Posted by: chrismaser | June 18, 2011

OF FLOODPLAINS, DAMS, AND LEVEES

LEVEES—AN IGNORED LESSON IN “CONDUIT 101”

Conduits transport things from one place to another as well as concentrate the energy of that which they transport. By this I mean, given a constant volume of water, the force of it coming out of a hose increases with the decreasing diameter of the hose. Anyone who has ever turned a nozzle knows this as a technique used in “power washing” a sidewalk or the outside of a house prior to painting it.

The same dynamic applies to a broad river being suddenly confronted with a narrow canyon through which to flow. As the volume is constrained, the velocity increases. Here, the positive lesson from the restricting action of a conduit is used in narrowing a stream or river with a concrete structure to increase the water’s velocity and therefore its ability to spin turbines and convert the energy of flowing water into electrical power for human use.

On the other hand, I remember seeing a negative dynamic of constraining the volume water and increasing its velocity at work in a mountain village in eastern Slovakia. There the people had lined the stream flowing through their village with concrete because the recent, clear-cut logging had denuded hillsides and was causing frequent flooding, where heretofore the stream had rarely done so. The concrete confined the water into a narrower, smooth channel, as opposed to the one of cobbles and boulders in years past. The consequence of this action was far greater erosion of the stream’s channel beyond where the concrete ended than would otherwise have been the case. Moreover, the deleterious effects of such a symptomatic fix was obvious—the stream’s velocity was simply exported downstream, where it did much, unnecessary damage.

Conversely, a floodplain, as the name implies, is a relatively open expanse that frequently floods. These are areas wherein storm-swollen streams and rivers spread out, decentralizing the velocity of their currents by encountering friction caused by the increased surface area of their temporary bottoms, whereon much of the floodwater’s energy is dissipated—among other critical biophysical processes. I saw this phenomenon in 1967 while working in the Terai of Nepal, where the Trisuli River had a floodplain more than a mile wide. I watched it fill within two days during the beginning of the monsoon rains.

Although this principle of friction slowing velocity is well known and is the idea behind disk-breaks on automobiles and hand-breaks on bicycles and wheelchairs, as well as the design of the parachute, people refuse to accept it whenever they covet the land claimed seasonally by a river. But when we refuse to accept a lesson from Nature’s biophysical principles, it forms an intellectual blockage in our potential understanding of the principles that ultimately govern social-environmental sustainability. The inertia of “informed denial” is the usual procedure when the immediate, economic cost of rectifying a mistake is thought to be great, which is nothing less than passing the debt to some other generation. Informed denial, as a remedy, is based on the same level of consciousness of cause and effect that initiated the problem in the first place—a reaction to dealing with an uncomfortable situation, which can only compound the problem, instead of a carefully considered response that could remedy it.

I do not know if what I am about to relate is a unique problem with the U.S. Army Corps of Engineers, but whether it is or not, the refusal to accept the biophysical constraints of Nature is a global issue. The Army Corps of Engineers is one of the oldest, largest, and most unusual agencies in the U.S. federal government. As a bureaucracy of the executive branch that takes its marching orders from Congress, it is a military organization with an overwhelmingly civilian workforce. It is also an environmental regulator that is generally viewed as suspect by environmentalists because members of Congress often authorize projects to steer federal money to their districts, and the Corps frequently justifies them with questionable cost/benefit analyses, a process that has reconfigured—artificially engineered—the American landscape. After all, the Corps’ motto is “Essayons,” French for “let us try.” The motto indicates that, throughout its history, the Corps has seen Nature as an enemy to subjugate by equating engineering and control with success and social progress.

