In fact, here's a press release from the State Comptroller from last year, projecting a $4.5 billion surplus for NYC in 2006. That would buy a lot of duct tape to fix some of those leaky pipes.
"New York City already has a surplus of $4.5 billion for fiscal 2006, and the Mayor is prudently proposing to set aside $1.2 billion to pay for future costs, leaving a net surplus of $3.3 billion, according to a report issued today by State Comptroller Alan G. Hevesi. In addition, the Comptroller’s Office projects that higher than expected revenues could add another $500 million by the time the year ends on June 30, making the total potential surplus $5 billion. Although the City still faces budget risks, the FY 2007 budget is currently balanced and the FY 2008 budget gap is manageable."
http://www.osc.state.ny.us/press/releases/feb06/022306a.htm