U.S. Army Corps Of Engineers Research Articles

The Clean Water Rule: defining the scope of the Clean Water Act

What waters are subject to federal regulatory protection by the US Clean Water Act (CWA)? Over the 43 y since passage of the CWA (formally the 1972 Federal Water Pollution Control Act [33 U.S.C. §§1251–1387]) little clarity and less consensus has emerged regarding this fundamental question. However, on 29 June 2015, the US Environmental Protection Agency (EPA) and the US Army Corps of Engineers (ACE) published the Clean Water Rule (https://federalregister.gov/a/2015-13435) to clarify which waters are subject to CWA protection. Publication of the Clean Water Rule created immediate, passionate political debates, largely focused on whether EPA and the ACE overstepped their jurisdiction. Within 5 d of publication of the rule, attorneys general from 31 states planned to ask EPA to delay implementation of the Clean Water Rule for at least 9 mo (http://www.courthousenews.com/2015 /08/03/thirty-one-states-fight-clean-water-rule.htm). As of 10 August 2015, 13 states had asked a federal judge to block the rule (http://www.mercurynews.com/breaking -news/ci_28615224/13-states-want-judge-block-new-federal -water). A Google® search on 13 August 2015 based on the keywords “Clean Water Rule” and “lawsuits” produced 22,500 results. As of 8 September, when this paper went to press, the rule was in effect in 37 states, and was stayed by preliminary injunction in 13 states (Alaska, Arizona, Arkansas, Colorado, Idaho, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, South Dakota, and Wyoming) (http://www2.epa.gov/cleanwaterrule/clean-water -rule-litigation-statement). In bright contrast to the well publicized, negative political reaction, the aquatic resource science and management communities appear to largely support the rule (e.g., http://www.freshwater-science.org/Policy /files/SFS_WOTUS_EPA-HQ-OW-2011-0880.pdf).

IN MEMORIAM: Thorndike Saville, Jr.

Thorndike Saville, Jr., a distinguished coastal engineer retired from the US Army Corps of Engineers, died 5 November 2014. Saville came from a family of engineers, with both his father and grandfather being accomplished hydraulic engineers. Saville's father, Thorndike Saville, Sr., helped pioneer coastal engineering in the United States, serving from 1930 to 1969 on the Beach Erosion Board (BEB) and then the Coastal Engineering Research Board (CERB). Saville attended Harvard University before joining the Army in 1943. During World War II he was a weather observer and collected meteorological data along the Atlantic coast and later in the Pacific, including New Guinea and the Philippines. After the war, he completed his undergraduate degree in Civil Engineering at Harvard in 1947. Then, he attended graduate school at the University of California, Berkeley, where he earned his master's degree under Prof. Joe Johnson using physical modeling to study sediment transport. In 1949 he joined the U.S. Army Corps of Engineers, working for the BEB. He studied sediment and water movement in the Mission Bay and San Diego area. The next year he transferred to Washington, DC, to the BEB facility at Dalecarlia Reservoir. Saville worked for the BEB until it was abolished in 1963. He was then appointed as Chief of the Research Division at the newly established Coastal Engineering Research Center (CERC), which is now the Coastal and Hydraulics Laboratory at the US Army Corps of Engineers Engineer Research and Development Center. Saville's research spanned a broad range of topics including sediment transport, wave generation, wave runup and overtopping, wave and water level statistics, rip rap stability, hydrographic surveying, and coastal inlets. Saville was named Technical Director of the CERC in 1971 and held the position until his retirement in 1981. During his tenure as director, the CERC produced the Shore Protection Manual, constructed the Field Research Facility in Duck, NC, and conducted a wide variety of coastal research. Saville's coastal engineering career also included leadership roles in professional organizations and awards. He was a member of the American Shore and Beach Preservation Association and served on its Board of Directors until 1988. Saville served as a member of the Coastal Engineering Research Council of the American Society of Civil Engineers (ASCE) Coasts, Oceans, Ports, and Rivers Institute. He was elected to the National Academy of Engineering in 1977 and received the ASCE John G. Moffatt-Frank E. Nichol Harbor and Coastal Engineering Award in 1979. Saville was a Professional Engineer, Fellow of ASCE, fellow of the Washington Academy of Sciences, and longtime active member of the World Association for Waterborne Transport Infrastructure (PIANC). Contributed by Jane McKee Smith

