April - June 2003 Sierran

THE ST. JOHNS BASIN-NEW MADRID FLOODWAY PROJECT
The Gap that’s far from the Mall: Part I - The Project
by Alan Journet, Trail of Tears Group Conservation Chairman


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The St. Johns Basin-New Madrid Floodway Project of the U.S. Army Corps of Engineers (USA-COE Memphis District) is designed to protect certain agricultural and residential areas of Southeast Missouri from the frequent severe flooding that they currently experience. Although the project promises significant human benefits and is extremely popular in the area, it threatens considerable environmental cost. This two part series will describe the nature of the project (Part I) and then explore environmental and other concerns (Part II).

See map.(figure 2)

The Southeast Lowlands

The wettest region in our state is the Southeast Missouri Lowlands. Not only does it receive the highest annual rainfall (some 55 inches), but it also undergoes frequent flooding. This local flooding is a result of headwater and backwater flooding.  Headwater flooding is caused by drainage of rainfall from surrounding uplands and the region itself which flows through channels and bayous southwards towards and into the Mississippi River. Backwater flooding, meanwhile, occurs when the seasonally high spring Mississippi River swollen by snowmelt from upstream backs up onto the surrounding floodplain. This combination of events results in frequent spring inundation of these Southeastern lowlands.

Over geological time, the meandering of the Mississippi has shifted through the area with the result that a wide and relatively flat floodplain now exists with abundant low points that form wetlands and swamps and that annually accumulate spring floodwaters.

A History of Wetland Forests


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When Spanish explorers passed through the area, and even when European settlers arrived years later, the Southeast Missouri lowlands supported some 2.5 million acres of bottomland hardwood and swamp forest with an occasional slightly higher and dryer zone of bottomland prairie. The value of this area for timber and agriculture was soon realized. Unfortunately, value was not seen in maintaining the natural resources and natural communities. By 1975 only 98,000 acres (4.1%) of the original forest remained, with only about 1% in tracts larger than 1000 acres.

Three hundred and fifty years ago, not only did the area support acres of fine hardwood timber to be harvested, but the soils also were found to be rich and fertile. The main problems confronting settlers were the difficulty of harvesting timber from wetland soils and swamps, and the hazard of farming cleared, sodden soil. As a result, land was rather cheap. However, with the ingenuity of a few landowners, the lowlands were “tamed”. Unfortunately the mechanism for taming was not benign.


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Through the activity of the Little River Drainage District around the turn of the last century, an extensive series of ditches was dug and dredged throughout the region. Instead of the meandering rivers seen elsewhere in the state, the waterways of these Southeast lowlands are long, straight drainage ditches (Figures 1 and 2). The improved drainage of the area led to the rapid removal of most of the hardwood forest for timber followed by the transformation of the lowlands into agricultural farmland. So successful was and is the drainage program that the Southeast lowlands now offer some of the most fertile and attractive soils in the State, supporting extensive acreages of soybeans, corn, and cotton. Indeed, many farms that were once bottomland hardwood forest and now are inundated during late winter and spring, employ extensive irrigation systems to extract groundwater for their crops.

Bottomland forest is now restricted to a few small remnants totaling only a few thousand acres. One such remnant is Big Oak Tree State Park providing a minuscule sanctuary for many local species of flora and fauna, and boasting several state and national champion trees – surviving here only because so few wetland forest acres remain throughout the southeast states (Figure 3). Evidence suggests that this park is already threatened by effective drainage channels which bring pesticides from surrounding cropland into the park, and take floodwaters out, causing the park to dry out and leading to adjustments in the floral community it supports (Figure 4).

The Levee System Creates the New Madrid Floodway


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The Mississippi River levee system as it presently exists was authorized after the huge flood of 1927 to protect riverfront occupants from the annual spring flooding that ironically was the source and sustenance of the fertile soils on which they depend. In combination with the deforestation of thousands of acres upstream the levee system has promoted rather than reduced spring floodwater severity and frequency. Knowing that the levee system might encourage high floodwaters that could threaten the city of Cairo nestled in the confluence of the Mississippi and Ohio Rivers, the Southeastern Missouri lowlands were enclosed in a double levee system (Figure 5). While the main Frontline levee was constructed along the west bank of the river from Bird’s Point (on the Missouri bank approximately across from Cairo) to New Madrid, a Setback Levee was constructed to cross the floodplain some miles behind it. This enclosed an area named the New Madrid Floodway which is now separated from the St. Johns Bayou Basin by the aforementioned Setback levee.


