The Source

by Martin Doyle

  The scale and uniformity of the levee along the main channel of the Mississippi River is astonishing: a solid wall of earth with a base spanning over 300 feet, stretching almost four stories tall at the crest, with a wide road running along the top. Imagine filling a college football stadium with a trapezoid of compacted dirt up to the top of the bleachers, building a road on top, and then lining up those dirt-filled stadiums side by side, continuously, from Vicksburg to Memphis on both sides of the river. That is what it takes to put the Mississippi River into its hydraulic straitjacket. And the levee goes on south to New Orleans and north far beyond Memphis, stretching thousands of miles upstream to Minneapolis, as well as along every major tributary from other rivers like the Ohio and Missouri to every other stream that touches the river.

  In May 2013, the Mississippi is just cresting at 1.26 million cubic feet per second (cfs, the standard descriptor of river flow, or discharge). To get a sense of just how much water goes down the Mississippi River, 1.26 million cfs amounts to 8.8 million gallons of water per second—enough to fill Lake Mead to the top of Hoover Dam in just over three days. This flood crest in May is actually the first of two pulses of water that will pass Vicksburg for the year due to the sheer size and diverse geography of the Mississippi River basin. This first pulse comes from the Ohio River valley and Upper Midwest, fed by all the thunderstorms and cold fronts that typically generate rain in the early spring. The second pulse is the snowmelt runoff from the Rockies and Great Plains, which works its way all the way through the gullet of the continent that is the Missouri River and then moves on through the Mississippi. The timing of the pulses is fairly regular, but the size can vary tremendously from year to year. The year 2013 is typical; the river is coming up to the top of its banks and at places reaches the bottom of the levee, but it is nowhere near the top of the levee, which can handle more than twice the flow of 2013.

  Kent Parrish manages 410 miles of levees for the Vicksburg District of the U.S. Army Corps of Engineers. Because the river in 2013 is passing a low flow, Parrish is very calm, and so were others in the offices of the Corps of Engineers in Vicksburg. The Corps is the federal agency tasked with controlling floods. Its engineers build levees and dams, and anytime there is a flood, levee break, or some other hydrologic disaster on a river, the Corps is in the thick of things using military trucks and helicopters for a variety of flood-fighting functions. But the highly visible role of the Corps belies what actually happens before, during, and after floods in the United States.

  Major levee districts of the lower Mississippi River Valley, including the Mississippi Levee District and Greenville, fitted together like patchwork.

  Parrish, as one of the Corps members tasked with levee management, says that much of the involvement of the Corps during floods is mundane: “We at the Corps just build the levees.” Parrish works largely out of the limelight, doing things like checking flood levels and making phone calls. The real work, Parrish says, is done by organizations in charge of the levees—the levee districts. They’re the ones who maintain the levees and bear the brunt during the flood itself. Levee districts are obscure compared to the Corps, yet they are ubiquitous—that becomes apparent when you take a close look at a map of flood control infrastructure along a large river. Some levees are labeled as belonging to the Corps; other levees are labeled as belonging to a specific district. Many of these districts sit downstream of an enormous flood control dam built and operated by the Corps of Engineers. A map of flood control infrastructure is the best way to begin appreciating the layered nature of flood control. A brief look at a map of levees clearly shows that the Corps may not be as central to understanding flood control as these largely unheard of and ignored levee districts.

  A levee district that Parrish works closely with is the Mississippi Levee Board, based about 100 miles upstream in Greenville, Mississippi. Greenville sits in the smack-dab middle of the Mississippi delta. Most cities along the Mississippi—Vicksburg, Yazoo City, and Baton Rouge, for example—developed in places where the river has meandered over to the edge of the valley and close to the bluffs. A city on a bluff has access to a river but protection from a flood. Greenville is close to the river but far away from either bluff. It is a city dependent on levees.

  Downtown Greenville is nestled just on the landward side of the levee with its old downtown area starting at the toe of the levee. On the river side, the levee is paved to allow parking for a city park. Going up the side of the levee is a series of brass numbers and lines. Each line marks the elevation the river reached during a flood, and the brass numbers record the year. As the sun sets in the west, the shadow cast by the levee creeps from the streets and rises slowly up the sides of buildings in a sequence not unlike how water would rise in the city if the levee failed.

  These levees are the literal and figurative turf of the Mississippi Levee Board, whose headquarters are small and inconspicuous: an office building outfitted with cubicles and fluorescent lighting. But inside the building is a hallway lined with black-and-white photographs of former chief engineers going all the way back to 1865, when levees throughout the South were in tatters after years of war punctuated by three enormous floods. The people in these pictures—General S. W. Ferguson, William Starling, and William Elam, among many others—are well known in the field of river science and hydraulic engineering, the authors of hallmark scientific publications and books on all manner of topics related to flood control. Rural Mississippi, and specifically Greenville, does not seem like a natural hotbed for luminaries of fluid mechanics and hydraulic engineering. It might seem that such engineers would make their homes down in Vicksburg or New Orleans with the Corps. But the levee district here in Greenville has always been a hub of engineering—a legacy being upheld by the current chief of engineers, Peter Nimrod.