For instance, the Corps of Engineers designs and builds structures to control flooding and to improve navigation, but it also issues permits for the alteration of such bodies of water as streams, rivers, marshlands, and estuaries. Although the Corps leaders today speak of “working in harmony with nature,” the Corps still proudly mobilizes its “Annual Campaign Against the Mighty Mississippi.” This on-going battle caused Burton Kemp, a former Corps geologist in Mississippi, to say it is not surprising when the Corps takes a militaristic approach to the environment. “I’m afraid it’s not a Corps of Scientists. It’s not a Corps of Biologists,” he says with a sigh. “It’s a Corps of Engineers.”1

One aspect of the program conducted by the Army Corps of Engineers is the practice of “channel improvement” in streams and rivers. These “improvements” lead to a straightening of a stream’s channel and a change of its shape, which in turn destabilizes the channel. Destabilization of the channel causes downstream effects—erosion of the banks; alterations of the channel’s bed; degradation of the aesthetics; and frequently undesirable changes in the composition of the plants and animals that inhabit the stream. From these numerous “improvements,” each planned with its own, isolated rationale (product-oriented, symptomatic thinking), comes the next, larger-order magnitude of massive flooding when the constrained waters release their pent-up energy through a breech in the levees designed to imprison their flow.2

To better understand what is meant by the sudden release of pent-up energy, let’s go back to the floods in California during the winter of 1996-1997, when sixteen crews worked to shore up some of the 1,100 miles of levees in the Sacramento-San Joaquin Delta. In other areas, crews used sandbags and plastic sheets to shore up critical sections in the 6,000-mile network of levees in northern California.3

A dozen major breaks in the levees occurred along the San Joaquin, Mokelumne, and Consumnes rivers, and many other places were threatened because of the day-to-day pressure of the water. “It’s a race with Mother Nature, but right now we’re ahead,” said Captain Mark Bisbee of the state Forestry Department.4

That said, a levee failed on the San Joaquin River on January 10, 1997, sending work crews fleeing through dense fog as a ninety-foot gap opened and water began rushing into neighboring fields, where it swamped up to 5,000 acres. A break in a levee near Lathrop allowed the flooding of more than 25 square miles and damaged as many as 400 homes.5

Water from a ruptured levee on the Feather River, 100 miles northeast of San Francisco, flooded a farm. The farmer and his wife lost $300,000 worth of cattle. “The sheriff’s department just wouldn’t let us in,” said the farmer, “so 200 head died a slow death. It was gruesome.” Some of the farmer’s cattle were ensnared in ditches or fences; one cow, snagged on a small gate, had to be burned free with torches. The stench of the rotting animals was everywhere. Thus, floods gave way to fields of death across northern California, where hundreds of drowned cows, horses, and other farm animals—their bloated carcasses tangled in barbed wire or mired in ditches—lay strewn across the soggy landscape.6

Although major losses of farm machinery, barns, homes, and wells appeared to be the immediate headache for farmers (including the loss of livestock for some), others were concerned about the survival of their crops. While an estimated 150,000 acres of red winter wheat was likely damaged, wheat farmers were most worried about the potential loss of topsoil to erosion from the rushing water.

With at least three reservoirs nearing their capacities, California water officials said the danger from flooding was far from over as runoff from rain and melting snow continued to build. Because of the water released from dams, some rivers (such as the Stanislaus and San Joaquin) would continue bulging with runoff inside their eroding levees until February, well after the storm event had passed. “It’s unfortunate,” said Jeff Cohen, of the California Water Resources Department, “that there is damage downstream, but it’s the requirement [draining water from the reservoirs].” He added that the Corps requires water to be drained from reservoirs before they reach capacity.7

And what about today’s news (2011) of deep winter snows followed by continuous rain in the Midwest, which has caused severe flooding throughout the Missouri and Mississippi River Basins, where the same scenario is being played out once again because nothing was learned from history:

• May 15—The Floodgates are opened in Butte LaRose, Louisiana, sacrificing people’s homes to save even more homes down river.

• May 17—U.S. Corps of Engineers tries to corral the river at record flood level in Natchez, Mississippi.

• June 2—Residents of Minot, North Dakota, evacuated as waters of the Souris River rise. Thousands escape rising flood waters in Montana, North Dakota, South Dakota, Nebraska, and Iowa, which could last weeks.

•June 15—Residents of Hamburg, Iowa, race to build temporary levee to hold back floodwater released from dams.

•June 16—Missouri River floodwaters reach Hamburg, Iowa. Will temporary levees Hold?

•June 16—It’s “Hell or High Water” as small towns are flooded to save big cities along the swollen Mississippi.8

Mahatma Gandhi said it well when he wrote, “It is because we have at the present moment everybody claiming the right of conscience without going trough any discipline whatsoever that there is so much untruth being delivered to a bewildered world.”