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According to the engineering design, the south end of this Floodway was left with unimpeded access to the river; thus the 1500 ft levee gap was born – not by mistake or shortage of funds, but by design (Figure 6). The engineering scheme was simple: should Cairo be threatened by rising floodwater, the north (Bird’s Point) end of the Frontline levee would be blown allowing the river to flow freely across its old floodplain and back out through the gap at New Madrid. Spreading the river over its historic floodplain would lower its elevation and protect residential Cairo.

As a result of this levee design, farmers purchasing the land knew that they were taking a chance that at some time in the future their potential cropland could be inundated. Inevitably, early 20th century land prices reflected this threat and its associated risks. As a result of the levee gap at New Madrid backwater flooding into the floodway occurs annually with some 17,000 acres in the floodway inundated every 2 years and some 75,000 acres susceptible to 30+ year floods.

St Johns Basin


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In the adjacent St. Johns Bayou Basin, a slightly different problem has developed. Generally, the drainage ditches carrying headwater flooding from the region and surrounding uplands successfully transmit excess surface run-off water into the Mississippi River via the St. Johns Bayou, passing through simple gravity gates in the Setback levee just east of New Madrid (Figure 7). Unfortunately for the residents of this area, however, to prevent backwater floods from inundating the St Johns Basin the gates must be closed when the Mississippi River elevation exceeds that of the bayou.

When the gates are manually closed, headwaters no longer able to escape into the Mississippi accumulate behind the gates and along the drainage ditches. As a result, some 10,000 acres are subject to 2-year floods while 55,000 acres are susceptible to 30+ year floods. Under extreme conditions, East Prairie can be inundated or cut-off from surrounding areas.

Residents Seek a Remedy - A Project is Born

Confronted with the flood problems, the generally economically disadvantaged residents of Southeast Missouri have long sought a solution to their plight. Promise was provided by the 1954 Flood Control Act (part of the Mississippi River Levee feature of the Mississippi River and Tributaries Project) which authorized closure of the 1500 ft levee gap. Unfortunately for local residents, however, the funding conditions of the authorization demanded a significant local cost share contribution which the community could not afford.

Subsequently, based on General Design Memoranda from the Chief of Engineers (USA-COE) and prepared in response to the Water Resources Development Act of 1976, the Water Resources Development Act of 1986 authorized remedies for the two areas. These became the St. Johns Basin and New Madrid Floodway projects. Though composed of two distinct elements, these have been rolled into one major project known by the joint title. This authorization also, however, contained a significant local non-Federal cost share requirement.

The project also receives support because it is argued to serve the national objective as defined by the Water Resources Council’s Economic and Environmental Principles for Water and Related Land resources Implementation Studies. This identifies beneficial projects as those that “contribute to national economic development consistent with protecting the nation’s environment…” A project can contribute to this National Economic Development (NED) objective by increasing the net value of the nation’s output of goods and services.

Federal Funds Become Local Cost-Share

In the early 1990s, President Bill Clinton was seeking mechanisms to promote local economic development. East Prairie was lucky enough to receive designation as an Economic Community, meaning it was eligible for significant financial assistance. The community selected the combined flood control project as the most important development it needed to promote local economic growth and enhance quality of life.

As a result of exceptions that were then incorporated into the Water Resources Development Act of 1996, the U.S. Department of Agriculture was permitted to contribute funds to the community that offset the local cost-share requirement and thus enabled the local requirement to be met and the project to go forward. As a result of this waiver, approved in Congress because it was promoted by 8th Congressional District Representative Jo Ann Emerson in her early years in Washington, federal funds were allowed to become the local cost-share component for the federally-funded Corps of Engineers project.

Project Analyses

The U.S. Army Corps of Engineers then developed a Supplemental Environmental Impact Statement released in April 1999. Displaying the convoluted history of the project, this 1999 statement was designated as a supplement to the 1982 Supplemental Impact Statement of the 1976 Final Environmental Impact Statement.