  Makeshift sidewalks in Greenville, Mississippi, during the flood of 1927.

  When he walks past the photos of his predecessors, Nimrod just sips from his coffee cup and slowly drawls, “Tha’s raight, it’s an intimidating hallway.” Along with its hall of fame, the little office building has a conference room of sorts that also serves as an impressive library and museum of all things flood related. The walls are lined with photos of historic floods when things didn’t go so well for the levee district: photos of refugee camps perched atop narrow levees surrounded by miles upon miles of water. Photos of the town of Greenville under five feet of water. Photos of sandbagging crews trying to fight off the last few inches of rising floodwaters. Photos that remind viewers of what the levee board works year round to avoid.

  Nimrod and his assistant engineer Bobby Thompson take an hour to describe what their lives on the front line of flood control are like. They describe the levees they manage, from the massive mainline levee to the more obscure levees of the backwaters and tributaries. They know every nook and cranny of every mole hill and mobile home along the hundreds of miles of levees in their district. While Kent Parrish and the Corps downstream are in charge of the planning and the broader system of levees all along the Mississippi River, Nimrod and the levee board handle the weedy details of day-to-day levee management in their particular geographic area. One such detail is hiring people to constantly mow the grass on the levees. Another is the need for widening and thickening the levees, which leads to the chronic issue of dealing with landowners. The board is currently negotiating with the recalcitrant owner of a mobile home, whose residence is in the way of one of the areas they need to widen. This, even though the levee board has eminent domain rights and the levee is the only thing standing between the owner’s home and the river. These are the kinds of things Nimrod and Thompson do in years like 2013, when the flow of the river is not too large. During floods, the levee district shifts into flood-fighting mode; it is the government entity inspecting every foot of levee night after night during floods, finding and organizing people to fill sandbags, and evacuating people from flood-prone lands in case the levee doesn’t hold.

  This se
emingly haphazard division of responsibilities creates confusion about flood control. Who is in charge? Who does what? Both the Corps and the Mississippi Levee Board are creations of government for flood control. Both have engineers, hydrologists, bulldozers, and boats. Both have different roles and responsibilities for flood control, but they overlap and intersect. This intersection, and the resultant confusion over who is in charge, is a product of federalism—the most essential element of American governance. In 1787, when the framers of the Constitution set to work on rethinking the structure of government, their foremost challenge was balancing the need for a more centralized national government against persistent desires for state and local autonomy. The result—federalism—is the notion that there should not be a single government, but rather what Woodrow Wilson would later describe as a “series of governments within governments.”1

  Under this system of federalism, the idea is that power should be shared and separated not just between branches of government but also between layers of government. From the federal government to the states and on down to counties, municipalities, villages, and townships, each layer would take on its own particular roles and responsibilities. The framers envisioned a national, central government that would provide for the broader interests only it could furnish, such as national security, economic development via free trade, or even basic scientific research. All other functions would be handed down to the lowest level of government—the closest to the community—that could handle the problem, since governments at this level best understand the true demands of their people and their region.2

  That was the idea. To put the idea into practice meant that government functions would first have to be distilled through the ideals of federalism. Thus, for flood control, the appropriate question was not “Which agency of government should be responsible for flood control?” Rather, the central question was “Which level of government should have the responsibility for flood control?” The answer to that question, like almost all innovations and developments in flood control, came out of the Lower Mississippi valley.

  Settlers who arrived in the Mississippi valley in the early nineteenth century were confronted with tens of thousands of miles of navigable rivers, bordered by some of the most fertile soils in the world. The pioneers’ dreams of turning this landscape into an alluvial empire were limited only by flooding. Major cities of the Mississippi valley—New Orleans, Vicksburg, Memphis, and St. Louis—all sit on topographic oddities that keep them just out of the reach of floods. To turn the potential of the river valley into reality, however, farmers had to control floods—and that meant building levees.

  At that time, the federal government was largely inert. The states took on almost every government role and responsibility, in turn seeking to push them on to local governments. Levee districts, initially formed in the 1830s in Mississippi and Louisiana, were the natural solution to flood control in this political climate. The entire state of Mississippi, for example, did not need to be taxed to accrue the funds to build levees, because much of the state was not flood prone. Instead, the Mississippi Levee Board, along with other districts along the river, was organized by planters in the flood-prone delta and recognized by the State of Mississippi as a formal unit of government, comparable to a municipal government of Greenville or Jackson. But whereas municipal governments have broad responsibilities, levee districts have only one: flood control. The district has the ability to tax landowners within the area, and it operates as a corporation with presidents, boards, and inspectors. Levee districts are to floods what modern school districts are to education: a function-specific unit of government that is self-governing for a specific purpose within a specified area.

