Here's a mental exercise: Think of the rain that falls on your head as if it were continuing to fall through the soil beneath your feet. That's how it's supposed to work. Rain falls fast through the air, hits the earth, then falls slowly through the soil until it reaches a level of rock beneath the soil, where it pools and is stored.
The lion's share of urban flooding takes place because we have sealed off the surface of the earth with concrete and rooftops. Rain runs off the land instead of soaking into it.
In the early 1980s before most of the phenomenal horizon-to-horizon urban sprawl that you see coming into Dallas on a plane, the U.S. Army Corps of Engineers figured out that people in the Dallas area were sealing off the earth faster than anybody could ever control with engineering.
Flood-works are mainly two things: reservoirs to store water that can't get into the soil, and levees to prevent rising water in a creek or river from flooding the area around it.
The Corps wound up threatening to take Dallas and several surrounding suburban communities to court to force them to stop sealing off all of the absorbent soil in the region creating a flood control nightmare no one would ever be able to get ahead of.
The out-of-court settlement reached by the Corps and the communities has been a total failure. The only reason we didn't realize it sooner was that up until this year we have been in a period of prolonged drought. What this year's heavy rains show us is that we are well on our way to the nightmare.
On June 25 the Corps gave me answers to a series of questions I had sent them dealing with the now 30-year-old out-of-court settlement on regional rainwater runoff. In their answers, the Corps told me that in these three decades of incredible urban sprawl in the watershed no one has been keeping track of overall development and runoff.
The out-of-court settlement created something called the “Corridor Development Certificate” or CDC process “to prevent increases in water levels and decreases in valley storage (the volume of rain that can fall without causing flooding).” Even though the Corps tried in the 1980s to make the CDC process broadly regional — since rain tends to be broadly regional — the Corps told me two weeks ago that the CDC process actually applies only to a narrow band of territory along the river, not the whole watershed:
“The CDC has no control over any potential changes in the rate at which runoff from other areas of the watershed reaches the Trinity,” the Corps said.
Wait. That's big news. For 30 years, the public has been given the impression that the Corps and local communities had signed a deal that limited runoff into the Trinity River. Now the Corps is saying the deal only covered water that comes from close to the river.
So what about water that comes from outside that band but nevertheless runs downhill all the way to the river? It's an important question, because we've paved everything from here to East Jesus, way beyond the area agreed upon in the 1980s. Who controls water from outside that area?
Nobody special. The Corps told me: “That leaves the vast remainder of the overall Trinity watershed up to the local governments and their ordinances for development permits to limit the effects of impervious surfaces created when projects are built within their jurisdiction.
“Some local governments have ordinances in place that attempt to limit the negative runoff effects of developments,” they said.
Let me guess. Some do not? So it's voluntary? Hit and miss? Like we think all those helter-skelter suburbs upriver from Dallas have been worrying a whole lot about sending too much water our way by allowing too much development? The response of the Corps was pretty clear. As far as the whole watershed is concerned, it's not their job. It's not anybody's job.
Let me just put it this way: fFood control in this whole region is out of control. No single entity even pays attention to it, let alone takes responsibility for planning and designing it. And the reason for that is obvious if we stop to think about it.
Whoever takes real responsibility for flood control winds up having to impose all sorts of development rules and regulations on Dallas but also on its bumptious suburban neighbors. And who wants that job? Nobody. So it wasn't done. Now as we have seen this spring, Mother Nature is going to do it for us by kicking our asses until we get our act together and get it done.
Dallas City Council member Philip Kingston is proposing that the city of Dallas halt all further spending on its Trinity River flood control and highway-building project and consider spending whatever it has left in the kitty for that project on flood control instead. He told me Wednesday that his plan would call for a region-wide study to determine what the current flood control plan is and what the implementation has been.
Kingston said some of his thinking was inspired by a recent column of mine in which I pointed out that the current plan is guaranteed to make flooding issues even worse in the future than they have been this spring by building new bottlenecks in the river. And he is also concerned about the overall design of the plan even beyond those questions.
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Yeah. Exactly. What is the plan? Does anybody even know?
Think about this. In its answers to me, the Corps was telling me that overall control of runoff, which is overall control of flooding, is in the hands of local communities, which may or may not be making any attempt to do anything about it.
Not to be an urban snob or anything, but some of the high-growth local communities north of Dallas are run with all the constraint and wisdom of 19th century California gold-rush towns. And we're depending on them to mind the store on flood control? What are we, fools?
Kingston is proposing a measure that is more than common sense. At some point flood control is basic life-and-death survival for the city and the region. He wants us to stop plunging ahead blindly and see where we stand. How can that be wrong? It's worth at least talking about, is it not?