After public comment, this was followed in October 2001 by the USA-COE Draft Report of the Revised Supplemental Environmental Impact Statement for the St. Johns Basin-New Madrid Floodway Project. Although this document contained an Appendix purporting to present public comments on the project, it actually comprised mainly letters from local folks, representatives, and organizations supporting the project; letters and lengthy submissions by opponents were omitted. This consequently presented a biased view of how the project was being received in the greater state and regional area. Following further public comment, the final document was the June 2002 Final Report of Revised Supplemental Environmental Impact Statement, containing some modifications, clarifications, and expansions from the draft version and including a designation of the preferred alternative from amongst those described and evaluated.

This project required water quality certification by the Missouri State Department of Natural Resources. When this was refused, the Corps elected to appeal the DNR decision to the Missouri Clean Water Commission, which has the power to overturn the DNR decision. The Environmental Defense Fund, which has long had an interest in the project, and wrote a lengthy critique of the 1999 DSEIS, has elected to file as a Defendant Intervener in this appeal to support the state DNR. The Ozark Chapter of the Sierra Club, meanwhile, has voted to join EDF in this intervention in support of the state DNR.

The Environmental Impact Statements delineate the essential elements of the combined project as outlined below.

New Madrid Floodway Component.

The main aspect of this, as discussed above, is closure of the 1500 ft engineered gap in the levee system just east of New Madrid where the frontline levee approaches the Setback levee (Figure 8). Closure will include a gravity gate and a1500 ft3/ second pumping station that will pump accumulated headwater ponding out of the floodway into the swollen Mississippi River when river elevation requires gate closure.


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St Johns Basin Component

The main element of this project is the installation of a 1000 ft3 / second pumping station east of the current gravity gate. This pumping station will be activated when the Mississippi River elevation exceeds that of the St. Johns Bayou requiring closure of the gravity gate. It will serve to pump headwater flooding accumulating behind the closed gate over the levee and into the Mississippi River channel.

An additional element of this component involves the dredging and widening of some of the lower bayou and major drainage ditch channels to enhance flow of headwaters from agricultural areas and residential communities southwards into the Mississippi River.

The Alternatives

During deliberations, the USACE considered nine alternatives as follows:

Alternative 1 – Without Project was required for considerations since against this all projects are measured.

Alternative 2 – The Authorized Project as described above with an annual benefit-to-cost ratio above 1.

Alternative 3 – The Avoid and Minimize Project is basically Alternative 2 with modification to reduce environmental impact (to be discussed in Part II of this series). This option also included consideration of three alternative levee closure locations:

i) The 1500 ft. levee closure at the current gap (approximately at levee mile 34.5) incorporating a gravity gate allowing variable river connectivity at the south end of the New Madrid Floodway, and pumping station to pump water out when the gates are closed. This is the Preferred Plan with an initial cost of $80.3 million (including construction and mitigation) and an annual benefit-to-cost ratio of 1.2. Annual benefits are estimated at $772 thousand for the St. Johns Basin element and $113 thousand for the New Madrid Floodway element, for a total overall benefit of $885 thousand. Benefits are derived largely from flood damage reduction, agricultural intensification, and urban and commercial improvements. It is noteworthy that the project designed to enhance agricultural profitability has a greater benefit by a factor of seven times in the St. Johns Basin where fewer acres are inundated, than in the New Madrid Floodway where more acres are flooded.

ii) A 6500 ft levee further upstream at levee mile 34.

iii) An 18500 ft levee even further upstream at levee mile 33.

Since option i became the preferred option, the remaining two levee locations were rejected.

Alternative 4 – The East Prairie Ring Levee and St. James Ditch option would involve a levee to protect virtually the entire community of East Prairie from the 25-year flood cycle. Although the industrial park and some areas would achieve 100-year external flood protection, because agricultural areas remain unprotected (a major goal of the endeavor) the benefit-to-cost ratio for this is computed to be below 0.5 and the alternative was rejected. This project, however, would avoid all environmental costs. Curiously, however, it was noted that flooding more severe than the ten-year event exceed the capacity of the city’s culverts, and the industrial park is flooded. It is also noted that the project does not address this critical issue – so presumably East Prairie will continue to suffer floods even with the project.

