FINAL REPORT 

June 2008 

(Revised August 14, 2008) 
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MAIN REPORT 

EXECUTIVE SUMMARY 

Background 

The Flood of 1993 provided a vivid demonstration of the vulnerabilities of the existing flood control 

systems on the Upper Mississippi River System (UMRS). Forty-seven deaths were attributed to the 

Flood of 1993, and assessments of the economic damages range from $15 to 20 billion including more 

than $2.9 billion in damages along the Mississippi River and its floodplain. The social disruption was 

beyond measure, with more than 70,000 homes damaged or destroyed and approximately 74,000 

persons evacuated from flooded areas. In-place flood risk management facilities built by the U.S. 

Army Corps of Engineers prevented an estimated $19 billion in potential additional damages. While 

the size and impact of the Flood of 1993 was unprecedented in recent history, floods of equal or 

greater magnitude will likely occur in the future, and the region will likely again be exposed to the 

destructive potential of the Mississippi and Illinois Rivers. 

The flood damage reduction facilities (Federal and non-federal) of the Upper Mississippi River 

System were not constructed in accordance with any overall systemic plan. These facilities have 

varying structural integrity, and provide varying levels of flood risk reduction for similar land uses. 

Not since 1981 (with the termination of the Upper Mississippi River Basin Commission) has there 

been an overall active planning authority for Upper Mississippi River System resources management. 

The Mississippi River Commission (MRC) has statutory authority for the general improvement of the 

river from the Head of Passes to its headwaters near Lake Itasca. The MRC started a process of 

listening, inspecting, and partnering in the Upper Mississippi Basin in 1997, but in its current capacity 

the Commission does not have the funded authority to implement plans of improvement in the basin as 

it does with the comprehensive Mississippi River & Tributaries (MR&T) project below Cape 

Girardeau, MO. 

The Flood of 1993 awakened renewed interest in developing a systemic approach to flood damage 

reduction on the Upper Mississippi River System. In authorizing this study, Congress recognized the 

need for a planning effort that develops a floodplain management plan in which there may be a Federal 

interest. 

The Upper Mississippi and Illinois River floodplains have extensive existing flood control projects 

consisting of levees and floodwalls and large tributary reservoirs. Many of the levee systems were 

originally built privately between 1880 and 1920 and upgraded later. The average age of all the 

systems, when the last major construction upgrade occurred, is just over 46 years. The average year of 

the last construction upgrade of the agriculture systems on the Upper Mississippi and Illinois Rivers 

was 1940, making the agriculture systems upgrade, on average, over 65 years old. The various 

systems level of protection is from less than 2 percent (50-year) up to the 0.2 percent (500-year) 

annual chance protection. In addition, there are numerous environmental areas, managed by Federal, 

state or local governments. Today, most components of this system were federally constructed or 

improved, and were planned and built incrementally (rather than systemically) under various 

authorities. There are separable areas of the floodplain which have non-federal projects, not meeting 

USACE design and construction standards. About three quarters of the existing urban systems exist at 

the 0.2 percent (500-year) annual chance level of protection. 

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The Importance of the Upper Mississippi River Basin 

The study area of the Upper Mississippi River Comprehensive Plan (Comprehensive Plan) is the 

Upper Mississippi River Basin drainage area above Cairo, IL, at the confluence of the Mississippi and 

Ohio Rivers exclusive of the Missouri River Basin, and encompasses approximately 185,000 square 

miles. 

The Upper Mississippi River System (UMRS) and associated environments have a rich record of 

human history spanning over 12,000 years that is increasingly being documented as one of the most 

archeologically and historically significant regions in the country. The abundant and diverse ecological 

resources found along the UMRS have attracted and sustained human populations for thousands of 

years, providing food, water, shelter, and transportation. In modern times, the Upper Mississippi River 

System has assumed a significant role in the development and prosperity of the Midwestern economy 

and way of life. The presence of the rivers provides many benefits to the States and counties along the 

river corridor. Benefits are derived from the employment and income generated from transportation of 

goods, recreation, hydropower production, and water supply for municipalities, commercial, industrial 

and domestic use. Some of these benefits are: 

• Commercial and recreational fishery. 

• About half of the 30 million residents of the watershed rely on the water from the UMR and its 

tributaries for municipal and industrial water supplies. 

• It provides for over $6.6 billion dollars in revenue annually from some 12,000,000 visitor-days of 

use by people that hunt, fish, boat, sightsee or otherwise visit the river, its magnificent bluffs and 

communities (Black et al. 1999). 

• Recreation and tourism employ 143,000 people in the corridor. 

• It provides the important benefit of over 1,191 river miles of diverse natural, rural and urban open 

space for human exploration, experiential education, spiritual renewal and aesthetic enjoyment. 

The primary impact area of the study lies within the 78 counties bordering the Upper Mississippi River 

and Illinois Waterway. Together, these counties contain nearly 5 percent of the nation’s population, 

with total population in 2000 of nearly 13.4 million.

Further, the importance of the entire Mississippi River Basin to the Nation is demonstrated by the fact 

that Congress established the Mississippi River Commission (MRC) in 1879, over 125 years ago. The 

Mississippi River Commission’s stated purpose by the Forty-Sixth Congress is “for the improvement 

of said river from the Head of Passes near its mouth to its headwaters.” The President appoints seven 

members, with the advice and consent of the United States Senate. 

The Comprehensive Plan 

The authority for and purpose of the Upper Mississippi River Comprehensive Plan (Comprehensive 

Plan) is contained in Section 459 of the Water Resources Development Act of 1999, which states in 

part that: “The Secretary shall develop a plan to address water resource and related land resource 

problems and opportunities in the upper Mississippi and Illinois River basins, from Cairo, Illinois, to 

the headwaters of the Mississippi River, in the interest of systemic flood damage reduction....” 

Due to the very large study area, the watershed encompasses about 185,000 square miles and about 

1,025 river miles, and in consideration of fiscal and time constraints, it was determined that the scope 

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would be limited to the Mississippi and Illinois Rivers floodplain and not be a comprehensive 

watershed analysis. Further, while the discharges of the tributaries including the Missouri River Basin 

were included in the flood frequency analysis for the Comprehensive Plan, no tributaries, except the 

Illinois River were studied or analyzed. This current analysis was performed to about a 

reconnaissance phase level, also known as Section 905(b) analysis. Any recommendation for 

authorization would typically require more detailed analysis in a later phase. 

The Comprehensive Plan followed the Corps of Engineers six planning steps used in the formulation 

of alternative plans. 

1. Identify Problems and Opportunities. The specific problems and opportunities are 

identified, and the causes of the problems discussed and documented. Planning goals are set, 

objectives established, and constraints identified. 

2. Inventory and Forecast Resource Conditions. This step characterizes and assesses 

conditions as they currently exist and forecasts the most probable without-project condition (or no 

action alternative) over the period of analysis. This assessment gives the basis by which to compare 

various alternative plans and their likely impacts. 

3. Formulate Alternative Plans. Alternative plans are developed in a systematic manner to 

ensure that reasonable alternatives are evaluated. 

4. Evaluate Alternative Plans. The evaluation of each alternative consists of measuring or 

estimating the economic benefits, costs, environmental impacts, and social effects of each plan, and 

determining the difference between the without-project and with-project conditions. 

5. Compare Alternative Plans. Alternative plans are compared, focusing on the differences 

among the plans identified in the evaluation phase and public comment. As part of the evaluations, 

the best plans are identified based upon those plans that provide the greatest economic benefits for the 

least cost. 

6. Select Recommended Plan. A recommended plan is selected based upon the comparison of 

alternative plans. If no alternative which can be implemented is identified, the recommended plan is 

the No Action alternative. 

In the execution of the Comprehensive Plan, coordination with various other Federal, state, local and 

non-governmental agencies and groups occurred through the Collaboration Team created in 2002. 

The coordination occurred through team meetings, teleconference calls, and electronic transmission of 

documents. 

The objectives developed from considering the problems, opportunities, and the authorizing language 

include: 

• minimize the threat to health and safety resulting from flooding by using structural and non-

 structural flood damage reduction measures; 

• reduce damages and costs associated with flooding; 

• identify opportunities to support environmental sustainability/restoration goals of the Upper 

 Mississippi and Illinois River floodplains as part of any systemic flood damage reduction 

 plan; 

• seek opportunities to address, in concert with flood damage reduction measures, other 

 floodplain specific problems, needs and opportunities to include: 

o continued maintenance of the navigation project and related commercial 

 infrastructure; 

o reduction of nutrient input and sedimentation into the rivers; 

o improved habitat management; 

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o bank caving and erosion reduction; 

o improved recreation opportunities; and 

• identify and recommend appropriate follow-on studies. 

The Comprehensive Plan used recently updated frequency water surface profiles from the Upper 

Mississippi, Missouri and Illinois River Flow Frequency Study (Flow Frequency Study) for frequency 

floods between the 50 percent (2-year) chance annual event and 0.2 percent (500-year) chance annual 

event. This is the first time since the Flood of 1993 that an updated frequency analysis is being used 

on a systemic basis. 

The Upper Mississippi River Comprehensive Plan investigated systemic flood risk management plans 

for the floodplain of the Upper Mississippi and Illinois Rivers. In developing the plans, both structural 

and nonstructural flood damage reduction alternatives were considered. Work accomplished within 

the Comprehensive Plan was an effort involving a Collaboration Team consisting of the Corps of 

Engineers Rock Island, St. Louis, and St. Paul Districts, a number of other Federal and state agencies, 

and attendance and participation by non-governmental organizations. In total, fourteen alternatives 

were considered, and eight alternative plans were evaluated in detail ranging from floodplain buyouts, 

non-structural plans, to structural alternative plans including various increases in the level of 

protection 

The evaluation of alternative plans is accomplished using the four accounts established in the Corps’ 

Principles and Guidelines to facilitate the evaluation and display of effects of alternative plans (ER 

1105-2-100): 

• The National Economic Development (NED) account displays changes in the economic value 

of the national output of goods and services. 

• The Environmental Quality (EQ) account displays non-monetary effects on ecological, 

cultural, and aesthetic resources including the positive and adverse effects of ecosystem restoration 

plans. 

• The Regional Economic Development (RED) account displays changes in the distribution of 

regional economic activity (e.g., income and employment). 

• The Other Social Effects (OSE) account displays plan effects on social aspects such as 

community impacts, health and safety, displacement, energy conservation, and others. 

The Corps seven Environmental Operating Principles, published in 2002, and the Chief of Engineers’ 

12 Actions for Change, which were issued in August 2006, were considered as alternative plans were 

developed and formulated. 

Alternative plan evaluation using the NED and EQ accounts is required. The hydraulic analyses of the 

alternative plans formulated utilizies the existing numerical hydraulic (UNET) models developed for 

the Flow Frequency Study along with a new, stochastically-generated, 1,000 years of tributary 

inflows. The alternative plans were evaluated using traditional expected value (damage and flood 

probability) analysis. Current stage frequency profiles were used to provide elevations for floods with 

varying probability. Alternative plans were evaluated from an ecosystem and environmental 

opportunities aspect in the five following major categories: mitigation; secondary development; 

ecosystem restoration; nutrients; and sediments. The environmental evaluation presented results in 

acres. 

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Regional Economic Development (RED) evaluation was accomplished in detail for three alternative 

plans. For the Upper Mississippi River Comprehensive Plan, RED benefits were computed by the 

Tennessee Valley Authority (TVA) for three alternatives. The TVA estimated that every dollar spent 

on comprehensive flood risk management reduction would generate as much as $5.00 in increased 

gross regional product. Projected employment was also evaluated. 

A series of four public meetings was held to present the Comprehensive Plan results. The public 

meetings were held the last week of June 2006, about a month after the draft Comprehensive Plan 

Report was released to the public. There was generally significant support for a reduction in flood risk 

in the UMRS. Though some questioned the need and advisability of such a potential large 

expenditure. Plan G, proposed by the Upper Mississippi, Illinois, and Missouri Rivers Association 

(UMIMRA), a member of the Collaboration Team, was strongly supported at the three public 

meetings held north of St. Louis, MO. Attendees at the fourth and last public meeting held at Chester, 

IL, located on the Mississippi River south of St. Louis, MO, opposed Plan G. Plan G, in addition to a 

high level of protection, required a 10,000 acre storage area located in the floodplain of Monroe 

County, IL, which is located just south of St. Louis. The storage area in Monroe County, IL was a 

major area of concern. The storage area would probably require purchase of the 10,000 acres, which 

local residents strongly opposed. Written correspondence in response to the public meetings including 

letters, emails, calls and petitions, was about evenly split, supporting and opposing Plan G. Over the 

months following the public meetings, a series of meetings was held with publics and representatives 

of the drainage and levee districts south of St. Louis, MO. In direct response to the meetings held and 

input received during this period, Plans B and G were the further refined and Plan M, was formulated. 

To complete alternative plan evaluation, the Comprehensive Plan obtained assistance from the Corps 

of Engineers Engineer Research and Development Center (ERDC), located in Vicksburg, MS, in 

applying the new Risk Informed Decision Framework (RIDF) methodology that draws from current 

practice in the fields of multi-criteria decision analysis (MCDA) and risk and uncertainty analysis. 

Plan H, with Plan D very close behind, and to a slightly lesser extent Plan M, emerged as the highscoring alternative plan using the RIDF methodology. 

CONCLUSIONS 

General Overview. 

The need for a comprehensive, systemic plan for flood risk reduction and floodplain management 

along the Upper Mississippi and Illinois Rivers has been recognized by numerous stakeholders and in 

numerous documents and forums including the post-1993 flood reports and the regional summit 

meetings of the mid-1990’s. This recognition ultimately led to the authorization of the Upper 

Mississippi River Comprehensive Plan (Comprehensive Plan) in the Water Resources Development 

Act (WRDA) of 1999 (Section 459), which states in part that, “The Secretary shall develop a plan to 

address water resource and related land resource problems and opportunities in the upper Mississippi 

and Illinois River basins, from Cairo, Illinois, to the headwaters of the Mississippi River, in the 

interest of systemic flood damage reduction ” 

The study investigated opportunities to develop and implement a systemic approach that reduces 

cumulative flood risk costs and annual flood damages, while simultaneously providing long term 

improvements to other system values and uses (ecological, economic, recreation, transportation, etc.). 

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A number of Corps studies completed since the Flood of 1993, provided the foundation for evaluation 

of a comprehensive systemic plan for flood risk reduction. 

The Upper Mississippi River Comprehensive Plan provides a possible framework to go forward with 

flood risk reduction by interested Federal, state and locals interests. In total, eight alternatives were 

evaluated in detail ranging from reconnection of the floodplain through buyouts to various levels of 

increases in the level of protection, up to a systemic 500-year level of protection. 

Two significant events occurred during the period of preparation of the draft report in 2005 that served 

to refine the study approach and analysis. First, two severe hurricanes, Katrina and Rita, hit the 

southern United States. The hurricane experience, in addition to the lessons of the Flood of 1993, 

resulted in a reexamination of approaches to flood risk management and flood mitigation, changing 

some perspectives and increasing the emphasis on risk informed decision making rather than relying 

on more narrowly defined economic decision criteria. Secondly, during the development of the report, 

the Corps of Engineers issued several engineering circulars, emphasizing collaborative approaches to 

planning and reaffirming the assessment of plans based on all four accounts: NED, EQ, RED and 

OSE. 

The lessons learned from the 1993 Flood and Hurricanes Katrina and Rita were incorporated into the 

UMR Comprehensive Plan, including the recognition that flood risk management is a shared Federal, 

state and local responsibility and any future improvements will need support from all interests. To 

assist in providing a framework for complex decision making, the project team and stakeholders 

utilized a Risked Informed Decision Framework (RIDF). RIDF is a planning tool which incorporates 

risk and uncertainty information into the decision process. One outcome of the process highlighted 

the importance of public health and safety. Prior to implementing RIDF, while Other Social Effects 

were considered, the analysis focused on net NED benefits in the selection process. However as 

indicated above, both the 1993 Flood and Hurricanes Katrina and Rita demonstrated that using the 

NED results as the primary decision tool does not adequately address public health and safety, 

especially in the event of infrequent floods. 

Evaluation of the project alternatives revealed very low National Economic Development benefits and 

high RED (state and local) benefits. In addition the impacts of the OSE and EQ accounts were 

considered as part of the evaluation. To meet the legislative requirement to develop a systemic plan 

for flood protection, it is clear that a collaborative partnership of Federal, state and local interests is 

necessary. The Corps can bring technical expertise (hydraulic, hydrologic, economic, environmental, 

and engineering) to such a collaborative partnership as well as coordination with existing Corps 

programs (Upper Mississippi River And Illinois Waterway System Navigation Environmental 

Sustainability Program (NESP); the Environmental Management Program (EMP); Illinois River Basin 

Restoration, Sec. 519 (Illinois 519)); and other environmental programs to help prioritize and locate 

environmental projects that benefit the Upper Mississippi River System. 

As the Comprehensive Plan was limited to the Mississippi and Illinois River floodplain, about 4,000 

square miles, rather than the entire watershed, there exists the possibility of performing watershed 

analysis on major tributaries in the future. 

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Conclusions 

Systemic Flood Risk Management. 

The existing flood risk management systems currently prevent 95-97% of the potential average annual 

flood damages on the system. However, the Flood of 1993 and Hurricanes Katrina and Rita have 

clearly shown that even low residual risk may not meet the Nation’s expectations with regard to public 

health and safety. If there would be an overtopping of a levee or floodwall, a catastrophic loss could 

result. 

None of the comprehensive, systemic flood damage reduction plans that were evaluated had net 

positive NED benefits. For the eight plans evaluated, benefit-to-cost ratios (BCR) were below 0.1. 

Initial analysis indicated NED benefit-to-cost ratios of greater than one for a project addressing critical 

transportation facilities (e.g. bridge approaches, etc.). 

Environmental Quality (EQ) opportunities exist within the Upper Mississippi River floodplain. 

Coordination between other Corps programs (NESP, EMP and Illinois 519) and the Comprehensive 

Plan could encourage wetland and conservation in areas that would also result in flood risk reduction. 

Existing conservation areas located in the Upper Mississippi and Illinois Rivers floodplain may be 

impacted by the rise in water surface profiles if a systemic flood risk management plan is 

implemented. 

Implementation of a large, systemic flood risk reduction plan would result in significant regional 

economic benefits. The Tennessee Valley Authority estimated that every dollar spent on 

comprehensive flood risk reduction (i.e., 500-year level of risk reduction for urban areas and 100-year 

or greater level of risk reduction for agricultural areas - Plans A, B, D, G, H or M) would generate as 

much as $5 in increased gross regional product for every dollar expended. Also, employment could 

increase by more than 20,000 jobs annually in the five-state Upper Mississippi Valley Region 

resulting from upgraded levee protection provided by the full implementation of a comprehensive 

flood risk reduction plan.

Other Social Effects (OSE) benefits for public health and safety and displacement would occur if a 

systemic alternative plan were implemented.

From a stakeholder view, the results of applying the Risked Informed Decision Framework (RIDF) 

indicated a preference for a comprehensive plan with a high level of risk reduction for the entire Upper 

Mississippi River System. 

Plans B, G, H and M are all similar in providing a high level of flood risk reduction. Plan H includes a 

cost comparison. For Plan H, the construction cost of increasing the system height, typically raising a 

levee, is compared to the cost of acquisition of the district, and the cost effective option, either the 

levee raise or acquisition, then becomes a part of Plan H for that site. Any district could choose not to 

be a part of the plan and then the district would stay “as is” or find other resources to improve the 

existing level of protection. Of the existing flood damage reduction systems, 37 systems should be 

further evaluated using a cost comparison methodology. 

A Regional or National oversight group (e.g., the Mississippi River Commission or an interstate 

group) would provide assistance to the states and local drainage and levee districts to implement a 

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comprehensive flood risk management plan. This oversight would provide a regular review of the 

water resources problems, needs and opportunities in a collaborative framework working with other 

Federal, state and local agencies and non-governmental organizations, stakeholders, and the interested 

public. This oversight group would be the catalyst to address the problems and needs collaboratively. 

The Corps could assist by bringing its leadership and expertise in technical areas (e.g., hydrology and 

hydraulics, economic and environmental analysis, and engineering) to bear in addressing the changing 

problems, needs, and opportunities of the region. The Corps could also help coordinate environmental 

programs, including NESP, EMP, and Illinois 519, to provide greater priority for projects benefiting 

flood risk reduction, navigation, bank caving, and erosion, watershed nutrient and sediment 

management, recreation needs, and other purposes. 

Reconstruction. 

The Upper Mississippi River Comprehensive Plan recognized the importance and benefit of the 

existing flood damage reduction systems in place. Due to the average age of the last major 

construction upgrade, over 45 years, and condition, the existing flood risk reduction systems need to 

be evaluated to determine the feasibility of reconstruction. Reconstruction could insure that the 

systems continue to provide the billions of dollars in benefits for the foreseeable future. The average 

year of last construction upgrade of the agriculture systems on the Upper Mississippi and Illinois 

Rivers was 1940, making the last system major construction upgrade, on average, over 65 years old. 

The reconstruction effort would focus on a feasibility phase level of evaluation of the system 

components including pump stations, gates, closures, and supporting infrastructure. Further, 

reconstruction would address, if necessary, the current frequency water surface profiles and the height 

of the existing protection systems to determine if the systems have to be raised to maintain the 

authorized level of protection. 

Critical Infrastructure – Transportation. 

Preliminary analysis of costs and benefits for the protection of one location crossing the Mississippi 

River indicates that the protection may be economically justified from an NED account evaluation, the 

traditional Corps evaluation account. A systemic analysis of the Upper Mississippi and Illinois Rivers 

for critical transportation infrastructure (e.g. bridge approaches, railroad infrastructure, etc.) using all 

four evaluation accounts may indicate that protection of the transportation infrastructure is worthwhile 

at several locations to insure that the transportation system continues to function during a significant 

flood event. The result of this analysis may indicate where priority plan implementation could occur 

to reduce the flood risk to critical transportation systems. During the Flood of 1993, major east 

west transportation arteries (roads and railroads) were severed causing significant delays and 

major rerouting of goods and individuals. In many cases the rerouting was in excess of 100 

miles. If a flood similar to the Flood of 1993 were to occur today, the container traffic 

disruption from the west coast to the major distribution center in the Chicago area would have 

national ramifications. The reduction of flood risk for this critical transportation infrastructure 

would fit within the total system plan. 

Systemic Hydrologic Analysis of the Upper Mississippi River System. 

The UMR Comprehensive Plan successfully developed a set of tools capable of analyzing the 

hydraulic, economic and environmental effects of systemic flood damage reduction alternatives. 

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The hydrologic body of knowledge of the Upper Mississippi and Illinois Rivers has dramatically 

increased as a direct result of the previously completed Flow Frequency Study and the Comprehensive 

Plan. The systemic modeling is a useable product for the future if maintained. It allows the 

determination of system-wide hydrologic impacts from actual and proposed changes. This modeling 

has the potential to substantially change the way this river system is managed. 

Specific findings of the hydraulic analysis of alternatives include: 

• The levees above Lock and Dam 19 at Keokuk, Iowa (study reaches 1 and 2) can be 

systemically raised without causing more than a one-foot increase in the 1 percent annual chance (100-

year) flood profile anywhere within reaches 1 and 2. 

• Likewise, the levees on the Illinois River (reach 4), river mile 0.0 to 160.0, can be raised 

without causing more than one foot of rise in the 1 percent annual chance (100-year) flood profile. 

• Several flood risk reduction measures (levee setbacks, realignments, and removal of bridge 

obstructions) have only a very localized reduction of water surface profiles. 

• Any raises to levees immediately above the confluence of the Missouri and Mississippi 

Rivers, or south of St. Louis on the Mississippi River, where limited non-leveed floodplain exists, 

would increase flood heights more than one (1) foot. The existing levee alignment in these areas will 

not allow significant flood risk reduction improvements. 

Emergency Action Scenarios. 

Members of the Collaboration Team expressed the need for an evaluation of Emergency Action 

Scenarios for the Upper Mississippi River System to be included as part of the Upper Mississippi 

River Comprehensive Plan. The evaluation of a series of Emergency Action Scenarios, temporary 

raising of levees during a flood emergency of up to three feet, was conducted to develop a better 

understanding of the hydraulic and economic impacts of emergency actions such as flood fighting. 

Hydrologic analysis of a series of scenarios concluded that: 

• There is no induced rise in frequency stage in Reaches 1 and 2 for any of the scenarios. This 

implies that induced damages are not a concern when determining emergency response priorities 

within these reaches. 

• There is no induced rise in frequency stage anywhere along the length of the Mississippi River 

or Illinois River (Reaches 1-4) caused by increasing the level of protection of only urban and industrial 

areas. 

• Induced damages could be a concern at some locations for systemic agricultural levee raises in 

Reaches 3 and 4. 

Potential Follow-on Studies 

The Comprehensive Plan efforts pointed to the need for several follow on studies. The first three 

follow-on studies are specifically recommended in the next section. The fourth study would assist in 

identifying the expected flood risk throughout the Upper Mississippi River System in a useable and 

understandable way to the general public, a key factor in reducing flood risk. 

1. Cost shared feasibility phase reconstruction analysis should be undertaken. This 

reconstruction analysis would be accomplished on individual flood risk management systems 

to evaluate whether rehabilitation on the aging infrastructure is needed and justified to assure 

that the existing system provides benefits in the future. This reconstruction analysis and 

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FEMA Flood Insurance Rate Map development are two immediate examples using the results 

of the hydrologic modeling in Follow-on Study No. 3. 

2. A systemic analysis of critical transportation systems should be performed to determine the 

feasibility of protecting river approaches for land based systems, highways and railroads. 

3. The hydrologic modeling for the Upper Mississippi River System should be maintained and 

updated as changes occur and new data is available. This would make the modeling and its 

results available to all Federal, state and local agencies in the future and would allow new 

tools to be incorporated as available. Existing information used to evaluate project benefits is, 

on the average, over 30 years old. Updating this information would provide decision-makers 

and the public with better quality data upon which to manage the system on a long-term basis. 

Also, The Flood Flow Frequency (FFF) study did not complete the GIS mapping of the 

Illinois River from Mile 42.0 to 90.0, and this should be completed. 

4. Development of a methodology to clearly convey the flood risk for the Upper Mississippi 

River System should be undertaken using a combination of technology tools, such as a 

geographic information system (GIS), and a series of river gages, so the public can relate a 

specific location to the expected flood risk. 

5. To close data gaps in our understanding of the river system, investments should be made in 

GIS-based computer modeling, a second generation Habitat Needs Assessment, long-term 

sediment monitoring, and pilot Projects for evaluating wetlands creation using existing 

agricultural drainage districts as a potential management tool for nutrients control and 

reduction. 

6. As the Comprehensive Plan was limited to the Mississippi and Illinois River floodplain, about 

4,000 square miles, rather than the entire watershed (185,000 square miles), there exists the 

need of performing a watershed analysis on individual tributaries.. 

RECOMMENDATIONS 

This Upper Mississippi River Comprehensive Plan is prepared in response to the Congressional 

directive contained in Section 459 of the Water Resources Development Act of 1999. While this 

report presents a Comprehensive Flood Risk Management Plan in response to Congressional direction, 

additional authority to implement the Comprehensive Plan is not being recommended nor requested at 

this time based upon the NED evaluation of alternative plans. Specifically, the congressional language 

required the development of a comprehensive plan for systemic flood damage reduction in the upper 

Mississippi and Illinois River basins. While none of the plans evaluated were feasible based on net 

National Economic Development (NED) benefits, decision makers may desire information beyond 

NED to ensure that their decision meets the needs of the Nation. Therefore, in an effort to be 

responsive to the congressional directive, the best performing of the plans evaluated was identified 

based upon consideration of the four evaluation accounts, NED, EQ, RED and OSE, using both 

traditional economic analysis and risk informed decision framework analysis techniques. 

Plan H, while not economically feasible when evaluated by NED guidelines, has been identified as the 

best performing plan of those alternative plans evaluated. Plan H includes a cost effectiveness 

consideration. For Plan H, the construction cost of increasing the system height, typically raising a 

levee, is compared to the cost of acquisition of the district, and the cost effective option then becomes 

a part of Plan H for that site. Any district could choose not to be a part of the plan and then the district 

would stay “as is” or find other resources to improve the existing level of protection. However, it 

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should be noted that Plan H has not been thoroughly vetted with the public and stakeholders. In 

addition, the following factors should be considered by decision makers. 

a. Implementation of Plan H would provide a significant increase in the level of risk reduction 

for the Upper Mississippi River System (UMRS). 

b. There is likely to be limited Federal interest, based upon current guidance, in plan 

implementation by Federal agencies. 

c. Regional or national oversight (e.g., the Mississippi River Commission) would be required to 

ensure the plan functions as a system over the implementation and operation phases of the 

project and project priorities are established to reflect the changing systemic needs. 

d. The States of Illinois, Iowa, and Missouri need to agree on the plan and plan implementation 

to insure the plan is acceptable. The Corps could provide facilitation and technical support to 

this effort. 

e. If Plan H were implemented as a comprehensive, systemic flood risk reduction plan for the 

Upper Mississippi and Illinois Rivers, significant additional technical analysis in all areas 

would be required before final plan design and implementation could be initiated to insure all 

potential impacts are adequately addressed. 

Continued collaboration between Federal agencies, state agencies, and stakeholders, may establish a 

comprehensive approach to flood risk reduction and floodplain management leading to consensus 

building for the UMRS. This would then allow other Federal and non-Federal agencies to bring to 

bear their authorities and capabilities toward implementation. 