A historical examination of the Corps of Engineers and natural valley storage protection: the economics and politics of ‘green’ flood control

Abstract Between 1972 and 1994, the US Army Corps of Engineers undertook five studies in New England evaluating the benefits and costs of protecting natural valley storage (NVS) areas—natural reservoirs—for flood mitigation. Only along the Charles River did benefits outweigh costs. Analysis of the studies finds that the costs of large-scale land acquisition will often exceed the sole benefits of avoided flood damages. To generate net benefits, there must be significant amounts of NVS lands still undeveloped, development pressure on those lands, and downstream areas that would sustain large damages. The NVS studies also raised questions of whether the Corps should be involved in land acquisition, and whether regulating land use could substitute for purchasing land. Note, these findings do not apply to other forms of natural flood-risk reduction, such as levee setbacks, green infrastructure for stormwater management, and multi-purpose projects, which have different economic and institutional contexts.

Initial Investigation into the Protection of Manufactured-Home Parks from Hurricanes Using Wind-Deflection Barriers

AbstractParks containing manufactured homes and trailers exist in the hurricane-prone areas of the southern United States. Homes in these parks may suffer heavy damage from high-speed winds. This paper’s objective is to present a methodology and to provide suggestions to the engineering community and protection agencies such as FEMA and the U.S. Army Corps of Engineers (USACE) about a method to lessen damage to groups of manufactured homes. To support the development of this methodology with analysis, an unsteady, Reynolds-averaged, Navier-Stokes computational tool was employed to model a manufactured-home park to evaluate how well a wind barrier installed along its upwind periphery could establish skimming flow over all the buildings in the park. A manufactured-home park that had existed in Punta Gorda, Florida, was studied because satellite pictures before and after it was heavily damaged by Hurricane Charley on August 13, 2004, were available. Computations were performed using a computer program and th...

Nearshore placement of dredged material to support shoreline stabilisation

Navigation channels transecting ebb shoals can influence the shoreline of adjacent beaches. Channels influence ebb shoal formation and sediment bypassing, which includes attachment bars where the shoal abuts the shoreline. Interruption or modification of sediment bypassing mechanisms at coastal inlets alters sediment supply to adjacent beaches, frequently resulting in shoreline erosion. Historically, structures and/or periodic beach fill have been implemented on impacted shorelines. The US Army Corps of Engineers maintains an entrance channel on the Savannah River near Tybee Island, GA, USA. This deep-draught navigation channel has influenced sediment bypassing by the ebb shoal and appears to have contributed to shoreline recession on the north part of Tybee Island. The Corps has addressed this recession issue by beach-placement of sand from an offshore borrow site. The Corps also dredges a significant amount of material from the entrance channel each year to maintain navigability. This dredged material is often greater than 70% sand. However, it is not considered suitable for beach placement. The Corps is investigating nearshore placement of this dredged material along Tybee Island. The goal of nearshore placement is to indirectly nourish the beach by increasing sand supply in the littoral zone. The proposed method of using dredged material will potentially provide a lower-cost alternative to expensive sand-mining and direct beach placement. Nearshore placement of this non-beach quality material will permit natural surf-zone processes to winnow the unwanted fine-grained material and transport it offshore. The Corps initiated a study to investigate the feasibility of nearshore placement for beneficial use of dredged material to nourish the littoral zone. This paper describes a portion of the issues and study methods. Specifically, hydrodynamic, wave and sediment transport models were utilised to assess the fate of dredged material placed in the nearshore. Optimal placement sites were selected based on the study findings.

A shift toward building with nature in the dredging and port development industries: managerial implications for projects in or near Natura 2000 areas.

Building with Nature is a new approach to designing water infrastructure, one that seeks to realize socioeconomic project goals in harmony with the environment. The Dutch dredging industry is promoting its application in the Netherlands, but similar concepts are emerging internationally. The Working with Nature concept has been developed under the auspices of the World Association for Waterborne Transport Infrastructure, Engineering with Nature by the US Army Corps of Engineers, and Flanders Bays 2100 by a group of Belgian dredging companies and international consultants. The research discussed in this article focuses on the feasibility of implementing the Building with Nature approach in the context of EU Natura 2000 governance. The initial expectation of the industry was that Natura 2000 regulations would obstruct innovative Building with Nature attempts. The empirical evidence points to a shift toward Building with Nature have taken place on the governance and project levels, and the goals of Natura 2000 and Building with Nature converging in practice. Using specific project-level variables identified by researchers, guidance for project development in Natura 2000 areas was proposed. We conclude by discussing the implications of the research results for the dredging industry dealing with Natura 2000 regulations in Europe and similar overarching nature regulations elsewhere.