Alternative 5 – The St. Johns Bayou Basin Only option would exclude all modifications to the New Madrid Floodway and focus on St Johns Basin. Though economically viable in benefit-to-cost ratio terms, this project was rejected since it fails to address the issue of protecting agricultural land in the New Madrid Floodway and local residents opposed it.

Alternative 6 – The Wildlife Refuge option involved the purchase of the lower portions of both the St. Johns Basin and New Madrid Floodway for creation of a wildlife refuge in which high quality wildlife and fishery habitat would be created. Since the local community disapproved of this option, it was rejected on the grounds that landowners would be unlikely to make the necessary land available for purchase.

Alternative 7 – New Floodway Levee Location option included a series of alternative levee closure locations beyond those identified in Alternative 3 (above):

i) A levee northeast of Big Oak Tree State Park was rejected because it would probably generate headwater flooding problems on land not now generally flooded.

ii) A 15,840 ft. levee at mile 32 provided a benefit cost ratio of 0.6 (listed incorrectly in the statement as a cost-benefit ratio) since agricultural land would be lost. This alternative received no local support.

iii) A 15000 ft levee at mile 27/28 provided a benefit cost ratio of just 0.3 (listed incorrectly in the statement as a cost-benefit ratio) since significant agricultural land would be lost even though mitigation needs would be reduced markedly. This alternative received no local support either.

Alternative 8 – The Silvicultural option would have converted the flooded area in the Basin and Floodway to forest through such efforts as the Wetland Reserve Program which offers incentives for such conversions. However, since this conservation program has long been available and landowners have not used it, this option was considered unworkable.

Alternative 9 – The Non-structural option would have included floodplain evacuation and relocation of residents, flood-proofing buildings, restrictions on future development, conservation and flood easements, and conversion of agricultural land to uses not damaged by repeated flooding. For various reasons associated with impracticability and ineffectiveness, this option was not further considered.

It is worth noting that the St. Johns Basin Only option was preferred by Missouri’s Department of Conservation, has a positive benefit-cost ratio, avoids many environmental costs, and affords 7/8ths of the economic benefit of the entire project. It is surprising, therefore, that the Corps did not pursue further an option that would combine this alternative with ring levees protecting the residential communities in the New Madrid Floodway. Furthermore, it also seems that an alternative focusing on the St. Johns Basin Only option combined with non-structural solutions in the New Madrid Floodway such as buy-outs and/or a wildlife refuge creation would also have been worth pursuing.

Benefits and Costs

The major human benefits of the combined project will be in the enhancement of agricultural opportunities and profits as the floodwaters will inundate less frequently and less extensively the farmland of both the New Madrid Floodway (reduced backwater flooding) and the St. Johns Bayou Basin (reduced headwater flooding). Additionally, the residents of the affected area hope to benefit directly from decreased residential and commercial flood frequency and severity. This is the hope not only of residents of East Prairie, on the St. Johns Basin side of the Setback levee, but also of residents of other small communities, such as Pinhook, located on the river side of the Setback levee in a frequently flooded wetland zone of the floodway. Pinhook, incidentally, a small community of some 20 – 30 homes, is one of the residential areas of Southeast Missouri historically occupied by African American residents.

Although the project holds promise of considerable benefits for the human residents of the area, some of these may represent exaggerated claims of benefits and underestimated claims of costs. Meanwhile, the project poses a threat to the non-human residents and the largely wetland communities they inhabit. Recall that what was once 2.5 million acres of wetland forest has already been reduced to just a few thousand acres, and these remnant patches are all very small and separate, two features of habitat fragmentation which make it a particularly serious threat to wildlife. It is for this reason that many of Missouri’s species of conservation concern are Southeast Missouri wetland inhabitants. Another concern is the threat to mussel populations inhabiting the channels. Additionally, there is a threat to the critical connectivity between wetland and river which allows the flooded areas to serve as nurseries for many Mississippi River fish species.

The fundamental and difficult questions surrounding the project concern whether the potential human benefits outweigh the potential financial (= federal taxpayer) and environmental costs. With this equation in mind, we should ask whether the preferred project represents the best compromise and also whether it incorporates and accounts accurately for all the appropriate environmental safeguards that such a project reasonably would be expected to include.

Part Two will explore these questions.