Reconstruction. 

It is recommended that a study authorization be established to address reconstruction needs for the 

Upper Mississippi and Illinois Rivers drainage and levee districts. The cost shared feasibility phase 

reconstruction analysis would then be accomplished on individual flood risk management reduction 

systems to evaluate whether rehabilitation of the aging infrastructure (e.g. pumps, gates, closures, etc.) 

is needed and justified to ensure that the systems provide their intended benefits into the future.

Critical Transportation Analysis. 

It is recommended that a regional feasibility study be conducted to evaluate higher levels of risk 

reduction for approaches to bridges crossing the Upper Mississippi and Illinois Rivers. This critical 

transportation feasibility study would include an analysis of all the Upper Mississippi and Illinois 

Rivers bridges/approaches to insure. The analysis could evaluate all four accounts (NED, EQ, RED, 

and OSE). Initial analysis indicates that there may be several locations justified for follow-on 

implementation. 

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Upper Mississippi River Comprehensive Plan 

Main Report 

UPPER MISSISSIPPI RIVER COMPREHENSIVE PLAN 

MAIN REPORT 

TABLE OF CONTENTS 

CONTENTS 

I. STUDY AUTHORITY .......................................................................................................................1 

II. PURPOSE AND SCOPE...................................................................................................................3 

A. Purpose ..........................................................................................................................................3 

B. Description of the Study Area .......................................................................................................3 

C. Scope .............................................................................................................................................4 

III. PRIOR STUDIES, REPORTS, AND EXISTING WATER PROJECTS ........................................7 

A. Prior Studies and Reports..............................................................................................................7 

B. Existing Water Projects on the Upper Mississippi River.............................................................10 

1. The Swamp Land Act of 1850 and Levee Construction before 1900......................................10 

2. Flood Control Acts of 1917 and 1928......................................................................................11 

3. 1930 Rivers and Harbors Act...................................................................................................11 

4. Flood Control Acts of 1936 and 1938......................................................................................12 

5. Flood Control Acts 1944 to 1958.............................................................................................13 

6. Flood Control Projects After 1960...........................................................................................14 

7. Other Water Resource Projects After 1960..............................................................................15 

IV. PLAN FORMULATION................................................................................................................19 

A. Planning Process..........................................................................................................................19 

1. Identify Problems and Opportunities.......................................................................................19 

2. Inventory and Forecast Resource Conditions ..........................................................................19 

3. Formulate Alternative Plans.....................................................................................................19 

4. Evaluate Alternative Plans.......................................................................................................19 

5. Compare Alternative Plans ......................................................................................................19 

6. Select Recommended Plan.......................................................................................................20 

B. Water Resources Development Act (WRDA) 1999, Section 459 ...............................................20 

C. Environmental Requirements ......................................................................................................20 

1. Federal Laws and Executive Orders ........................................................................................20 

2. Corps Policy - Environmental Operating Principles................................................................20 

D. Collaboration Team.....................................................................................................................22 

E. IDENTIFY PROBLEMS AND OPPORTUNITIES, AND INVENTORY AND FORECAST 

FUTURE CONDITIONS..................................................................................................................23 

1. Existing Conditions..................................................................................................................23 

a. Nature of Flooding on the Upper Mississippi River System ...............................................24 

b. Existing Damage Reduction Protection Systems.................................................................26 

d. Critical Infrastructure...........................................................................................................41 

e. Existing Economic Conditions ............................................................................................48 

f. Existing Ecosystem Conditions............................................................................................48 

(1) Land Cover ....................................................................................................................48 

(2) Threatened and Endangered Species .............................................................................50 

2. Future Without Project Conditions..........................................................................................50 

a. Introduction..........................................................................................................................51 

b. Climate and Its Potential Effects on Floods.........................................................................51 

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c. Watershed Land Use and Development...............................................................................51 

d. Floodplain Land Use and Development...............................................................................51 

(1) Environmental................................................................................................................51 

(2) Commercial Development .............................................................................................52 

(3) Residential Development...............................................................................................52 

(4) Transportation Development within Floodplain............................................................52 

(5) Critical Infrastructure Development within Floodplain.................................................53 

(6) Agricultural Use of the Floodplain ................................................................................53 

e. Flood Protective Works........................................................................................................53 

(1) Existing Levees/Floodwalls...........................................................................................53 

(2) New Levees/Floodwalls.................................................................................................54 

(3) Upland Reservoirs..........................................................................................................55 

f. Institutional...........................................................................................................................55 

(1) Federal Programs...........................................................................................................55 

(a) Department of Agriculture.........................................................................................55 

(b) U.S. Fish and Wildlife Service ..................................................................................55 

(c) Federal Emergency Management Agency.................................................................55 

(d) U.S. Army Corps of Engineers..................................................................................56 

(2) State Programs...............................................................................................................56 

(3) Non-Governmental Organizations (NGOs.....................................................................56 

3. Problems and Opportunities.....................................................................................................56 

a. The Problem.........................................................................................................................57 

(1) Flood Damage................................................................................................................57 

(2) Ecosystem Resources.....................................................................................................58 

(a) Floodplain Connectivity ............................................................................................58 

(b) Water Pollution..........................................................................................................58 

(c) Sedimentation ............................................................................................................59 

b. Goals and Opportunities. .....................................................................................................59 

c. Planning Constraints. ...........................................................................................................60 

d. Inventory and Forecast Resource Conditions ......................................................................61 

F. Formulation of Alternative Plans .................................................................................................61 

1. Identify Measures and Strategies .............................................................................................62 

a. Flood Damage Reduction Measures ....................................................................................62 

b. Ecosystem Restoration Measures ........................................................................................63 

2. Plan Formulation Philosophies and Design Criteria ................................................................65 

a. Philosophies.........................................................................................................................65 

b. Design Criteria.....................................................................................................................66 

(1) The existing level of protection .....................................................................................66 

(2) Increase of one foot for the 1 percent annual chance (100-year) flood..........................66 

(3) Minimize water surface profile rise at Thebes, IL. ........................................................66 

(4) The ratio of total average annual damages per acre.......................................................66 

3. Description of Alternative Plans..............................................................................................67 

G. ALTERNATIVE PLAN EVALUATION ...................................................................................79 

1. Hydraulic, Economic and Environmental Evaluation of Alternative Plans.............................79 

a Hydraulic Evaluation ............................................................................................................80 

b. Economic Evaluation...........................................................................................................80 

(1) General Methodology ....................................................................................................80 

(2) Social Impacts................................................................................................................83 

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c. Hydraulic and Economic Evaluation Results.......................................................................84 

d. Environmental Evaluation ...................................................................................................92 

(1) General Methodology ....................................................................................................92 

(a) Mitigation ..................................................................................................................92 

(b) Secondary Development............................................................................................92 

(c) Ecosystem Restoration Opportunities .......................................................................93 

(d) Nutrients Reduction...................................................................................................93 

(e) Sediments Reduction .................................................................................................93 

(2) Plans Quantified for Environmental Impacts.................................................................94 

(3) Plans Not Quantified for Environmental Impacts..........................................................96 

2. Risk Informed Decision Framework (RIDF) Evaluation.........................................................96 

a. Why RIDF?..........................................................................................................................96 

b. Alternative Plans Evaluated using RIDF.............................................................................97 

c. RIDF Results........................................................................................................................97 

H. COMPARISON OF ALTERNATIVE PLANS ..........................................................................98 

I. OTHER FLOOD RISK MANAGEMENT CONCEPTS CONSIDERED..................................101 

1. Emergency Action Plan / Emergency Action Scenarios.........................................................101 

a Emergency Action Scenarios..............................................................................................101 

b Methodology for an Emergency Action Plan .....................................................................104 

2. Reconstruction of the Existing Flood Risk Management System..........................................105 

a Wood River Levee System Reconstruction. .......................................................................106 

b The St. Louis Flood Protection System, Missouri. .............................................................106 

c WRDA 2007, SEC 5070.....................................................................................................107 

V. COORDINATION AND PUBLIC VIEWS ..................................................................................109 

A. Coordination..............................................................................................................................109 

B. Public Views..............................................................................................................................110 

1. Correspondence......................................................................................................................110 

2. UMIMRA Preferred Plan.......................................................................................................110 

VI. CONCLUSIONS ..........................................................................................................................113 

VII. RECOMMENDATIONS ............................................................................................................119 

ACRONYMS AND ABBREVIATIONS............................................................................................121 

REFERENCES ....................................................................................................................................122 

GLOSSARY ........................................................................................................................................123 

TABLES 

Table 1. Environmental Requirements (Federal Law/Executive Orders).............................................21 

Table 2. Description of the Four Reaches.............................................................................................24 

Table 3. Summary of Existing Flood Control Systems ........................................................................27 

Table 4. Mississippi River – Summary of Start of Damages for Existing Systems .............................33 

Table 5. Illinois Waterway – Summary of Start of Damages for Existing Systems.............................33 

Table 6. Drainage and Levee Districts with Major Flood Protection Infrastructure ............................35 

Table 7. Critical Infrastructure at Risk of Inundation due to the 500-year Frequency Flood Event ....42 

Table 8. Critical Infrastructure at Risk of Inundation due to the 500-year Frequency Flood Event ....46 

Table 9. Land Cover Class Distribution ...............................................................................................49 

Table 10. Species within the Upper Mississippi River System Floodplain Listed as Threatened or 

Endangered under the Federal Endangered Species Act (ESA)............................................................50 

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Table 11. Number of Species Listed Threatened and Endangered in Each State .................................50 

Table 12. Description of Ecosystem Restoration Options ....................................................................64 

Table 13. Summary Description of Alternative Plans ..........................................................................77 

Table 14. Evaluation of Plan A - 500-yr Urban, 500-yr Ag .................................................................85 

Table 15. Evaluation of Plans B, D and E ............................................................................................87 

Table 16. Evaluation of Plan H - Comparison of Cost of Protection/Acre vs. Buyout/Acre...............89 

Table 17. Plan J, Water Surface Change - Maximum, Average & Minimum Water Surface Change 90 

Table 18. Plans Quantified for Specific Types of Environmental Impact ............................................94 

Table 19. Summary Evaluation of Alternative Plans............................................................................99 

Table 20. Evaluation of Emergency Action Scenarios – Induced Rise ( measured in feet) ...............103 

Table 21. Evaluation of Emergency Action Scenarios – Average Annual Damages .........................103 

FIGURES 

FIGURE 1. The Upper Mississippi River Basin.....................................................................................5 

FIGURE 2. Study Area Indicating the Four Reaches and Corps offices................................................6 

FIGURE 3. Sample Damage Curve ......................................................................................................81 

FIGURE 4. RIDF Decision Scores by Plan and Metric........................................................................98 

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FIGURES 

FIGURES FOLLOWING PAGE 120

For each of the 4 Reaches - Drainage and Levee Districts 

 (12 Sheets total) - Transportation 

 - 1993 Flood Extent 

Plan B – 3 sheets - Overall System, Sheet 1 of 2 and Sheet 2 of 2

Plan C – 3 sheets - Overall System, Sheet 1 of 2 and Sheet 2 of 2

Plan D – 3 sheets - Overall System, Sheet 1 of 2 and Sheet 2 of 2

Plan E – 3 sheets - Overall System, Sheet 1 of 2 and Sheet 2 of 2 

Plan G – 3 sheets - Overall System, Sheet 1 of 2 and Sheet 2 of 2 

Plan M – 3 sheet – Overall System, Sheet 1 of 2 and Sheet 2 of 2 

APPENDICES 

A Environmental Planning and Analysis 

B Hydrology and Hydraulics 

C Economic Analysis 

D Engineering and Cost Estimates 

E Cultural Resources 

F Public Involvement 

G Real Estate 

H Recreation 

I Risk Informed Decision Framework 

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UPPER MISSISSIPPI RIVER COMPREHENSIVE PLAN 

MAIN REPORT 

I. STUDY AUTHORITY

Authority for the Upper Mississippi River Comprehensive Plan (Comprehensive Plan) is contained in 

Section 459 of the Water Resources Development Act of 1999, which states: 

SEC. 459. UPPER MISSISSIPPI RIVER COMPREHENSIVE PLAN. 

(a) DEVELOPMENT. - The Secretary shall develop a plan to address water resource and related 

land resource problems and opportunities in the upper Mississippi and Illinois River basins, from 

Cairo, Illinois, to the headwaters of the Mississippi River, in the interest of systemic flood damage 

reduction by means of - 

(1) structural and nonstructural flood control and floodplain management strategies; 

(2) continued maintenance of the navigation project; 

(3) management of bank caving and erosion; 

(4) watershed nutrient and sediment management; 

(5) habitat management; 

(6) recreation needs; and 

(7) other related purposes. 

(b) CONTENTS. - The plan under subsection (a) shall - 

(1) contain recommendations on management plans and actions to be carried out by the 

responsible Federal and non-federal entities; 

(2) specifically address recommendations to authorize construction of a systemic flood control 

project for the upper Mississippi River; and 

(3) include recommendations for Federal action where appropriate and recommendations for 

follow-on studies for problem areas for which data or current technology does not allow 

immediate solutions. 

(c) CONSULTATION AND USE OF EXISTING DATA. - In carrying out this section, the 

Secretary shall - 

(1) consult with appropriate Federal and State agencies; and 

(2) make maximum use of data in existence on the date of enactment of this Act and ongoing 

programs and efforts of Federal agencies and States in developing the plan under subsection (a). 

(d) COST SHARING. - 

(1) DEVELOPMENT. - Development of the plan under subsection (a) shall be at Federal expense. 

(2) FEASIBILITY STUDIES. - Feasibility studies resulting from development of the plan shall be 

subject to cost sharing under section 105 of the Water Resources Development Act of 1986 (33 

U.S.C. 2215). 

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(e) REPORT.—Not later than 3 years after the date of enactment of this Act, the Secretary shall 

submit to the Committee on Transportation and Infrastructure of the House of Representatives and 

the Committee on Environment and Public Works of the Senate a report that includes the plan 

under subsection (a).

Section 404 of the Water Resources Development Act of 2000 modified the study completion date 

as follows: 

SEC. 404. UPPER MISSISSIPPI RIVER COMPREHENSIVE PLAN. 

Section 459(e) of the Water Resources Development Act of 1999 (113 Stat. 333) is amended by 

striking ‘‘date of enactment of this Act’’ and inserting ‘‘first date on which funds are appropriated 

to carry out this section’’.

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II. PURPOSE AND SCOPE 

Post-1993 flood reports, the regional summit meetings of the mid-1990s, several subsequent studies, 

and various stakeholders recognized the lack of, and subsequent need for, a comprehensive, systemic 

plan for flood risk management and floodplain management along the Upper Mississippi and Illinois 

Rivers. This recognition ultimately led to the authorization of the Upper Mississippi River 

Comprehensive Plan (Comprehensive Plan) in the Water Resources Development Act (WRDA) of 

1999 (Section 459). The primary purpose of this effort was the development of an integrated strategy 

and implementation plan for flood risk management on the Upper Mississippi River System. It is also 

intended to address, as applicable, other components of floodplain management, including: continued 

maintenance and improvement of the navigation project; improved management of nutrients and 

sediments; environmental stewardship; and recreational opportunities. 

Flood damages continue to be incurred throughout the Upper Mississippi River System. Opportunities 

to develop and implement a systemic plan that reduces cumulative flood protection costs and annual 

flood damages while simultaneously providing long-term improvements to other system values and 

uses (ecological, economic, recreation, transportation, etc.) were investigated. Multiple studies have 

been completed since the Flood of 1993. These efforts provided the foundation for evaluation of a 

comprehensive systemic plan for flood risk management. 

A. PURPOSE 

The purpose of the Comprehensive Plan is to “develop a plan to address water resource and related 

land resource problems and opportunities in the upper Mississippi and Illinois River basins,....in the 

interest of systemic flood damage reduction...” 

Long-term ecosystem management and sustainability planning also benefits from the development of a 

systemic conceptual plan for flood risk management. For example, fish and wildlife management, 

particularly in the lower reaches of the system, depends heavily upon active water level management. 

Any flood risk management planning could benefit these facilities. 

The Comprehensive Plan investigated systemic flood risk management plans for the Upper Mississippi 

and Illinois Rivers. In developing the plans, both structural and nonstructural flood risk management 

alternatives were considered. In addition, other system needs associated with flood risk management 

were considered. 

The Comprehensive Plan was developed as a collaborative effort involving the U.S. Army Corps of 

Engineers’ District at Rock Island, St. Louis, and St. Paul as well as a number of Federal and state 

agencies and non-governmental organizations. 

B. DESCRIPTION OF THE STUDY AREA 

The study area encompasses portions of five states—Minnesota, Wisconsin, Iowa, Illinois, and 

Missouri—extending more than 800 miles along the Mississippi River from Minneapolis-St. Paul 

downstream to southeast Missouri (below St. Louis), and along 200 miles of the Illinois River 

downstream from (but not including) the metropolitan Chicago area to the confluence with the 

Mississippi River. 

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4 

The study area is the Upper Mississippi River Basin drainage area above Cairo, IL, at the confluence 

of the Mississippi and Ohio Rivers exclusive of the Missouri River Basin, and encompasses 

approximately 185,000 square miles (figure 1). The total acreage of the river-floodplain system 

exceeds 2.6 million acres of aquatic, wetland, forest, urban, grassland, and agricultural habitats. The 

distribution of leveed floodplain as proportion of total floodplain area is approximately: 

• 3% north of Lock and Dam 13 on the Mississippi River; 

• 50% from Pool 14 through Pools 26 for the Mississippi River; 

• 80% in the open river - Mississippi downstream of its confluence with the Missouri River; and 

• 60% of the lower 160 miles of the Illinois River. 

The upper boundary of the study area is near St. Paul, MN (River Mile 864.8). The downstream 

boundary is at Thebes, IL (River Mile 43.7), the upstream limit of the Mississippi River and 

Tributaries (MR&T) Project. The MR&T Project is a comprehensive flood control and navigation 

project on the Lower Mississippi River authorized by the Flood Control Act of 1928, providing 

systemic flood protection to the Gulf of Mexico. 

The study area includes the major metropolitan areas of St. Louis, MO; Davenport, IA; LaCrosse, WI; 

and the Twin Cities of Minneapolis and St. Paul, MN. 

There are currently over 140 flood protection systems in place in the Mississippi and Illinois River 

floodplains protecting urban and agricultural areas. The average of the of existing systems is about 46 

years old. This is a major concern as many of the systems exceed their design and useful life. Most of 

the systems—approximately 100 total—are federally-constructed, locally-owned and operated (100 

percent non-federal), with the remaining systems having been constructed over the years by private 

interests. In total, these systems include over 2,200 miles of floodwalls and levees. In addition, there 

are numerous environmental areas, managed by Federal, state or local governments. 

The year 2000 population in the study area exceeds 9.7 million (adjacent counties to the river plus one 

county removed from other adjacent counties). The study area watershed encompasses about 185,000 

square miles (118.4 million acres), about 1,100 river miles, and 140 separate flood protection projects. 

The river floodplain system exceeds 2.6 million acres, with approximately 43% currently protected by 

floodwalls and levees, of aquatic, wetland, forest, urban, grassland, and agricultural habitats. 

C. SCOPE 

Due to the very large study area, the watershed encompasses about 185,000 square miles and about 

1,100 river miles, and in consideration of fiscal and time constraints, it was determined that the scope 

would be limited to the Mississippi and Illinois Rivers floodplain and not be a comprehensive 

watershed analysis. Further, while the discharges of the tributaries including the Missouri River Basin 

were included in the frequency analysis, no tributary was studied or analyzed. This analysis could 

only be performed to about a reconnaissance phase level, also known as Section 905(b) analysis. Any 

recommendation for authorization would typically require more detailed analysis in a follow-on phase. 

The Comprehensive Plan used recently-updated frequency water surface profiles obtained from the 

Upper Mississippi, Missouri and Illinois River Flow Frequency Study for frequency flood events 

between 50 percent chance annual (2-year) and 0.2 percent chance annual (500-year). This is the first 

time since the Flood of 1993 that updated frequency analysis is being used on a systemic basis. 
Upper Mississippi River Comprehensive Plan 

Main Report 

Figure 1. The Upper Mississippi River Basin

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Figure 2. Study Area Indicating the Four Reaches and Corps Offices

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III. PRIOR STUDIES, REPORTS, AND EXISTING WATER PROJECTS 

A. PRIOR STUDIES AND REPORTS 

Following are concise descriptions of previous, related studies and reports (presented chronologically). 

Comprehensive Master Plan for the Upper Mississippi River System; U.S. Army Corps of 

Engineers, 1982. Public Law 95-502 authorized the construction of a new dam and a 1,200-foot lock 

at Alton, Ill., and directed the Upper Mississippi River Basin Commission to prepare a Comprehensive 

Master Plan for the Management of the Upper Mississippi River System. The Upper Mississippi River 

Basin Commission was composed of the state and Federal agencies that had a legislated interest or 

mission affecting the UMR. The Corps of Engineers, with its many activities on the river, was a 

member of the Commission and was a lead agency in the study. The report recommended that 

Congress immediately authorize the engineering, design, and construction of a second chamber, 600 

feet in length, to complement the new 1200-foot chamber at the Lock and Dam No. 26 replacement 

project. Non-structural and minor structural improvements were recommended at other locks in the 

system, in addition to monitoring traffic movements to gather data for future use in evaluating possible 

improvements to the navigation project. The Master Plan proposed a ten-year environmental program 

that would include habitat rehabilitation and enhancement projects. Also recommended were a longterm resources monitoring program with a computerized analysis and retrieval system, a program to 

develop federally-owned lands for recreation, and an assessment of regional economic benefits 

generated by people using the river for various recreational activities. The five affected states—

Illinois, Iowa, Minnesota, Missouri, and Wisconsin—have since established the Upper Mississippi 

River Basin Association (UMRBA) to coordinate inter-agency water resources planning and to further 

the implementation of the recommendations of the Master Plan study. 

The Great Flood of 1993 Post-Flood Report of the Upper Mississippi River and Lower Missouri 

River Basins; U.S. Army Corps of Engineers, 1994. This post-flood report documents information 

for use by professionals within and outside the Corps of Engineers in connection with future planning 

programs associated with reservoir water-control management, floodplain management, and 

emergency management. The report summarizes the meteorology of the 1993 flood event, including 

antecedent conditions that led to the flooding conditions. The hydrology and hydraulic parameters of 

this flood are compared to previous events, and there are numerous tabulations of river stages, 

discharges, frequencies, and flood extent mapping, as well as descriptions of the effect that levees and 

reservoirs had on the flood. The Corps of Engineers’ activities during the flood are documented, 

including reservoir operations, and emergency and recovery measures. A preliminary description and 

appraisal of flood damages is provided. 

Science for Floodplain Management into the 21st Century: A Blueprint for Change; Scientific 

Assessment and Strategy Team, 1994. The Scientific Assessment and Strategy Team (SAST) was 

established by a directive of the White House on November 24, 1993, to provide scientific advice and 

assistance to officials responsible for making decisions with respect to flood recovery in the Upper 

Mississippi River Basin. The SAST had responsibilities to the FMRC as well as responsibilities 

independent of the FMRC to obtain, organize, analyze, and distribute scientific data and information. 

An assessment was made of selected sub-systems within the river basin providing information on how 

they contribute to flooding, how they respond to flooding, and how they have been affected by 

changes in flood pulse. 

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Sharing the Challenge: Floodplain Management into the 21st Century Interagency Floodplain 

Management Review Committee, 1994 (commonly referred to as The Galloway Report . The 

Interagency Floodplain Management Review Committee was established as part of the 

Administration’s Flood Recovery Task Force. The mission of the review committee was to delineate 

the major causes and consequences of the 1993 flooding; evaluate the performance of existing 

floodplain management and related watershed management programs; and make recommendations to 

the Administration’s Floodplain Management Task Force on changes in current policies, programs, 

and activities of the Federal Government that would most effectively achieve risk reduction, economic 

efficiency, and environmental enhancement in the floodplain and related watersheds. Major 

conclusions of this report include: 

• establishing environmental quality and national economic development as co-equal objectives 

of planning 

• supporting collaborative efforts among federal agencies and across state, tribal, and local 

governments 

• providing for coordination of the multiple federal programs to enhance the floodplain 

environment and provide natural storage 

• ensuring that existing federally constructed water resources projects continue to meet their 

intended purposes and are reflective of current national social and environmental goals, 

requiring periodic review of completed projects 

Floodplain Management Assessment of the Upper Mississippi River and Lower Missouri Rivers and 

Tributaries; U.S. Army Corps of Engineers, 1995. This study was authorized by House Resolution 

2423, dated 3 November 1993, which was signed into law as part of the Energy and Water 

Development Appropriations Act of 1994 (Public Law 103-136). The law provided the Corps of 

Engineers with appropriations to conduct studies in the reaches of the Upper Mississippi and Lower 

Missouri Rivers and their tributaries flooded in 1993. The assessment addressed 11 objectives: 

(1) description of the existing land and water resources and projections of future conditions; 

(2) identification of the desires of interested parties within the study area reflecting the diversity of 

opinions on alternative uses of floodplain resources; 

(3) description of how the land and water resources could be used to provide varying outputs; 

(4) description of the forces impacting on the use of the land and water resources; 

(5) development of a broad array of alternative land and water resource actions, including policy 

changes; 

(6) evaluation and prioritization of alternative land and water resource actions; 

(7) preparation of the assessment report, including recommendations for further studies; 

(8) identification of critical facilities needing added flood protection; 

(9) examination of differences in Federal cost sharing for construction and maintenance of flood 

control projects on the Upper and Lower Mississippi Rivers; 

(10) evaluation of the cost effectiveness of alternative flood control projects; and 

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(11) recommendation of improvements to the current flood control system. 

Key findings of the Floodplain Management Assessment Report are as follows: 

• Flood damages in urban floodplains with inadequate or not flood protection continue to 

 be a major problem. 

• No single alternative provides beneficial results throughout the system. 

• It is essential to evaluate hydraulic impacts systemically. 

• If all agricultural levees had been successfully raised and strengthened, urban flood protection 

would have been placed at much greater risk. 

• Flood stage changes resulting from the removal of agricultural levees are highly dependent on 

subsequent use of the floodplain. 

A Balanced Management for the Upper Mississippi, Illinois and Missouri Rivers; Delft Hydraulics, 

1997. In October 1996, the Upper Mississippi, Illinois and Missouri Rivers Association (UMIMRA) 

commissioned a team from Delft Hydraulics, based in the Netherlands Delft provided an external 

look at current river system management. The report indicated Delft’s view that the current approach 

to river management is not well balanced among the various river resources, and that a more ideal 

“integrated approach” is warranted. The report further suggested that a more active role could be 

played by governmental agencies, and that a means be developed for private concerns to be heard and 

incorporated. This would best be done in an open atmosphere where discussions could take place 

without pre-defined positions. The main conclusions of the report suggested that: 

• more government leadership, either the Corps of Engineers or a Review Commission, was 

required in river management 

• the US Army Corps of Engineers plays a key role in the river’s management 

• active participation of stakeholders in the planning process is needed 

• improvements be made to the economic development and benefit/cost analysis 

• interests of farmers should be taken into account 

• governments should invest in expanding river navigation 

• cost-effective levee improvements should be implemented 

• ecological values of the system would best be served by integrated management of the river 

and river basin. 

Upper Mississippi River System Flow Frequency Study; U.S. Army Corps of Engineers, 2004. In 

October 1997, the U.S. Army Corps of Engineers, in partnership with state and Federal agencies, 

initiated a study to develop flow frequencies for the main-stem Upper Mississippi, Lower Missouri, 

and Illinois Rivers. The Upper Mississippi is that portion of the river above the mouth of the Ohio 

River and includes the Illinois River. The Lower Missouri is that portion of the river below Gavins 

Point Dam. Five Corps Districts —Omaha, Kansas City, St. Paul, Rock Island, and St. Louis—

participated in this study effort. The Corps prepared existing flow frequency data for the upper and 

middle reaches of the Mississippi River in 1979. Existing flow frequency relationships for the 

Missouri River were developed in 1962. Flow frequencies were not developed for the tributaries. 

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The Corps and partnering state and Federal agencies selected and applied flow frequency analysis 

methods and analyzed the effects of reductions in flood runoff attributable to existing flood control 

reservoirs. The resulting flow-frequency relationships were used in conjunction with a onedimensional, unsteady, flow model (UNET) to develop frequency profiles for the study area. 

Final Integrated Feasibility Report and PEIS for the UMR-IWW System Navigation Feasibility 

Study; U.S. Army Corps of Engineers, 2004. This study was initiated in April 1993 to address the 

potential economic losses to the nation from significant traffic delays at locks on the commercial 

navigation system between 2000 and 2050. In 2001, the study was restructured to address the ongoing 

cumulative effects of navigation, and the ecosystem restoration needs, with a goal of attaining an 

environmentally sustainable navigation system, in addition to insuring an efficient transportation 

system for the future. The study area extends from Minneapolis-St. Paul downstream to the confluence 

of the Ohio River and the IWW from Grafton, IL, upstream through the Thomas J. O'Brien Lock in 

Chicago. It includes 37 locks (29 on the UMR and 8 on the IWW) and approximately 1,200 miles of 

navigable waterway within portions of Illinois, Iowa, Minnesota, Missouri, and Wisconsin. 

