Who knew sand flowed under the Trinity? Everybody but the folks building bridges there.
Public officials are saying things now about the Trinity River in downtown Dallas that make no sense, are impossible to believe and may even be sort of crazy.
Here's the basic: The whole multibillion-dollar Trinity River project, Dallas' Big Dig, is on hold and in trouble because the U.S. Army Corps of Engineers say they have "discovered" sand in the Trinity River bottoms.
The sand, they say, might destabilize the levee system that protects downtown from flooding. They have halted work, although they deny it, on a new bridge over the river, because of the sand.
They say they didn't know.
I'm not sure I can even express how insane that is. It's like going to the beach and saying you discovered sand. Had to cancel the whole picnic.
The Trinity River bottoms are nothing but sand. Everyone has always known that. Always.
French utopians knew it in 1855. That's not a joke. It's a fact. In 1855 several hundred French utopians arrived on the west bank of the Trinity River in what is now Dallas, where they established a short-lived colony called La Reunion. One of them, a scientist named Emil Remond, wrote home saying the area would be ideal for brick-making because of the huge amounts of sand in the river bottom.
In 1918 Ellis W. Shuler, a founding faculty member at SMU, wrote a book on the geology of Dallas County saying that the huge sand and gravel deposits along the Trinity River made the region ideal for the manufacturing of cement.
And guess what? Sand and gravel mining along the Trinity River eventually created such a large industry that an area just three miles north of the La Reunion lands became known as "Cement City." Could just as easily have been called "Sand City."
Something's just missing here. Something is not being told to us.
The Corps of Engineers revealed in early April they had ordered a halt to basic construction of the first Calatrava suspension bridge over the Trinity River at the western terminus of the Woodall Rodgers Freeway, after some heavy construction equipment started wobbling around on what turned out to be quicksand.
More recently the Corps ordered the city to carry out a 20-month, $29 million project of core sampling and analysis along the 30-mile Dallas floodway system, citing as one of the reasons the recent discovery of sand near and under the levees.
My colleague Sam Merten and I have both asked the Corps on multiple occasions how it could have approved construction of the Calatrava bridge without knowing about the sand. Kevin Craig, manager of the Trinity River project for the Corps, told me the Corps didn't know about the sand until one very bad day a year ago when a drilling rig boring a 54-inch diameter shaft 90 feet down to bedrock ran into a subterranean layer of flowing sand—sand charged with underground water.
When Merten asked Craig a similar question, Craig said, "We didn't have all the geotechnical data. We approved that with the understanding that we would have geotechnical people on site as they were drilling, and that's where we really found the sand."
No. No. First of all, you don't test the soil by launching the full project—a bridge slated to cost at least $115 million—and then watching to see if it works out. Second of all, the French utopians. Third of all, the Corps did know.
Of course they knew. They're the U.S. Army Corps of Engineers. Look at me. This is serious. In the big report the Corps released April 3 revealing that the Dallas levee system is all screwed up, they referenced a document in the footnotes called, "Seepage Investigation, blah blah blah" dated 1953. I asked for a copy. It took forever. I got a copy.
At the back of the report is a map of the area right where the Calatrava bridge is being built and a log of test borings that the Corps made in July 1952, before rebuilding the Dallas levees. At almost the exact point where the Calatrava bridge is being built now, the log shows a layer of sand beginning five feet beneath the surface of the ground and extending down five more feet in depth.
On top, you have a layer of clay—a cap. Water can't flow through clay. But beneath the clay is sand. Water can move through sand.
This is more than you ever wanted to know about sand, but I have been talking to engineers about it and doing some reading. There are two Trinity Rivers out there—the one we see and a more ancient Trinity, the grandfather of the one we can see, that flows beneath the surface through what are called "water sands."
If you do something radical to change the water pressure in the water sands, like drill a big hole, water will flow through the sand toward the hole you have drilled.
Everybody knows that. I always have difficulty getting construction industry people to talk to me on the record about this project because they don't want to be black-balled from future government projects. But anyone who has done construction anywhere near the Trinity River knows that sand, water sand, flowing sand and collapsing pier shafts are common pitfalls.
The pitfalls are especially tricky, however, when you get anywhere close to a levee, especially in flood conditions. If you have done anything to create an open channel between the underground river and the one above the surface, then the underground water, pressurized by the flood, will start ripping around, carving out caverns in the clay above it and even shooting up out of the ground where it can find a weak spot in the clay cap.
That's called a sand boil. It can take down a levee in hours. It's serious business, and it's what they are worried about.
At a city council committee briefing last week, council member Angela Hunt asked the city manager's staff, "Is there a reason we did not undertake a geotechnical analysis before now?
"I guess what I'm just curious about," she said, "is that we discovered recently that there is sand in some parts of the levees that concerns us, and I'm kind of wondering why..."
Assistant City Manager Ramon Miguez cut her off right there: "I beg to differ with that, Miss Hunt," he said. "We have known there was sand. There is sand that was discovered there 50-60 years ago.
"There is now a greater level of concern with regards to that sand than there existed 50-60 years ago," he said. "The sand has always been there."
"So we've known about the sand," Hunt said. "It's just that we're more concerned about it?"
"Yes," he said. "That would be a more accurate depiction of what's happened here."
Well, maybe. The Corps says they didn't have the information. I asked the Texas Department of Transportation. The bridge is their project.
TxDOT spokesman Tony Hartzel told me, "While this is a TxDOT contract, the city of Dallas designed the bridge and therefore obtained the required permits from the U.S. Army Corps of Engineers. The Corps approved the permits for the project after the city met all requirements at the time."
The city told me they did have geotechnical data for the area under the bridge, but it wasn't data that had to do with levees.
Look, it's about drilling holes in the ground and seeing what kind of dirt comes out. In this case, obviously a whole bunch of sand would have come out because there's a whole bunch of sand down there. The French utopians could have told you that.
It does not add up.
I don't believe that Corps officials or city or state or federal highway officials are lying to us, exactly, about what has gone wrong with the Trinity River Project. But they are trying really hard not to tell us the full story.
Private parties have poured tens of millions of dollars into the Calatrava signature bridge project. One of those persons sat next to me in the very front row of folding chairs at the mayor's recent press conference on the Trinity River project. Before I recognized her, I thought, "Wow, I've never seen bling like that on a reporter before, even Laura Miller."
Then I recognized her and noticed the very intense attention she was paying when the mayor talked about the bridge. Sure. She probably wants to know if she threw her money away.
The mayor and other officials are insisting that work is "moving forward" on the first bridge. On May 5, when Sam Merten asked Craig, the Corps project manager, how that could be true, Craig said, "I guess it's the definition of moving forward" and then went on to say they're investigating to see if they can move forward.
I call that not moving forward.
Just think if they can't finish it. Think how the lady in the bling will feel. Her family's money will be down a rat hole.
There's a lot of tension over this thing and a whole lot of utterly loopy evasion going on, topped off by Mayor Tom Leppert's Through the Looking Glass press conference last week to tell everybody how splendidly things are moving along.
Not. Moving. Along. Dead in the water, or should I say sand?
Hey, I know the subject of water sands is not an intriguing dinner table topic for everybody the way it is for me. You know how I can tell? When my wife and I go out to dinner, people trip over themselves trying to sit next to her, not me. Well, and she knows about gardening, so it could be that too.
But I can tell you this much: If your instincts tell you that none of this Trinity stuff makes any sense lately and it must be screwed up as a junkyard...
Trust your instincts.
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