San Mateo city leaders this week again backed the concept of a California high-speed train zipping through their city, although they listened to residents' concerns about the project and had some of their own.

As some nearby cities mobilize efforts to derail the train's planned route through the Peninsula, the San Mateo City Council said at a study session Monday it still thought the benefits of high-speed rail zooming through their city outweighed the potential negative impacts to the community.

The council envisions the train being a convenient, greener alternative to flying and would serve residents who wanted to travel throughout the state.

"I just think it's the way to go," said Councilman Jack Matthews. "I think there's a golden opportunity here."

The council did, however, spend about an hour listing its concerns with the project.

Ideally, council members said, the bullet train should whisk through San Mateo on raised tracks between the Hillsdale and Hayward Park Caltrain stations, and on depressed tracks or inside a tunnel through downtown. Otherwise, an elevated rail line could divide the city's downtown, which has residences, businesses and restaurants interspersed on each side of the existing Caltrain tracks.

"We feel that is going to be a barrier that would really divide our community, in the downtown area in particular," Matthews said. "Our downtown really does straddle the tracks."

A handful of residents spoke at the public hearing Monday, calling for as little impact as possible on the downtown area. They also voiced concerns on noise pollution and the effect on nearby developments.

The city will summarize Monday's meeting in a letter to the California High Speed Rail Authority next month. The authority is taking comments until April 6 as it prepares to plan out the San Francisco-to-San Jose portion of the line.

Menlo Park, Atherton and other cities have sent letters to the authority, raising concerns about noise pollution, increased traffic, and property loss through eminent domain that could occur to make room for the new tracks.

The San Mateo City Council on Monday briefly discussed the idea of joining a consortium of mostly southern Peninsula cities that has been forming to present a unified front to the authority in advance of the April 6 deadline.

However, the council said it did not want to share a voice with the cities — some of which have taken more radical opposition to the rail line. Deputy Mayor John Lee noted that Menlo Park and Atherton sued the authority last year. San Mateo will meet with officials from Burlingame and Millbrae on a regular basis to discuss the project, City Manager Susan Loftus said.

While supporting the rail project, San Mateo officials had their own concerns.

The council wanted to see the tracks elevated south of downtown, and depressed tracks or tunnels through downtown. The rail line's grade change must be gradual; the tracks can only be lowered one foot for every 100 feet of track.

Mayor Brandt Grotte and other council members said tunneling through downtown would be ideal, though it would prove much costlier than above-ground tracks.

"I think (tunneling) is the only way to go," Grotte said.

The council also reinforced the need for grade separations, where the tracks run above the street, at 25th, 28th and 31st avenues as part of the project. The train requires grade separations to run at high speed.

Grotte also called for information on how many property owners would be affected by potential eminent domain actions.

Reach Mike Rosenberg at mike.rosenberg@dailynewsgroup.com.