The principal navigation problem addressed by the study is the potential for significant traffic delays 

on the Upper Mississippi River-Illinois Waterway (UMR-IWW) Navigation System within the 50-

year planning horizon. The principal environmental problems addressed by the study were changes to 

ecosystem structure and function that have occurred since initiation of the operation and maintenance 

of the existing 9-Foot Channel Navigation Project. The primary opportunities are to reduce or 

eliminate commercial traffic delays and improve the national and regional economic conditions while 

restoring, protecting, and enhancing the environment. 

The goal of the feasibility study was to outline an integrated plan to ensure the economic and 

environmental sustainability of the UMR-IWW Navigation System so it continues to be a nationally 

treasured ecological resource as well as an efficient national transportation system as designated by 

Congress in the 1986 Water Resources Development Act (Public Law 99-662). The Chief of 

Engineers has recommended implementing system-wide ecosystem restoration and navigation 

efficiency measures. Congress authorized the UMR-IWW System Navigation and Ecosystem 

Sustainability Program in Title VIII of the Water Resources Development Act of 2007. 

B. EXISTING WATER PROJECTS ON THE UPPER MISSISSIPPI RIVER 

The following sections summarize the major water resource projects by the Federal government along 

the Upper Mississippi and Illinois Rivers. 

1. The Swamp Land Act of 1850 and Levee Construction Before 1900. Much of the Upper 

Mississippi River floodplain was included in Federal legislation known as the Swamp Land Act of 

1850. Under its provisions, specified states (including Missouri, Iowa, and Illinois), were eligible to 

acquire selected areas of “swamp and overflow” lands. The states were expected to reclaim “said 

lands by means of levees and drains” to both lessen the destructive force from excessive flooding and 

eliminate malaria-breeding swamps. Proceeds from reclaimed land sales were to be used for further 

reclamation and for construction of roads to make the lands accessible. Although not successful in 

generating adequate funds for drainage and flood control, the plan provided for the vast transfer of 

lands from the Federal government to the states and from the states to counties and levee boards and 

later to private ownership. Thus, the primary significance of the swampland grants was that huge 

areas of land became available for settlement and agricultural use (Petterchak, 2000). 

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Some farmers began building levees on the upper and middle Mississippi River before the Civil War. 

Soon after the war, they organized into levee districts and began the first concerted effort to secure the 

river’s floodplains for agriculture. They extended and raised levees and began draining the lands 

behind them. Before the Corps became involved in levee construction, these farmers had defined 

many of the floodplains that would be taken from the river. Whereas channel constriction had altered 

the entire upper river, reclamation and levee building would transform the river most significantly 

below Rock Island, IL. 

The Corps of Engineers began implementing flood control on the UMR under its navigation 

improvement authority. During the 1880s, individuals and organizations occupying the floodplain 

began pushing for Federal help. As early as 1884, the Sny Island Drainage District—enclosing over 

110,000 acres—south of Quincy, IL, asked the Federal government to rebuild its 50-mile-long levee. 

The Corps reviewed the project and concluded that the levee did not help navigation and successfully 

recommended against government support. But the levee district persisted, and in the 1886, 1888, 

1890, 1892 and 1896 Rivers and Harbors Acts, Congress authorized funding to preserve portions of 

the Sny Island levee in danger of eroding. The Corps used these funds to repair and riprap the levee 

and to build wing dams to direct the river’s current away from it. 

Pressure continued from other levee proponents, and in 1894, Congress instructed the Corps to survey 

the Mississippi River’s west bank from Flint Creek, just north of Burlington, IA, to the Iowa River, 

and the river’s east bank from Warsaw, IL to Quincy, IL. Congress directed the Corps to determine 

how the construction of these two levees could improve navigation. Based on Corps surveys, 

Congress, in 1895, authorized funding for both levees. In each case, the Corps was to improve 

navigation “by preventing the water from overflowing the natural and artificial banks along that part of 

the river, and deepening the channel ...”. The Corps completed the nearly 50-mile Warsaw to Quincy 

Levee in 1896 and the 35-mile Flint Creek Levee in 1900. 

 2. Flood Control Acts of 1917 and 1928. Responding in part to requests from states located 

along the Mississippi River, Congress passed an official flood control act in 1917. As the country’s 

first flood control act, it allowed the Corps to work on levees from the Head of Passes in Louisiana to 

Rock Island and on the Sacramento River, in California. This act, more so than the 1936 Flood 

Control Act, marks the formal beginning of the Corps involvement in flood control on the upper and 

middle Mississippi River. Through this act, the Federal government assumed an official role in 

securing the Mississippi River’s floodplains for agriculture and gave the Corps a new mission for 

managing the middle and upper Mississippi River, a mission Congress strengthened in the 1928 Flood 

Control Act. Under these two acts, the Corps helped fortify levees in 11 levee and drainage districts 

that enclosed over 260,000 acres of floodplain. 

 3. 1930 Rivers and Harbors Act. Between 1925 and 1930, Midwestern business and navigation 

interests fought to restore commerce and to persuade Congress to authorize a new project for the river, 

one that would allow the river to truly compete with railroads. It would draw support from the largest 

and smallest businesses in the valley, from most of its cities, from the Midwest’s principal farm 

organizations, and from the major political parties. Responding to this movement, Congress included 

the 9-foot channel project in the 1930 Rivers and Harbors Act. 

To create a 9-foot channel, the Corps chose a system of locks and dams and quickly determined that 

the dams would have to be quite low. Numerous villages and cities rested just above ordinary high 

water. Railroads following the river on each bank were often just out of reach of high water. At larger 

river cities, industrial developments lined the river. Because of the small difference between the 

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natural high water mark and the elevation of railroads, buildings, and other structures along the river 

and as well as of the small range of the annual flood stages, the Corps concluded that the dams would 

have to be designed not to increase flood stages. While they expected that contracting the river near 

the dams would increase the flood height at the dams by as much as 1 foot, they had calculated that 

this effect would dissipate within a few miles above the dam. Given the location of dams, the 

engineers expected no adverse effects from flooding by this effect. 

In 1940, the Corps completed the 9-foot channel project. Twenty-six locks and dams now crossed the 

river between Minneapolis, MN and Alton, IL. The 9-foot channel project again reconfigured the 

upper Mississippi River’s landscape, hydraulic character, and environment. The pools created by the 

dams permanently flooded thousands of acres that had been seasonally flooded before. Because the 

engineers took damage to cities, towns, and villages into consideration in planning the location of the 

dams, few of these entities would require special protection. The greatest flowage effects would occur 

to agricultural lands, floodplain forests, and brush lands. 

 4. Flood Control Acts of 1936 and 1938. In 1936, Congress passed the first national flood 

control act. Along with the 1938 Flood Control Act, this act broadened the Corps’ role in flood 

control on the Mississippi River. These acts provided for flood control reservoirs, urban or local flood 

protection projects, and floodplain management. For the middle and upper river’s main stem, 

however, the acts focused on agricultural levees. Under the 1936 Flood Control Act, Congress 

authorized 26 projects for the Mississippi River’s main stem above the Ohio River. Of these, 25 

called for raising and enlarging existing levees protecting agricultural lands. Only the East St. Louis 

and Vicinity project was authorized to protect an urban area. Congress extended its protection of the 

main stem’s agricultural levees in the 1938 Flood Control Act. The five levee improvement projects 

authorized in this act were to protect existing levee and drainage districts in Illinois between Alton and 

the mouth of the Ohio River. Together with the agricultural levee improvements authorized under the 

1936 act, these projects fortified most of the levee system on the Mississippi River in Missouri and 

Illinois. And as the Corps had reinforced the levee system above Alton under the acts preceding 1936, 

the Corps had helped secure most of the important agricultural levees between Rock Island and the 

Ohio River. 

Congress extended the Corps’ flood control work to the middle and upper river’s tributaries in the 1936 

act. Congress had authorized improvement of many of the Illinois River’s agricultural levees in the 

1928 act, but little work had been approved for other tributaries. In 1936, Congress authorized 15 

projects for the Illinois River—14 for agricultural levee and drainage districts and 1 for a levee setback 

and floodway improvement. Demonstrating its willingness to consider non-levee projects, Congress 

authorized four flood control reservoirs for the main stem’s tributaries in the 1936 Act and another in 

the 1938 Act. In 1936, it provided for dams and reservoirs at Decorah, IA, on the Upper Iowa River, 

and for the Des Moines River approximately 60 miles below Des Moines (Red Rock project). 

For Illinois, Congress approved the Carlyle dam and reservoir on the Kaskaskia River, and for 

Minnesota, it approved the Lac qui Parle dam and reservoir on the upper Minnesota River. The 

Decorah, Carlyle, and Red Rock projects were specifically aimed at protecting urban populations, 

although they guarded agricultural lands as well. The Lac qui Parle project had the more general 

objective of safeguarding the Minnesota River valley downstream. In 1938, Congress authorized the 

Coralville dam and reservoir, on the Iowa River, to protect Iowa City and some 1,073 square miles 

downstream. With these projects, Congress had authorized four of the major reservoirs that would be 

built on the upper Mississippi River’s tributaries above the mouth of the Missouri River. 

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 5. Flood Control Acts 1944 to 1958. In the 1946 Flood Control Act, Congress authorized work 

for only two main stem agricultural levee districts—Prairie du Rocher and Sny Island. Also Congress 

approved the Illinois River Flood Control Project, an unusual project in that it called for reclaiming a 

levee district from agriculture. 

Urban levees were the principal focus, however. In 1944, Congress enacted local projects for Sabula, 

Des Moines, and Elkport, IA, and Galena, IL. Only Sabula lay on the main stem. In the 1948 Flood 

Control Act, Congress authorized no projects for the Mississippi River below the Twin Cities. It did 

approve a channel diversion project to protect Aitkin, MN on the Mississippi River north of 

Minneapolis, a project to defend South Beloit on the Rock River in Illinois and a project to protect 

agricultural bottomlands along the Henderson River. In Section 205 of the 1948 act, Congress gave 

the Secretary of the Army the power to approve flood protection works under $2 million (today this 

limit is $7 million). Although the Corps has built many projects under this authority, these projects 

have not been examined in this discussion. 

In the 1950 Flood Control Act, Congress again focused on urban flood protection, authorizing projects 

for Canton and Cape Girardeau, MO, on the Mississippi River, and another urban project for 

Beardstown, located on a small tributary of the Illinois River. In neither act did Congress authorize 

agricultural projects for the main stem, and only authorized the Henderson River agricultural project 

for the upper river’s tributaries. 

Congress returned to the Mississippi River’s agricultural levees in the 1954 Flood Control Act. Up 

until 1936, Congress had concentrated on the agricultural levees between Rock Island and Alton. In 

the 1936, 1938, and 1946 Flood Control Acts, it had authorized the Corps to reinforce the levee system 

below Alton. With the 1954 Act, Congress authorized the modernization of the reach between Rock 

Island and Alton. Under this act, Congress called for the modification or construction of 14 rural 

levee projects within the Rock Island District. Between Rock Island, IL and Hamburg, IL, this act 

called for improving 386 miles of levee “to protect agricultural land along both sides of [a] 200-mile 

stretch of the Mississippi River.” The act also included the Upper Iowa River project near New Albin, 

IA, which entailed improving the outlet of the river at its confluence with the Mississippi River to 

protect agricultural lands. Through this act, as they had done under the others, farmers strengthened 

their hold on the upper Mississippi River’s floodplains. 

Urban projects received attention as well. The 1954 act included projects for four urban areas: Alton, 

IL; Hannibal, MO; and Sabula and Muscatine, IA. Although Muscatine and Hannibal lay on the 

Mississippi River, the projects at these cities were designed to protect the cities from flooding on 

tributary rivers. As in 1950, the 1954 Act neither authorized work on agricultural levees on the upper 

Mississippi River’s tributaries, nor did it approve any urban levees for cities on tributaries off the 

Mississippi River. 

With the most important agricultural levees on the upper and middle Mississippi River being secured, 

Congress concentrated on urban levees and broad flood protection on the Mississippi River tributaries 

in the 1958 Flood Control Act. In it, Congress approved four projects for Minnesota: the Winona and 

St. Paul-South St. Paul projects on the Mississippi River, the Mankato-North Mankato project on the 

Minnesota River, and the Rushford project on the Root River. Rather than a levee, Congress 

authorized a large earthen dam to protect the small town of Spring Valley, WI, on the Eau Galle River. 

The largest project under the 1958 Act was the Saylorville dam and reservoir on the Des Moines 

River, approximately 11 miles above the city of Des Moines. Congress authorized this reservoir to 

supplement the flood storage capacity of the Red Rock reservoir to reduce the flood levels 

downstream on the Des Moines River, especially at Des Moines, and to lower flood levels on the 

Mississippi River. 

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 6. Flood Control Projects After 1960. Between 1960 and 1980, the Corps finished many of the 

agricultural flood protection projects authorized in the 1950s and early 1960s and began building 

many of the urban projects authorized during these years. In these two decades, Corps engineers 

completed 25 agricultural and nine urban flood protection projects for the upper and middle 

Mississippi River. After 1980, urban projects dominate. From 1980 to the Flood of 1993, the Corps 

dedicated only one agricultural levee and eight urban projects on the main stem. 

The greatest change in the upper and middle Mississippi River Basin after 1940 came on tributary 

rivers. While work by local interests and the Corps on agricultural projects on the Illinois River had 

dramatically changed this tributary before 1940, few other tributaries had been greatly altered by 

reclamation and flood protection projects by this time. After 1940, however, and especially after 

1960, the basin’s tributary rivers would be changed in important ways. 

Seven lake and reservoir projects were finished between 1967 and 1987 serve a variety of purposes. 

The Red Rock Reservoir, completed in 1969, and the Saylorville Reservoir, completed in 1977, help 

protect Des Moines, IA, and agricultural lands below from floods on the Des Moines River. Along 

with the Coralville Reservoir, completed in 1958, these projects also serve to reduce flood levels on 

the Mississippi River. In Illinois, the Corps completed the Carlyle Dam in 1967 and the Shelbyville 

Dam in 1970, both on the Kaskaskia River. While Carlyle helps defend both agricultural and urban 

areas, Shelbyville protects primarily agricultural lands. Rend Lake, a multiple-purpose project which 

has 109,000 acre-feet of storage for flood control, 160,000 acre-feet for joint purposes, and 25,000 

acre-feet for conservation and sediment retention, was completed in 1972. This project is located on 

the Big Muddy River in southern Illinois. In Missouri, the Corps completed the Clarence Cannon 

Dam and Mark Twain Lake in 1987. This multiple-purpose dam provides hydroelectric power, flood 

protection and low flow augmentation storage and recreational use. 

Two dams that provide flood protection but which were designed to promote wildlife concerns are the 

Devil’s Kitchen Dam on Grassy Creek, a tributary of the Big Muddy River in Illinois, and the Big 

Stone Lake-Whetstone River Dam on the upper Minnesota River. The Devil’s Kitchen project, 

completed in 1960, is one of three structures that store water for the Crab Orchard National Wildlife 

Refuge. The Big Stone Lake-Whetstone River Darn, finished in 1974, provides a conservation pool of 

2,800 acres for wildlife purposes. Thus, since 1960, Congress and the Corps have expanded the upper 

and middle Mississippi River basin’s urban flood protection infrastructure dramatically. 

Between 1965 and 1966, the Bureau of the Budget gathered a team of specialists from various 

agencies to reassess the Government’s flood management program. As one focus of their study, the 

team was to examine whether the nation was developing its floodplains wisely. In 1966, based on this 

report, President Lyndon Johnson issued E. O. 11296, directing Federal agencies to evaluate the flood 

hazard potential before locating new buildings in the floodplain. In 1968, Congress followed with the 

National Flood Insurance Act, and in 1973, with the Flood Protection Disaster Act. Under the latter 

act, Congress required communities wanting Federal assistance for financing or constructing structures 

in the floodplain to initiate land use restrictions and required individuals to buy flood insurance. 

Conflict over its cost and effect stalled the nation’s flood protection program between 1970 and 1986. 

During this era, Congress passed no major bill for water resources projects. Environmental concerns, 

budget deficits, less support for water projects, and impasses over the Water Resources Council’s 

Principles and Standards were the primary reasons. The Principles and Standards had required the 

Corps to evaluate both the national economic development and environmental quality objectives and 

to measure the beneficial and negative effects for all projects. It outlined a process and methods of 

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evaluating alternative means solutions, and it made capital intensive projects harder to justify. And 

under Presidents Jimmy Carter and Ronald Reagan, the Office of Management and Budget viewed the 

civil works program as “a controllable, discretionary, government expense.” 

After a 14-year hiatus, Congress passed the Water Resources Development Act of 1986. In this act, 

nonstructural flood control was given greater status. Also cost sharing (50/50) for planning feasibility 

phase studies was required. 

Again after a hiatus, this time over sever years, Congress passed the Water Resources Development 

Act of 2007 (WRDA 2007) over the President’s veto. 

Several projects located in the Upper Mississippi River basin which have a relationship to the 

Comprehensive Plan were authorized by the Water Resources Development Act (WRDA) of 2007. 

WRDA 2007 authorized the reconstruction of two major flood protection systems located in the St. 

Louis Metropolitan area, the Wood River Drainage and Levee District 

7. Other Water Resource Projects After 1960. 

For the Upper Mississippi River System, the Corps has a number of programs and authorities that can 

be utilized for ecosystem restoration. Coordination activities for EMP, NESP, and Illinois River Basin 

Restoration will utilize the same multi-agency coordination structures, including the River Resources 

Coordination Team (RRCT), River Resources Forum (RRF), and River Resources Action Team 

(RRAT). This joint coordination will help to ensure efficiency among restoration and monitoring 

activities and a forum for interagency comment and discussion on the collective efforts. 

Programs and Authorities 

Upper Mississippi River - Environmental Management Program (EMP). The EMP established in 

1986 is comprised of two elements—Habitat Rehabilitation and Enhancement Projects (HREPs) and 

the Long Term Resource Monitoring Program (LTRMP). This ongoing system program provides a 

combination of monitoring and habitat restoration activities. Restoration activities under the EMP are 

limited to the Mississippi River and navigable portions of its tributaries (which includes the Illinois 

River) and their adjacent floodplains. 

The HREPs employ a variety of restoration measures to address the unique circumstances of a 

particular area in order to protect, preserve, and enhance fish and wildlife habitat in the Upper 

Mississippi River System (UMRS). As of February 2004, 73 HREPs are in various stages of planning, 

design, construction, and post-construction evaluation, and more than 40 HREPs have been completed. 

Project planning, engineering, construction, and monitoring approaches applied to HREPs have 

evolved with the program and have resulted in improved efficiency, productivity, and responsiveness. 

The LTRMP provides resource managers and decision makers with information necessary for 

maintaining the UMRS as a sustainable multiple-use large river ecosystem. The goals of the LTRMP 

include: (1) developing a better understanding of the ecology of the UMRS and its resource problems; 

(2) monitoring resource changes; (3) developing alternatives to better manage the UMRS; and (4) 

providing for the proper management of LTRMP information. 

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Navigation and Ecosystem Sustainability Program (NESP). This effort encompasses the 

subsequent planning and design efforts related to the Upper Mississippi River - Illinois Waterway 

System Navigation Feasibility Study completed in September 2004. These efforts address the need for 

navigation improvements and ecosystem restoration in an area which includes 854 miles of the Upper 

Mississippi River—with 29 locks and dams between Minneapolis/St. Paul and the mouth of the Ohio 

River—and 327 miles of the Illinois Waterway—with eight locks and dams. Restoration activities 

would be limited to the main stem rivers and adjacent floodplains. The study area lies within portions 

of Illinois, Iowa, Minnesota, Missouri, and Wisconsin. Recommendations authorized in WRDA 2007 

include: 

• $2.2 billion in navigation improvements. (50/50 funding with the Inland Waterway 

Users Trust Fund) 

• Mooring facilities at Lock and Dams 12, 14, 18, 20, 22, 24, La Grange 

• Switchboats at Lock and Dams 20, 21, 22, 24, and 25 

• Conduct development and testing of an appointment scheduling system 

• 1,200’ chambers at locks 20, 21, 22, 24, and 25, Peoria, and La Grange 

• $1.7 billion of ecosystem restoration (100 percent funding for projects on Federal 

lands, 65/35 cost share on non-Federal lands) 

• Projects of less than $25 million each: island building; floodplain 

restoration; water-level management; backwater/side-channel 

restoration; wing dam/dike alterations; island and shoreline protection; 

topographical diversity; use of dredged material for environmental 

purposes; tributary confluence restoration; spillway, dam, and levee 

modifications to benefit the environment; and land and easement 

acquisition. 

• Fish Passage (UMR dams 4, 8, 22, and 26) 

• Changes in water-level control at UMR dams 25 and 16 

Illinois River Basin Restoration (Section 519, WRDA 2000): The project area includes the entire 

Illinois River watershed and not just areas along the main stem river. Section 519 of WRDA 2000 

authorized: (1) the development of a Comprehensive Plan (completed May 2007) addressing 

ecosystem restoration, long-term resource monitoring, and evaluation of new technologies and 

innovative approaches, and (2) construction of critical restoration projects. This effort is part of the 

State of Illinois’ Illinois Rivers 2020 initiative, a proposed 20-year, $2.5 billion, Federal-state effort to 

restore and enhance the Illinois River Basin. Anticipated benefits include reducing sediment deliver to 

the Illinois River mainstem and backwaters and improving critical habitats for fish, waterfowl, and 

other aquatic organisms. 

While this report presents a Comprehensive Plan in response to Congressional direction, additional 

authority to implement the Comprehensive Plan was not recommended nor requested. However, it 

was recommended that critical restoration projects continue to be pursued under existing Section 

519(c) authority though the normal budget process. At this time 16 critical restoration projects 

throughout the basin have been identified and are in various states of planning and design. Most 

restoration activities undertaken under Section 519 authority would be located in the watersheds of the 

Illinois River, these areas are not covered by the EMP and NESP authorities. While this 

comprehensive plan identifies the need and estimates the costs for significant main stem restoration it 

is anticipated that most of the implementation work in these areas (approximately 75 percent or more) 

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would actually be funded and conducted through the existing EMP and NESP. A similar breakdown 

of efforts is planned for main stem system monitoring and adaptive management activities. 

Environmental Continuing Authorities Program (CAP). The Environmental CAP encompasses 

ongoing Corps of Engineers Authorities to perform various small ecosystem restoration projects with 

non-Federal Sponsors, including. 

•Section 206 of the 1996 Water Resources Development Act - Aquatic Ecosystem 

Restoration. These projects are for improving the quality of the environment by 

restoring habitat for fish and wildlife. A project is approved for construction after 

investigation shows engineering, economic and environmental feasibility. These 

projects are cost-shared 65 percent Federal and 35 percent non-Federal. Each project is 

limited to a Federal cost of $5 million. Such projects will usually include manipulation 

of the hydrology in and along bodies of water, including wetlands and riparian areas. 

Deep water dredging to improve habitat conditions for the over-winter survival of fish 

in an otherwise shallow lake area is an example of this type of project. 

•Section 1135 of the 1986 Water Resources Development Act - Project Modification 

for Improvement of the Environment. These projects are for modifications to an 

existing Corps project and/or its operations. The work must improve the quality of the 

environment by restoring habitat for fish and wildlife. Justification is based on a 

comparison of monetary and non-monetary costs vs. benefits. These projects are costshared 75 percent Federal and 25 percent non-Federal. Each project is limited to a 

Federal cost of $5 million. An example of this type of project might be to construct 

water control structures within a wetland to better optimize conditions for the 

production and availability of waterfowl-preferred food plants near an existing Corps 

project. 

•Section 204 of the 1992 Water Resources Development Act - Beneficial Use of 

Dredged Material. These projects protect, restore and create aquatic and/or wetland 

habitats associated with dredging for authorized Federal navigation projects. A project 

is constructed after investigation shows engineering, economic and environmental 

feasibility. These projects are cost-shared 75 percent Federal and 25 percent nonFederal. Placing dredged material from the maintenance of a navigation channel at a 

specific location is an example of this type of project. 

East St. Louis Interior Flood Control Project (E. St. Louis IFC). The project is located in Madison 

and St. Clair Counties, Illinois, along the east bank of the Mississippi River. The project area includes 

approximately 55,000 acres of flood plain that is protected by a levee system along the Mississippi 

River, the Chain of Rocks Canal, the Prairie du Pont Canal, and the Cahokia Creek Diversion Channel 

and an additional 51,000 acres of upland area that drain into these bottomlands. Section 310 of 

WRDA 2000 (PL 106-541) modified the original project authority (for flood damage reduction) to 

include ecosystem restoration as a project purpose. Section 1001 of WRDA 2007 (P.L. 110-114) 

authorized the ecosystem and recreation project per the Chief’s Report dated December 22, 2004. The 

ecosystem restoration project will restore bottomland forest habitat (1,700 acres); flood plain prairie 

habitat (1,100 acres); marsh and shrub swamp habitat (840 acres); lake habitat (460 acres); and upland 

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riparian forest (380 acres). It will also restore 10 miles of flood plain stream and 178 miles of 

tributary streams. Flood damage reduction is incidental to the restoration project with an estimated 

$1,445,000 in reduced average annual flood damages. This project will be cost-shared 65% Federal 

and 35% Non-Federal. 

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IV. PLAN FORMULATION 

The Upper Mississippi River Comprehensive Plan followed the Corps of Engineers’ Six Step Planning 

Process specified in Engineering Regulation (ER) 1105-2-100. The process is described below. 

A. CORPS OF ENGINEERS’ SIX STEP PLANNING PROCESS 

The process identifies and responds to problems and opportunities associated with the Federal 

objective and specified State and local concerns. The Federal objective of water and related land 

resources project planning is to contribute to national economic development consistent with 

protecting the nation’s environment, pursuant to national environmental statues, applicable executive 

orders, and other Federal planning requirements. The process provides a flexible, systematic, and 

rational framework to make determinations and decisions at each step so that the interested public and 

decision makers are fully aware of the basic assumptions employed, the data and information 

analyzed, the areas of risk and uncertainty, and the significant implications of each alternative plan. 

If a Federal and state interest is identified, the process culminates in the selection of a plan to be 

recommended to Congress for implementation. As part of identifying the selected plan, a number of 

alternative plans are developed and compared with the no action alternative, allowing for the ultimate 

identification of the national economic development (NED) Plan. 

The NED Plan is the plan that maximizes the net economic development benefits, consistent with the 

Federal objective. In addition to considering the economic benefits, the environmental impacts of the 

alternatives, the socioeconomic impacts, and the cultural properties impacts of the alternatives are 

considered. 

The six steps used in the plan formulation process include: 

1. Identify Problems and Opportunities. The specific problems and opportunities are 

identified, and the causes of the problems discussed and documented. Planning goals are set, 

objectives established, and constraints identified. 

2. Inventory and Forecast Resource Conditions. This step characterizes and assesses 

conditions in the Upper Mississippi River System as they currently exist and forecasts the most 

probable without-project condition (or no action alternative) over the period of analysis. This 

assessment gives the basis by which to compare various alternative plans and their likely impacts. 

The without-project condition is what the river and its uses are anticipated to be like over the 

planning period without any action implemented as a result of this study. 

3. Formulate Alternative Plans. Alternative plans are developed in a systematic manner to 

ensure that reasonable alternatives are evaluated. 

4. Evaluate Alternative Plans. The evaluation of each alternative consists of measuring or 

estimating the economic benefits, costs, environmental impacts, and social effects of each plan, 

and determining the difference between the without- and with-project conditions. 

5. Compare Alternative Plans. Alternative plans are compared, focusing on the differences 

among the plans identified in the evaluation phase and public comment. As part of the 

evaluations, the best plans are identified based upon those plans that provide the greatest economic 

benefits for the least cost. 

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20 

6. Select Recommended Plan. A recommended plan is selected and justification for its selection 

is prepared. If no alternative plan is identified that can be implemented, then the recommended 

plan is the No Action Alternative. 

B. WATER RESOURCES DEVELOPMENT ACT (WRDA) 1999, SECTION 459 

In addition to the six step planning process, Section 459 of the Water Resources Development Act of 

1999, lists three requirements specific to the Comprehensive Plan process: 

(b) CONTENTS. - The plan under subsection (a) shall - 

(1) contain recommendations on management plans and actions to be carried out by the 

responsible Federal and non-federal entities; 

(2) specifically address recommendations to authorize construction of a systemic flood control 

project for the upper Mississippi River; and 

(3) include recommendations for Federal action where appropriate and recommendations for 

follow-on studies for problem areas for which data or current technology does not allow 

immediate solutions. 

C. ENVIRONMENTAL REQUIREMENTS 

1. Federal Laws and Executive Orders. Table 1 provides a summary of the environmental 

requirements applicable to all Corps studies. A more detailed description of these requirements, along 

with Corps Planning Guidance Documents, can be found in Chapter 1, Environmental, of the 

supplemental CD.