With Gandhi’s statement in mind, you may be wondering where the people’s responsibility lies in these stories about flooding. It has to do with priority and people’s choices. In bygone times, people lived in Willamette Valley of Oregon, California’s Central Valley, and throughout the valleys of the Midwest, where they farmed the land in concert with the rivers, including the periodic floods, because they knew where the floodplain was and respected it. Despite the wisdom exhibited in time past, it has long been American tradition to wrest every useable acre from Nature, lest an acre be thought of as “unproductive”—hence the Bureau of Reclamation, which is really the “Bureau That Attempts To Subjugate Nature.”

If the rivers could be controlled and the flooding stopped, then more of the “unproductive” acres could be made to produce the commodities people want. So dams and levees were constructed. If they failed to produce the desired control, more dams and levees were built. In the end, however, they are proving no match for Nature, as the above stories illustrate. But there is something left unsaid by the stories; namely, it’s the choices people made that brought all this about.

Let’s look at just five possible choices people could have made prior to the California floods of 1996-1997: (1) do not live or farm in the floodplain; (2) farm in the floodplain without dams and levees and plan for, be prepared for, and accept the risk of periodic flooding in the fields; (3) live and farm in the floodplain without dams and levees and plan for, be prepared for, and accept the risk of periodic flooding; (4) live and farm in the floodplain with dams and levees in place, thinking the problem of flooding is solved, but move after a levee breaks once or twice; (5) live and farm defiantly in the floodplain with dams and levees in place, regardless of the dire consequences of periodic flooding.

All these choices represent different levels of self-imposed constraints—or the lack thereof—on one’s own behavior based on different perceived values for monetary gain and lifestyle. The choice that seems to have been generally accepted over time is the last one: live and farm defiantly in the floodplain regardless of consequences. This, then, becomes the primary social constraint or “fixed point” around which all human residential, rural, and commercial development is still made to revolve, despite the fact that sooner or later the rivers will remember their floodplains and reclaim them—at least temporarily and at tremendous financial and personal cost.

When their irresponsible risk-taking fails, people want the government (hence society at large) to rescue them, despite their having known the ill-advised risk of building in the floodplain with its inevitable consequences. But why should the people at large, through personal taxes paid to the government, be expected to bail out those individuals who make unwise choices based on ignorance and arrogance when they gamble for such high stakes, which they will inevitably lose? Do we, through our taxes, bail someone out of financial trouble when they lose heavily in a high-stakes game of craps in a casino in Las Vegas? Building in a floodplain and wagering in a game of craps are both forms of gambling, so what is the difference? Where is personal responsibility? How is one to learn responsibility if one does not have to accept the full measure of the consequences of their choices?

It was not always this way, according to Scott Faber, director of floodplain programs for American Rivers, based in Washington, D.C. According to Faber, “Floods may be acts of God, but flood losses are acts of hubris.”9 Predictable, natural events turn into “social disasters” when people try to control such things as the level of water in rivers with dams and levees to allow housing and commercial developments to “flood” the historic floodplains.

“At the turn of the century there was virtually no development in floodplains. Over the last 60 years, government programs have assumed responsibility for flood ‘control’ by building and repairing levees, providing relief, and subsidizing flood insurance. These programs actually put people in harm’s way by eliminating incentives for local communities to direct new development away from flood-prone areas.”10

Levees and dams create a false sense of security, which encourages people to build in flood-prone areas and thus increases the potential for personal catastrophe when a levee fails or a dam must be opened. Thus, thousands of flood-weary Midwesterners decided in 1993 to stop “playing chicken” with the Mississippi and Missouri rivers. They opted instead for a voluntary program that relocated more than 8,000 homes and businesses, even whole towns, onto the bluffs, so that thousands of people were literally high and dry when floodwaters returned in 1995.

As development continually encroaches on floodplains, however, the snowmelt and rainfall that was once absorbed slowly and naturally by the land now courses rapidly into rivers, which get higher and faster as they increase in size and flow toward centers of human population. An isolated decision to drain a wetland, clear-cut a forest, build a house, pave a parking lot, or put in a new street has little measurable effect on flooding, but the tyranny of thousands of tiny, unwise, seemingly unrelated decisions can result in social devastation, as a cumulative effect.

