The California High-Speed Rail Authority will delay releasing a highly anticipated analysis of design options for the Peninsula segment of the rail line because of a recent decision to begin construction in the Central Valley.

The authority had previously planned to release the Environmental Impact Report (EIR) for the San Francisco-to-San Jose segment of the $43 billion line in December. The report will evaluate the various design alternatives for each portion of the segment and consider the impacts of the most feasible alternative.

Preliminary versions of the report identified at-grade and elevated trains as the most likely design options for the Peninsula, with tunneling or open trenching in some areas.

Earlier this month, the authority decided to start construction of the 800-mile line in the Central Valley after a grant from the Federal Railroad Administration allocated $715 million specifically for that region of the state. The authority has yet to determine whether the voter-approved project will make its debut on the Merced-to-Fresno or the Fresno-to-Bakersfield portion of the Central Valley segment.

Robert Doty, director of the Peninsula Rail Program (a partnership of Caltrain and the rail authority), released a statement Friday afternoon saying that the decision by the FRA and the rail authority to give Central Valley the priority "will likely impact the prioritization of the environmental review process for all high-speed-rail sections currently under study."

"This means that the scheduled December 2010 release of the Draft EIR/EIS for the San Francisco to San Jose section will need to be rescheduled for a future date," wrote Doty, who is responsible for the design of the Peninsula segment.

He did not specify when this document will be released.

Doty wrote that the decision to delay the EIR for the Peninsula segment will give the rail authority an opportunity to further refine the document and to educate the public about the project. California voters approved a $9.95 billion bond for the project in November 2008.

"For communities, this means more time (to) learn about the project and to prepare to review and comment on the environmental document," Doty wrote.

Peninsula cities have been busily preparing for the new report by hiring engineering consultants, hosting public hearings and lobbying rail officials to give more preference to underground tunnels. Earlier this month, more than 500 people attended a rally in Burlingame to protest the project in its current form.

Palo Alto Mayor Pat Burt, who sits on the Peninsula Rail Consortium, had publicly called on the rail authority on several occasions in the past month to delay the EIR for the local segment, noting that the recent decision to start the system in the Central Valley makes the Peninsula document less urgent. The rail project has been heavily criticized on the Peninsula, with Palo Alto, Menlo Park and Atherton all suing the rail authority over the adequacy of earlier environmental documents.

Burt, who also sits on the council's High-Speed Rail Committee, warned at a recent meeting that if the rail authority goes through with its December deadline, it would run the risk of having a "stale EIR" -- one that lies dormant for so long that it no longer serves any legal purpose. He emphasized at the Oct. 25 council meeting that it's not clear when the rail authority will have the funding it needs to build the Peninsula segment.

Doty noted in his announcement that the FRA had allocated $16 million in its recent grant for rail-related improvements on the Peninsula segment and said this qualification "positions the San Francisco-San Jose section well for future federal and other funding."