2. Corps Policy - Environmental Operating Principles. In 2002, the U.S. Army Corps of 

Engineers (USACE) published a doctrine referred to as the Environmental Operating Principles and 

Implementation Guidance (EOP). EOP describes ways in which the Corps’ missions must be 

integrated with natural laws, values, and sound environmental practices. The EOP doctrine is intended 

to result in an organizational culture change over time, and embraces the following seven principles: 

1. strive to achieve environmental sustainability 

2. consider environmental consequences 

3. seek a balance and synergy between human development activities and natural systems 

4. accept corporate responsibility and accountability for environmental actions 

5. assess and mitigate cumulative impacts to the environment 

6. build and share and integrated scientific, economic, and social knowledge base 

7. respect the views of individuals and groups in Corps activities 

 

To the extent consistent with Section 459, the Corps has applied EOP during the Comprehensive Plan 

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Upper Mississippi River Comprehensive Plan 

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Table 1. Environmental Requirements (Federal Laws and Executive Orders) 

Bald Eagle Protection Act (16 U.S.C. 668) Clean Air Act (42 U.S.C.§§ 7401-7671g) Clean Water Act (33 U.S.C. 1251 et seq.) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (42 U.S.C. §§ 9601-9675) Endangered Species Act (16 U.S.C. 1531 et seq.) Farmland Protection Policy Act (7 U.S.C. 4201 et seq.) Fish and Wildlife Coordination Act (16 U.S.C. 661 et seq.) Food Security Act of 1985 (16 U.S.C. §§ 3801-3862) National Environmental Policy Act (NEPA) (42 U.S.C. 4321-4347) National Historic Preservation Act (16 U.S.C. 470 et seq.) Noise Control Act (42 U.S.C. §§ 4901-4918) Resource, Conservation and Rehabilitation Act (RCRA)(42 U.S.C. 6901 et seq.) Floodplain Management, E.O. 11988 Protection and Enhancement of the Cultural Environment, E.O. 11593 Protection and Enhancement of the Environmental Quality, E.O. 11514 Protection of Wetlands, E.O. 11990 Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, E.O. 12898 

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D. COLLABORATION TEAM 

In August 2002, a Collaboration Team (CT) was formed specifically for the Comprehensive Plan, 

consisting of representatives from Federal and State Government agencies and certain nongovernmental organization representatives who have significant responsibilities for or interest in 

various aspects of floodplain management, particularly flood risk management, economic 

development, and natural resources. Interaction with CT provided a source of extensive public 

involvement. Additional information on the CT is found in Appendix F, Public Involvement. 

The Collaboration Team has worked with the Corps’ Product Development Team (PDT) throughout 

the duration of the study. The CT provided comment and input on identifying, validating, and 

prioritizing system-level problems, needs, and opportunities; measures and strategies (called 

philosophies); and alternative plans. The members of the CT help to facilitate project coordination 

and communication efforts, particularly with respect to their particular agencies, organizations, and 

publics. 

The CT contributed ideas, comments and discussion to all facets of the Upper Mississippi River 

Comprehensive Plan process. For example, at the first CT meeting, Step 1 of the Corps’ Planning 

Process—Identify Problems and Opportunities—was initiated. 

While the emphasis of the Comprehensive Plan is on systemic planning, knowledge by the CT in both 

systemic and local context, insured that the problems were identified and understood by all. Using 

input and discussion from the CT Meeting held August 2002, the PDT established initial objectives. 

The PDT provided a “strawman” list of objectives which were provided to the CT, and then discussed 

and finalized, as presented in this report, at the next CT meeting in December 2002. 

The inventory of the existing flood risk management systems on the Mississippi and Illinois Rivers, 

with over 150 systems spread over a thousand river miles, benefited from input by the Collaboration 

Team to help insure data and information quality in Step 2, Inventory and Forecast Resource 

Conditions. 

The first component of Formulate Alternative Plans, Step 3 in the Planning Process, is to identify 

measures and strategies which, when combined, form alternative plans, the second component of 

Planning Step 3. The PDT brainstormed and developed a list of over 30 strategies, which the CT 

preferred to name Philosophies. Collaboration Team insight and discussion resulted in the 

Philosophies presented in this report. The Corps PDT developed a list of all flood risk management 

and ecosystem restoration measures which may be applicable. The CT and PDT determined the more 

applicable and useful measures before the development of systemic alternative plans (indicated in 

BOLD in the following section). The final component of planning Step3— reformulate and develop 

additional alternatives based upon what is learned—resulted in the full array of systemic plans 

considered. 

It was a CT request which resulted in the development and subsequent initial evaluation of the 

Emergency Action Scenarios, analyzing temporary emergency measures, such as flood fighting, to 

reduce flood risks. 

Step 4 of the Six Step Planning Process is Evaluate Alternative Plans. Due to a CT request, evaluation 

of the regional economic development (RED) benefits of several early alternative plans was 

accomplished in 2004 and included in the evaluation of plans. 

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E. IDENTIFY PROBLEMS AND OPPORTUNITIES, AND INVENTORY AND FORECAST 

FUTURE CONDITIONS 

 1. Existing Conditions. The Upper Mississippi River System and associated environments have 

a rich record of human history spanning over 12,000 years. The abundant and diverse ecological 

resources found along the Upper Mississippi River System have attracted and sustained human 

populations for thousands of years, providing food, water, and transportation. Today, the Upper 

Mississippi River System continues to provide a multitude of goods and services to many users 

including: serving as a vital transportation network, a vital riverine ecosystem, a commercial and 

recreational fishery, providing recreational and tourism opportunities, and serving as a source of 

industrial and municipal water supply. 

The Upper Mississippi River System is a vital part of our national economy. The navigable portion of 

the system and the locks and dams that allow waterway traffic to move from one pool to another are 

integral parts of a regional, national, and international transportation network. The system is 

significant for certain key exports and the nation’s balance of trade. For example, in 2000, the Upper 

Mississippi River System carried approximately 60 percent of the nation’s corn and 45 percent of the 

nation’s soybean exports. 

The Mississippi River represents the largest riverine ecosystem in North America and the third largest 

in the world. The System’s ecosystem consists of over 2.7 million acres of aquatic and floodplain 

areas consisting of bottomland forests, islands, backwaters, side channels, and wetlands; supporting 

more than 300 species of birds, 57 species of mammals, 45 species of amphibians and reptiles, 150 

species of fish, and nearly 50 species of mussels. More than 40 percent of North America’s migratory 

waterfowl and shorebirds depend on the food resources and other life requisites (shelter, nesting 

habitats, etc.) that the system provides. 

Elevations within the Upper Mississippi River System drainage basin range from 300 feet above sea 

level (Cairo, IL) to 1,950 feet above sea level (Timms Hill, WI). The average river slope is 0.5 feet 

per mile. The predominant landform in the basin is flat to irregular plains that are composed of a thick 

layer of silt (from 3 to 300 feet thick). 

The Upper Mississippi River System supports a wide range of recreational opportunities including 

boating, camping, hiking, hunting, and trapping. Annually, the system supports $1.2 billion in direct 

and secondary expenditures, and supports 12 million visitor-days of use by people who hunt, fish, 

boat, sightsee and otherwise visit the river and communities (USACE Technical Report EL-95-16, 

1995). 

Floodplain use varies from north to south on the Upper Mississippi River System. Above Clinton, IA, 

the relatively narrow floodplain is largely undeveloped with the exception of isolated urban 

communities that occupy a small (percentage-wise) portion of the floodplain. The remaining 

floodplain areas remain susceptible to seasonal flooding and generally consist of backwater 

complexes, floodplain forests, and marshlands. South of Clinton, IA, and particularly below Keokuk, 

IA, much of the floodplain has been converted to agricultural use. Levee and drainage districts 

(predominately established in the late 1800s and early 1900s) operate and maintain levee and drainage 

systems to protect the agricultural fields. The distribution of leveed floodplain (urban and 

agricultural) as a proportion of the total floodplain area is approximately: 

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Upper Mississippi River Comprehensive Plan 

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The distribution of leveed floodplain as proportion of total floodplain area is approximately: 

• 3 percent north of Lock and Dam 13 on the Mississippi River; 

• 50 percent from Pool 14 through Mel Price on the Mississippi River; 

• 80 percent in the open river (Mississippi downstream of its confluence with the 

Missouri River); and 

• 60 percent of the lower 160 miles of the Illinois River (below Peoria Dam). 

 a. Nature of Flooding on the Upper Mississippi River System. There is no single cause of 

flooding on the Upper Mississippi River System. Either snowmelt, rain on snow, or rainfall can cause 

major flooding at various locations within the study area. The following events drove major floods in 

the Upper Mississippi River Basin: 

• 1965 - A rainfall-snowmelt event occurring in late winter and early spring, the type of 

event expected for this region. This is the event of record on the Upper Mississippi 

from St. Paul to Clinton, IA. 

• 1993 - Major multiple season event, caused primarily by late spring and summer 

convective rainfall of similar pattern to typical summer events, but of greater 

persistence, depth, and duration. This was the event of record from Keokuk, IA to St. 

Louis on the Mississippi River. 

The inspection of major historic floods implies the following important climatologic aspects of Upper 

Mississippi flooding: 

Location Climatological Aspects

Upper Mississippi, Northern Reach 

(St. Paul to Clinton) 

Flood regime dominated by rain 

on snow events 

Upper Mississippi Transition Region 

(Clinton to Keokuk) 

Rainfall or rain on snow may cause 

 a major flood event 

Upper Mississippi Southern Reach 

(Keokuk to Thebes) & Illinois River 

Rainfall events cause major floods 

of record 

In recognition of the climatological differences that result in major floods in the different regions, and 

the differences in floodplain use (discussed in Section IV.D.1), the study area, encompassing the entire 

upper Mississippi River and the Illinois Waterway, was divided into a series of four reaches (figure 2). 

Table 2 provides a description of the reaches used in this study. 

Table 2. Description of the Four Reaches 

Reach Description Range of River Miles 

1 Vicinity of St. Paul, MN to Lock and Dam 13 at Clinton, IA 863.9 to 522.5 

2 Lock and Dam 13 at Clinton, IA to Lock and Dam 19 at Keokuk, IA 522.5 to 364.2 

3 Lock and Dam 19 at Keokuk, IA to Thebes, IL 364.2 to 43.7 

4 Illinois Waterway 291.0 to 19.4 

24 
Upper Mississippi River Comprehensive Plan 

Main Report 

The Great Flood of 1993 resulted in catastrophic damages throughout much of the Upper Mississippi 

River Basin. Forty seven deaths were attributed to the flood, and damages due to heavy rainfall and 

flooding exceeded $15 billion. Approximately one-half of the flood damages were related to 

agricultural losses. In-place flood risk management facilities such as levees and reservoirs, and 

floodplain management practices prevented additional damages. Corps of Engineers facilities 

prevented an estimated $19 billion in potential damages. The region has suffered losses due to 

significant flooding as summarized below. 

It is essential to evaluate hydraulic impacts systemically. The existing flood risk management projects 

built by the U.S. Corps of Engineers have prevented in excess of $83 billion in damage from the 

Upper Mississippi River flooding during the past several decades. For the 1993 flood, assessments of 

the economic damages range from $15 to 20 billion including more than $2.9 billion in damage along 

the Upper Mississippi and its floodplain, not including other social and environmental impacts. 

Impacts to critical infrastructure resulted in tremendous economic losses during the 1993 flood. The 

trucking industry was forced to re-route much of its traffic, (at one point there were no bridges open 

across the river for over 200 miles). Rail traffic was also impacted. At one time during the ’93 Flood, 

seven of eight rail lines across the state of Missouri were closed. 

Following is a summary of recent historical flood damages on the Upper Mississippi River System. 

Historically notable floods on the Upper Mississippi River prior to 1947, for which there are no 

reliable damage figures, include the floods of 1828, 1844, 1851, 1868, 1880, 1881, 1888, 1892, 1920, 

and 1922. The flood damages and descriptions discussed below were taken from U.S. Army Corps of 

Engineers’ Post Flood Reports for the respective floods. 

• In 1947, three above-normal rainstorms, combined with other rainfall events, created flood 

conditions on the Mississippi River downstream of Keokuk, IA, (Reach 3) in June and July. 

Damages in rural areas (rural in 1947) were approximately $35 million and damages in urban 

areas exceeded $15 million. Twelve persons lost their lives during this flood and nearly 

14,000 persons were displaced. Nearly 1 million acres were inundated. 

• The 1965 flood resulted in damages primarily in Reaches 1 and 2. Record snowfall and above 

normal rainfall contributed to record flood crests along the Mississippi River. Damages in 

urban areas were in excess of $40 million and damages to agricultural areas were nearly $18 

million while transportation suffered approximately $150,000 in damage. 

• A severe flood in 1973 caused damages primarily in Reaches 2, 3 and 4. Above-normal 

rainfall in the spring of 1973 resulted in high levels of runoff, three flood crests, and new 

record flood stages. This was also a flood of long duration—in excess of four months. 

Damage in urban areas was nearly $43 million, agricultural areas was close to $20 million, 

while other damages such as impacts to transportation, flood fighting costs, etc. was over $12 

million. 

• In February 1974, a backwater effect from high stages on the Ohio and Lower Mississippi 

Rivers caused flooding in study Reach 3. Additionally, heavy rains throughout Iowa and 

Illinois resulted in 2 more crests. Damages in urban areas in 1974 were under $1 million, 

while damages in rural areas exceeded $12 million. 

• Heavy rainfall caused three spring flood events the following year, 1995. No record flood 

stages were set and damages were largely in rural areas—approximately $8 million. The high 

stages inundated 238,000 acres. 

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Upper Mississippi River Comprehensive Plan 

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26 

• In 1985 and 1986 floods caused by heavy rains resulted in damages along the Mississippi and 

Illinois Rivers. The 1986 flood caused nearly $29 millions in damage in the state of Illinois 

and approximately $14 million in Missouri. 

• The 1993 flood was a major, regional flood impacting all study reaches. From March until 

July, the general weather pattern above-normal precipitation as well as heavy snow cover, 

contributed to significant flooding. The precipitation amounts were some of the wettest on 

record for June, July, and August in the states of Illinois, Iowa, Minnesota, Missouri, and 

Wisconsin. Record flood stages were set in Reach 2. Millions of acres were inundated. 

Damages from this flood event in urban areas were approximately $1.5 billion, while damages 

in rural areas were approximately $1.4 billion. Nearly $60 million was expended to repair 

flood risk management systems under the Public Law 84-99 program. 

• A significant flood occurred in 2001 in Reach 2. No consistent flood damage data was 

collected during this flood, but Federal program payouts by the Federal Emergency 

Management Agency exceeded $12 million, while the Small Business Administration paid out 

over $5 million. 

 b. Existing Damage Reduction Protection Systems. The Upper Mississippi and Illinois 

River floodplains have extensive existing flood control projects consisting of levees and floodwalls 

and large tributary reservoirs. Many of the levee systems were originally built privately between 1880 

and 1920 and upgraded later. The most recent upgrade was accomplished on average over 45 years 

ago. The various systems level of protection is from less than 2 percent (50-year) up to the 0.2 percent 

(500-year) annual chance protection. Most components of this system were federally constructed or 

improved, and were planned and built incrementally (rather than systemically) under various 

authorities (See Section III B, Existing Water Projects on the Upper Mississippi River). There are 

separable areas of the floodplain which have non-federal projects, not meeting USACE design and 

construction standards. About three quarters of the existing urban systems exist at the 0.2 percent 

(500-year) annual chance level of protection. 

Table 3 provides a summary of the existing flood control systems on the Upper Mississippi River and 

Illinois Waterway. 

Tables 4 and 5 display the variance in approximate level of start of damages of the existing flood risk 

management projects on the Upper Mississippi River and Illinois Waterway, respectively, as well as 

those unprotected areas that are in the study area. 
Upper Mississippi River Comprehensive Plan 

Main Report 

Table 3. Summary of Existing Flood Control Systems

Location State River Navigation Pool Type of Construction Urban or Ag Mid-poinFridley MN Mississippi 1 Non-Federal Urban 863.9 St. Paul MN Mississippi 2 Federal Urban 838.5 South St. Paul MN Mississippi 2 Federal Urban 833.3 Newport MN Mississippi 2 Non-Federal Urban 831.5 South St. Paul - Reach 2 MN Mississippi 2 Non-Federal Urban 831.3 Inver Grove MN Mississippi 2 Non-Federal Urban 830.5 Lake City MN Mississippi 4 Non-Federal Urban 773.3 Cochrane WI Mississippi 5 Non-Federal Urban 742.3 Winona MN Mississippi 6 Federal Urban 727.4 LaCrosse WI Mississippi 8 Non-Federal Urban 699.0 Genoa WI Mississippi 8 Non-Federal Urban 679.5 Lansing IA Mississippi 9 Non-Federal Urban 662.7 Marquette IA Mississippi 10 Non-Federal Urban 634.7 McGregor IA Mississippi 10 Non-Federal Urban 633.4 Clayton IA Mississippi 10 Non-Federal Urban 624.6 Glen Haven WI Mississippi 10 Non-Federal Urban 618.3 Guttenburg MN Mississippi 10 Federal Urban 615.4 Dubuque IA Mississippi 12 Federal Urban 580.6 East Dubuque IL Mississippi 12 Non-Federal Urban 580.0 Pool 12 Overwintering IL Mississippi 12 Wildlife Area Other 568.5 Pleasant Creek IA Mississippi 13 Wildlife Area Other 550.8 Green Island IL Mississippi 13 Non-Federal Ag 547.3 Sabula IA Mississippi 13 Federal Urban 535.0 Spring Lake IA Mississippi 13 Wildlife Area Other 534.3 Fulton IL Mississippi 14 Federal Urban 519.8 Clinton IA Mississippi 14 Federal Urban 517.3 Meredosia IL Mississippi 14 Federal Ag 511.5 Princeton Refuge IA Mississippi 14 Wildlife Area Other 505.2 East Moline IL Mississippi 15 Federal Urban 489.3 

27 
Upper Mississippi River Comprehensive Plan 

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Table 3. Summary of Existing Flood Control Systems

Location State River Navigation Pool Type of Construction Urban or Ag Mid-poin

Bettendorf IA Mississippi 15 Federal Urban 486.6 Rock Island IL Mississippi 16 Federal Urban 481.2 Milan IL Mississippi 16 Federal Urban 478.5 Andalusia IL Mississippi 16 Non-Federal Urban 473.4 Andalusia IL Mississippi 16 Wildlife Area Other 463.0 Muscatine/Madd Creek IA Mississippi 17 Federal Urban 456.0 Drury IL Mississippi 17 Federal Ag 455.2 Muscatine-Louisa County IA Mississippi 17 Non-Federal Ag 448.5 Muscatine Island IA Mississippi 17 Federal Urban 448.4 Big Timber IA Mississippi 17 Wildlife Area Other 444.0 Bay Island IL Mississippi 17 Federal Ag 442.6 Lake Odessa IA Mississippi 17 Wildlife Area Other 437.5 Iowa River-Flint CR Upper IA Mississippi 18 Federal Ag 427.9 Keithsburg IL Mississippi 18 Non-Federal Urban 427.6 Iowa River-Flint CR Middle IA Mississippi 18 Federal Ag 416.4 Oquawka IL Mississippi 18 Non-Federal Urban 416.0 Henderson #3 IL Mississippi 18 Non-Federal Ag 413.2 Iowa River-Flint CR Lower IA Mississippi 19 Federal Ag 408.1 Henderson #1 IL Mississippi 19 Federal Ag 407.3 Burlington Industrial IA Mississippi 19 Federal Urban 406.5 Henderson #2 IL Mississippi 19 Federal Ag 402.4 Green Bay IA Mississippi 19 Federal Ag 391.0 Niota IL Mississippi 19 Non-Federal Urban 385.0 Keokuk IA Mississippi 20 Private Urban 364.0 Des Moines/Mississippi IA Mississippi 20 Federal Ag 359.0 Mississippi & Fox Upper IA Mississippi 20 Non-Federal Ag 357.8 Mississippi & Fox Lower IA Mississippi 20 Non-Federal Ag 356.2 Hunt-Lima IL Mississippi 20 Federal Ag 351.7 Gregory IA Mississippi 20 Federal Ag 351.3 

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Upper Mississippi River Comprehensive Plan 

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Table 3. Summary of Existing Flood Control Systems

Location State River Navigation Pool Type of Construction Urban or Ag Mid-poin

Canton MO Mississippi 21 Federal Urban 342.0 Indian Grave Upper IL Mississippi 21 Federal Ag 338.8 Union Township IL Mississippi 21 Federal Ag 333.3 Indian Grave Lower IL Mississippi 21 Federal Ag 332.9 Fabius MO Mississippi 21 Federal Ag 327.8 Marion County MO Mississippi 22 Federal Ag 322.4 South Quincy IL Mississippi 22 Federal Urban 321.7 Reiff, Nick MO Mississippi 22 Non-Federal Ag 320.0 South River Industrial/American Cyanamid MO Mississippi 22 Federal Urban 319.0 South River MO Mississippi 22 Federal Ag 315.7 Bay Island MO Mississippi 21 Wildlife Area Other 311.5 Hannibal MO Mississippi 22 Federal Urban 309.5 Sny Island Reach I IL Mississippi 22 Federal Ag 307.6 Sny Island Reach II IL Mississippi 24 Federal Ag 292.5 Ted Shanks State CA MO Mississippi 24 Wildlife Area* Other 289.6 Sny Island Reach III IL Mississippi 24 Federal Ag 282.3 Clarksville Refuge MO Mississippi 25 Wildlife Area Other 275.0 Petus-Burns-Prewitt-Jeager MO Mississippi 25 Private Ag 271.6 Clarksville Levees MO Mississippi 25 Private Ag 269.0 Sny Island Reach IV IL Mississippi 25 Federal Ag 268.8 Kissinger Levee District MO Mississippi 25 Non-Federal Ag 266.4 MRA (Rip-Rap Landing) IL Mississippi 25 Wildlife Area Other 265.5 Busch-Goose Pasture Farms MO Mississippi 25 Private Ag 264.1 Cannon Wildlife Refuge MO Mississippi 25 Wildlife Area* Other 262.2 Annada D & LD MO Mississippi 25 Private Ag 262.2 Elsberry Drainage District MO Mississippi 25 Non-Federal Ag 255.9 Elsberry Drainage District MO Mississippi 25 Non-Federal Ag 255.9 Kings Lake Drainage District MO Mississippi 25 Non-Federal Ag 249.0 Sandy Creek MO Mississippi 25 Non-Federal Ag 245.7 

29 
Upper Mississippi River Comprehensive Plan 

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Table 3. Summary of Existing Flood Control Systems

Location State River Navigation Pool Type of Construction Urban or Ag Mid-poin

Foley Drainage District MO Mississippi 25 Non-Federal Ag 245.0 Batchtown Wildlife Area IL Mississippi 25 Wildlife Area Other 244.3 Cap Au Gris MO Mississippi 26 Non-Federal Ag 241.2 Winfield D & LD MO Mississippi 26 Non-Federal Ag 238.9 Brevator MO Mississippi 26 Non-Federal Ag 238.1 Schramm MO Mississippi 26 Private Ag 237.3 Old Monroe MO Mississippi 26 Private Ag 236.8 Heitman MO Mississippi 26 Private Ag 236.4 Marstan-Portuchek MO Mississippi 26 Private Ag 236.1 Peruque Creek MO Mississippi 26 New Levee Ag 231.4 St. Peters Drainage Assoc. No. 1 (Urban) MO Mississippi 26 Federal Urban 230.0 St. Peters Drainage Assoc. No. 1 (Ag) MO Mississippi 26 Non-Federal Ag 229.8 Consolidated North County MO Mississippi 26 Non-Federal Ag 206.3 Wood River IL Mississippi 27 Federal Urban 198.1 Columbia Bottoms Levee MO Mississippi 27 Wildlife Area Other 194.2 Chouteau Island IL Mississippi 27 Non-Federal Ag 191.2 Chouteau, Nameoki and Venice IL Mississippi 27 Federal Urban 189.9 Gabaret/Cabrolet Island IL Mississippi 27 Non-Federal Ag 187.3 St. Louis Flood Protection Project MO Mississippi Open River Federal Urban 181.7 Metro East Sanitary District IL Mississippi Open River Federal Urban 179.4 Prairie Du Pont IL Mississippi Open River Federal Urban 170.7 Columbia IL Mississippi Open River Federal Ag 160.9 Harrisonville IL Mississippi Open River Federal Ag 142.9 Harrisonville - A IL Mississippi Open River Federal Ag 142.9 Harrisonville - B IL Mississippi Open River Federal Ag 142.9 Stringtown IL Mississippi Open River Federal Ag 139.5 Fort Chartres and Ivy Landing IL Mississippi Open River Federal Ag 134.0 Prairie Du Rocher & Modoc IL Mississippi Open River Federal Ag 124.5 Ste. Genevieve Urban Levee MO Mississippi Open River Federal Urban 123.8 

30 
Upper Mississippi River Comprehensive Plan 

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Table 3. Summary of Existing Flood Control Systems

Location State River Navigation Pool Type of Construction Urban or Ag Mid-poin

Ste. Genevieve Levee District No. 2 MO Mississippi Open River Private Ag 119.5 Kaskaskia Island MO Mississippi Open River Federal Ag 113.4 Bois Brule MO Mississippi Open River Federal Ag 103.2 Degognia & Fountain Bluff IL Mississippi Open River Federal Ag 91.8 Grand Tower IL Mississippi Open River Federal Ag 78.9 Miller Pond IL Mississippi Open River Federal Ag 70.7 Preston IL Mississippi Open River Federal Ag 70.7 Clear Creek IL Mississippi Open River Federal Ag 61.0 Cape Girardeau MO Mississippi Open River Federal Urban 52.2 E. Cape Girardeau & Clear Creek IL Mississippi Open River Federal Ag 51.5 N. Alexander County IL Mississippi Open River Federal Ag 51.5 Hubble Creek MO Mississippi Open River New Levee Ag 49.3 Hennepin IL Illinois Peoria Federal Urban 204.9 Herman Levee IL Illinois Peoria Non-Federal Ag 178.0 Komatsu IL Illinois Peoria Non-Federal Urban 164.6 East Peoria Sanitary District IL Illinois Peoria Federal Urban 162.4 East Peoria IL Illinois Peoria Federal Urban 161.2 Peoria Sanitary District IL Illinois Peoria Non-Federal Urban 160.0 Keystone IL Illinois LaGrange Non-Federal Urban 157.5 Pekin-LaMarsh IL Illinois LaGrange Federal Ag 152.4 Banner Special IL Illinois LaGrange Federal Urban 141.9 Banner Marsh IL Illinois LaGrange Wildlife Area Other 141.0 Spring Lake IL Illinois LaGrange Federal Ag 141.0 Rice Lake IL Illinois LaGrange Wildlife Area Other 135.0 East Liverpool IL Illinois LaGrange Federal Ag 130.1 Liverpool IL Illinois LaGrange Federal Urban 127.2 Lake Chautauqua IL Illinois LaGrange Wildlife Area Other 126.8 Thompson IL Illinois LaGrange Federal Urban 123.4 Lacey, Langellier, W. Matanzas, Kerton Valley IL Illinois LaGrange Federal Ag 115.6 

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Upper Mississippi River Comprehensive Plan 

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Table 3. Summary of Existing Flood Control Systems

Location State River Navigation Pool Type of Construction Urban or Ag Mid-poin

Big Lake IL Illinois LaGrange Federal Ag 105.7 Kelly Lake IL Illinois LaGrange Federal Ag 101.7 Hager Slough IL Illinois LaGrange Non-Federal Ag 92.0 Lost Creek IL Illinois LaGrange Federal Ag 89.7 Sanitary Dist. of Beardstown IL Illinois LaGrange Federal Urban 88.6 Coal Creek IL Illinois LaGrange Federal Ag 88.5 Crane Creek IL Illinois LaGrange Federal Ag 84.2 South Beardstown IL Illinois LaGrange Federal Ag 84.2 Little Creek IL Illinois Alton Federal Ag 76.7 McGee Creek IL Illinois Alton Federal Ag 71.4 Meredosia and Willow Creek IL Illinois Alton Federal Ag 69.4 Coon Run IL Illinois Alton Federal Ag 68.9 Smith Lake IL Illinois Alton Private Ag 67.2 Oakes IL Illinois Alton Private Ag 66.3 Valley City IL Illinois Alton Federal Ag 65.1 Mauvaise Terre IL Illinois Alton Federal Ag 64.8 Robertson IL Illinois Alton Private Ag 63.3 Scott County IL Illinois Alton Federal Ag 59.3 Walnut Creek IL Illinois Alton Non-Federal Ag 56.3 Big Swan IL Illinois Alton Federal Ag 53.6 Hillview IL Illinois Alton Federal Ag 46.6 Village of Pearl IL Illinois Alton Private Urban 43.2 Hartwell IL Illinois Alton Federal Ag 40.7 Keach IL Illinois Alton Federal Ag 35.3 Schaefer-Farrow IL Illinois Alton Private Ag 32.6 Bluffdale Farms IL Illinois Alton Non-Federal Ag 32.3 Eldred-Spankey IL Illinois Alton Federal Ag 28.1 Nutwood IL Illinois Alton Federal Ag 19.4 

32 
Upper Mississippi River Comprehensive Plan 

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33 

Table 4. Mississippi River – Summary of Start of Damages for Existing Systems 

Number < 50 yr 50 yr 50 – 100 yr 100 yr 100-200 yr 200 yr 200-500 yr 

Urban 42 10 2 0 3 2 1 3 

Federal 27 --- --- --- 1 1 1 3 Non-Federal 14 10 2 --- 2 --- --- --- Private 1 --- --- --- --- 1 --- --- 

Agriculture 59 23 6 3 5 10 11 2 

Federal 36 --- 5 3 4 10 11 2 Non-Federal 14 12 1 --- 1 --- --- ---  Private 9 9 --- --- --- --- --- --- 

Other 32 31 --- --- 1 --- --- --- Unprotected 34 

Table 5. Illinois Waterway – Summary of Start of Damages for Existing Systems 

Number < 50 yr 50 yr 50 – 100 yr 100 yr 100-200 yr 200 yr 200-500 yr 

Urban 11 5 2 0 3 0 0 1 

Federal 7 3 2 --- 1 --- --- 1 Non-Federal 3 1 --- --- 2 --- --- --- Private 1 1 --- --- --- --- --- --- 

Agriculture 30 16 4 1 1 1 2 1 

Federal 23 10 3 1 1 1 2 1 Non-Federal 3 3 --- --- --- --- --- --- Private 4 3 1 --- --- --- --- --- 

Other 6 6 --- --- --- --- --- --- Unprotected 3 
Upper Mississippi River Comprehensive Plan 

Main Report 

The existing flood risk management projects built by the U.S. Army Corps of Engineers have 

prevented in excess of $83 billion in damage from Upper Mississippi River flooding during the past 

several decades. 

c. Age and Condition of the Flood Risk Management Systems. The Upper Mississippi River 

Comprehensive Plan recognized the importance and benefit of the existing flood damage reduction 

systems in place. Due to the average age of the last major construction upgrade, over 45 years, and 

condition, the existing flood risk reduction systems need to be evaluated to determine the feasibility of 

reconstruction. Reconstruction could insure that the systems continue to provide the billions of dollars 

in benefits for the foreseeable future. The average year of last construction upgrade of the agriculture 

systems on the Upper Mississippi and Illinois Rivers was 1940, making the agricultural systems, on 

average, over 65 years old. Table 6. Drainage and Levee Districts with Major Flood Protection 

Infrastructure, summaries the major components of the existing flood risk management systems on 

the Upper Mississippi River and Illinois Waterway. 