  Following the ideals of federalism, levee districts were scaled for the problem: they were large enough to build longer, more consistently constructed, and better financed levees than individual landowners could provide in a piecemeal way. Yet the districts were small enough to ensure local knowledge of what needed to be done. State governments had some roles to facilitate or standardize operations in their districts. For instance, state governments bought stock in levee districts to bolster their finances and also provided some engineering design standardization across districts, much like statewide education standards for schools today. But these local government units did the actual work.3

  Levees were not limited to the Mississippi valley. Most other states adopted the levee district approach, making them a fairly common unit of local government in the Deep South. Yet devolving functions of government to the most local level can have widely variable effects, for success depends on local initiative, expertise, and diligence. Not all levee districts had the right combination. Shortly after the “forty-niners” frantically settled the Central Valley of California, the city of Sacramento formed an impromptu levee district in response to flooding in 1850. Rather than building a levee along the river, Sacramento built a levee encircling the entire town; the levee failed when the first flood hit only two years later.4

  Competence was not the only issue; initiative was also a chronic problem for local government districts. For example, the historian John Thompson unearthed the minutes from a meeting of the Big Swan Levee District in Illinois, where the work of levee building and maintenance was often a side project for farmers. As the minutes reflect, those present were no more serious than they would be about a town hall or a homeowner association meeting:5

  After a long delay and much misunderstanding about when and where it [the meeting] would be held, and evening arrived and one by one the [Levee] Commissioners arrived all full of farming interests and community gossip, maybe one or more had heard some good questionable jokes.

  So after every subject had been exhausted and no hint or allusion to what purpose might have been in mind relative to the gathering one fellow began to reach for his hat, and another without any hat having his hand on the door knob, the Chairman suggested that we might hear the minutes of the previous meeting if any, along with such and said bills paid or otherwise disposed of and so I begins to rummage through these notations, noting that one Commissioner had left and as I glanced up from the bill reading, I heard the lower door slam as the last commissioner had vacated the premises, and thereby assumed that the meeting was adjourned.

  ________________ Chairman _____________ Secretary

  Sign here if you ever come back.

  While smaller districts in some regions of the country were flippant with their tasks, levee districts of the Lower Mississippi valley—particularly the Mississippi Levee Board of Greenville—attended to every detail of levee building and maintenance. Throughout the nineteenth and early twentieth centuries, the districts bought land for levees, built the best levees they could, and then rebuilt or repaired the levees damaged by floods. The seriousness of this task is evidenced by the steep taxes the districts set for themselves to raise funds for hiring the country’s best hydraulic engineers. Thanks to the central role of levee districts in flood control, and to the burgeoning agricultural economy of the region, these districts had become nuclei of hydraulic engineering expertise by the turn of the twentieth century. The United States was completely reliant on levees for flood control, and federalism left that responsibility to levee districts.

  Yet levees are not the only tool available for controlling floods. The goal of flood control is to get all the precipitated water out of a watershed in the most controlled form possible. Levees simply constrict the flow of the river to a controlled pathway and have the additional benefit of narrowing the river, which increases water velocity and makes the river deeper. Making the flow deeper and faster causes the river to further erode its own bed and so reduces the elevation of floods.

  Another approach to flood control is to straighten a river by removing meanders. When rivers go along their natural crooked, tortuous paths, the water flows through turns and bends that slow down its speed dramatically. When rivers are straightened, flow speeds up, allowing more water to flow by at
lower depths and thus decreasing the height of floods, all while scouring out the bed.

  A third option for flood control is to use outlets or bypasses to get water out of the valley. Flood bypasses are essentially controlled, additional channels designed to take some of the river’s flow and lessen the amount of water in the main channel. The Atchafalaya River is a natural outlet—a second channel—for the Mississippi to reach the Gulf of Mexico. It starts just below Baton Rouge but upstream of New Orleans. Flood control at New Orleans could use this natural outlet to decrease the amount of flow in the main channel at New Orleans.

  The fourth approach is the most radical. It uses time instead of space to stretch out a flood or to control the volume of water flowing through the river at any time. This is where reservoirs play a role. Reservoirs can capture small tributary floods in the early spring and then gradually release the floodwater over a long time through the summer. If carefully planned and engineered, the release of flow from tributary reservoirs can be coordinated so that the downstream flood never reaches a critical level. Engineers often talk about reservoirs “shaving the peak off of floods.”

  Levees, managed by local governments, were by far the most common approach to flood control until the mid-twentieth century. Although levee districts typically requested greater state funds, and the states in turn lobbied for greater involvement from the federal government, the federal government remained distant, convinced that flooding was a local problem. During the mid to late nineteenth century, the federal government gave enormous deference to state governments. In areas where an interstate commerce interest was not clearly involved, the federal government kept the responsibility for flood control at arm’s length.