Pittsburgh Councilman Doug Shields has introduced legislation demanding that PennDOT find a solution to the flooding that sometimes closes the "bathtub" on the Parkway East and disrupts life in the city.

The bathtub is the depressing (as in gloomy) 1,900-foot-long depressed (as in a trough) westbound section along the Monongahela River lip of the Golden Triangle.

When the river spills onto the road and fills the bathtub with water, as it did during Hurricane Frances, Hurricane Ivan and recent heavy rains locally, the parkway westbound is of no benefit to anyone without a boat. Drivers are forced to detour on Fort Pitt Boulevard in the heart of the city to get to the Fort Duquesne or Fort Pitt bridges and points beyond.

"Who was the rocket scientist that designed the bathtub?" Ron Biagiarelli, of West Mifflin, asked in an e-mail.

Shields' resolution asks PennDOT to "act immediately to resolve this matter with the appropriate solution, including but not limited to extending the height of the apparently too-low flood wall." When the Parkway East closes, he said, the city has to deploy extra police to handle the resulting traffic mess, partly because the road also serves as Interstate 376.

Even when the Parkway East is open, the city is a traffic mess every day. The city should act immediately to resolve this matter. And the ridiculously high parking tax, too.

Now some history.

When the Parkway East was planned in the late 1940s, the interstate highway system was in the talking stage. When the parkway was built in the early 1950s, it was a road to the suburbs, connecting to Business Route 22, west of Monroeville. It was never meant to carry today's volume of cars or 40-ton commercial trucks.

Engineers located the highway along the Monongahela River at the edge of Downtown because there was nowhere else to put it. The city asked the state to shoehorn the westbound lanes, just above river level, between the Mon Wharf and the westbound lanes of bifurcated Fort Pitt Boulevard and to build the high concrete walls that support the boulevard.

In 1980, while he was engineer in charge of the PennDOT District 11 office, Roger Carrier conceived and built the first flood wall, only a couple of feet tall. He also ordered today's stronger, taller (6 feet) wall as part of Parkway East reconstruction in the mid-1980s.

Now some facts.

When the Mon River hits 18 feet, water is even with the edge of the Mon Wharf. At 19 feet, it laps at the foot of the Parkway East floodwall. At 25 feet, or flood stage, the water spills over the wall and into the bathtub.

I don't mean to confuse you, but when the water reaches 21 feet, PennDOT's gravity drain system no longer works. PennDOT closes valves to prevent the water from backing up through the drains and flooding the highway. Any water that leaks through, plus any rainwater that accumulates on the road, flows into a basin at a low point, where two automatically activated sump pumps send it back over the wall and into the river.

When the water level gets to 25 feet and comes over the wall, 1,000 pumps wouldn't save the parkway.

So what about Shields' demand that PennDOT build a higher wall?

Sorry, but PennDOT thought of that years ago, when planning took place for reconstruction of the parkway in the Downtown area.

Engineers determined that 6 feet was as high as they could build the wall without having the bathtub float. What?

That's correct, PennDOT District 11 Executive Karl Ishman and Deputy Executive for Maintenance Andy Kost explained last week.

"PennDOT didn't arbitrarily decide the height of the flood wall," Ishman said. "They measured how much hydrostatic pressure, or water pressure in the ground, that it would take to make the section float like a barge."

While the department realizes the disruption caused when the parkway closes, Kost said the wall had worked pretty well despite the bathtub being filled with water three times over the past five months.

The record bears him out. The last time the parkway had to be closed because of flooding was Nov. 20, 2003. Before that, it was in 1996.

Meanwhile, the wall has enabled the parkway to remain open on dozens of occasions when the Mon Wharf was flooded, so it has been a traffic savior.

There's one more flood-prone section in the same area. It's the lowest part of the new "Interstate Connector" that dips close to Mon Wharf level as it carries traffic from the Fort Duquesne Bridge to the elevated section of the Parkway East toward Monroeville.

That ramp, threaded among other ramps at a corner of Point State Park, also had to be closed two weeks ago because of high water.

PennDOT chose not to proceed with a $750,000 option to install pumps similar to those in the parkway bathtub for such a short distance and, because of the elevation, it's less prone to be flooded. Instead, PennDOT installed new connections in the drainage system and check valves to prevent any backflow.

Even if PennDOT had put in the pumps, the river would have flooded and closed the connector this time.

Next question, Mr. Ishman and Mr. Kost.

If you can't build a higher flood wall, why not raise the road?

"The new minimum height clearance for interstates is 17 feet, 6 inches," Ishman said. "We don't have the room to do that" in the spaghetti of ramps, roads and overpasses between Grant Street and the Fort Pitt Bridge.

Now you know the story.

Elsewhere. Officials in Seattle have reached agreement on plans for a 1.7-mile, $225 million light-rail extension to Sea-Tac Airport.

Believe it! PennDOT budgeted more than $194 million and stockpiled more than 500,000 tons of road salt preparing for this winter.

Plate du jour. While driving on McKnight Road, Kay Mentzer, of the North Hills, spotted the Pennsylvania personalized license plate U LOOZ. Is there A WINNER out there?

First Published: January 23, 2005, 5:00 a.m.