34 
Upper Mississippi River Comprehensive Plan 

Main Report 

Table 6. Drainage and Levee Districts with Major Flood Protection Infrastructure 

Highway 

Closure 

Structures 

(Number)

Railroad 

Closure 

Structures

(Number)

Fed 

Construction 

Comp Date

Pumping 

Stations

(Number)

Gravity 

Drains 

(Number)

Relief 

Wells 

(Number)

Drainage & Levee District

Gatewells

(Number)

River State 

St. Paul Miss IA 1963 3 4 3 1 10 5 South St. Paul Miss MN 1 3 2 1 13 Winona Miss MN 1985 5 3 5 1 11 Guttenberg Miss MN 1973 2 2 5 Banner Special 

Illinois IL 1941 2 

Big Lake 

Illinois IL 1942 1 

Coal Creek 

Illinois IL 1950 1 2 

Crane Creek 

Illinois IL 1940 5 

East Liverpool 

Illinois IL 1941 4 

East Peoria 

Illinois IL 1945 

East Peoria Sanitary District 

Illinois IL 1954 

Lacey, Langellier, W Matanzas, and Kerton Valley 

Illinois IL 1950 3 

Liverpool 

Illinois IL 1942 1 

Ottawa 

Illinois IL 2000 6 

Pekin and LaMarsh 

Illinois IL 1940 2 2 

Seahorn 

Illinois IL 1939 2 6 

Sid Simpson 

Illinois IL 1966 1 4 77 

Sid Simpson 

Illinois IL 1937 16 

35 
Upper Mississippi River Comprehensive Plan 

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Drainage & Levee District River State

Fed 

Construction 

Highway 

Comp Date

Closure 

Structures 

(Number)

Railroad 

Closure 

Structures

(Number)

Pumping 

Stations

(Number)

Gravity 

Drains 

(Number)

Gatewells

(Number)

Relief 

Wells 

(Number)

Sid Simpson 

Illinois IL 1941 3 80 

Sid Simpson 

Illinois IL 1941 80 

Sid Simpson 

Illinois IL 1941 80 

Spring Lake 

Illinois IL 1940 2 9 

Village of Liverpool 

Illinois IL 1998 2 3 

Bay Island and SubDistrict No. 1 Miss IL 1958 2 1 9 Bay Island and SubDistrict No. 1 Miss IL 1962 Bay Island and SubDistrict No. 1 Miss IL 1962 2 Bettendorf Miss IA 1990 5 14 Burlington Northern Bottoms Miss IA 1984 7 14 Canton Miss MO 1963 2 1 Clinton Miss IA 1981 3 12 Des Moines/Mississippi Miss MO 1968 1 2 Iowa/Flint Creek Miss IA 1971 1 4 10 Iowa/Flint Creek Miss IA 1971 2 2 Iowa/Flint Creek Miss IA 1971 1 6 Iowa/Flint Creek Miss 1971 3 Drury Miss IL 1963 3 4 Dubuque Miss IA 1973 3 2 East Moline Miss IL 1983 Fabius Miss MO 1963 10 

36 
Upper Mississippi River Comprehensive Plan 

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Drainage & Levee District River State

Fed 

Construction 

Highway 

Comp Date

Closure 

Structures 

(Number)

Railroad 

Closure 

Structures

(Number)

Pumping 

Stations

(Number)

Gravity 

Drains 

(Number)

Gatewells

(Number)

Relief 

Wells 

(Number)

Fulton Miss IL 1983 1 2 14 Green Bay Miss IA 1966 6 Green Island Miss IA Gregory Miss MO 1970 2 1 Hannibal Miss MO 1993 2 1 Henderson County District No. 1 Miss IL 1967 5 13 Henderson County District No. 2 Miss IL 1966 1 4 Hunt-Lima Lake Miss IL 1972 19 4 Hunt-Lima Lake Miss IL 1972 3 5 Hunt-Lima Lake Miss IL 1972 1 Indian Grave Miss IL 1971 5 Indian Grave Miss IL 1971 1 Indian Grave Miss 1971 3 Marion County Miss MO 1967 5 Meredosia Miss IL 1977 2 3 2 Muscatine Island Miss IA 1958 1 2 Muscatine/Mad Creek Miss IA 1982 Rock Island Miss IL 1980 1 Sabula Miss IA 1957 Sny Island Miss IL 1968 3 Sny Island Miss IL 1968 4 15 Sny Island Miss IL 1968 1 29 6 Sny Island Miss IL 1968 6 3 Sny Island Miss IL 1968 1 South Quincy Miss IL 1989 1 2 South River Miss MO 1966 

37 
Upper Mississippi River Comprehensive Plan 

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Drainage & Levee District River State

Fed 

Construction 

Highway 

Comp Date

Closure 

Structures 

(Number)

Railroad 

Closure 

Structures

(Number)

Pumping 

Stations

(Number)

Gravity 

Drains 

(Number)

Gatewells

(Number)

Relief 

Wells 

(Number)

South River Industrial Miss MO 1 Union Township Miss MO 1947 2 Big Swan 

Illinois IL 1934 1 

Blue Waters Pump Sta Miss IL 4 Bois Brule Miss MO 1957 Cape Girardeau Miss MO 1964 3 2 Chouteau, Nameoki, & Venice Miss IL 1955 7 

See 

MESD 

Clear Creek Miss IL 1962 1 1 6 CN&V Pump Station Miss IL Columbia Miss IL 1955 1 130 Coon Run D&LD 

Illinois IL

Degognia & Fountain Bluff Miss IL 1955 1 1 208 Dively D&LD 

Kaskaski I a L

East Cape Girardeau & Clear Creek Miss IL 1953 1 1 3 66 Eldred-Spanky 

Illinois IL 7 

Elsber ry DD Mis M s OFestus - Crystal City Miss MO 2008 1 2 Fish Lake D&LD Miss IL Fort Chartres & Ivy Landing Miss IL 1958 18 2 5 142 Grand Tower Miss IL 1959 2 149 Hardin Sec 14 

Illinois IL

Harrisonville Miss IL 1957 Hartwell Illinoi IL 1933 2 

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Upper Mississippi River Comprehensive Plan 

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Drainage & Levee District River State

Fed 

Construction 

Highway 

Comp Date

Closure 

Structures 

(Number)

Railroad 

Closure 

Structures

(Number)

Pumping 

Stations

(Number)

Gravity 

Drains 

(Number)

Gatewells

(Number)

Relief 

Wells 

(Number)

s 

Hillview 

Illinois IL 1934 4 

Indian CK Sec 208 

Illinois IL 14

Kaskaskia Island Miss IL 1943 4 5 Keach 

Illinois IL 1933 5 

Little Creek 

Illinois IL 59 2 8 

Macoupin Creek Sec 20 

Illinois IL 1 2 

Main & N Main St Levee Miss MO 2 Mauvaise Terre 

Illinois IL 1936 3 

McGee Creek 

Illinois IL 1986 1 1 

Meadows School Miss MO Meredosia & Willow Creek 

Illinois IL 1977 

Meredosia D&LD 

Illinois IL

Meredosia Lake & Willow Creek 

Illinois IL 1944 14 4 42 

Metro East Sanitary District (MESD) Miss IL 1950 12 11 27 505 Miller Pond Miss IL 1955 New Pankey's Pond D&LD 

Illinois IL 1

North Alexander County Miss IL 1957 Nutwood 

Illinois IL 1932 3 

Prairie Du Pont and Fish Lake Miss IL 1950 2 2 2 9 160 

39 
Upper Mississippi River Comprehensive Plan 

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40 

Drainage & Levee 

District River State

Fed 

Construction 

Comp Date

Highway 

Closure 

Structures 

(Number)

Railroad 

Closure 

Structures

(Number)

Pumping 

Stations

(Number)

Gravity 

Drains 

(Number)

Gatewells

(Number)

Relief 

Wells 

(Number)

Prairie Du Rocher & Modoc Miss IL 1959 1 1 156 Preston Miss IL 1959 1 1 2 Scott County 

Illinois IL 1933 4 

St. Louis Flood Protection Project Miss MO 1980 13 3 28 St. Peters Urban Levee Mis M s O Ste. Genevieve Urban Levee Miss MO 2 5 Stringtown Miss IL 1957 Valley City 

Illinois IL 2 

Willow Creek D&LD 

Illinois IL 2

Wood River Miss IL 1983 11 11 57 TOTALS 56 50 223 180 286 1,960 
Upper Mississippi River Comprehensive Plan 

Main Report 

d. Critical Infrastructure. Impacts to critical infrastructure resulted in tremendous economic 

losses during the 1993 flood. The trucking industry was forced to reroute much of its traffic to more 

lengthy routes due to closures of bridges and interstate highways. Bridge closures proved to be 

problematic for other businesses, as employees and customers often did not have normal bridge access 

across rivers in going to and from work, causing major disruption for many. 

Rail traffic was also impacted, either by flooded rail lines, erosion of rail beds, or by constrained 

bridges. At one time during the flood, seven of eight rail lines across the State of Missouri were 

closed. 

A Presidential Commission defined critical infrastructure on a national basis. Critical infrastructure 

are those deemed to be so vital that the incapacity or destruction of critical components within them 

would have a debilitating regional or national impact. Items included in a follow-on Executive Order 

(E.O. 3010) were: 

• electrical power systems 

• gas and oil 

• transportation 

• emergency services 

• telecommunications 

• water supply systems 

• banking and finance 

• continuity of government 

In addition, information on hazardous materials production, storage, and waste facilities was deemed 

critical by the Water Resources Council in 1978. An analysis of available information on the Upper 

Mississippi and Illinois River system resulted in the following tables of critical infrastructure in the 

500-year (approximately) floodplain within the boundaries of the three Corps of Engineers Districts. 

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Upper Mississippi River Comprehensive Plan 

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MISSISSIPPI RIVER 

Table 7. Critical Infrastructure at Risk of Inundation Due to the 500-year Frequency Floo

Levee District

Superfund 

Hazardous Waste Handlers 

Petrochemical Storage 

NPDES 

Water Intakes 

Water Wells 

Power Plants 

Power Substations 

Television Towers 

Radio Towers 

Cellular Phone Towers 

Pager Towers 

Hospitals 

Nursing Homes 

Schools 

Airports 

Post Offices 

Prisons 

St. Paul District 

Pool Above St. Anthony Falls 1 1 

POOL 1 POOL 2 39 7 4 2 POOL 3 21 1 POOL 4 3 2 2 1 1 POOL 5 2 1 POOL 5 A POOL 6 POOL 7 POOL 8 35 4 8 1 3 1 1 POOL 9 1 2 POOL 10 2 5 1 1 Rock Island District Guttenbe rg 3 1 Dubuque 1 30 6 1 East Dubuqu e 1 Clinton 25 3 1 2 1 1 1 1 Fulton 3 1 1 Meredos ia 2 

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Upper Mississippi River Comprehensive Plan 

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MISSISSIPPI RIVER 

Table 7. Critical Infrastructure at Risk of Inundation Due to the 500-year Frequency Floo

Levee District

Superfund 

Hazardous Waste Handlers 

Petrochemical Storage 

NPDES 

Water Intakes 

Water Wells 

Power Plants 

Power Substations 

Television Towers 

Radio Towers 

Cellular Phone Towers 

Pager Towers 

Hospitals 

Nursing Homes 

Schools 

Airports 

Post Offices 

Prisons 

Rock Island DistrictEast Moli ne 2 1 Bettendo rf 1 5 4 Rock Island Arsen al 1 Rock Island 4 1 1 1 1 Andalus ia 2 1 Muscatine-Madd Cree k 4 Muscatine Island 33 3 26 1 1 1 2 1 1 Iowa-Flint Creek No.4 1 1 1 1 Des Moines County No. 7 1 Keithsburg 1 2 1 Des Moines County No. 8 2 0 0 1 Oquaw ka 1 Green Ba y 1 1 Nio ta 1 Des Moines-Mississippi 2 1 Hunt-Lima 3 3 1 Indian Grave Upper 2 3 Indian Grave Low er 1 Canton 1 3 1 Fabius River 3 1 1 1 Marion Count y 2 Sny Reach I 1 1 4 1 1 Unprotected 1 50 11 26 34 42 6 2 2 1 6 

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Upper Mississippi River Comprehensive Plan 

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MISSISSIPPI RIVER 

Table 7. Critical Infrastructure at Risk of Inundation Due to the 500-year Frequency Floo

Levee District

Superfund 

Hazardous Waste Handlers 

Petrochemical Storage 

NPDES 

Water Intakes 

Water Wells 

Power Plants 

Power Substations 

Television Towers 

Radio Towers 

Cellular Phone Towers 

Pager Towers 

Hospitals 

Nursing Homes 

Schools 

Airports 

Post Offices 

Prisons 

St. Louis District Bois Brule 2 3 1 Brevat or 1 Chouteau Islan d 1 Clear Cre ek 9 3 East Cape Girardeau 1 1 2 1 2 1 Miller Pond 1 North Alexand er 1 1 Preston 4 1 3 1 1 Big Five 1 5 3 9 2 1 8 2 2 Columbia Bottom s 1 Columb ia 1 1 1 Consolidated N. County 1 2 2 1 Degonia & Fountain Bluff 2 1 1 1 1 1 2 Grand Tower 1 2 1 Degonia & Grand Tower 2 2 3 1 2 1 2 Elsber ry 0 1 1 Fol ey 1 Fort Chartres & Ivy Landing 1 1 Harrisonville 7 1 6 3 Harrisonville, Stringtown 8 1 6 3 1 Kaskaskia Isla nd 1 

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Upper Mississippi River Comprehensive Plan 

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MISSISSIPPI RIVER 

Table 7. Critical Infrastructure at Risk of Inundation Due to the 500-year Frequency Floo

Levee District

Superfund 

Hazardous Waste Handlers 

Petrochemical Storage 

NPDES 

Water Intakes 

Water Wells 

Power Plants 

Power Substations 

Television Towers 

Radio Towers 

Cellular Phone Towers 

Pager Towers 

Hospitals 

Nursing Homes 

Schools 

Airports 

Post Offices 

Prisons 

St. Louis DistrictKing's La ke 1 Old Monroe 1 1 Pettus-Burns-Prewitt-Jaeger 1 Prairie Du Rocher 3 2 2 2 1 Saint Pete rs 2 2 7 1 Sandy Cree k 1 Sny Island NO. 3 3 Sny Island NO. 4 3 1 St Genevieve NO .2 1 Winfield L&D D 1 2 Unprotected 16 1 36 12 38 3 2 1 7 4 5 TOTALS 4 313 46 119 81 154 11 5 0 12 12 1 0 1 61 20 34 2 

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Upper Mississippi River Comprehensive Plan 

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ILLINOIS RIVER 

Table 8. Critical Infrastructure at Risk of Inundation Due to the 500-year Frequency Flood Event 

Levee District 

Superfund 

Hazardous Waste Handlers 

Petrochemical Storage 

NPDES 

Water Intakes 

Water Wells 

Power Plants 

Power Substations 

Television Towers 

Radio Towers 

Cellular Phone Towers 

Pager Towers 

Hospitals 

Nursing Homes 

Schools 

Airports 

Post Offices 

Prisons 

Fire Stations 

Rock Island District Ottawa High Scho ol 1 East Peoria Sanitar y 2 1 East Peoria 1 1 1 1 1 Pekin-LaMars h 2 1 Liverpo ol 1 La cy 3 Big Lak e 1 Hager Sloug h 1 2 Coal Cre ek 1 Beardstown Sanitary/Lost Cr. 5 3 1 0 1 2 7 1 2 Crane Cre ek 1 0 1 Unprotected 28 9 41 26 31 4 5 1 1 7 2 3 3 St. Louis District Bluffdale Far ms 2 Eldr ed 1 Farro w 2 Hartwe ll 2 2 Keach 1 1 

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47 

ILLINOIS RIVER 

Table 8. Critical Infrastructure at Risk of Inundation Due to the 500-year Frequency Flood Event 

Levee District 

Superfund 

Hazardous Waste Handlers 

Petrochemical Storage 

NPDES 

Water Intakes 

Water Wells 

Power Plants 

Power Substations Television Towers Radio Towers Cellular Phone Towers 

Pager Towers 

Hospitals 

Nursing Homes 

Schools 

Airports 

Post Offices 

Prisons 

Fire Stations 

St. Louis District Nutwo od 1 3 Unprotected 2 6 11 14 1 1 1 Big Sw an 2 3 Hillview 3 2 Indian Creek NO. 2 2 2 Mauvaise Terre 2 1 3 2 2 McGee Cre ek 1 1 1 Meredosia Lak e 3 1 Mud Cre ek 1 1 New Pankeys Pon d 1 Scott Coun ty 4 2 Valley Ci ty 2 1 Willow Creek 1 2 1 5 1 1 2 1 1 Unprotected 1 1 5 3 TOTALS 0 33 16 54 38 94 7 8 0 3 3 0 1 3 51 7 7 0 9 
Upper Mississippi River Comprehensive Plan 

Main Report 

 e. Existing Economic Conditions. The study area encompasses portions of five states—

Minnesota, Wisconsin, Iowa, Illinois, and Missouri—extending nearly 800 miles along the Mississippi 

River from Minneapolis-St. Paul downstream to southeast Missouri (below St. Louis), and along 200 

miles of the Illinois River downstream from (but not including) the metropolitan Chicago area to the 

confluence with the Mississippi River. The year 2000 population of the study area exceeds 9.7 

million. This figure includes those living in counties adjacent to the Mississippi and Illinois Rivers, 

plus one county removed from these adjacent counties. The area includes major metropolitan cities 

and manufacturing centers, medium and small towns, and large concentrations of agricultural activity. 

The study area (in its entirety) exhibits the following profile characteristics: 

• Population growth is lower than the national growth trend over the last decade. 

• The area’s population is more rural than the nation as a whole and is less racially diverse. 

• High school graduation rates are higher than the national average. 

• Personal income per capita is similar to the national average. 

• Unemployment rates are lower than the national average. 

These characteristics vary widely among regional sub-areas within the study area. The Tennessee 

Valley Authority (TVA) compiled an Existing Economic Conditions report dated March 2004 in 

support of the Comprehensive Plan. 

f. Existing Ecosystem Conditions 

 (1) Land Cover. There is a diversity of land cover types in the study area. An analysis of 

land cover was compiled through the Upper Mississippi River System Environmental Management 

Program. A summary of this compilation can be found in Table 9. 

The Upper Mississippi River System floodplain area encompasses over 2,700,000 acres. Agriculture 

is the dominant land cover class, followed by water habitat, floodplain forests and other various 

classes of vegetation. Land cover classes are unevenly distributed throughout the river system, and the 

absolute floodplain area of river reaches and pools may also differ greatly. The largest differences 

occur in the amount and distribution of agricultural land and the proportion of open water in the 

floodplain. Agriculture dominates the floodplain south of Rock Island, IL (Pool 14), and open water 

occupies a greater proportion of the floodplain between Minneapolis (Pool 1) and Clinton, IA (Pool 

13). Wetland classes are generally more abundant between Minneapolis and Clinton. 

Geomorphic areas, or aquatic and terrestrial features within river reaches, are parts of the river system 

that have similar geologic origins, formed by similar river processes or manmade structures. The 

geomorphic area data (Appendix E, Cultural Resources) is limited to UMR Pools 4 through 26, a 

reach of the Middle Mississippi River (RM 31-75), and the Illinois River La Grange Pool. From Lake 

Pepin, MN to St. Louis, MO the data shows that approximately 40 percent of the total floodplain area 

(including both aquatic and floodplain areas) is leveed, but levees are concentrated south of Rock 

Island, IL (figure 1). The presence of levees closely approximates the amount and location of 

agriculture in the floodplain. The distribution of leveed floodplain as a proportion of total floodplain 

area is approximately: 

• 3 percent north of Pool 13; 

• 50 percent from Pool 14 through Pools 26; 

• 80 percent in the open river; and 

• 60 percent of the lower 160 miles of the Illinois River. 

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Upper Mississippi River Comprehensive Plan 

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Table 9. Land Cover Class Distribution Upper Mississippi River System (including the Illinois River) in Acres 

LEVEED AREASStudy Reach Aquatic Non-Forest Forest Agriculture Developed Other Mississippi River  Pools 1-13 1,597 5,804 1,930 1,551 6,919 0  Pools 14-19 2,860 11,786 10,026 128,025 14,845 0  Pools 20-Open River 11,669 51,619 42,161 502,806 59,729 0 Illinois River 4,196 15,879 11,257 220,792 7,468 0 TOTAL 20,323 85,088 65,374 853,174 88,961 0 UNLEVEED AREASStudy Reach Aquatic Non-Forest Forest Agriculture Developed Other Mississippi River  Pools 1-13 163,597 115,951 104,155 47,242 42690 88  Pools 14-19 75,476 22,650 55,642 95,581 27,566 0  Pools 20-Open River 135,400 54,738 139,987 215,341 17,787 0 Illinois River 72,556 41,621 84,178 84,000 19,354 0 TOTAL 447,029 234,961 383,962 442,164 107,397 88 ALL AREASStudy Reach Aquatic Non-Forest Forest Agriculture Developed Other Mississippi River  Pools 1-13 165,194 121,755 106,086 48,793 49,609 88  Pools 14-19 78,336 34,437 65,668 223,605 42,411 0  Pools 20-Open River 147,069 106,358 182,148 718,147 77,516 0 Illinois River 76,752 57,500 95,435 304,792 26,822 0 TOTAL 467,352 320,050 449,337 1,295,337 196,358 88 2

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Upper Mississippi River Comprehensive Plan 

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Contiguous floodplain susceptible to seasonal flooding constitutes approximately 23 percent of the 

floodplain area system-wide. Islands are approximately 8 percent of the floodplain area, bringing the 

total terrestrial area to approximately 70 percent of the floodplain from Minneapolis to St. Louis. 

 (2) Threatened and Endangered Species. The list of species in Table 10 was developed 

as a part of the Upper Mississippi River – Illinois Waterway System Navigation study. This list of 

threatened or endangered species is current as of April 2005. This list is representative of the 

federally-listed species within the study area, except for the extreme southern extent of the study area, 

which is downstream of the area considered by the Navigation Study. Chapter 1, Environmental, of 

the supplemental CD contains additional detail on federally-listed species. 

Table 10. Species within the UMRS Floodplain Listed as Threatened or Endangered under the 

Federal Endangered Species Act (ESA) 

Common Name Scientific Name Federal Status

Decurrent false aster Boltonia decurrens Threatened 

Higgins' eye pearly mussel Lampsilis higginsii Endangered 

Pink mucket pearly mussel Lampsilis abrupta Endangered (Extirpated) 

Winged mapleleaf Quadrula fragosa Endangered 

pocketbook mussel Potamilus capax Endangered (Extirpated) 

Scaleshell mussel Leptodea leptodon Endangered (Extirpated) 

Pallid sturgeon Scaphirhynchus albus Endangered 

Bald eagle Haliaeetus leucocephalus Threatened 

Interior least tern Sterna antillarum Endangered 

Indiana bat Myotis sodalist Endangered 

States along the Upper Mississippi River System have a number of species identified that fall within 

their own state classification of endangered or threatened (Table 11). Analysis completed for the 

Upper Mississippi River – Illinois System Navigation Study identified State listed species that 

potentially occur within the floodplains of the Mississippi and Illinois Rivers. Additional detail on 

state-listed species is contained in Appendix A, Environmental Planning and Analysis. 

Table 11. Number of Species Listed Threatened and Endangered in Each State

Listed Species Wisconsin Minnesota Iowa Illinois Missouri 

fish 21 21 15 31 52 

mussels 18 30 14 27 24 

invertebrates 24 49 15 25 62 

mammals 2 15 7 8 11 

birds 26 28 7 34 29 

reptiles/amphibians 10 14 19 22 28 

plants 128 276 147 331 374 

 

2. Future Without Project Conditions 

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Upper Mississippi River Comprehensive Plan 

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a. Introduction. While existing conditions establish a starting point for the planning process, 

a base condition—against which all actions will be measured—must be set out for the entire 50-year 

planning time frame. Forecasting what will happen within the floodplain and the extent of flooding in 

the future, without any action towards a systemic flood risk management system, is essential to being 

able to determine the extent of problems, opportunities, and the costs, benefits and impacts of 

alternative plans of improvement. The most likely future set of baseline conditions is designated the 

Future Without Project Conditions. 

Given the lengthy period of analysis, it is usually impossible to predict with accuracy what will 

happen in a complex ecosystem where man and nature are so actively engaged. Given the broad 

geographic expanse of this planning effort and the associated level of funding available, certain 

simplifying assumptions were necessary. As discussed in the various categories of this section, given 

the uncertainties associated with making those predictions, the appropriate assumption is that existing 

conditions will continue into the future. 

b. Climate and Its Potential Effects on Floods. Potential climate change, its direction and 

its extent, is currently the subject of much scientific data gathering and analysis. The fact that some 

global warming is occurring has become increasingly accepted within the scientific community. 

Exactly how global warming would affect different regions of this country is still the subject of much 

analysis and debate. The results of General Circulation Models used to project future climate are 

ambiguous. Although flood magnitudes and frequencies may change as a result of global warming, 

the evidence is not strong enough to project even the direction of change for the Upper Mississippi and 

Missouri River basins (reference Flow Frequency Study).

For the purposes of this study, it is assumed that whatever climate changes occur within the 50-year 

planning timeframe will have little effect on the types of vegetation, cropping patterns or flood 

frequencies as currently determined. 

c. Watershed Land Use and Development. Within the 714,000 square mile watershed of 

the Upper Mississippi River (529,000 square miles of this are within the Missouri River basin), it is 

assumed that development will continue to occur in the uplands, especially around existing urban 

areas and along transportation corridors. This would involve a certain amount of conversion from 

crop, pasture, and forest land to urban, commercial, and residential uses. For small watersheds, 

undoubtedly urban development increases runoff and, if not mitigated, could increase flood peaks. 

However, it is assumed that increased runoff from much of the new development would be mitigated 

through the construction of on-site detention basins. Overall, future development in isolated areas of 

the watershed where on-site detention is not developed could alter the timing of the runoff from such 

areas in ways that would affect each flood event differently. However, for large floods on the Upper 

Mississippi River, this effect is assumed to be minor given the size of these developed areas versus 

that of the entire watershed. 

d. Floodplain Land Use and Development 

(1) Environmental. Environmental Chapter 1 provides a qualitative summary of past, 

present and future (without project) conditions for each of the river’s significant floodplain 

environmental resources. Much of the background information for that write-up was derived from the 

UMRS-EMP Long-Term Resource Monitoring Program’s Trends Analysis Report (1998).

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Upper Mississippi River Comprehensive Plan 

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Consistent with the Navigation Study, the Comprehensive Plan has assumed that the baseline 

environmental project condition (over the next 50 years) will be similar to that of the existing resource 

condition. Many river managers assert that, without strong and active intervention by governmental 

agencies and environmental Non-Governmental Organizations (NGOs), the river will continue to 

degrade somewhat over time. However, ongoing ecosystem restoration efforts by the states, the 

USFWS, the USFS, the National Resources Conservation Service (NRCS), the Corps, and others will 

continue into the future even without the opportunities presented by a systemic flood reduction plan. 

These ecosystem restoration programs are discussed further in the Environmental Appendix. 

(2) Commercial Development. There are several forces which are expected to induce future 

commercial development in the floodplain: the natural attraction of easily developed land; the need to 

be near a reliable source of water (either directly from the river or from alluvial aquifers); and the need 

to be located adjacent to water transportation. On the other hand, there is at least one strong force 

which discourages future commercial development—the National Flood Insurance Program, which 

not only mandates actuarial rates (i.e. unsubsidized rates) for new construction, but also requires local 

governments to enact and enforce strict zoning with respect to development within the base (1 percent 

chance) floodplain. 