Rather than work together to solve regional problems (systems thinking), most communities and rural landowners simply pass the water downstream as fast as possible (symptomatic thinking). More dams and levees cannot eliminate human problems associated with flooding because dams and levees fostered the problem in the first place, and more of the same is hardly the cure. Periodic flooding, at times of mammoth proportions, is one of Nature’s non-negotiable constraints, especially during cool, wet periods in the weather cycle, which heretofore has been another of Nature’s non-negotiable constraints. Hence, a wise community will both recognize and bow with humility to Nature when Nature is clearly beyond human control.

Government agencies, which represent the majority will of the people in the Midwestern and Western United States at least, have not been interested in the long-term future of the landscape because the computed, but often unrealistic, cost-benefit ratio is on the side of utility.11 Clearly, we have yet to understand that a problem caused on one level of human consciousness cannot be fixed on the same level of consciousness

If we are willing to risk moving to a high level of consciousness, we can either prevent or repair much of the damage our shortsighted human activities cause—provided, that is, we put the biophysical principles governing Nature ahead of our short-term economic desires. Take, for example, the Snake River near Jackson, Wyoming, where engineers, people from the Jackson Hole Conservation Alliance, the Wyoming Department of Fish and Game, and local officials had planned in 1998 to return part of the Snake River to a more natural condition.

For nearly 40 years, levees that line about 23 miles of the Snake River near Jackson had entrained high water from the melting snows of spring in the Teton Mountains and allowed lavish homes to invade the cottonwood forest of the river’s floodplain. Although researchers had known for some time the ecological havoc wreaked by dams, only relatively recently have they begun to recognize the ecologically destructive nature of levees and their “free-form cousin” riprap, which are piles of rock and earth dumped by landowners along streams and rivers to guard against erosion. It is not surprising, therefore, that the 15-foot-high serpentine piles of rock created by the U.S. Army Corps of Engineers to protect farmers’ fields and hay meadows from flooding and erosion had caused serious and unexpected problems along one of the world’s most scenic stretches of river.

The river had for centuries been true to its rhythm of flooding and receding in a fluid motion that constantly redesigned its five or six channels or braids as it dissipated the energy of its floodwaters each spring. But when squeezed into one or two rigid channels, the upper Snake River has lost its ability to flood during the spring runoff. This loss increased the velocity of spring runoffs within the levee straitjacket, which in turn caused the raging spring torrents to destroy many of the large islands in the remaining channels, islands that were at one time occupied by willows and cottonwood trees. The luxuriant forests of cottonwood that once lined the river’s banks were fading into a past era for lack of young trees to replace the dying of the old because cottonwoods require periodic flooding to reproduce successfully. Moreover, Snake River cutthroat trout, which need clean gravel in which to spawn, had suffered from the channelization because floodwaters no longer flushed and rejuvenated their spawning gravels.

Therefore, in the autumn of 1998, the Teton County Natural Resource District and the U.S. Army Corps of Engineers began testing methods of breathing old life back into the river by allowing its old rhythms of flooding to return. But such an endeavor would take a different level of consciousness, as Rik Gay, manager of the project for Teton County, pointed out when he said, “Rivers don’t just go downstream. We need to think in three dimensions. Rivers also move laterally and below the ground.”

There is a sober reminder in all of this, however. The levees along the upper Snake River not only narrowed and denuded the river over four decades but also allowed million-dollar housing developments to flourish, which caused Bill MacDonald, manager of the Snake River project for the Army Corps of Engineers, to observe that restoring the natural flow of the river was “not feasible” because “behind those levees are millions, if not billions, of dollars in real estate.”12

Nevertheless, for a system to be viable, its processes must remain functional, which requires its biophysical integrity to remain intact. As always, the ecological folly and economic greed of our contemporary decisions—as the adult trustees of planet Earth—become the consequences we bequeath all generations to come as a never-ending story of cause and effect that increasingly impoverishes their lives by diminishing their viable, social-environmental choices in like measure.

