Loop basements will remain flooded for at least 15 more days, mainly because city and federal officials Thursday backed away from a proposal to drain downtown basements through a jury-rigged connection to the Deep Tunnel storm water sewer system.
The U.S. Army Corps of Engineers official now in charge of the flood recovery effort, Gen. Russell Fuhrman, said it would be too dangerous to remove the water more quickly because it would increase water pressure that could damage building foundations and the nearly century-old, 60-mile freight tunnel system.
Mayor Richard Daley told a meeting of business leaders Thursday that the quick-drain plan to the Deep Tunnel system, proposed by the Metropolitan Water Reclamation District, was no longer being given serious consideration.
Water district officials had suggested Monday that they could drain downtown in four or five days by installing a makeshift connection between the freight tunnels and the Deep Tunnel system. And, for two days, they were drilling holes in an effort to make that connection. But work was halted Wednesday under orders from the city.
Fuhrman estimated that 12 days would be needed to pump or drain the water out safely.
”The water is exerting a tremendous pressure on the walls of the tunnel and the building foundations. If you take it out too quickly, the walls could cave in,” said Fuhrman, adding that it`s premature to discuss how it`s going to be done.
Daley`s chief of staff, David Mosena, said, however, that huge, high-powered pumps may be employed.
But the work to get the water out of the basements can`t even begin until the breach in the freight tunnel under the Chicago River at Kinzie Street-the cause of the underground flood in the Loop-is sealed off.
Fuhrman said his ”best guess” was that the work to isolate that broken section will by finished by late Sunday.
But John Kenny, vice president of Wheeling-based Kenny Construction Co., which is carrying out the repair work, said, ”I`m not so sure I`m as optimistic as that.”
He had good reason for caution. On Thursday, efforts to plug the broken section were hampered by heavy debris on the tunnel floor.
Sand, silt, concrete and at least one large chunk of clay loosened by the repair attempt were four feet deep in sections of the 7-foot-6-inch high tunnel, forcing work crews to abandon plans to use an inflatable thick-rubber balloon called a ”bladder” as a plug.
Instead, workers late Thursday prepared to pump cement down a shaft on the east bank of the river. One official said it was hoped that a cement wall could be created in the tunnel by daylight Friday. But another said the work could take 24 hours to complete.
The move to plug the tunnel on the east side of the river is part of an effort to isolate the broken section from the rest of the tunnel system under the Loop. In addition to that plug, two are planned for the west side of the river.
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The breach has to be isolated so that it doesn`t reopen and cause another underground flood of downtown. On Thursday, officials reported a ”very minimal” current in the flooded freight tunnel, possibly caused by the breach.
But the work to seal the breach has proved to be extraordinarily time-consuming.
On Wednesday, crews used one of two shafts drilled on the east side of the river to pour thousands of sandbags and tons of gravel down into the tunnel.
This formed a temporary blockage that reduced the water current in the tunnel to near zero, permitting divers to go down the second shaft, 20 feet to the west, and safely investigate the tunnel.
The sandbag-gravel wall in the tunnel, however, wasn`t a sufficiently secure plug, so Kenny and other officials overseeing the repair effort had planned two other blockages.
One would have been constructed west of the shaft used by the divers. This would have been made up of the inflated rubber bladder, buttressed by 40- and 50-pound sandbags.
The second would have been a pile of concrete that would have been poured down the divers` shaft in between the bladder and the original sandbag-gravel wall.
The debris on the tunnel floor frustrated those plans. And among that debris was a giant 400-pound piece of clay, about four feet tall, that had fallen into the tunnel when the divers` shaft was initially drilled.
On Thursday night, a diver spent 1 1/2 hours trying to break up the clay, as part of an effort to clean up the tunnel floor.
Most of the time, the cleanup was done using pumps that created a vacuum and pulled water and debris up through an 8-inch-wide pipe and then dumped it back in the river away from the broken tunnel.
