The pre-construction work involves relocating utility equipment along a half-block stretch of Columbus Avenue near Union and Powell streets. It will take about four months, according to the SFMTA.
The work will be followed in early 2013 by 10 months of construction on a shaft to retrieve the tunnel boring machines for the $1.6 billion Central Subway project, which will create a new branch of Muni's T-Third line that will connect the South of Market neighborhood to Chinatown.
Under the current plans for the subway, which is expected to open in 2019, the last stop on the line will be in Chinatown, but the tunnel will extend past Chinatown into North Beach. SFMTA officials say this will allow crews to retrieve the boring machines in 2014.
The planned work has prompted one man to file a lawsuit, and other neighbors and merchants who are angry about how the construction will affect them are threatening to file a second one.
Marc Bruno, a North Beach resident with the group Save North Beach, filed a lawsuit on July 31 asking a San Francisco Superior Court judge for an immediate temporary restraining order to block the project.
That request was denied last Thursday, but an injunction hearing is scheduled in the case on Aug. 29, Bruno said.
Bruno said, "This process from day one has been a top-down one, and the city broke off all communication ... when we started to ask them questions for which they had no answers."
The group considering filing a second suit, Citizens for Sensible Transit, sent a letter to the city on July 31 asking for the project to be delayed.
The group contends that the construction work is more expansive than what was previously approved and is a guise to facilitate an as-yet-unapproved future subway station in North Beach.
Attorney Susan Brandt-Hawley said today that Citizens for Sensible Transit is still waiting for a response from the city and has not decided whether to file a lawsuit.
Muni spokesman Paul Rose said, "We're confident the project will move forward," but declined to comment further.
The construction work begins today will continue Monday through Friday from 7 a.m. to 3:30 p.m. It will require lane closures on some streets.
More information about the Central Subway project can be found at www.centralsubwaysf.com.