The net effect of these competing forces upon future floodplain development is difficult to predict. In 

larger urban areas where land is scarce and local/state regulations, or their absence, make levee 

building feasible, it is possible that a small number of new levees, primarily for the purposes of 

commercial and industrial development, would be constructed. However, it is expected that, even in 

the very limited cases of new levee building, construction would be forced back out of the floodway 

and that resulting protected areas would be small compared to the river’s floodplain, thus producing 

little to no effect on major flooding events 

(3) Residential Development. Residential development is subject to some of the same forces 

that influence commercial development. Actuarial flood insurance rates on new home construction 

tend to discourage development within the base (1 percent chance or 100-year) floodplain. Moreover, 

following the past few major floods, there have been substantial state and FEMA funds available to 

buy out severely damaged home owners. In at least one instance, this has extended to the buy out of 

virtually an entire town, Valmeyer, IL. Some new homebuilding can be expected in farming areas, but 

even in this case, it is anticipated that nearly every new home would have its first floor elevated above 

the base flood, in compliance with local regulations. Also, as average farm size continues to grow, it 

would be expected that the number of floodplain farm houses would decrease. The net effect over the 

50-year planning time frame is projected to be a slight decrease in residences within the floodplain, 

but given the difficulties in quantifying this for a broad study of this nature, no change has been 

assumed for the purposes of quantifying flood damages and benefits. 

(4) Transportation Development within Floodplain. Inasmuch as highway usage shows no 

signs of lessening in the near future, it seems reasonable to project a continued upward trend, at least 

to some degree, throughout the 50-year planning time frame. This is reinforced by a population which 

continues to grow in the five-state basin area. From 1980 to 2000 the five-state area’s population 

increased 10.3 percent, from 28,072,000 to 31,281,000. Given an upward trend in traffic, at least 

some road building would appear to be necessary within the planning period. This can be significant 

since most state transportation agencies have standards which call for elevating major highways across 

floodplains at higher than natural ground level and sometimes higher than the base flood elevation. In 

these cases, highways can, in effect, act as dams in obstructing overbank flow in times of flooding. 

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Upper Mississippi River Comprehensive Plan 

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Bridges can also cause a swell effect on floodwaters when designed without sufficient allowances for 

high flows. However, it is anticipated that such development would occur along existing roadway 

corridors and would be an expansion of existing crossings rather than entirely new crossings. 

Moreover, new bridges must meet state and Federal requirements concerning impacts to flood levels. 

Therefore, although the next 50 years will see increased highway construction, and, to a lesser extent, 

railway crossings, it is not projected that significant impacts to flood heights will occur. 

 

(5) Critical Infrastructure Development within Floodplain. In 2000, the population in the 

Comprehensive Plan study area was over 9.7 million, an increase of 8.2 percent from 1990, 

significantly lower than the national growth rate of 13.2 percent during the same period. With 24.3 

percent of its population living in rural areas, the region is more rural compared to the rest of the 

nation, as defined by the U.S. Census Bureau. All critical infrastructure within the study area is 

outlined in Tables C-2a and C-2b in Appendix C, Economic Analysis. Infrastructure growth will tend 

to mirror population growth and thus will also be below the national average. Based on historical area 

population growth rates it is anticipated that future development of critical infrastructure will mirror 

current development and stay below the national average. Future development will be also restricted 

by floodplain regulations. 

(6) Agricultural Use of the Floodplain. For the purposes of this study, agricultural usage of 

the floodplain, in terms of acreage, is expected to continue into the future at approximately current 

levels. If anything, worldwide competition and its effects on grain prices may slightly lessen the 

amount of acreage in grain production over time. In recent years there has also been a tendency for 

governmental agencies and NGOs to selectively buy floodplain land either for the purposes of 

ecosystem restoration or forest development where soil type and hydrologic conditions make it 

conducive to those uses. However, with the passage of the Energy Policy Act of 2005, both of these 

factors may be somewhat offset by laws and policies which strongly support ethanol production. 

While the possibility exists that land usage may tend toward slightly less agricultural floodplain usage 

in the future, no change in overall agricultural usage has been projected for this study due to the global 

economic uncertainties associated with making such projections for a 50-year time frame. 

Agricultural productivity per acre is expected to increase throughout the planning time frame given 

anticipated advances in seed development, fertilization, and more efficient agricultural practices. 

Cropping patterns are projected to remain much as patterns that exist today. These latter two 

assumptions, of course, assume no significant climate change affecting rainfall, growing season or 

other natural factors affecting grain production. 

Upper Mississippi River and Illinois Waterway System Navigation and Ecosystem Sustainability 

Program (commonly known as NESP) used the Global Grain Model and Shipper Stated Preferences to 

forecast low and high traffic scenarios in 2007. The Global Grain Model is a production world wide 

equilibrium model developed by the Corps Navigation Economics Technologies (NETS) research and 

development program. 

 e. Flood Protective Works 

(1) Existing Levees/Floodwalls. The existing Upper Mississippi River and Illinois 

Waterway flood control projects were not intended or authorized to eliminate all flood risk potential 

within the study area. There is a known and accepted risk of flood events which would exceed the 

design levels of the many existing projects. Estimates of damages which would occur under these low 

probability-high impact scenarios are included in U.S. Army Corps of Engineers “damage curves” and 

53
Upper Mississippi River Comprehensive Plan 

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annual damage calculations. The intersection of design-exceeding floods with their associated 

damages is referred to as residual annual damages. These are the annual probability-based damages 

which could occur with an existing project. Significant damages and impacts would likely occur with 

catastrophic design-exceeding flood events. The Great Flood of 1993 provides insight into these 

impacts. These would be the realities of such a significant event: 

• Infrastructure would be directly and severely impacted. Roads, railroads, and bridges 

are impassible, hindering emergency health and safety services, commerce, and 

community mobility. 

• Utilities would be impaired. Water supplies could be lost (i.e., Des Moines, 1993). 

Communications systems and power plants operations could be affected or shutdown. 

• People would be displaced and property damaged. Lives could be lost or seriously 

disrupted. Property damage could be in the billions of dollars. 

• Restoration and recovery for infrastructure, utilities, people and businesses would take 

weeks, months, or years. 

During the 1993 Flood, no major urban flood protection project was overtopped along the Mississippi 

and Illinois Rivers. This is obviously fortunate, but this scenario could occur in the future. For 

example, if a design-exceeding flood occurred at St. Louis and East St. Louis, the human cost and 

city/regional impact could be enormous. Flood risk management projects provide huge benefits, but 

also impart a false sense of security. What might occur with the low-probability design-exceeding 

flood must be considered within the planning and community response process. 

In the existing “system” of levees and floodwalls, as appurtenant structures such as gravity drains, 

closure structures, pump stations and relief wells age beyond their original projected life (usually 50 

years or less), it is anticipated that these structures will deteriorate and could fail to perform as 

intended during a flooding situation. In the worst cases, failures of these components and 

appurtenances could result in failure of an entire levee system resulting in inundation of tens of 

thousands of acres, even at flood levels significantly below the crown of the levees. This study does 

not attempt to project if and where these failures will occur, but this phenomena has likely evidenced 

itself in the St. Louis area during the past few major floods. Some future pressure for raising or 

strengthening levees is also foreseen, especially in urban areas or in levee systems which protect 

municipalities. However, except in cases where projects are currently underway by the Corps, e.g. 

Muscatine, IA, and East Peoria, IL, this study does not attempt to project levee raises or strengthening, 

given the uncertainties in predicting exactly where they will occur. A third effect, as discussed above, 

could involve the buying out of entire levee districts and converting their use to one of habitat 

restoration. Two such examples would be the Little Creek Levee District, also known as Spunky 

Bottoms, and the Emiquon Levee District in the Illinois River floodplain. In summary, while all of 

these changes, which already evidence themselves in the present, are likely to continue to occur to 

varying degrees in the future, the computation of flood damages is based on a continuation of the 

existing system into the future. 

(2) New Levees/Floodwalls. Given the degree to which the Upper Mississippi and Illinois 

River Valleys have already been leveed, no additional agricultural levees have been projected for the 

50-year planning time frame, other than those currently in planning by the Corps. However, as 

developable land becomes scarcer, it is considerably more likely that pressure will be felt in urban 

areas to construct a certain amount of new levees. Even so, given the uncertainties associated with 

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Upper Mississippi River Comprehensive Plan 

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predicting just where such levee building will occur, no additional major urban levees have been 

assumed for purposes of damage quantification in this study. 

(3) Upland Reservoirs. Reservoirs form major components of the flood risk management 

system on the Upper Mississippi River, but few of any size exist within the Illinois River basin. 

However, given the scarcity of relatively unencumbered sites and the high costs of construction, no 

new reservoirs are projected in the future for either river. 

 f. Institutional 

(1) Federal Programs 

 (a) Department of Agriculture. The future without conditions of this study assume 

that the various programs of the Department of Agriculture would continue in their 

present form and at their present funding levels. These programs include 

 Emergency Watershed Protection Program 

 Emergency Wetlands Reserve Program 

 Conservation Reserve Program 

 Wetlands Reserve Program 

 Cooperative River Basin Program (authorized by PL 83-566) 

 Watershed Protection Program (authorized by PL 83-566) 

 Sodbuster and the Swampbuster Provisions of the Food Security Act of 1985 

 Forestry Incentive Program 

The future without condition also assumes price and income support programs similar to 

their current form. It also assumes that the U.S. Forest Service will continue to acquire inholdings within designated U.S. Forest Service boundaries as they become available from 

willing sellers. This includes some land that lies within leveed floodplains. 

 (b) U.S. Fish and Wildlife Service (USFWS). It is assumed that the USFWS will 

continue to maintain and operate refuge lands within the floodplains of the Mississippi 

and the Illinois Rivers, including certain lands that it manages for the Corps. There may 

also be collaborative efforts with state agencies and non-governmental organizations, as 

discussed in on the following page. 

 (c) Federal Emergency Management Agency. The future without condition 

assumes that the National Flood Insurance Program (NFIP) and the Hazard Mitigation 

Grant Program (Section 404, Stafford Act) will continue in their current forms. The NFIP 

requires that all structures located lower than the base flood, 1 percent chance annual 

(100-year) flood event, purchase flood insurance if the owner receives a loan from a 

federally-insured bank or other financial institution. The Hazard Mitigation Grant 

Program, using a small portion of the insurance premiums, provides funding for mitigation 

projects, such as buyout of structures which are frequently inundated. 

Their collective effect will be to discourage future floodplain construction and to 

gradually remove existing flood prone structures from the floodplain. 

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Upper Mississippi River Comprehensive Plan 

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(d) U.S. Army Corps of Engineers. The future without condition assumes that the 

current programs of the Army Corps of Engineers will continue in the same form as they 

currently exist. This means a continuation of the P.L. 84-99 program to provide 

assistance to non-federal entities during times of flooding and to assist in the rehabilitation 

of flood protective works for damages caused by floods when economic feasibility is 

demonstrated and other conditions are met. Federal assistance should continue to both 

federally-constructed levee systems and to those systems constructed by local interests 

who adhere to minimum Federal design standards and maintenance criteria. 

 

It is assumed that ecosystem restoration programs such as the Section 1135 (WRDA 1986) 

and Section 206 (WRDA 1996) Continuing Authorities and the Upper Mississippi River 

Environmental Management Program (WRDA 1986 as amended) will continue at roughly 

their current funding levels. 

It is assumed that over the 50-year planning time frame, a limited number of new levees in 

urban areas will be constructed. However, these new levees are expected to be fairly 

small in comparison to the urban levees that already exist. Due to the difficulty in 

determining the exact sites where construction will occur, no attempt has been made in 

either the hydraulic or economic analyses to model these effects. 

It is assumed that over the 50-year planning time frame, federally-constructed projects, as 

they near the end of their projected life, will be examined to determine whether 

reconstruction of certain deteriorated components is feasible and in the Federal interest. 

(2) State Programs. It is assumed that the five basin states will continue to participate in 

floodplain ecosystem restoration projects, either collectively without Federal agency assistance or in 

partnership with the Corps of Engineers and the USFWS and certain Non-Governmental 

Organizations. It is assumed that those states which have programs to oversee the permitting of 

levees, e.g. Illinois, will continue to exercise those programs similar to their current form. 

(3) Non-Governmental Organizations (NGOs). It is assumed that in the future without 

project condition, environmental NGOs, such as the Nature Conservancy, the American Land 

Conservancy and the Audubon Society, will continue to work to acquire and restore certain floodplain 

properties to recapture their natural values and floodplain functions. One such effort is the Middle 

Mississippi River Partnership which involves a collaboration of Federal and state agencies as well as 

NGOs in an effort to restore and enhance sustainable natural resources on public and private lands 

within the middle Mississippi River corridor. It is assumed that NGOs such as the Upper Mississippi, 

Illinois, and Missouri Rivers Association, which focus on the commercial activities of the floodplain 

(agricultural, industrial, transportation, etc), will continue to work to see that these values are also 

served in future development plans. 

 3. Problems and Opportunities. The first step, Step 1 of the six step planning process, is to 

identify the problems and opportunities. The Economic and Environmental Principles and Guidelines 

for Water and Related Land Resources Implementation Studies (P&G)(WRC, 1983) has been utilized 

to guide the development of the Comprehensive Plan. The Federal objective in the planning process 

(as defined by P&G) is to contribute to national economic development, consistent with protecting the 

nation’s environment. 

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In accordance with Sec. 459 of the Water Resources Development Act (WRDA) of 1999, the Federal 

objective for the Comprehensive Plan is flood damage reduction, i.e., flood risk management. While 

addressing this primary objective, certain other objectives are to be evaluated to the extent that they 

relate to flood risk reduction. These secondary objectives include navigation project maintenance; 

bank caving and erosion; watershed nutrients and sediments management; habitat management; 

recreation needs; and other related purposes. 

The Upper Mississippi River Comprehensive Plan effort was developed in a collaborative 

environment as described below. This is an extension of the collaborative working relationship among 

Federal, state, and local agencies and other non-federal organizations/interest groups that has been in 

place in the UMRS for a number of years. The UMRS collaboration has resulted in development and 

agreement with the following Guiding Principle. 

Guiding Principle for the Upper Mississippi River System 

“The balance of economic, ecological and social conditions so as to meet the current, 

projected and future needs of the Upper Mississippi River System without 

compromising the ability of future generations to meet their needs.” 

The problem and opportunities sections of Step 1 of the Corps Six Step Planning Process are discussed 

as follows. They have been broadly written to capture the immediate study opportunities for flood risk 

management and to provide a framework for discussing potential future follow-on study 

recommendations that are more encompassing in nature. 

 a. The Problem 

 

(1) Flood Damage. Despite more than 100 years of private and Federal investment in local 

flood protection systems, significant damages continue to occur during major flood events. The Flood 

of 1993 provided a vivid demonstration of the vulnerabilities of the existing flood control systems on 

the Upper Mississippi River System. Assessments of the economic damages caused by the Flood of 

1993 range from $15 to 20 billion, including more than $2.9 billion in damages along the Mississippi 

River and its floodplain. The social disruption was beyond measure, with more than 50,000 homes 

damaged or destroyed and approximately 54,000 persons evacuated from flooded areas (NOAA, 

1994). While the size and impact of the Flood of 1993 was unprecedented in recent history, floods of 

equal or greater magnitude are anticipated to occur in the future, and the region may again be exposed 

to the destructive potential of the Mississippi River. 

The flood risk management facilities (Federal and non-federal) of the Upper Mississippi River System 

were not constructed in accordance with any overall systemic plan. These facilities have varying 

structural integrity, and provide varying levels of flood protection for similar land uses. Not since 

1981 (with the termination of the Upper Mississippi River Basin Commission) has there been an 

overall planning authority for Upper Mississippi River System resources management (McGuiness, 

2000). System-wide, coordinated, and integrated management of the Upper Mississippi River System 

is not currently the mission of any one agency. Today, separate government programs address a host 

of floodplain concerns. 

The Flood of 1993 awakened renewed interest in developing a systemic approach to flood risk 

management on the Upper Mississippi River System. In authorizing this study, Congress recognized 

the need for a planning effort that develops an implementable floodplain management plan for which 

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there is a Federal interest. That plan needs to address the immediate problem of reducing future flood 

risk, but also needs to evaluate the potential for a future, more-resources inclusive, integrated river 

resources management program. 

(2) Ecosystem Resources. Since the early 1800s, the Upper Mississippi River ecosystem has 

been drastically affected by the loss of wetlands and other habitats. This was due to water pollution, 

land use changes (i.e. urban development, agriculture, forestry, and mining), navigation improvements 

(i.e. locks and dams, dikes, revetments, and dredging), and flood risk management improvements 

(levees, floodwalls, and reservoirs). Likewise, the Illinois River ecosystem has suffered a series of 

ecologically adverse events, including Lake Michigan water diversion, floodplain drainage, water 

pollution, commercial navigation, and accelerated sedimentation. 

More recently, pollution controls and environmental restoration projects have helped improve 

conditions on the Upper Mississippi River System for some species. However, the disruption of the 

natural ecosystem has caused a loss in the abundance of certain other populations of native species and 

has resulted in an increased number of species being listed as state threatened. The nature of Upper 

Mississippi River System habitat degradation is more fully characterized below. 

(a) Floodplain Connectivity. Seasonal flooding is an ecologically important process in 

large river floodplain ecosystems because such flooding connects the river with its floodplain. In the 

Upper Mississippi River-Illinois Waterway, many low elevation floodplain areas are no longer subject 

to seasonal flooding because they are permanently flooded from impoundment by navigation dams. 

Comparing pre-dam and post-dam conditions, total open water area has decreased or remained stable 

in Pools 4 and 10 through 26, the Open River, and the Illinois River, but it increased in Pools 5 

through 9. Decreases in water area are attributable to several geomorphic processes including loss of 

contiguous backwaters; filling of isolated backwaters; loss of secondary channels; filling between 

wing dams; and delta formation. Increases in water area are apparent where dam impacts inundated 

significant amounts of low elevation floodplain in lower pool areas. 

In addition, constructing levees reduces aquatic habitat connectivity with floodplain habitats. Aquaticterrestrial connectivity is important for many physical, chemical, and biological functions. Floodwater 

flow moves sediment and nutrients over the floodplain to shape it and to enrich the soils and 

rejuvenate marshes, prairies, and forests. Chemical transformations in floodplain habitats consume 

and transform nutrients to balance input and outputs and nutrient discharge to coastal areas (Gulf of 

Mexico). Biological responses to flooding can be diverse and prolific; microbial and invertebrate 

production thrives on inundated floodplain vegetation, fish feed on the invertebrates and spawn in 

flooded land, stranded fish feed a variety of predators and scavengers, and shorebirds are drawn to 

exposed mudflats surrounding backwater lakes. Reduced connectivity to floodplain habitats impacts 

the functions described above, and also impacts connected habitats and receiving waters by 

concentrating sediments and nutrients in smaller areas or shunting them downstream. 

(b) Water Pollution. The water quality of the Upper Mississippi River System has 

improved in response to a mandated treatment of domestic sewage (USACE, 1998). However, the 

river still receives a mixture of contaminants from agricultural, industrial, municipal, and residential 

sources. For example, heavy metals accumulated in riverbed sediments could be a long-term problem 

for aquatic life, especially in sites downstream of metropolitan areas. 

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Watershed nutrients is a water pollution problem specifically called out in the Section 459 legislation, 

and for that reason, it is the central water quality concern addressed in this report. The nutrients topic 

is fully addressed in Chapter 6. 

Several factors have contributed to the increase in the Upper Mississippi River System nutrients 

loading. First, the expansion of agriculture prior to the 1980s resulted in a loss of 26 million acres of 

wetlands (along with its natural capacity for denitrification). Second, there has been a substantial 

increase in the application of nitrogen fertilizer to crop fields, and third, the use of drainage tiles has 

accelerated the drainage of nitrogen fertilizer containing groundwater from the system. 

Nutrient loading has the potential to degrade water quality and aquatic life along the river system per 

se. Most Upper Mississippi River System states have significant river miles impaired by high nutrient 

concentrations. Impaired waters are those not fully supporting one or more resource uses, including 

swimming, fish consumption, aquatic life, and/or drinking water. 

In addition to basic compliance with Federal environmental laws dealing with water quality, the 

Comprehensive Plan provides an opportunity to explore flood risk management compatible methods 

(such as wetlands restoration), for nitrogen load reduction by denitrification and nitrogen retention. 

(c) Sedimentation. Sedimentation is a major socio-economic problem in the Upper 

Mississippi River System. It has caused portions of the floodplain to fill, thereby decreasing channel 

conveyance and increasing flooding. It has also caused maintenance problems in reservoirs; blockage 

of inflow/outflow pipes for water supply facilities and power plants; blockage of the entrances to 

harbors and marinas; the filling of drainage ditches; increased cost of water treatment; and aesthetic 

and structural damages (including erosion at bridges). 

Sediment can also be a major physical or chemical pollutant. High levels of turbidity can limit the 

penetration of sunlight into the water column, thereby limiting the growth of plants. Gravel beds 

covered with fine sediment could also impact fish spawning. Metals tend to be highly attracted to 

ionic exchange sites that are associated with fine clay particles. Iron and manganese coatings 

commonly found on clay also attract these pollutants. Many of the persistent, bio-accumulating and 

toxic organic contaminants are strongly associated with sediment. 

For years, Federal and state agencies have been reporting that decreasing budgets have greatly reduced 

the amount of sediment monitoring being conducted in the basin. The USGS’ “sediment program” has 

not changed significantly in magnitude since the late 1990s. Funding has usually been directed at 

ongoing sediment problems for only short-term analysis. It has been 20 years since major sediment 

monitoring of the Upper Mississippi River System tributaries was performed. If funding is not reestablished, there will be a large historical data gap that will be statistically difficult to overcome. 

The 1993 flood showed the value of installing flood-prevention measures and land-treatment practices 

on watershed agricultural lands. National Resources Conservation Service projects prevented many 

millions of dollars in damages during this flood event, with lower crop losses in areas with upland 

watershed treatment. 

b. Goals and Opportunities. The overall goal of the Comprehensive Plan is to develop a 

systemic, comprehensive flood risk management plan for the Upper Mississippi and Illinois Rivers, 

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sufficiently comprehensive to address flood risk management needs and supportive of evolving longterm economic and environmental sustainability goals. 

Specific objectives are to: 

• minimize the threat to health and safety resulting from flooding by using structural and non-

 structural flood risk management measures; 

• reduce damages and costs associated with flooding; 

• identify opportunities to support environmental sustainability/restoration goals of the Upper 

 Mississippi River and Illinois River floodplain as part of any systemic flood risk management 

 plan; 

• seek opportunities to address, in concert with flood risk management measures, other 

 floodplain specific problems, needs, and opportunities to include: 

o continued maintenance of the navigation project and related commercial 

 infrastructure; 

o reduction of nutrient input and sedimentation into the rivers; 

o improved habitat management; 

o bank caving and erosion reduction; 

o improved recreation opportunities; and 

• identify and recommend appropriate follow-on studies. 

An additional objective expressed by some stakeholders is to develop a systemic flood risk 

management plan to be able to pass a very large flood, thereby avoiding a disaster similar to the 1993 

flood. 

On a system as large as the Upper Mississippi River System, the number of potential flood risk 

management alternatives and permutations is significant. In the same vein, the Floodplain 

Management Assessment (USACE, 1995) and Galloway Report provide an extensive representation of 

flood risk management related opportunities; categorically, these opportunities include various 

modifications to levees, reservoirs, flood insurance programs, flood fighting, buyouts, flood 

response/recovery, and crop insurance. However, the scope and funding of the Comprehensive Plan 

precludes the Corps’ ability to address, in detail, all of the measures identified in those reports. The 

Comprehensive Plan does provide a limited opportunity to begin the development of a conceptual, 

analytical, and collaborative framework for increasing our understanding of the processes impacting 

upon floodplain communities. 

c. Planning Constraints. Following identification of problems and opportunities which result in 

the development of goals and objectives, Step 1 concludes with planning constraints. 

The study-specific constraints identified for the Comprehensive Plan include: 

• As per the Water Resources Development Act of 1999, Section 459, flood damage reduction, 

i.e., flood risk management, is the emphasis (study authorization places primary emphasis on 

flood damage reduction, and secondary emphasis on other project purposes). 

• Make maximum use of existing data (Reference WRDA of 1999, Section 459). 

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• Environmental measures are linked to flood risk management (for inclusion, environmental 

measures need to be related to flood risk management measures). 

• Need for future site-specific studies (due to funding limitations, project development process 

will be tiered). Any site-specific studies would follow the traditional cost sharing 

requirements of feasibility phase studies, 50 percent Federal and 50 percent non-federal cost. 

• Due to funding availability, certain current or future floodplain activities, issues, conditions, 

and alternative futures that are components of a comprehensive plan related to environmental 

quality will be minimally addressed during the course of this study. 

• Limit alternative plans to those that increase the hydraulic profile at any location to no more 

than 1.0 feet, associated with FEMA criteria, for the base flood (the one percent chance annual 

flood event). 

• Conduct the analysis in a timely manner within budget, a fiscal constraint..

d. Inventory and Forecast Resource Conditions. Step 2 of the planning process is to inventory 

and then forecast the expected future condition assuming no project were implemented. Data and 

information on the existing conditions and forecasted future conditions was presented earlier in 

paragraph E. 1. Existing Conditions and E. 2. Future Without Project Conditions. Steps 1 and 2 of 

the planning process are closely interrelated and very iterative in nature. Frequently the inventory of 

existing conditions and forecast of future of future conditions is needed to determine the analysis goals 

and objectives.

F. FORMULATE ALTERNATIVE PLANS 

Plan formulation—the development of alternative plans to address the objectives and opportunities 

identified—is Step 3 of the Corps’ Six Step Planning Process. Plan formulation is composed of 

several main parts leading to the final development of the array alternative plans considered. 

Step 3 typically includes three major components: 

1. identify measures and strategies (termed philosophies by the Collaboration Team); 

2. combine measures and philosophies to develop alternative plans; and 

3. based upon an initial evaluation of the alternatives, reformulate and develop additional 

alternatives based upon what is learned 

The Comprehensive Plan further considered plan formulation results in light of the Chief of 

Engineers’ 12 Actions for Change, which were issued in August 2006. The 12 Actions are: 

• Effectively Implement a Comprehensive Systems Approach: Comprehensively design, 

construct, maintain and update engineered systems to be more robust, with full stakeholder 

participation. 

1. Employ integrated, comprehensive and systems-based approach 

2. Employ risk-based concepts in planning, design, construction, operations, and major 

maintenance 

3. Continuously reassess and update policy for program development, planning guidance, 

design and construction standards 

4. Employ dynamic independent review 

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5. Employ adaptive planning and engineering systems 

6. Focus on sustainability 

7. Review and inspect completed works 

8. Assess and modify organizational behavior 

• Communication: Effective and transparent communication with the public, and within the 

Corps, about risk and reliability. 

9. Effectively communicate risk 

10. Establish public involvement risk reduction strategies 

• Reliable Public Service Professionalism: Improve the state of the art and the Corps’ 

dedication to a competent, capable workforce on a continuing basis. Make the commitment to being a 

“learning organization” a reality. 

11. Manage and enhance technical expertise and professionalism 

12. Invest in research 

 1. Identify Measures and Strategies 

a. Flood Risk Management Measures. Using past experience, holding brainstorming 

sessions, and eliciting public and Collaboration Team input, the following list of possible flood risk 

management measures was developed. Bold-faced type indicates measures generally preferred during 

the discussions. (PW) indicates a measure that was identified by the public at the November 2002 

Public Workshops or in response to the workshop notice requesting input. Appendix F, Public 

Involvement describes the results of the Public Workshops in detail. 

1. Flow Diversions 

 A. Diversion Channels 

 B. Timed use of off-channel (behind levee) storage (PW)

2. Upland Detention 

 A. Flood Control Reservoirs (PW) 

 1) New 

 2) Modified regulation of existing 

 B. Dry Detention Basins 

 C. Watershed Small Ponds and Detentions (PW)

 D. Wetlands restoration 

 E. Grasslands restoration 

3. Channel Modifications 

 A. Channel Geometry-increased Channel Capacity (using underwater weirs) (PW)

 B. Reduced Energy Loss 

 1) Vegetation management 

 2) Channel Straightening 

 3) Modifying/reducing constrictions - bridges, levees (PW) 

 C. Overbank conveyance-increase (PW)

 1) Levee set-backs (PW) 

 2) Re-alignment of levees/structures 

 3) Remove Levee (PW)

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63

4. Levees and Floodwalls 

 A. Raising levees/structures (PW) 

 B. Controlled overtopping of levees/structures (PW)

 C. Low Profile Berms to protect environmentally sensitive areas 

5. Reduction in Existing-Condition Damage Susceptibility 

 A. Local non-structural measures including flood proofing 

 B. Relocation/Acquisition/Buy-outs (PW)

 C Improved Flood-Warning/Preparedness 

6. Reduction in Future-Condition Damage Susceptibility 

 A. Land use/Construction regulation (floodplain management) (PW) 

 B. Easement - Conservation and flowage (PW) 

b. Ecosystem Restoration Measures. Flood risk management reduction is the primary purpose 

of the Comprehensive Plan (Section 459 of the WRDA of 1999). Therefore, opportunities for 

ecosystem restoration are limited to those that could be implemented in conjunction with flood risk 

management alternative plans. Also considered was the type of habitat management strategy that 

might be applied at a given floodplain site, as this could ultimately impact the number of manageable 

habitat acres. Up to four different options for floodplain ecosystem management were evaluated 

against each of the flood risk management alternative plans. The options are described in Table 12. 

