Updated (Tuesday, 12:30 a.m.): According to reports from the MTA, water entered the under-river tubes connecting Manhattan to Brooklyn as the Sandy storm surge overtook the city as well as the 1 train tunnel between Chambers St. and South Ferry.

We can confirm that there has been water infiltration into the New York City Subway tunnels under the East River. We cannot confirm a depth. — MTA (@MTAInsider) October 30, 2012

Additionally, Ted Mann of The Wall Street Journal reported that water had entered all five subway tubes that run between Lower Manhattan and Brooklyn as well as the 7 train’s Steinway Tubes. Various stations and tunnels have flooded as well.

Earlier in the day, the MTA offered up some information on salt water interacting with the subway system. Even after removal, salt remains on sufaces, and the salte can accelerate corrosion. Any surface impacted by flooding has to be cleaned or replaced. It’s difficult to estimate the time required to clear a flooded tunnel and bring equipment and stations back into service. The timeline depends upon the height of the storm sturge, its speed and the extent of flooding. Generally, the longer a tunnel is flooded, the longer it will take to return to service.

According to the MTA, up to four feet of water entered a Lower Manhattan station as well earlier on Monday. Kevin Ortiz, Transit spokesman speaking on CBS 2, stressed that it could take anywhere from 14 hours to more than four days to restore service if the tunnels are flooded. Once salt water hits switches and signals, all bets are off for any quick service restoration until the system can be inspected and repaired.

Speaking with The Wall Street Journal, MTA Chairman Joe Lhota said the extent of flooding is “quite serious.” Despite earlier rumors that suggested we could go a week without subway service, Lhota cautioned against such a set timeline. “We’re trying to get an estimate of what if anything we’re dealing with here,” he said.

Still, one MTA source told Ted Mann that “it could be a long time” until full service is restored. No official estimates will be released until the extent of the flooding and damage can be determined, and the MTA repeatedly downplayed early rumors of a week-long service outage:

Rumors are wrong. The MTA cannot assess damage until Tuesday. It is way too early for a subway reopening timetable. — MTA (@MTAInsider) October 30, 2012

Here’s what Adam Lisberg, the authority’s head spokesman, said via Twitter:

Entire Hudson River is flowing into Ground Zero, Carey Tunnel and subways. It sounds like Niagara Falls. Too dark for pic. — Adam Lisberg (@adamlisberg) October 30, 2012

Meanwhile, speaking on WNYC, transit reporter Andrea Bernstein said that Bowling Green is the station under water. Pumps are operating on generators and are independent of the power outages currently plaguing Manhattan south of 39th Street. It’s unclear how the rest of the system is impacted right now. I’ll keep updating this post as more information comes in (and, with the lights flickering, as long as I have power).