As the forecast for Hurricane Sandy started to show potential for a 13-foot storm surge into the New York harbor a call was placed to the Rock Island District to tap into unwatering expertise.
"Rock Island has an unwatering reputation," said Roger Less, chief, Design Branch. "Any time there is flooding or a need for pumping, our name seems to come up."
Hurricane Sandy made landfall during the evening hours of Monday, Oct. 29 – that morning Rock Island District was already assembling a team of experts at the request of the New York District.
The initial team was comprised of Roger Perk, assistant chief, Programs and Project Management Division; John Behrens, mechanical engineer; Jim Bartek, chief, General Engineering Section; and Less. As they began to make travel arrangements, it became apparent that traveling via commercial air was going to delay the team’s arrival, so the Mississippi Valley Division’s G3 took to the skies delivering them to New York.
As the storm hit, a formal mission assignment for technical assistance from the Federal Emergency Management Agency arrived; with the mission growing even larger as the initial team was in the air to New York.
"We arrived to see a state police escort awaiting us," said Less. "I don’t think the urgency of Rock Island’s support to the mission really hit us until then – especially at speeds up to 90 mph as we traveled into the city."
The escort took them right into Brooklyn delivering them to their hotel late Tuesday afternoon and the team quickly got to work.
The Deputy Commander of the New York District, Lt. Col. Mike Clancy, met with them at 6 p.m. and gave them a six-hour tour of Lower Manhattan showing them the areas of concern including the World Trade Center construction site.
"We got our first look at the city via flashlight. It was then that we confirmed that we were dealing with millions of gallons of water rather than billions," said Less.
The Districts reputation for unwatering stems mainly from Hurricane Katrina when they unwatered an estimated 250 billion gallons of water in less than two months from the Greater New Orleans Metro Area. They have since deployed to New Orleans in support of Hurricane Rita, Gustav and most recently Hurricane Isaac. The District also received a FEMA mission during 2008 along the Upper Mississippi River and in 2011 on the Missouri River in support of the record flooding.
"A lot of people have asked about what the differences were between unwatering New York City versus New Orleans," said Less. "A few key ones - there were no breaches allowing water to return to the city – we were only dealing with trapped water. Two, no search and recovery was needed. The New York City Transit Officials closed the tunnels prior to hurricane landfall. And third, we were dealing with millions of gallons instead of billions. Now, that’s not to say that New York City didn’t have its challenges….remember we were in New York City where mass transit is the primary means of transportation and the presidential election was days away."
During the late night recon, the team started to formulate a plan. The team had also expanded with the ramp-up of the mission. In addition to the original four, more people arrived on Wednesday including Al Lee, Regional Business Director for the Mississippi Valley Division, to head up the mission. Col. Mark Deschenes, District commander and Denny Lundberg, chief, Engineering and Construction, also arrived to provide Command and Control – taking some of the pressure off the New York District.
In total, ten people from the Rock Island District supported the unwatering mission following Hurricane Sandy in addition to assigned New York District staff.
The first day was spent understanding the lay of the ground (tunnels in this case) and finding and meeting with the key people they needed to coordinate with.
"Finding a set of maps that showed us everything was challenging not to mention finding consistent names for the tunnels," said Less.
Prior to the storm hitting, the New York District had arranged for a Deployable Tactical Operations System (DTOS) to be staged and ready for use. The mobile "office in a box" complete with computer capabilities, communication systems, network access and office space, was delivered to Battery Park on Wednesday and served as the team’s headquarters.
The unwatering team was assigned ten sites. The next hurdle was identifying the type of pumping assets that were required to remove the water as efficiently as possible and where they were going to come from.
"We were dealing with confined spaces which required smaller pumps with flexible hoses that could go up stairs and around corners," said Less.
Donjon Marine, a salvage contractor for the Navy, was identified and within a day had mobilized, delivered equipment and began pumping operations.
In most of the locations, pumps and hoses were lowered down utility and ventilation shafts. The water was then pumped back into the harbor either directly or through existing storm drains.
"We had to balance pumping water into the storm drains. If we pumped too much, it would overload the storm drains and cause additional flooding," said Less.
Another concern was the infrastructure itself.
"If you draw the water down too fast, the water on the other side of the tunnel walls and structures doesn’t have time to gravity drain at the same rate, this can collapse a wall and create further damages," said Tom Heinold, assistant chief, Operations Division, who was part of the team serving as a liaison between the Unwatering Team and the Corps’ Emergency Operations Center in Washington DC.
Each tunnel had unique challenges that the team worked through with the local and state authorities like the Mass Transit Authority and Port Authority. The team maximized the existing resources in their unwatering effort even reversing the flow through fire lines in one location to remove the trapped water. In another location, they used a two-stage pumping operation. After dropping equipment 100 feet down, they then had to go another mile horizontally with another set of pumps.
In all underground locations ventilation was a concern as the hurricane surge had flooded the existing ventilation equipment. The carbon monoxide levels were monitored carefully with those in direct contact wearing personal carbon monoxide detectors to ensure their safety. At times, pumping needed to be slowed down or stopped until auxiliary ventilation restored the air quality.
In total, 286 million gallons of saltwater was removed from New York City’s subways and tunnels in nine days. This heroic team effort brought together the professionalism and technical expertise of the Corps of Engineers in supporting communities during disasters.