The Economics and Politics of 'Green' Flood Control: A Historical Examination of Natural Valley Storage Protection by the Corps of Engineers

Between 1972 and 1994, the New England Division of the US Army Corps of Engineers undertook five studies evaluating the benefits and costs of protecting natural valley storage (NVS) areas as a flood mitigation strategy in various watersheds. NVS lands function as natural reservoirs, temporarily storing floodwaters. In only one case—along the Charles River in Massachusetts—were the benefits found to outweigh the costs. Along the Charles, the Corps acquired approximately 8,500 acres of floodplain land to keep as open space in perpetuity. This paper reviews the five studies in detail to inform ongoing interest in green approaches to flood control. The analysis finds that large-scale land acquisition to contain major riverine flood events is difficult to justify by avoided flood damages alone. For such a project to generate net benefits, there must be significant amounts of NVS lands still undeveloped, substantial development pressure on those lands, and downstream areas that would sustain high levels of damage in the event of a flood. Perhaps more importantly, however, these studies raise two fundamental institutional questions: (1) Should the Corps, or the federal government more broadly, be involved in land acquisition? (2) Should regulating land use be preferred over purchasing NVS land? The economic and political issues uncovered in the historic examination of these five studies suggest an explanation for the current focus on other approaches to green flood control, such as multipurpose projects, levee setbacks, and green infrastructure to manage stormwater.

A Reliability-Based Evaluation of the Effects of Geometry on Levee Underseepage Potential

Levee foundations along meandering rivers are often modeled in seepage analyses with simplified models consisting of two layers having uniform thickness and soil properties. While this may simplify the analysis and allow for use of simplified reliability methods, it is important to realize the limitations of these simplifying assumptions. Due to the complex geomorphic regime that is often encountered in the fluvial environment, levee foundation geometry can range from simple to very complex. Variations in layer thickness and continuity affect the pore pressure and seepage regime and, consequently, affect the potential for internal erosion of the foundation soils. A study has been performed to assess the effects of complex subsurface geometry on the susceptibility of levees to underseepage related internal erosion. Reliability-based internal erosion analyses have been performed on eight hypothetical levee profiles using two analytical methods. The first-order second-moment-blanket theory (FOSM-BT) method applies a simplified reliability assessment technique to the US Army Corps of Engineers “Blanket Theory” equations. This method requires that the analysis profile be simplified to meet the requirements of the equations and places limitations on how the uncertainty of the various input parameters is modeled. The more complex response surface-Monte Carlo simulation method is capable of modeling more complex geometries and multiple failure modes and is flexible in how uncertainty of the various input parameters are modeled. The results of the two methods are compared to evaluate the effectiveness of the FOSM-BT in evaluating internal erosion potential in increasingly complex levee foundation conditions.

Nutrient Contributions from Alluvial Soils Associated with the Restoration of Shallow Water Habitat in the Lower Missouri River

AbstractThe Missouri River has been extensively altered as the result of channelization, bank stabilization, and the construction of six main stem reservoirs. In response to the resultant habitat loss, the US Army Corps of Engineers was tasked with restoring approximately 8100 ha of shallow water habitat (SWH), in part, for the benefit of the endangered pallid sturgeon (Scaphirhynchus albus). Construction of off‐channel habitats involves the removal and disposal of excavated alluvium either by direct discharge into the river or by secondary erosion, which raised concerns regarding the introduction of sediment and associated nutrients into the Missouri River.Soils from nine side‐channel chutes were sampled to represent nutrient concentrations from habitat restoration activities. Soils from 12 historically undisturbed sites were also sampled to represent reference conditions in the Missouri River flood plain. The results of this study indicate that nutrient characteristics of soils from selected SWH locations generally are similar to those of historically undisturbed soils. The estimated mass of total phosphorus from chutes accounted for 1.9% of Missouri River and 0.5% of Mississippi River total phosphorus loads during the 1993–2012 analysis period. The mass of nitrate, the constituent most closely related to gulf hypoxia, was 0.01% or less of the Missouri and Mississippi River nitrate loads. Sediment volumes from the chutes accounted for 3.1 and 1.5% of total suspended loads from the Missouri and Mississippi Rivers. Overall, the introduced sediment from side‐channel chute construction associated with SWH restoration accounts for a small portion of total nutrient and sediment transport in the Missouri and Mississippi Rivers. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. River Research and Applications published by John Wiley & Sons, Ltd.