It is critical, therefore, that we trustees raise the level of our social-environmental consciousness because what really needs to be done to protect the ecological integrity of rivers for all generations is to cease building in the floodplains. One way to accomplish that is to terminate the federal subsidy for both flood insurance and the repair of levees, thereby making local governments pay the cost. In the meantime, however, many communities still have riparian areas—and some even have floodplains—that are not only important to understand but also critical to protect.
 


Related Posts:

• Water–A Captive Of Gravity

• Riparian Areas And Floodplains

• The Hydrological Continuum

• Principle 1: Everything is a relationship

• Principle 5: All relationships result in a transfer of energy.

• Principle 7: All relationships have one or more tradeoffs.

• Do We Owe Anything To The Future?— Part 1

• Do We Owe Anything To The Future? — Part 2


ENDNOTES

1. Michael Grunwald. An Agency of Unchecked Clout. The Washington Post. September 10, 2000.

2. The discussion of the U.S. Army Corps of Engineers is based on: (1) Jim Robbins. Engineers Plan to Send a River Flowing Back to Nature. The New York Times. May 12, 1998, (2) Michael Grunwald. The corps’ divided mission. LA Times-Washington Post Service. In: The Oregonian, Portland, OR. February 17, 2000, (3) Michael Grunwald. More powerful than a river. The Washington Post. In: Albany (OR) Democrat-Herald, Corvallis (OR) Gazette-Times. November 23, 2000, (4) Frederic J. Frommer. Groups identify ‘wasteful’ Corps water projects. The Associated Press. In: Corvallis Gazette-Times, Corvallis, OR, March 3, 2000, and (5) Amalie Young. Court: Snake dam operation violates Clean Water Act. The Associated Press. In: Corvallis Gazette-Times, Corvallis, OR, February 17, 2001.

3. John Howard. Crews struggle to save California levees. The Associated Press. In: Corvallis Gazette-Times, Corvallis, OR. January 7, 1997.

4. The New York Times. California Crews Bolster Levees; Drinking Water Faces Peril. January 7, 1997.

5. The Associated Press. Levy failure causes new floods in California. In: Corvallis Gazette-Times, Corvallis, OR. January 11, 1997.

6. John Howard. Receding floodwaters reveal fields of dead cows, horses. The Associated Press. In: Corvallis Gazette-Times, Corvallis, OR. January 10, 1997.

7. Matthew Yi. Brimming reservoirs keep California flood threats alive. The Associated Press. In: Corvallis Gazette-Times, Corvallis, OR. January 10, 1997.

8. (1) http://abcnews.go.com/GMA/video/louisiana-opens-floodgates-13606724; (2) http://abcnews.go.com/WNT/video/mississippi-floods-record-set-natchez-us-corps-engineers-corral-river-us-13625204, (3) http://abcnews.go.com/GMA/video/residents-evacuated-water-levels-rise-13742043; (4) http://abcnews.go.com/WNT/video/iowa-flooding-will-levees-hold-13850965; (5) http://abcnews.go.com/Nightline/video/southern-flooding-hell-high-water-13617945; (6) http://abcnews.go.com/GMA/video/missouri-river-floodwaters-hit-iowa-13854513.

9. Scott Faber. Get people off of nation’s floodplains. Corvallis Gazette-Times, Corvallis, OR. January 21, 1997.

10. Ibid.

11. Luna B. Leopold. Ethos, equity, and the water resource. Environment 2 (1990):16-42.

12. The foregoing discussion about restoring part of the Snake River to a more natural condition is base on Jim Robbins. 1998. Engineers Plan to Send a River Flowing Back to Nature. The New York Times, New York, NY. May 12.


Note: This piece is excerpted in part from my 2009 book, “Social-Environmental Planning: The Design Interface Between Everyforest and Everycity,” published by CRC Press, Boca Raton, FL.


Text © by Chris Maser 2011. All rights reserved.

Protected by Copyscape Web Copyright Protection


If you want to contact me, you can visit my website. If you wish, you can also read an article about what is important to me and/or you can listen to me give a presentation.



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Responses

  1. Tell it like it is, bro. Jesus warned them long ago not to build their houses on the sand.


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