Lands included as flood risk management buyouts would have to meet two general screening criteria: 

(1) the cost of levee improvements for a given Drainage and Levee District would have to exceed the 

value of the lands protected, i.e. it would be cheaper to protect the site from flood risks by acquiring its 

land--rather than by investing in a structural solution), and (2) levee areas must be less than 10 percent 

urbanized, the area should be suitable for ecological restoration by not being significantly threatened 

by urban development either now or during the next 50 years. The same site development measures 

described for Option 2 would be applied for buyouts as well. Similar to Option 2, the affected lands 

would be actively managed for fish and wildlife purposes. This option addresses a more literal 

interpretation of the WRDA 1999 language that states "flood damage reduction and floodplain 

management by means of”...habitat management. 
Upper Mississippi River Comprehensive Plan 

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Table 12. Description of Ecosystem Restoration Options

Option Description 1 No Action No additional habitat management of Upper Mississippi River System floodplain.2 Conservation Easements Acquired in 

Conjunction with Plan Flowage Easements 

A payment for residual property rights on flood risk management flowage easement lands wlandowners (on a voluntary basis) as conservation easements for future fish and wildlife maoption could encourage enhanced Federal funding to support the management of existing staprograms (e.g. CREP, WRP, EMP programs, etc.). Lands under these conservation easemewide variety of available habitat improvement methods.

3 Buyouts Lands included as flood risk management buyouts would have to meet two criteria: (1) the c

for a given Drainage and Levee District would have to exceed the value of the land protecteless than 10% urbanized. The same site development measures described for Option 2 wouSimilar to Option 2, the affected lands would be actively managed for fish and wildlife purpmore literal interpretation of the WRDA ’99 language that states “flood damage reduction ameans of...habitat management...”

4 Conservation Easements on Lands 

adjacent to Levees Construction 

This measure is similar to Option 2. However, since no flowage easements would be involvinterests landward of the levees would be tantamount to the cost of a fee simple acquisition. 

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 c. Identify Philosophies (Strategies) and Design Criteria 

1. Philosophies. Alternatives should be formulated to achieve flood risk management—

termed by the Corps as national economic development benefits, and also achieve gains in 

National Ecosystem Restoration (NER) and sustainability benefits as possible. The first 

component of Plan Formulation is to identify measures and philosophies (strategies) which, when 

combined, then form alternative plans, the second component. The PDT brainstormed and 

developed a list of over 30 strategies, which the CT preferred to name philosophies. Collaboration 

Team insight and discussion over several months and meetings resulted in the philosophies 

presented in the report. Developing the philosophies and measures ends the first component of 

Step 3.

Prior to developing specific alternatives, the following plan formulation philosophies, in no preference 

order, were developed to guide the formulation of systemic alternative plans: 

• Use non-structural techniques. Apply permanent buyouts, relocation and other 

appropriate non-structural measures to reduce flood risks. 

• Uniform level of protection for the entire system and by reach. The Comprehensive 

Plan is to consider systemic plans which provide uniform levels of protection 

everywhere along the Mississippi and Illinois Rivers. 

• Uniform level of protection by land use (urban, critical infrastructure and non-urban). 

Plans should be consistent by major land use for the Upper Mississippi River system. 

• Minimize loss of life 

• Minimize impacts to adjacent properties. As discussed in Constraints and Design 

Criteria following, the maximum induced impact allowed for alternative plans is a one 

foot rise in water surface elevations. 

• Emergency Action Plan (Flood Routing Plan). As requested by the Collaboration 

Team, analyze temporary emergency raises to the existing flood risk management 

systems during a major flood event to determine the impacts of emergency measures, 

from both benefit and induced rise standpoints. 

• Flexibility (to meet a wide range future conditions) 

• Achieve flood risk management with maximum gains in NER/sustainability. Gains in 

national environmental restoration are always considered per the Environmental 

Operating Procedures and other Corps planning policies. 

After considering and evaluating initial alternative plans, the list of philosophies was expanded by 

adding the following philosophies. The changes specifically identify that alternative plans be systemic 

in breadth, consider critical infrastructure, and add the potential of reconstruction of existing systems. 

1. The alternative should cover a range of scope from a very high level of flood 

protection to lesser levels. The 0.2 percent chance annual (500-year) protection was 

the highest level of protection considered with other alternative plans having systemic, 

uniform level of protection progressively less. 

2. The alternatives should specifically address critical infrastructure, including 

transportation access (bridges/approaches) across the Mississippi and Illinois Rivers. 

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3. A reconstruction option should be considered to evaluate the condition of the existing 

flood protection systems and propose rehabilitating them, as justified, to their original 

performance, which may have become degraded over time due to the age of the 

systems. 

2. Design Criteria. Four design criteria were established collaboratively to be applied 

uniformly and consistently in the development of alternative plans for the entire study area. 

The following four design criteria were used to formulate the alternative plans, except as noted in the 

detailed description of individual plans. 

(1) The existing level of protection. In areas where the existing level of protection 

exceeds that of the proposed alternative plan, the existing flood protection system 

would remain unchanged. 

(2) Increase of 1 foot for the 1 percent chance annual (100-year) flood. 

Floodplain development is managed by local, state, and Federal laws and statutes. 

Floodways for state or local communities in the Federal Insurance Program are 

developed using an allowable induced rise in the water surface profile of one foot for 

the one percent chance annual (100-year) flood. This minimum criterion is set by 

FEMA for floodways and can be modified by state and local ordinances to develop 

even more stringent guidelines. For example, the State of Illinois has imposed a 

maximum allowable stage increase of 0.1 foot for floodways with allowable 

compensation to all landowners that exceed the allowable impact. This management 

tool for floodplains was used to develop one of the Comprehensive Plan criterions that 

could be accepted by local, state and Federal Floodplain Managers. The criterion set 

for all plans (except as noted) in this study is not to exceed the one-foot rise in water 

surface profile for the one percent chance annual (100-yr) flood. 

(3) Minimize water surface profile rise at Thebes, IL. Thebes, IL, is the 

downstream limit of the Comprehensive Plan and the upstream limit of the existing 

Mississippi River & Tributaries (MR&T) Project. The MR&T levee systems protect 

thousands of square miles of floodplain from a Project Design Flood. Induced water 

surface profile raises from the Upper Mississippi River System passed below Thebes 

would necessitate costly mitigation measures to restore the existing levels of 

protection to the MR&T Project. Therefore, every attempt was made to limit the 

hydraulic impact of the various alternatives at Thebes, IL. The limitations of this 

criterion were explored as part of Alternative Plan G, described in Section 3. 

Combine Measures and Philosophies to Develop Alternative Plans which follows 

next. 

(4) The ratio of total average annual damages prevented per acre. When 

determining which areas to include in an alternative that cannot be applied 

systemically to every existing drainage and levee district due to induced water surface 

profile rises, the districts with the highest ratio of average annual damages to acres 

protected were included first. For example, if in a given reach an alternative plan 

could only afford to improve the level of protection of one levee district due to 

induced hydraulic impacts that exceed the previous criteria, the levee district with the 

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higher ratio of total average annual damages per acre would be selected for 

improvement, and the others would remain at their current height. 

3. Combine Measures and Philosophies to Develop Alternative Plans 

 a. Description of Alternative Plans. The following is a list of the alternative systemic plans 

considered for the Upper Mississippi River Comprehensive Plan, the second component of planning 

Step 3, Formulate Alternative Plans. The Plan Summary designates by land use type the level of 

protection for the land use type for the particular plan. 

All the existing urban systems provide at least a minimum of a 1 percent (100-year) annual chance 

level of protection. On the Mississippi River, 21 of the 27 Federal systems are designed to provide 

protection for the 0.2 percent (500-year) annual chance flood event and therefore the analysis was 

simplified to just consider a uniform 0.2 percent annual chance level of protection for urban systems. 

Non-structural flood risk management strategies, flood proofing and raising structures in place, for 

example, were considered but screened out as impractical to apply on a systemic basis, As the 

analysis of non-structural flood risk management strategies is very site specific, it was beyond the 

capability of the Comprehensive Plan to formulate and evaluate this type of analysis. Buyout and then 

relocation of structures and facilities was included in plan formulation and not screened out, 

Alternative Plans H and J. If an alternative plan is being implemented in the future, non-structural 

measures, such as flood proofing, should be fully considered as the detailed site implementation 

analysis occurs. 

No Action Alternative 

Description. The No Action plan represents the future condition without any Corps project as a result 

of the Comprehensive Plan. Refer to Section 2, Future Without Project Conditions. All other 

alternative plans, Plans A through M, are compared to this, the No Action plan, to determine the 

benefits and costs of each plan. If no action is taken, significant flooding could occur on the system. 

Plan Summary

• Urban - no change to the existing level of protection which varies by location 

• Agricultural – no change to the existing level of protection which varies by location 

• Unprotected towns – no change to the existing level of protection which varies by 

location 

• Other existing unprotected areas – no protection 

• No mitigation required 

Discussion. The No Action plan represents the future conditions without any project as a result of this 

study. In general, the landscape will remain generally as it exists. Significant changes will occur only 

in relatively localized areas. 

Alternative Plan A. Confined – 0.2 Percent Chance Annual (500-year) Urban and Agricultural 

Protection 

Description. This alternative plan involves protecting areas with existing levees/floodwalls to the 0.2 

percent chance annual level of protection. The 0.2 percent chance annual (500-year) level of 

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protection applies to urban, agriculture and unprotected communities. Briefly, as used in this report, 

confined means the flows are confined between the levees in the river channel and overbank area or 

between the levee on one bank and the bluff on the opposite river bank. Flood waters are not allowed 

to overtop any levee. It is assumed for analysis purposes, that levees would be raised as needed to 

keep the flood waters out of the levee areas, confined to the river. Design criteria 2 and 3 above do not 

apply to Plan A. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) protection 

• Agricultural – 0.2 percent chance annual (500-year) 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. This alternative plan applies a uniform, high level of protection to existing protected 

areas and unprotected urban areas regardless of its impacts on flood profiles. This means that the 

design flood event, a 0.2 percent chance annual event, was contained by the raised levee systems, also 

called the confined hydrologic condition, was not allowed to overtop protection systems. Uniformly 

raising all areas in this manner will potentially result in significant increases in flood heights in some 

portions of the system, greater than 7 feet. This plan is considered unacceptable due to the large 

induced rise in flood heights. This alternative plan represents the upper bound (regarding increases in 

the line of protection) on structural plans for flood risk management considered in this study. 

All the other alternative plans are considered unconfined from a hydrologic standpoint. Within the 

context of the Comprehensive Plan, unconfined means allowing no more than a one foot water surface 

profile rise. The river is no longer confined between the levees or levee and bluff. With a one foot 

rise, the analysis lets river flows overtop leveed areas to insure no more than the one foot water surface 

profile rise. The analysis to determine how to achieve the one foot limit is very analysis intensive 

requiring much trial analysis to not exceed the one foot rise criteria. 

The four alternative plan design criteria, discussed above, apply to the following plans except as noted 

below. 

Alternatives B through E represent consistent levels of protection across major land use types (urban 

and agricultural). In order to meet the 1.0 foot allowable maximum rise standard, as well as to 

minimize impacts to the Lower Mississippi River, some agricultural levee districts will, by necessity, 

need to be excluded from improvement. The selection of levee districts that can be included in the 

plans followed the procedures discussed in Section 2.b, Design Criteria using national economic 

development (NED) criteria. 

Alternatives B through E would result in preventing an additional increment of potential future flood 

risks. The NED analysis indicates that all plans have benefit to cost ratios less than 1.0. If the plans 

were implemented, substantial regional economic benefits would result. 

Alternative Plan B. 0.2 percent chance annual (500-year) Urban and Agricultural Protection 

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Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level of protection if the increase in the level of protection can be 

accomplished and not induce flood profile rises greater than one foot. 0.2 percent chance annual (500-

year) level of protection applies to urban, agriculture and unprotected communities. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) protection 

• Agricultural – 0.2 percent chance annual (500-year) 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. This alternative plan applies a uniform, high level of protection to existing protected 

areas and unprotected urban areas. For areas south of St. Louis, MO, due to the design criteria of no 

more than a one foot induced rise, no districts can be raised to the plan design level, 0.2 percent 

chance annual event. However, analysis indicates that if there is any induced rise south of St. Louis 

due to plan implementation upstream, north, of St. Louis, the districts south of St. Louis can be raised 

to compensate or mitigate for the induced rise within the design criteria. 

Alternative Plan C. 0.2 percent chance annual (500-year) Urban / 200-yr Agricultural 

Protection 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level for urban areas and the 200-yr level for agricultural areas. Unprotected 

urban areas would also be protected to the 0.2 percent chance annual (500-year) level. The hydraulic 

impacts of this alternative on flood profiles and the Lower Mississippi River would be minimized 

through creation of additional storage areas and/or the exclusion of some agricultural districts from the 

plan. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) protection 

• Agricultural – 0.5 percent chance annual (200-yr) protection 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. Alternative Plan C was not evaluated in detail due to limited resources and time and it 

falls between two evaluated plans, Alternative Plans B and D. 

Alternative Plan D. 0.2 percent chance annual (500-year) Urban / 1 Percent chance annual (100-

yr) Agricultural Protection 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level for urban areas and approximately the 100-yr level for agricultural 

areas (the level of protection would be left intentionally insufficient to obtain FEMA certification). 

Unprotected urban areas would be protected to the 0.2 percent chance annual (500-year) level. The 

69
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hydraulic impacts of this alternative on flood profiles and the Lower Mississippi River would be 

minimized through creation of additional storage areas and/or the exclusion of some agricultural 

districts from the plan. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) protection 

• Agricultural – approximately 100-yr protection 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. This floodplain management plan was intentionally developed such that for existing 

protected areas which require a raise in protection height, the new height would be less than required 

to obtain Federal Emergency Management Agency (FEMA) certification as providing protection for 

the base, or 1 percent chance annual, flood event. This plan would minimize new floodplain 

development in concert with current Federal policies of not inducing floodplain development while 

raising the level of protection for many of the agricultural levee districts. 

Alternative Plan E. 0.2 percent chance annual (500-year) Urban / 2 Percent chance annual (50-

yr) Agricultural Protection 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level for urban areas and the 50-yr level for agricultural areas. Unprotected 

urban areas would be protected to the 0.2 percent chance annual (500-year) level. The hydraulic 

impacts of this alternative on flood profiles and the Mississippi River and Tributaries (MR&T) 

Project, would be minimized through creation of additional storage areas and/or the exclusion of some 

agricultural districts from the plan. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) protection 

• Agricultural – 50-yr protection 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. As with alternative plan D, this floodplain management plan was intentionally developed 

such that for existing protected areas which require a raise in protection height, the new height would 

be less than required to obtain Federal Emergency Management Agency (FEMA) certification as 

providing protection for the base, or 1 percent chance annual, flood event. 

Alternative Plan F. 0.2 percent chance annual (500-year) Urban and Highway Approach 

Protection 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level for urban areas, and the use of ring levees to protect smaller urban 

centers within predominantly agricultural levee districts. In addition, the highway approaches to major 

river bridge crossings would be raised to an elevation above the 0.2 percent chance annual (500-year) 

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flood event. The hydraulic impacts of this alternative on the Lower Mississippi River would be 

minimized through creation of additional storage areas and/or the exclusion of some agricultural 

districts from the plan. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) 

• Do not raise Agricultural protection 

• Inside Agricultural – protect communities (ring levee encompassing only existing 

 development) 

• Inside Agricultural – bridge approaches only protected if needed for emergency access. 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. This alternative provides a high level of protection to urban areas and primary east-west 

(Mississippi River) and north-south (Illinois Waterway) bridge crossings. In general, this alternative 

is likely to produce smaller hydraulic impacts than plans which include agricultural levee district 

raises due to the isolated nature (and existing high level of protection) of urban areas on the system. 

However, the raising of bridge approaches across the floodplain has the potential to increase flood 

heights locally. This plan would necessitate the inclusion of bridge-like openings in the raised road 

and railroad approachs to provide additional flood conveyance which significantly increases the cost 

of Plan F. As the analysis of Alternative Plan F is very site specific, it was beyond the capability of 

the Comprehensive Plan to design and evaluate this plan. 

Alternative Plan G. 0.2 percent chance annual (500-year) Urban and Agricultural Protection 

With No Minimization of Impacts to Lower Mississippi River Valley 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level of protection. 0.2 percent chance annual (500-year) level of protection 

applies to urban, agriculture and unprotected communities. The goal by relaxing the third design 

criteria, minimize impact downstream to the MR&T Project, is to allow additional systems south of St. 

Louis to raise their level of protection. This plan requires a 10,000 acre storage area located in 

Monroe County, IL which then allows six drainage and levee districts south to raise to the 0.2 percent 

chance annual (500-year) event level of protection. 

Plan Summary

• The third criteria to minimize impacts on the MR&T Project does not apply to this plan 

• Urban - 0.2 percent chance annual (500-year) 

• Agricultural – 0.2 percent chance annual (500-year) 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. This alternative tests the sensitivity of Alternative Plan B with regards to meeting the 

criteria for no, or minimal, impacts to water surface profiles at the downstream limit of the study to 

avoid impacts to the MR&T Project. Removal of this criterion may allow for additional agricultural 

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districts to be included in the plan; however, the plan would still need to meet 1.0 foot maximum rise 

standard. Actual induced rise for Plan G at the MR&T Project is 0.4 feet for the 1 percent (100-year) 

flood event. This induced rise may require mitigating this rise on the MR&T Project if Plan G were to 

be implemented. In order to meet this standard, some agricultural levee districts would, by necessity, 

need to be excluded from the plan. Plan G allows six drainage and levee districts south to raise to the 

0.2 percent chance annual (500-year) event level of protection. In addition, the MR&T Project would 

have to be raised to mitigate for any induced rise from the Upper Mississippi River. During the public 

meetings held in June 2006, there was considerable support Plan G at the three meetings held north of 

St. Louis but substantial opposition to Plan G at and after the public meeting held south of St. Louis, 

mainly due to the required 10,000 acre storage area located in Monroe County, IL. 

Alternative Plan H. 0.2 percent chance annual (500-year) Urban and Agricultural Protection 

With Cost Effective Buyouts 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level of protection. 0.2 percent chance annual (500-year) level of protection 

applies to urban, agriculture and unprotected communities. The hydraulic impacts of this alternative 

on the Lower Mississippi River would be minimized through creation of additional storage areas 

and/or the exclusion of some agricultural districts from the plan. This plan is identical to Plan B, with 

the exception of areas where the cost of the levee improvement exceeds the value of the land to be 

protected. 

The analysis, considers on a district by district basis, which is less expensive, or more cost effective, 

the cost of raising the level of protection to the 0.2 percent chance annual level of protection as 

compared to the value of economic activity and assets protected. 

For this analysis, it was assumed that for areas for which it is more cost effective, i.e., less expensive, 

to acquire the protected area than raise the level of protection, acquisition would be an option on a 

levee district by district basis. If Alternative Plan H were to be implemented, a detailed site specific 

analysis would be required to make a determination as to the cost effective option. Also any district 

could choose not to be a part of the plan. Then the district could stay “as is” or have to find other 

resources to improve the existing level of protection. If a district were acquired then the area(s) could 

be actively managed for ecosystem benefit. For the analysis at this time, it is assumed that the levees 

would remain in place at their current height, and the water levels within the interior of the drainage 

district would be actively managed for wildlife purposes and flood storage, if needed. Another 

ecosystem option to consider and evaluate if this plan were to be implemented would include 

degrading the levee to allow connection of the floodplain to the river, a goal of ecosystem restoration 

by NESP. A detailed analysis is required but the induced rise for the 1 percent annual chance flood 

event would be no more than one (1) foot, the system design criteria. 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) 

• Agricultural areas – 0.2 percent chance annual (500-year), cost effective comparison 

 of the levee improvement cost versus value of land cost 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

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Discussion. For agricultural areas with existing protection, a comparison of the cost to implement the 

raise (construction cost estimate) to the cost to acquire was made using an average cost of $6,000 per 

acre when this analysis was done in 2005. In many districts the value of land has increased 

significantly since this analysis was done. The more cost effective option would then be chosen if this 

plan were to be implemented. As initially formulated, for agricultural districts it was either raise the 

level of protection to 0.2 percent chance annual or acquisition, purchase. Further, while the discussion 

indicates a district by district analysis, if more than one district is required to make a closed system, 

then the analysis has to be done for the entire system, not just for one district. 

Alternative Plan I. Relocation of Urban Resources Outside of the 100-Year Floodplain 

Description. Plan I would involve a change in floodplain management policies to restrict urban 

development in the 1 percent chance annual (100-year) floodplain, and the removal of existing flood 

protection systems in agricultural areas to increase floodplain connectivity. Urban areas with at least 

1.0 percent chance annual (100-year) protection would not be impacted. 

Plan Summary

• Urban areas – buyout all structures below 100-yr flood level 

• Do not raise agricultural protection 

• Inside agricultural – buyout communities 

• Bridge approaches – no protection for approaches 

• Unprotected towns – buyout 

• Existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. While floodplain mapping for the 1 percent chance annual event, also known as the base 

flood event by FEMA, is available in many areas, due to the large area of the Comprehensive Plan 

analysis, it was impossible the determine the cost of removal of existing structures within the 1 percent 

chance floodplain and relocate critical infrastructure. Therefore Alternative Plan I was not considered 

further. Alternative Plan J, is very similar and was evaluated as explained following.

Alternative Plan J. Floodplain Management 

Description. This alternative involves a change in floodplain management policies to restrict urban 

development in the 0.2 percent chance annual (500-year) floodplain, and the removal of existing flood 

protection systems in agricultural areas to increase floodplain connectivity. Permanent evacuation of 

flood prone developed areas involves the acquisition of lands by purchase, the removal of. 

(Interagency Floodplain Management Review Committee, 1994). 

Objectives of this alternative are to: 

 1. reduce the vulnerability of the nation to loss of life and property and the disruption 

 of societal and economic resources caused by flooding; 

 2. sustain, restore, or enhance the natural resources, ecosystems, and other functions 

 of the floodplain; and 

 3. improvements, and the relocation of the population from such areas. Lands acquired in this 

manner could be used for recreation, ecosystem restoration, or for unprotected agriculture at the higher 

elevations. 

Plan Summary

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• Urban – 0.2 percent chance annual (500-year) protection 

• Agricultural Levees – removed/no protection and buyout developed areas in 

 agricultural levee districts 

• Unprotected towns – no protection/buyout 

• Unprotected agricultural– no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. Economic resources in the floodplain will always be at risk. Traditional structural 

approaches to floodwater management have provided significant protection from flooding. However, 

there can be disadvantages to using structural approaches, including: increased risk of catastrophic 

flooding if structures fail or the flood risk management system capacity is exceeded; damage to natural 

resources and natural floodplain function; and increased economic damages if catastrophic flooding 

occurs. A second approach is to evacuate floodplains and move residents and their public and private 

investments to less risky areasprevent repetitive losses from flooding. 

To evaluate Alternative Plan J, it was assumed that the bluff represented the 0.2 percent chance 

floodplain limit so that boundary could be determined using readily available geographic information 

system (GIS) data. A cost per acre for all the acres protected by existing flood risk management 

systems was one part of the cost of Plan J. Additionally, infrastructure located within the floodplain 

would likewise be relocated, or if not practical, protected against a major flood event. The cost of the 

infrastructure relocation or protection was assumed to be equal to the cost of obtaining the land. 

This plan evaluated the impacts of removing all agricultural levees along the Mississippi and Illinois 

Rivers. Existing urban levees/floodwalls are assumed to remain intact. Agricultural levee removal 

could result in a mixture of floodplain development. To capture this uncertainty, two bounds, or 

conditions, of floodplain developments were evaluated in this plan. The lower bound is that the 

floodplain would turn totally into an agricultural regime. The upper bound would be that the 

floodplain would revert back to natural ecological succession in the floodplain. If agricultural levees 

would be removed, then the impact to water levels on the floodplains could be within the bound 

created. 

Alternative Plan K. Protection of Regional Critical Infrastructure 

Description. This alternative involves providing 0.2 percent chance annual (500-year) protection to 

regional critical infrastructure—as defined by the Presidential Commission on Critical Infrastructure—

using structural (levees, road raising) and/or non-structural methods (flood proofing, relocation, etc.). 

Plan Summary

• Urban - 0.2 percent chance annual (500-year) protection 

• Agricultural – 0.2 percent chance annual (500-year) (structural or non-structural) if 

 levee protects regional critical infrastructure – no raise otherwise 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

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Upper Mississippi River Comprehensive Plan 

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Discussion. The analysis across the system did not indicate a sufficient concentration of critical 

infrastructure in any reach or sub-reach to merit further evaluation of this alternative, with the possible 

exception of transportation systems. 

Alternative Plan L. Protection of All Bridge Approaches 

Description. This alternative involves structurally raising all bridge approaches and floodplain 

highways to the 0.2 percent chance annual (500-year) level, plus freeboard or, if less expensive, the 

raising of existing levees to protect the bridge approaches. When raising of the bridge approach, or 

highway, with a solid embankment would induce a rise in the 0.2 percent chance annual (500-year) 

flood level, openings would be provided to minimize the induced rise. 

Plan Summary

• Bridge approaches raised/protected to 0.2 percent chance annual (500-year) level 

• Mitigation of all impacts due to plan implementation 

Discussion. This alternative plan would consider all river crossings over the Mississippi and Illinois 

Rivers in the study area. As the analysis of Alternative Plan L is very site specific, it was beyond the 

capability of the Comprehensive Plan to design and evaluate this plan. 

Alternative Plan M. 0.2 percent chance annual (500-year) Urban and Agricultural Protection 

with No Minimization of Impacts to Lower Mississippi River Valley and No Storage Area in 

Monroe County, IL. 

Description. This plan involves protecting areas with existing levees/floodwalls to the 0.2 percent 

chance annual (500-year) level of protection. 0.2 percent chance annual (500-year) level of protection 

applies to urban, agriculture and unprotected communities. The goal by relaxing the third design 

criteria, minimize impact downstream to the MR&T Project, is to allow additional systems south of St. 

Louis to raise their level of protection. This plan eliminates the 10,000 acre storage area located in 

Monroe County, IL, which is included in Plan G, and then Plan M allows one (six with Plan G) 

drainage and levee district south of St. Louis to raise to the 0.2 percent chance annual (500-year) event 

level of protection. Alternative Plan M is a refinement of Alternative Plan B. 

Plan Summary

• The third criteria to minimize impacts on the MR&T Project does not apply to this plan 

• Urban - 0.2 percent chance annual (500-year) 

• Agricultural – 0.2 percent chance annual (500-year) 

• Unprotected towns – 0.2 percent chance annual (500-year) protection (levee 

 encompassing only existing development) 

• Other existing unprotected areas – no protection 

• Mitigation of all impacts due to plan implementation 

Discussion. This alternative tests the sensitivity of Alternative Plan B with regards to meeting the 

criteria for no, or minimal, impacts to water surface profiles at the downstream limit of the study to 

avoid impacts to the MR&T Project and Alternative Plan G with eliminating the 10,000 acre storage 

area. Removal of these criterion may allow for additional agricultural districts to be included in the 

plan; however, the plan would still need to meet 1.0 foot maximum rise standard. Actual induced rise 

for Plan M at the MR&T Project is 0.3 feet for the 1 percent (100-year) flood event. This induced rise 

75
Upper Mississippi River Comprehensive Plan 

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76

may require mitigating this rise on the MR&T Project if Plan M were to be implemented. In order to 

meet this standard, some agricultural levee districts would, by necessity, need to be excluded from the 

plan. Plan M allows three drainage and levee districts south of St. Louis to raise to the 0.2 percent 

chance annual (500-year) event level of protection. In addition, the MR&T Project would have to be 

raised to mitigate for any induced rise from the Upper Mississippi River. 

Table 13 displays a summary of the alternative plan features. 
Upper Mississippi River Comprehensive Plan 

Main Report 

Table 13. Summary Description of Alternative Plans 

No Action and Alternative Plans A through F 

Plan No Action Plan A Plan B Plan C Plan D Plan E Plan F Plan Description No Action Confined 500-yr 500-yr 

200-yr Ag 

levee 

protection 

~100-yr Ag 

levee protection 

50-yr min Ag 

levee protection 

Local protection 

towns & bridg

approaches @ 50

H&H Condition No Change Confined Unconfined Unconfined Unconfined Unconfined Unconfined Urban Systems No Change 500-year 500-year 500-year 500-year 500-year 500-year Agricultural Districts No Change 

500-year 500-year 200-year 100-year 50-year Protect towns & 

bridge approacheonly, not Ag land

Unprotected towns No Change 

500-yr ring levee with no new development' 

500-yr ring levee with no new development' 

500-yr ring levee with no new development' 

500-yr ring levee with no new development' 

500-yr ring levee with no new development' 

500-yr ring levee no new developm

Other Existing Unprotected No Change No protection No protection No protection No protection No protection No protection Note/other information 

No analysis of briapproach, 2 examof ring around tow(Hull, Eldred) 

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Upper Mississippi River Comprehensive Plan 

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78

Alternative Plans G through M 

Plan Plan H Plan I Plan J Plan K Plan L PlPlan Description 

500-year cost effective buyout 

Buyout development in 100-yr floodplain 

No development in 500-yr floodplain, buyout development in Ag areas, remove Ag levees 

500-yr for Ag with regional critical infrastructure 

Local protection for all bridge approaches @ 500-yr 

501' 

H&H Condition Unconfined Unconfined Unconfined Unconfined Unconfined UnUrban Systems 500-year 500-year 500-year 500-year 500-year 50Agricultural Districts 

500-year except purchase when more cost effective than levee raise Buyout towns 

Remove/breach existing levees - reconnect areas to river - buyout towns/structures 

500-year IF contains regional critical infrastructure 

500-year for levees with bridge approaches 50

Unprotected towns 

500-yr ring levee with no new development' Buyout towns Buyout towns 

500-yr ring levee with no new development' 

500-yr ring levee with no new development' 

50no 

Other Existing Unprotected No protection No protection No protection No protection No protection No Note/other information 

Protecting all approaches not viable. 

