The Anadromous Strain

Always against the stream

Paul Sharke, Senior Technical Editor -- Design News, October 24, 2005

It was author John McPhee that I first learned the word anadromous. It describes salmon, shad, and other fish who swim uphill from salt to fresh water to breed. A writer would appreciate McPhee's applying it in a completely different context, to that of ships entering the Mississippi River from the Gulf of Mexico. Theirs was a problem of "anadromous navigation," he wrote in his 1989 book The Control of Nature.

The trouble was that the river had always deposited silt at the river delta. "Southern Louisiana," McPhee writes, "is a very large lump of mountain butter." It took the imagination and personal funds of an engineer by the name of James Eads to ultimately solve the problem. His solution? Two parallel jetties that forced the current of the river to speed up and sweep out a channel to the sea.

The recent hurricane there had me thinking of this book. The New Yorker magazine, where McPhee's first essay in the volume, "Atchafalaya," originally ran, recently reprinted the story here http://rbi.ims.ca/4399-532 so you don't have to go to your library to pick it up.

McPhee describes the legacy system of levees and control gates that keep the Mississippi River in place. His story perfectly relates the idea that engineers seldom get a clean screen to start from. Designs invariably begin where previous ones have left off.

Even mechanical engineer A. Baldwin Wood, whose low lift screw pumps would take over the task of keeping New Orleans dry, had to convince the city that his pump was a proper replacement for the ones already in place. Eventually, he did, as these documents describe http://rbi.ims.ca/4399-533, http://rbi.ims.ca/4399-534.

Put it this way: New Orleans and the Mississippi have long depended on engineering for their survival. If it wasn't for engineering, the river would have probably been captured already by the steeper Atchafalaya. And without the river running by it, New Orleans would "turn into New Gomorrah," McPhee tell us.

Even after Katrina, it was the engineers—not the politicians, reporters, or lawyers working at Blame Co.—that restored the operation of the city by restarting the pumps, as this New York Times article points out. http://rbi.ims.ca/4399-535 (registration required, or try www.bugmenot.com).

This satellite image makes the devastation more visible than mere words ever could. http://rbi.ims.ca/4399-536. Ours is a hostile planet. Engineering makes it a little more habitable.

As I write this, yet another hurricane prepares to take a swipe at the Gulf states. I can only imagine the blame humans are going to take for it. Global warming, the experts will tell us.

A professor at the University of Virginia says that, yes, humans have been altering the climate for thousands of years. If it wasn't for the earth's warming thanks to agriculture, he says, we'd have long ago plunged into another ice age. William Rudimann published his thoughts in Scientific American just last March http://rbi.ims.ca/4399-537 and you can read more about him here http://rbi.ims.ca/4399-538.

Maybe we've actually stabilized the planet's climate, as we have the rambling of the mighty Mississippi, all because humans have a penchant for swimming upstream.

Reach Paul at paul.sharke@reedbusiness.com.

« Back | Print