memo also outlines building restrictions in front of the wind tunnel which impose a height limit of 25 to 35 feet on the Bayview parcel where Google has planned its 42-acre campus.