Airtightness in New and Retrofitted U.S. Army Buildings

The Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) recently developed design/construction strategies that improve the energy efficiency, reduce the potential for mould, and improve indoor air quality in newly constructed buildings and buildings undergoing major renovations. ERDC-CERL performed building envelope leakage tests on Army facilities to test their general integrity and the effect of increased airtightness on building energy consumption. Results were used to develop airtightness criteria and performance requirements for new construction and major renovation projects, which have been included in Army design/construction strategies.Since 2009, the U.S. Army Corps of Engineers (USACE) has implemented an airtightness requirement in all new construction and building enclosure renovation projects. Engineering and Construction Bulletin (ECB) 2012–16 set levels of airtightness for building enclosures at the material, assembly, and system level. ECB 2012–16 requires whole building air leakage tests to be conducted at completion of construction to verify the constructed air barrier system’s performance. The current Air Leakage Test Protocol for Building Envelopes developed by ERDC-CERL, the Air Barrier Association of America (ABAA), and other industrial partners was published in May 2012.This paper presents the results of airtightness tests before and after the new requirements were established, updated results for air leakage tests of more than 285 newly constructed and renovated large buildings, and a performance analysis of the design and construction process, air barrier materials, building use, and construction types. These data may support future decisions regarding airtightness levels to be adopted for commercial buildings.

Dredging of the fractured bedrock-lined Mississippi River Channel at Thebes, Illinois

The usually abundant slow soaking rain systems and evening thunderstorms that characterize the Great Plains climate from May through August (Hoerling 2013) were absent in 2012. As a result, the Ohio and Mississippi rivers dropped to near record levels from July of 2012 through January of 2013, and the US Army Corps of Engineers (USACE) faced a new challenge to their ability to control the Mississippi River. The 2012 drought reduced the channel depths on the upper Mississippi River between Cairo, Illinois, and St. Louis, Missouri, to only 0.3 to 1.8 m (1 to 6 ft) above the 2.7 m (9 ft) deep navigation shipping channel created by USACE in response to the 1930 Rivers and Harbors Act. Of greatest concern was the bedrock-lined river shipping channel near Thebes, Illinois, which threatened to ground barge traffic transporting critical agricultural supplies, including fertilizers and grain.

The Changing Requirements of Airtightness in the US for Commercial Buildings - The Airtightness of Mid and High-Rise Non-Residential Buildings

Concern over the airtightness of commercial buildings in North America goes back to the mid nineteen sixties, and with increasing concern in the mid-seventies, primarily due to the energy crisis, but also due to building performance, comfort and durability issues. The Model Canadian National Building Code was the first to adopt airtightness requirements for air barriers in 1985 and quantify it in 1995. In 2001 Massachusetts became the first state in the US to adopt a quantified airtightness requirement for air barrier materials and criteria for their design and construction in commercial and high-rise residential buildings. Many Standards and guides followed suit with airtightness requirements, including ASHRAE 90.1 2010 and IECC 2012, making airtightness mandatory in all commercial buildings built to those Standards and Codes. The US Army Corps of Engineers instituted airtightness testing requirements for all its new and renovated buildings in 2009. It requires that a whole building air leakage test be performed at completion of construction to verify performance of the constructed air barrier system. The Air Leakage Test Protocol for Building Envelopes was developed by the USACE Engineer Research and Development Center (ERDC) together with the Air Barrier Association of America (ABAA). In the meantime, ASHRAE decided that there was a lack of scientifically gathered and reported data on modern mid- and high-rise non-residential buildings built since the year 2000. It instituted a research study, 1478 RP, to measure and report air leakage rates for existing mid- and high-rise buildings, to develop a protocol for testing large buildings and to analyze the results with respect to design and construction parameters.