But that effort was carried out blind.
Even when a diver was in the shaft and down near the top of the tunnel, he couldn`t see where he was directing the vacuum pipe. And the divers weren`t permitted to be in the tunnel while the vacuuming was occurring for safety reasons.
All that could be done was to put the nozzle of the pipe in one spot and suck up whatever was there, and then move it to another spot and repeat the process, said John Chiangi, president of Brand Marine and Utility Services of Essex, Conn., the diving firm operating at the shaft Thursday.
”We`re being overly cautious because of the environment we are in,” he said. ”If the diver was out in a pond, he would stand right by the nozzle. But, because of the uncertainty about the tunnel, we`re moving him away from the nozzle.
”This is taking longer than normal because of the risks.”
Jerry Kenny, president of Kenny Construction and brother of John Kenny, said the heavy debris made it impossible to use the bladder in the east side tunnel because the bladder wouldn`t have been able to adequately block the tunnel once it was inflated with water.
In addition, the debris created such cramped quarters in the tunnel that a diver would have been hard-pressed to try to set up the 400-pound, 7-foot-long uninflated bladder.
So the decision was made to skip the bladder and go forward with the plan to pump concrete down the divers` shaft.
But even then, further vacuuming of the tunnel floor immediately under the divers` shaft was necessary so that the cement could form a good grip on the sides of the horseshoe-shaped tunnel.
Kenny declined to say how long that work might take, but he noted that, like everything in the repair effort, it would be a slow process because officials needed to be sure the cement was hardening adequately.
The result of the work is expected to be a pyramid-shape mound of cement that will be a more permanent block of that section of the tunnel than the sandbag-gravel wall.
”We`ll know when we fill it because it`ll start coming up the shaft,”
said John Kenny.
To create a third blockage on the east side, officials said another smaller shaft may be drilled between the two now there. Then, cement or grout would be pumped down the new shaft to create another mound that would harden into a third wall against the water.
Officials hope to begin working on the two plugs on the west side of the river on Friday.
Two plugs are needed because the freight tunnel that crosses the river splits into a Y on the west side, with one arm heading north and one going south.
”We`re hoping to God everything on the west side is clean,” said John Kenny.
If that`s so, the work to create the plugs will be able to go forward more smoothly, and it will probably be possible to use the inflatable bladders, officials said.
Originally, officials had planned to do one west side shaft and then the second. But, to speed the process up, both are going to be worked on simultaneously.
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Daley and U.S. Rep. Dan Rostenkowski (D-Ill.), chairman of the House Ways and Means Committee, visited the work at the river and Kinzie Street around midday. At one point, they talked to diver Shane Albertson, 27, of West Virginia, as he was preparing for a dive. Albertson was lowered in the open-sided cage to the tunnel floor to check on progress of the vacuuming.
Meanwhile, Commonwealth Edison said that 11 buildings remained without full power because of severe flooding on the premises.
In addition, Michael Kelly, an Edison spokesman, said the utility began a ”planned outage” which took seven buildings off line so that a transformer now submerged in the basement of Marshall Field`s can be disconnected.
The outage was started at 8 p.m. Thursday and could continue until 8 p.m. Friday. The buildings affected are the Prudential Building, 140 E. Randolph St.; 111 E. Wacker Drive, also known as 1 Illinois Center; 78 E. Washington St., which is the city`s Cultural Center; 333 N. Michigan Ave.; 119 N. State St., which is Marshall Field`s; 225 N. State St., which is the United of America Building and is also known as 1 E. Wacker Drive; and 35 E. Wacker Drive.
Kelly said the transformer is a submersible unit, but it is not designed for extensive submersion.
”This water is not going anywhere. There is no optimism they can get rid of that water any time soon. Should it (the transformer) blow because of the extended submersion, we could have extended an unplanned outage affecting all seven of those buildings since they are tied together in one network,” Kelly said.