Termination Shock

Willem was supposed to rendezvous with the others near Houston. He could have done this directly by getting on Interstate 10 and driving due west for three hundred and fifty miles. But now that he was so close he couldn’t not go into New Orleans. It had been his first big city. Chicago had always been too far from their suburban home, so enormous and brutal and forbidding. But on the family’s vacation trips to Louisiana, teenaged Willem, bored out of his mind, had learned how to take public transit into New Orleans, how to find the French Quarter, and, in particular, how to find the gay part of it, which was ancient and well-established. On the whole his experiences there had been pretty tame, but later, when he had ventured into the night life of Amsterdam, he had been able to do so sure-footedly.

Later in life, he’d got to know people there. Very different people: ones he’d met at conferences where inhabitants of low-lying places came together to obsess about sea level. They’d be surprised if a personal representative of the Queen of the Netherlands just turned up without any advance notice. But he had a perfect alibi: he had gone to check in on his father. So before pulling out of the driveway he sent a message to Hugh St. Vincent, a department head at Tulane, announcing his presence in the area, apologizing for the late notice, and asking if there was anything new worth seeing. Hugh would understand that Willem was not asking for recommendations on where to eat beignets or listen to jazz.

Then Willem pointed his truck toward New Orleans. He passed up an opportunity to jump on an interstate, preferring an old two-laner. The landscape was flat by American standards, but not by Dutch. The usual American roadside scene of convenience stores, mobile home parks, and equipment depots interspersed with wooded areas. On the map it looked like a sponge, with water coming practically up to the road, but if you didn’t know that, it would just look like normal dry land, exuberantly green, with a lot of trees. His practiced eye noted that the bed of the road was elevated a couple of feet above the surrounding earth.

A few miles short of New Orleans, he came to the Bonnet Carré Spillway, which was not much to look at but was probably at the top of the list of must-see attractions for the climate change tourist. Here all the roads and railways had been funneled into the five-mile-thick isthmus separating the Mississippi’s left bank from Lake Pontchartrain. Running athwart all that was a mile-wide sluice connecting the two. Or rather it was capable of doing so when it was opened. A hundred years ago they’d constructed a spillway barring its Mississippi end. This was a palisade consisting of seven thousand massive vertical timbers arranged vertically in a frame of concrete and steel, deeply anchored in the river’s bank. To one side, these were scoured by the flow of the Mississippi. To the other side was what passed for dry land: a wetland stretching from there to the lake, striped with drainage ditches and speckled with puddles and ponds, passing beneath elevated highways and railroads.

The summed pressure of the Mississippi water on the vast palisade must have been huge, but the pressure on any one single timber—they were about the size of railroad ties—was modest enough that it could be pulled up to create a slit that would let some water through. Rail-mounted cranes moved along the top of the frame pulling the timbers up or pushing them down to regulate the volume of flow diverted from the river into the sluice and thence to Lake Pontchartrain, which had its own outlet to the Gulf of Mexico.

They’d built all this after the terrible flood of 1927, which had inspired the blues song “When the Levee Breaks.” It was intended as a safety valve, a bypass to be opened at rare moments of dire need, when heavy rains falling upstream—which was to say anywhere between the Rocky Mountains and the Alleghenies—had swollen the river to the point where it was threatening to overtop or burst through the levees and inundate New Orleans. Several times in the ensuing ninety years it had been used just as planned. But then in 2019 they’d been forced to leave it wide open for four months because of a wet winter. Other years since had not been quite as bad as that, but 2019 had inaugurated a new pattern, which was that the spillway was partially open more often than not.

For all its immensity, you could drive right over the Bonnet Carré Spillway and not take note of it. You’d see the water under the causeway, of course. But around here there was a lot of water.

The Mississippi was about seven Rhines. When this spillway was wide open, it diverted two and a half Rhines into the lake.