Changing life jacket wearing behavior: An evaluation of two approaches

In the United States during 1999-2012, about 4 per cent of adults wore life jackets while engaged in recreation on powerboats. Educational campaigns have promoted life jacket use. Mandatory use regulations target primarily children or boaters on personal watercrafts or water skiing. We describe findings from two interventions - 'Wear It California!', a targeted marketing campaign in the California Delta region and mandatory wear regulations at four US Army Corps of Engineers (USACE) lakes in the state of Mississippi. Before the campaign in the Delta, adult wear was 8.5 per cent, increasing to 12.1 per cent during the first year, dipping to 9.4 per cent during the second year, and rising slightly to 10.5 per cent 3 plus years after the campaign. Before mandatory regulations at USACE lakes, adult wear was 13.7 per cent, increasing to 75.6 per cent during the first year, 70.1 per cent during the second year, and remaining high at 68.1 per cent in the third year. Policymakers should consider these findings when choosing how to increase life jacket use.

Improving hydroturbine pressures to enhance salmon passage survival and recovery

Barotrauma caused by rapid decompression during hydroturbine (turbine) passage may occur as fish move through the low pressure region below the turbine runner. This scenario is of particular concern in North American rivers with populations of ESA-listed salmon. The US Army Corps of Engineers (USACE) and the Pacific Northwest National Laboratory released Sensor Fish into lower Snake and Columbia River turbines to determine the magnitude and rate of pressure change fish might experience. Recorded pressures were applied to simulated turbine passage (STP) in laboratory studies to determine the effect of rapid decompression on juvenile Chinook salmon. These STP studies have increased our understanding of how pressure effects fish passing through turbines and suggest that the ratio of pressure change [acclimation pressure (the depth upstream of the dam where fish are neutrally buoyant) divided by nadir pressure (lowest pressure)] is highly predictive in determining the effect on smolt survival. However, uncertainty remains in smolt acclimation depth prior to entering turbine intakes at hydroelectric facilities. The USACE continues to make progress on salmon survival and recovery efforts through continued research and by applying pressure study results to turbine design. Designing new turbines with higher nadir pressure criteria is likely to provide safer fish passage for all salmonid species experiencing turbine passage.

Project Benchmarking: Tool for Mitigating Conflicts, Claims, and Disputes through Improved Performance

AbstractThe construction industry significantly contributes to the U.S. economy. However, this important industry is negatively affected with many challenges including safety issues, design errors, delay, and changes. To this end, performance measurement has become a commonly used tool for evaluating processes, managing human resources, and formulating corrective strategies. One of the most important aspects of performance measurement is the ability to perform benchmarking. Using case studies of projects carried out by the U.S. Army Corps of Engineers (USACE) in its Vicksburg District, this paper investigates how benchmarking can be used to evaluate and measure performance of the associated contractors, and thus mitigate conflicts, claims, and disputes. The utilized methodology encompassed three interdependent steps in which the writers: (1) collected project data for 40 contractors who performed work for USACE using file reviews for submittals, requests for informations (RFIs), claims, progress reports, ...

Testing a mediation model of customer service and satisfaction in outdoor recreation

This paper examines a model of customer service and satisfaction in the outdoor recreation experience. More specifically, it focuses on the question of whether domain-level satisfaction mediates the relationships between specific customer service attributes and the overall evaluation of an experience. Data were collected through a nationwide assessment of customer service at US Army Corps of Engineers (COE) lakes. Face-to-face interviews were conducted at 10 COE lakes located throughout the United States (n=2933 completed interviews). The survey instrument measured three levels of visitor satisfaction (19 individual attributes, four domains, and overall satisfaction). Study results supported the hypothesized model by confirming the relationships between individual customer service attributes, satisfaction within customer service dimensions (or domains) and overall satisfaction. The influence of some items, however, overlapped across multiple dimensions. The relevant items accounted for between 29% and 41% of the variance associated with satisfaction within the customer service domains. In turn, satisfaction within the domains explained 15% of the variance in overall satisfaction. Management implicationsVisitor satisfaction is one of the fundamental concepts in outdoor recreation. This research investigated the relationship between subjective evaluations of overall client satisfaction with several of its components. Results suggest the following insights for managing outdoor recreation areas to improve visitor satisfaction:•Findings underscore the importance of maintaining and improving the esthetics of recreation areas. Feelings about the appearance of the area were the strongest predictor of satisfaction with facilities, and influenced satisfaction in the other domains as well.•Current and accurate information was found to be the most important determinant of satisfaction with information services, highlighting the need for recreation managers to continually review and update information provided to the public.•Surveys of customer satisfaction in outdoor recreation areas should not only consider tangible indicators of facilities, services, and information, but also intangible aspects of the outdoor recreation experience. Factors such as the opportunity to recreate without crowding affected visitors' feelings of satisfaction with facilities and services as well as their satisfaction with their overall outdoor recreation experience.

A comparative slope stability analysis of sheet pile supported I-wall in New Orleans, Louisiana with sheet pile penetrating into sand layer

Computer modelling and stability analyses of the New Orleans I-walls with and without the consideration of gap formation has drawn significant attention of the engineering community during the post Katrina period. In addition, when the sheet pile penetrates into sand layer, seepage becomes an integral part of the stability analysis. Basic guidelines have been developed for the analysis of this problem by other researchers and documented by the U.S. Army Corps of Engineers (USACE). However, the inherent complexity of the problem and uncertainties associated with the choice of analysis methods warrant for further investigation of this problem in detail so that more useful insights can be gained. In this paper, a comprehensive analysis of this complex coupled problem of seepage and stability of a typical New Orleans I-wall is presented using different limit equilibrium methods of slope stability analysis. Useful comparisons are made between the analyses results and methodologies. The authors believe that the findings of this study will enhance the understanding of the behaviour of the I-wall sheet pile system subjected to seepage forces, when different limit equilibrium methods of analyses are invoked.

A Multigrid Wave Forecasting Model: A New Paradigm in Operational Wave Forecasting

Abstract A new operational wave forecasting system has been implemented at the National Centers for Environmental Prediction (NCEP) using the third public release of WAVEWATCH III. The new system uses a mosaic of grids with two-way nesting in a single model. This global system replaces a previous operational wave modeling suite (based on the second release of WAVEWATCH III). The new forecast system consists of nine grids at different resolutions to provide the National Weather Service (NWS) and NCEP centers with model guidance of suitable resolution for all areas where they have the responsibility of providing gridded forecast products. New features introduced in WAVEWATCH III, such as two-way nesting between grids and carving out selected areas of the computational domain, have allowed the operational model to increase spatial resolution and extend the global domain closer to the North Pole, while at the same time optimizing the computational cost. A spectral partitioning algorithm has been implemented to separate individual sea states from the overall spectrum, thus providing additional products for multiple sea states. Field output data are now packed in version 2 of the gridded binary (GRIB2) format and apart from the standard mean wave parameters, they also include parameters of partitioned wave spectra. The partitioning is currently limited to three fields: the wind-wave component, and primary and secondary swells. The modeling system has been validated against data using a multiyear hindcast database as well as archived forecasts. A new software tool developed by the U.S. Army Corps of Engineers (USACE) is used to extend the analysis from overall error estimates to separate skill scores for wind seas and swells.

The media and discretionary behaviour of bureaucrats

Due to the public good character of protective measures against natural disasters, their allocation is very often in the realm of bureaucratic and expert agencies. I analysed the effect of negative media reports on a bureaucratic agency's output decisions by applying a Vector Autoregression (VAR) model on annual data of the US Army Corps of Engineers' (USACE) spending on flood protection from 1968 to 2008. The results showed that the negative media reports about the agency subsequently increase formal output.

Impacts of 2011 Len Small levee breach on private and public Illinois lands

A griculture, the dominant land use of the Mississippi River Basin for more than 200 years, has substantively altered the hydrologic cycle and energy budget of the region (NPS 2012). Extensive systems of US Army Corps of Engineers (USACE) and private levees from the Upper Mississippi River near Cape Girardeau, Missouri, southward confine the river and protect low-lying agricultural lands, rural towns, and public conservation areas from flooding. The Flood of 2011 severely tested these systems of levees, challenging public officials and landowners to make difficult decisions, and led to extensive damage to crops, soils, buildings, and homes. One of these critical levees (figure 1), the Len Small, failed, creating a 1,500 m (5,000 ft) breach (figure 2) where fast-moving water scoured farmland, deposited sediment, and created gullies and a crater lake. The Len Small levee, built by the Levee and Drainage District on the southern Illinois border near Cairo to protect private and public lands from 20-year floods, is located between mile marker 21 and mile marker 35 (figure 1). It connects to Fayville levee that extends to Mississippi River mile marker 39, giving them a combined length of 34 km (22 mi) protecting 24,000 ha (60,000 ac) of farmland…