MMMrisNO RE
Upper Mississippi River Comprehensive Plan 

Main Report 

G. ALTERNATIVE PLAN EVALUATION.

The Flood Control Act of 1936 established the policy that flood control on navigable waters or their 

tributaries is in the interest of the general public welfare, and is therefore a proper activity of the 

Federal Government. It provided that the Federal Government, cooperating with state and local 

entities, may improve streams or participate in improvements “for flood control purposes, if the 

benefits to whomsoever they may accrue are in excess of the estimated costs, and if the lives and 

social security of people are otherwise adversely affected.” The 1936 Act, as amended, and, more 

recently the Water Resources Development Act of 1986 and other acts, specify the details of Federal 

participation. 

Planning step 4, evaluation of alternative plans, is accomplished using the following four accounts 

established in the Corps’ Principles and Guidelines to facilitate the evaluation and display of effects of 

alternative plans (ER 1105-2-100): 

• The national economic development (NED) account displays changes in the economic 

value of the national output of goods and services. 

• The Environmental Quality (EQ) account displays non-monetary effects on ecological, 

cultural, and aesthetic resources including the positive and adverse effects of ecosystem 

restoration plans. 

• The regional economic development (RED) account displays changes in the distribution 

of regional economic activity (e.g., income and employment). 

• The Other Social Effects (OSE) account displays plan effects on social aspects such as 

community impacts, health and safety, displacement, energy conservation, and others. 

1. Hydraulic, Economic and Environmental Evaluation of Alternative Plans. 

Analysis of the NED and EQ accounts is required. Evaluation of RED or OSE accounts is 

discretionary. For the Upper Mississippi River Comprehensive Plan, RED benefits were computed by 

the Tennessee Valley Authority (TVA, 2004) for Alternatives A, B, and D. The TVA estimated that 

every dollar spent on comprehensive flood control at the 500-year (for urban areas) and 100-year 

(agricultural areas), which includes Plans A, B and D, would generate as much as $5.00 in increased 

gross regional product. Gross Regional Product is defined as an estimate of each state or region’s 

share of the nation’s gross domestic product, which is the total value of the goods and services 

produced by labor and property in the United States. Also, employment is projected to increase by 

more than 20,000 jobs annually in the five-state Upper Mississippi Valley Region resulting from 

upgraded levee protection provided by implementation of either Plan A, B, or D. More complete 

results of the TVA analysis of RED benefits are summarized in Appendix C, Economic Analysis. 

The evaluation processes used to determine the hydraulic impacts, potential flood risk management 

benefits, and implementation costs of the alternative plans is briefly described below. Detailed 

discussion of methods and assumptions can be found within the individual technical appendices. In 

the evaluation of induced flooding impacts, three main areas are considered for potential induced 

water surface profile impacts: 1) existing flood protection systems; 2) unprotected 

communities/towns, and; 3) other unprotected areas. 

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Upper Mississippi River Comprehensive Plan 

Main Report 

Generally, for the existing flood protection systems and unprotected communities along the 

Mississippi and Illinois Rivers, any induced flooding impacts by a rise in the water surface profile are 

mitigated by raising the height of the protection systems, either the existing system or the new levee 

around a community. Due to a lack of data and information, there is no accounting of the impact of 

induced flooding on currently unprotected areas. 

Alternative plans were evaluated to varying levels of detail. With limited available data, funding and 

time, only about half of the plans formulated could be evaluated. For example, alternative plan C lies 

between plans B and D and was not specifically evaluated as the evaluation of plan C could be 

inferred from plans B and D. Plan I is buyout within the existing 1 percent chance annual floodplain. 

However, data is not readily available identifying the floodplain and structures and other property 

within that floodplain; therefore, it was not evaluated. Plan J, buyout of the 0.2 percent chance annual 

(500-year) floodplain was accomplished by assuming that this floodplain was essentially bluff to bluff 

and then sampling a few levee districts for structures to obtain cost of the buyout. Plan K addressing 

critical infrastructure was considered by first estimating how much critical infrastructure lies within 

the protected levee areas, about one third of all critical infrastructure, meaning about two thirds is 

located in the unprotected floodplain, so no further was accomplished. 

For some alternatives, representative test areas were evaluated to assess the overall applicability for 

system-wide application. Other alternatives were screened based upon hydraulic modeling results 

which showed little to no effect of the alternative. In some instances, alternatives were screened based 

upon the results of evaluations on similar, bounding alternatives which showed them to be 

unacceptable. 

 a. Hydraulic Evaluation. The hydraulic analyses of alternative plans formulated utilize the 

existing numerical hydraulic (UNET) models developed for the Flow Frequency Study (FFS) along 

with a new, stochastically-generated, 1,000 years of tributary inflows. The hydraulic models were 

reassembled to begin and end at more hydraulically significant break points, the four study reaches, 

than the jurisdictional Corps District boundaries. Each model simulation, using the full 1,000 years of 

tributary inflow record produces a series of 1,000 annual peak stages at each model cross section 

location. These computed peak stages are used to form a non-analytical stage frequency curve at each 

location. Comparing the computed stage frequency from each alternative simulation with that of an 

existing condition simulation provides the stage impacts for each alternative. These stage impacts are 

then applied to the published frequency water surface elevations from the Flow Frequency Study to 

produce a final frequency water surface elevation to be used in computing economic flood risks and 

construction costs for each alternative. 

Only the US Army Corps of Engineers or similar Federal agency would have the capability to 

develop, calibrate and apply hydrologic modeling for a multi-state area, an entire region. The regional 

modeling application insures that any and all impacts, whether local and far reaching can be fully 

determined, considered and evaluated in the Upper Mississippi River System. 

 b. Economic Evaluation 

(1) General Methodology. This study area was evaluated using traditional expected value 

(damage and flood probability analysis). Risk and uncertainty analysis was not undertaken for this 

reconnaissance level of detail. Current stage frequency profiles were used to provide elevations for 

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Upper Mississippi River Comprehensive Plan 

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floods with varying probability. The river stage associated with the 0.2 percent chance annual (500-

year) flood elevation) was recorded for each evaluation location. 

Average annual damages (AAD) are defined as the monetary value of national economic development 

(NED) flood loss that can be expected in any given year based on the magnitude and probability of 

loss from all possible flood events. AAD is the calculated area under the Damage/Frequency curve 

(figure 3). This is estimated by the function: 

∑ ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ ⎟

⎠

⎞ ⎜

⎝

⎛ + = ∗− −

−

n

x x

xx

DD AAD PP

1

1

1 2 )(

where: 

AAD = Average (Expected) Annual Damage 

X = Flood event 

P = Probability (%) of flood event 

D = Flood event damage 

n = Probability/Damage points 

0

2000

4000

6000

8000

10000

12000

14000

0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1

Frequency

Damages (000's)

y = f(x)

Figure 3. Sample Damage Curve 

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Upper Mississippi River Comprehensive Plan 

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Average annual benefits (AAB) are defined as the difference in AAD between the without project 

(existing condition) and with project condition. 

Construction costs detailed in this report are in 2005 price levels. Interest during construction (IDC) 

and annualized costs are computed using a 5-3/8 percent rate as mandated for (FY05) Federal water 

resource projects. IDC is an opportunity cost (alternate use of Federal funds) which is added to project 

costs. Annualized costs are computed identical to a loan amortization, over an analysis period, at the 

project interest rate. A three-year construction span and a 50-year period have been used for the IDC 

and annualizing calculation, respectively. 

These water surface profiles were used evaluate both the without project and with project conditions. 

For the with project conditions, several different alternatives were analyzed. 

Several assumptions were made to develop data to uniformly analyze each flood protection project. 

Again, because of the broadness of the study, the level of detail of.this analysis could only be 

performed to about a reconnaissance phase level, also known as Section 905(b) analysis. Therefore, 

each flood protection project would have a single midpoint elevation and a single or beginning 

damage elevation to simplify the analysis of the average annual damages for each flood protection 

project. Furthermore, a start of damages elevation was calculated for each flood protection project. 

This elevation is presented in terms of approximate flood frequency. 

Flood risk information (i.e., structure and content values; depth-damage estimates) for existing 

projects in the study area was gathered from a variety of sources. Much information was provided by 

previously completed USACE project studies (Basin, Reconnaissance, Feasibility, etc) or available 

summaries from those studies. This type of data varies widely in age (i.e., anywhere from 30 to 50 

years old) and in land use reporting (changes in usage may be unknown). The dollar denominated 

values for flood damage data has been adjusted to current price levels using Engineering News-Record 

(ENR) cost factors. 

For cost estimation, civil engineering studies focused primarily on developing generic quantities 

associated with levee construction and levee modifications. Using a spreadsheet format, formulas 

were developed to compute quantities for the more significant levee quantities to include levee 

degradation, new levee materials, berm materials, additional levee right-of-way, acreage of seeding, 

acreage of clearing and stripping, crushed stone, asphalt cement concrete, and other needed items. 

Each Corps of Engineers District developed a spreadsheet for their respective levee and floodwall 

systems in order to calculate and document quantities. 

In general, national economic development (NED) analysis assumes that all resources are fully 

employed. As a consequence, regional economic development (RED) effects can occur only when 

resources are transferred from one or more regions of the country to the project region. Therefore, 

RED effects should not be included in NED Benefit/Cost computations for project justification. Some 

reasons information provided by RED effects may have a bearing on project decision making are: 

• RED effects are often of prime interest to local sponsors and can play an important role in 

securing their support for Corps water resources projects; 

• RED effects can form the basis for allocating project cost sharing requirements; 

• Presenting RED effects leads to more informed decision-making. 

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Using the NED rule only insures that a project will generate the largest possible economic pie. 

Applying NED describes benefits accrued on a national basis. RED describes changes in distribution 

of income and employment. Regional effects for Comprehensive Plan alternatives are presented in the 

Economics Appendix for each of the five Midwestern States bordering the Upper Mississippi and 

Illinois Rivers. 

 (2) Social Impacts. The following description summarizes potential social impacts of the 

various plans. Please refer to Appendix C, Economic Analysis, for relative impacts point assignments 

matrix and discussion. 

Noise. Any systemic noise impacts would be short-term and likely minor during construction. 

No appreciable long-term effects are anticipated. 

Aesthetics. Alternative Plan A would lead to moderate negative impacts, relative to existing 

conditions, since existing levees would be considerably higher to cover 500-year protection with 

associated rise in 500-year flood elevations. There may be minor adverse impacts to communities for 

structural alternatives, relative to existing conditions, as these would mostly occur with existing 

levees. The main exception is for Plan H where the impacts of some levee raises are off-set by benefit 

of more substantial levee removal (and greater aesthetic value). Note that aesthetic impacts could be 

greater on a site-specific basis, particularly with communities that do not have flood protection under 

existing conditions but would be afforded such protection under the proposed alternatives. Minor 

beneficial impacts for Plan I as removal of flood-prone properties could improve aesthetic value. 

Moderate beneficial for Plan J as removal of some levees may improves aesthetic views of the river. 

No impact for Plan K or L. These are focused on critical infrastructure which are usually more limited 

and would not result in substantial to aesthetic value, relative to existing conditions. 

Recreational Opportunities. No change for most alternatives, relative to existing conditions. 

There could be some recreation created through levee removal and/or creation of storage areas for Plan 

H and Plan J. 

Public Health and Safety. Alternatives raising the existing protection may have only minor 

beneficial effects because substantial rises in flood heights could be dangerous, even if levees and 

floodwalls are raised accordingly. The dangers of increased flood heights eliminate some of the 

benefits of increased protection. For other alternatives, it is assumed that moderate beneficial effects 

relative to existing conditions as the increases in flood heights would be considerably less.. 

Transportation. It is assumed that major benefits to transportation would accrue for Plans A, 

B and G as 500-year agricultural protection would protect roads and travel within leveed areas. A 

moderate benefit is assumed for Plans C, F and H as the impacts would be slightly less. There would 

be a minor benefit to transportation for Plan D. Under Plan K, transportation benefits would be major, 

as this targets critical transportation areas impacted by flooding. Plan L implementation would 

improve transportation around bridges, which becomes important during flood conditions. For all 

other plans, the effects are assumed to be negligible relative to existing conditions. 

Community Cohesion. Minor community cohesion benefits would accrue for structural 

alternatives, relative to existing conditions, except for Plan H, where beneficial impacts would be 

likely offset by “negative” buyouts. It is likely that community cohesion would be negatively 

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impacted under Plan I due to the potential for breaking apart or moving all or part of a community. 

Plans J, K and L would not greatly affect community cohesion. 

Community Growth and Development. Alternative plans raising existing levee system to the 0.2 

percent annual chance would have positive impacts for increased growth, relative to existing 

conditions. The new levee structures would not limit floodplain development with new 500-year 

protection. Some minor, positive impacts would occur for other structural alternatives, with existing 

levees being raised which could promote growth, but ring levees with no new development could 

negatively impact growth in these areas. Relative to existing conditions, this is likely only a minor 

beneficial impact. It is assumed that there would be negative impact from non-structural plans, as 

these plans would relocate properties out of the floodplain and/or discourage future growth within the 

floodplain. Neither critical infrastructure alternative would have an effect, relative to existing 

conditions. It is realized that if further development would occur within the floodplain, higher residual 

damages would also be expected to occur. This potential would exist in any levee system. 

 

Business and Home Relocation. The actions discussed here could have a range of impacts 

for home/business relocation. Improved levees under Alternatives A, B, C, D, and E would improve 

conditions to where business and homes would be less likely to be moved. Conversely, some negative 

impacts would be observed at Plans H, I and J, as these would include levee and home buyouts. 

Existing/Potential Land Use. Plan A and Plan G would provide the greatest opportunity for 

existing and future land use as these plans provide the greatest protection. Alternatives B, C and D 

provide for moderate beneficial impacts, though less than Alternative Plan A. Alternatives C, D, E 

and F would provide only small additional opportunities for land use, relative to existing conditions. 

Plan H provides small improved changes for land use, but also negative impacts through levee 

buyouts. Alternatives I and J would include more extensive levee removal or removal of properties 

from the floodplain, a “negative” impact for existing and potential land use. Plan J would have the 

greater impact as it involves removal of agricultural levees and would affect the most acreage of land 

removed (or limited) from potential future agricultural use. However, Plans I and J would provide the 

greatest potential for restoration, and thus would see a different form of potential future value (a 

potential environmental benefit). 

Controversy. Plan A would be extremely controversial for not only the project area but also 

downstream in the lower river area. Plans I and J would be controversial because of impacts to 

landowners. Most structural plans, i.e., Alternatives A, B, C, D, E, F, and G, would have varying 

levels of controversy due to cost, perceived economic benefits, changes in flood elevations and levee 

buyout actions. Plans K and L would not be as controversial, as fewer landowners would be impacted. 

c. Hydraulic and Economic Evaluation Results. The following section provides summary 

outputs, by reach, of the alternative evaluation results. Detailed listing of modeling results and cost 

estimates can be found in appendices B, C, and D. 

Alternative Plan A. Confined - 0.2 percent chance annual (500-year) Urban and Agricultural 

Protection. Flood storage available from all the levee areas was eliminated from the river in the 

UNET model. The levees would be considered raised as high as needed to insure no overtopping. 

The hydraulic model could only recognize the non-leveed floodplain. 

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The water surface differences that this plan caused is shown in Appendix B, Hydrology and 

Hydraulics, Table B-10 at the main gages. The profile increases were dramatic for reaches 3 and 4. 

The maximum increase for Reach 3 on the Mississippi River is 2.7 feet for the 100-year flood between 

river miles (RMs) 86 and 101; 4.6 feet for the 200-year flood between RMs 91 and 93; and 7.9 feet for 

the 0.2 percent chance annual (500-year) flood between RMs 89 and 93. The maximum increase on 

the Illinois River in Reach 4 is 1.33 feet between RMs 48 and 49; 1.97 feet between RMs 49 and 54; 

and 3.11 feet between RMs 43 and 56. The stage increases below the Meredosia Gage on the Illinois 

River is partially due to the backwater effects from the Mississippi River. The plan produced no 

measurable increases in water surface elevations within reaches 1 and 2. 

For each leveed area, the flood risk management benefits were computed, , as the net reduction in 

average annual damages. Construction and real estate costs, by leveed area, were computed and 

annualized for comparison to benefits. The annualized benefits and costs, by reach, are summarized in 

Table 14. A complete tabulation of benefits and costs, by leveed area, are presented in Appendix D, 

Engineering and Cost Estimates.

Table 14. Evaluation of Plan A - 500-yr Urban, 500-yr Ag

Reach 

Annualized 

Benefits ($) 

Annualized 

Costs ($) 

Benefit-to-cost 

Ratio 

1 

2 

3 

4 

Total 

3,564,000 

1,826,000 

10,394,000 

3,385,000 

19,169,000 

41,836,000 

24,981,000 

389,694,000 

115,027,000 

571,538,000 

0.09 

0.07 

0.03 

0.03 

0.03 

Construction First Cost $8.74 million 

The BCR for this alternative is significantly below 1.0. The remaining, residual damages associated 

with this alternative are shown in Appendix C, Economic Analysis. 

Alternatives B, C, D, and E. 0.2 percent chance annual (500-year) Urban and Variable 

Agricultural Protection. For each of these alternatives, hydraulic modeling was used to identify 

which agricultural districts could be included in the alternative to meet the design criteria of allowing 

up to 1.0 foot of rise in the hydraulic profile, and minimal rise at the lower end of the study area. Only 

agricultural districts in Reach 4 had to be removed from the alternative to meet the criteria. In 

addition, two designated storage areas were added to help meet the criteria of no significant impact to 

the Lower Mississippi River. These storage areas would be preserved for use as storage during peak 

flood periods to reduce stages. 

Alternative Plan C was not evaluated. Due to limited budget and time and the fact that C is bounded 

by Alternative Plans B and D and the costs and benefits for C could be inferred, it was deemed more 

important to put effort on other plans. 

Similar to Alternative Plan A, the flood risk management benefits were computed, for each individual 

leveed area, as the net reduction in average annual damages. Construction and real estate costs, by 

leveed area, were computed for each alternative and annualized for comparison to benefits. The 

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86

annualized benefits and costs, by reach, are summarized in Table 15. A complete tabulation of 

benefits and costs, by leveed area, are presented in Appendix D, Engineering and Cost Estimates. 
Upper Mississippi River Comprehensive Plan 

Main Report 

Table 15. Evaluation of Alternative Plans B, C, D, and E 

Alternative Plan Protection Level Reach Annualized Benefits ($) Annualized Costs ($) B Construction First Cost $5,006,758,000 

500-yr Urban 500-yr Ag 

1 2 3 4 

Total 

3,564,000 1,836,000 4,785,000 3,276,000 

13,461,000 

42,174,000 29,270,000 

146,012,000 109,781,000 327,237,000 

C 500-yr Urban 

200-yr Ag 1 1 1 

D Construction First Cost $3,758,685,000 

500-yr Urban 100-yr Ag 

1 2 3 4 

Total 

3,562,000 1,700,000 4,936,000 2,091,000 

12,289,000 

41,798,000 20,904,000 

115,589,000 

67,373,000 

245,664,000 

E Construction First Cost $2,905,510,000 

500-yr Urban 50-yr Ag 

1 2 3 4 

Total 

3,532,000 1,601,000 4,233,000 1,888,000 

11,254,000 

41,716,000 16,045,000 65,655,000 66,484,000 

189,900,000 

1 Based upon the preliminary results from Alternatives B, D, and E; detailed benefit and cost analysis of this alternative was not pursued. 

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As shown in Table 15, alternatives B, C, D, and E have BCRs significantly below unity. The 

remaining, residual damages associated with these alternatives are shown in Appendix C, Economic 

Analysis. 

Alternative Plan F. 0.2 percent chance annual (500-year) Urban and Highway Approach 

Protection. The analysis and evaluation of Alternative Plan F was not accomplished. The evaluation 

would require a very detailed, site specific analysis beyond the resource availability of the current 

Comprehensive Plan. To determine a construction cost estimate, each bridge approach would have to 

be analyzed to determine the impacts of the approach raise and then the determination of the flow 

openings required to mitigate this induced rise, a very time and effort intense analysis for each site. In 

a similar site specific analysis, an estimate to provide local protection for each community within the 

agricultural levee districts would be required. Major construction costs would include levee cost, 

interior drainage and providing emergency access. 

Alternative Plan G. 0.2 percent chance annual (500-year) Urban and Agricultural Protection w/ 

no Minimization of Impacts to Lower Mississippi River Valley. Alternative Plan G is a modification 

of Alternative Plan B. Modifications were made the districts downstream of St. Louis in an attempt to 

maximize the area protected while continuing the first criteria of a maximum induced rise of no 

greater than one foot. Levee setbacks, levee degradations, and bridge modifications were all tested in 

developing this alternative. 

As previously stated, only agricultural districts within Reach 4 were eliminated from Alternative Plan 

B due to impacts to the Lower Mississippi River. Removing this criteria may allow additional leveed 

areas to be included. First, the Jefferson Barracks Bridge, carrying I-255 across the Mississippi River, 

was modified to have a larger flow area in the overbank on the Illinois side. Removing a portion of 

the embankment and raising it as a roadway on piers achieved this. The Columbia District was left at 

its existing elevations. The levee protecting a 10,000-acre segment at the northern end of the 

Harrisonville District was degraded to the 10 percent chance annual (10-year) flood elevation. The 

remainder of the Harrisonville District was raised to the 0.2 percent chance annual (500-year) level of 

protection. Additionally, Kaskaskia Island, Bois Brule, and Prairie Du Rocher districts were all raised 

to the 0.2 percent chance annual (500-year) level of protection. 

The total construction cost would be about $5.9 billion. 

Alternative Plan H. 0.2 percent chance annual (500-year) Urban and Agricultural Protection 

with Selective Buyouts. The Alternative Plan H is an outgrowth of alternatives A, B, C, D, and E, all 

of which display a very low BCR. Examination of results of the five alternatives indicated that 

Alternative Plan H—buying marginal districts—may be more cost effective than providing a high 

level of protection. In addition, if buying districts was actually implemented, ecosystem restoration 

benefit opportunities would be bountiful in the districts purchased. 

It should be noted that this analysis of Alternative Plan H, which is presented in more detail in 

Appendix C, Economic Analysis, does not return a BCR of greater then 1.0; it does not have positive 

net national economic benefits. 

Table 16 displays a summary of the plan evaluation by reach. Assuming that a real estate cost of 

$6,000 per acre which includes the land cost and all assistance and associated costs and fees, for 

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approximately one half of the levee districts it may be more cost effective to purchase rather than 

protect to the 0.2 percent flood event level (500-year). 

Table 16. Evaluation of Alternative Plan H 

Comparison of Cost of Protection/Acre vs. Buyout/Acre 

(Using $6,000/acre cost to buy, including all fees)

Reach 

More Cost Effective 

to Purchase 

Raise Existing 

Protections 

 1 1 35 

 2 0 22 

 3 17 63 

 4 21 24 

Total 39 144 

It should be noted that Plan H as initially formulated assumed that existing levees would remain in 

place. However, a detailed design analysis would be required to determine the best course of action if 

this plan were to be implemented. A comparison of benefits, both positive and adverse, and other 

impacts would have to be performed to determine whether to use all or some of the leveed areas for 

flood storage, and what level of protection is desirable, if any, for ecosystem restoration purposes. 

The timing of the flood event, which is uncontrollable, could have a significant impact on this 

analysis. Additional options to consider if Plan H were to be implemented include whether to obtain 

the leveed areas in fee or to obtain a flowage easement, leaving the area in private ownership. If 

purchased in fee title, would it be better to manage the area with the levee remaining to some level or 

removed to allow floodplain connection to the river. Floodplain reconnection to the river is an 

ecosystem measure authorized by NESP. 

Alternative Plan I. Relocation of Urban Resources Outside of the 100-Year Floodplain. The 

analysis and evaluation of Alternative Plan I was not accomplished, as insufficient data exist. The 

data needed to evaluate this plan is the identification of the floodplain and an inventory of structures in 

the 1 percent chance (100-year) floodplain. In many rural areas, the floodplain has not mapped and 

available in a readily useable format and an inventory of structures is not available. 

Alternative Plan J. Floodplain Management. Alternative Plan J, buyout of the floodplain, bluff to 

bluff, is evaluated below. It is assumed the existing levees would be partially degraded to allow the 

river to recapture, reuse the floodplain. If this plan were implemented the existing water surface 

profile would be modified. To give a sense to this change in water surface profile, two resulting 

alternative land use types for the Overbank area were analyzed. The area to continue to be farmed, 

agricultural use, or be allowed to revert to natural conditions, most often forest or prairie. The 

following results of this analysis were obtained. 

Table 17 displays the changes to water surface elevations for each Reach for the maximum, average 

and minimum change for the Reach. The two alternatives are agricultural growth and natural growth. 

The values represent the changes in water surface profile and discharges for the 1 percent chance 

annual (100-year) flood, the 0.5 percent chance annual (200-year) flood and 0.2 percent chance annual 

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(500-year) flood event. Reach 1 was not studied for this plan because the levees are all urban levees in 

the system. 

To capture this uncertainty, a bound of floodplain developments was created in this plan. The lower 

bound would be that the floodplain would turn totally into an agricultural regime. The upper bound 

would be that the floodplain would revert back to natural ecological succession in the floodplain. 

Table 17. Alternative Plan J, Water Surface Change - Maximum, Average & Minimum Water Surface Change

100-Year Agricultural Growth Natural Growth

Reach Maximum Average Minimum Maximum Average Minimum 

2 0.10 -1.50 -6.10 0.00 -1.10 -4.10 

3 1.30 -4.40 -8.30 0.10 -2.70 -5.30 

4 0.13 -2.83 -5.93 0.07 -2.18 -4.73 

200-Year Agricultural Growth Natural Growth

Reach Maximum Average Minimum Maximum Average Minimum 

2 0.10 -1.70 -6.40 0.00 -1.10 -4.40 

3 2.60 -4.10 -8.10 0.90 -2.10 -5.10 

4 0.17 -2.88 -6.09 0.08 -2.18 -4.77 

500-Year Agricultural Growth Natural Growth

Reach Maximum Average Minimum Maximum Average Minimum 

2 0.10 -1.70 -6.80 0.00 -1.20 -4.40 

3 4.80 -3.10 -8.40 2.30 -0.50 -5.00 

4 0.22 -2.74 -6.32 0.12 -2.01 -4.58 

The Upper Mississippi River and Illinois Waterway currently have many flood risk management 

projects which provide high levels of protection to urban and agricultural areas. These projects were 

planned and constructed incrementally rather than systemically. Based upon annual estimates of 

damages prevented by federally-constructed projects, the majority of flood conditions (and flood risks) 

are protected against. From the perspective of average annual damages (flood frequency versus flood 

risk for the range of possible floods), greater than 99 percent of expected annual damage has been 

reduced by existing projects on the Mississippi River. Greater than 97 percent of expected annual 

damage has been reduced on the Illinois Waterway. Therefore, this study is pursuing alternatives 

which would reduce the remaining (less than) 1 percent of expected annual damages for the 

Mississippi River areas and the remaining (less than) 3 percent of annual damages for the Illinois 

Waterway areas. These are the residual annual damages of the existing “system” of flood control 

projects. 

The cost estimate for Alternative Plan J includes the land purchase cost, the buyout cost for small 

communities and other structures such as farmsteads located in agricultural areas and the cost to either 

degrade or open the existing levees to eliminate the existing flood protection. Another major cost 

classified as relocations is not included in the Plan J cost estimate. Relocations could include the cost 

to relocate transportation systems and other vital systems such a water and wastewater treatment 

facilities. 

The total cost of Alternative Plan J would be about $3.2 billion. 

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Alternative Plan K. Protection of Regional Critical Infrastructure. Using GIS with critical 

infrastructure point data combined with the water surface profiles and levee districts, it was 

determined that almost 65 percent of critical infrastructure located in the Mississippi and Illinois 

River floodplain is located in unprotected areas. 

No further analysis was accomplished due to the following factors: 

• the critical infrastructure is largely located outside of existing lines of protection 

• the infrastructure is not concentrated in locations to provide additional protection 

• the additional footprint needed to increase the line of protection would cover the infrastructure 

The exception is transportation, specifically bridge crossings. Evaluating bridge crossing is the 

purpose of Alternative Plan L 

Alternative Plan L. Protection of Critical Bridge Approaches. During the 1993 flood, approach 

roads leading to several Mississippi River bridges were flooded, impassable, and out of use for up to 

90 days. These impacted approach roads generally run through floodplain levee districts. As the 

analysis below indicates, significant detour impacts ensue from the loss of use of these approach 

roads. Cross-river traffic and within-reach traffic are at risk. There is extensive personal, commercial, 

and public vehicle traffic directly affected by closure of these bridges. 

Without reliable protection, it is assumed that the approach roads would be flooded (based on 

approach road low elevations) and traffic impeded with the same frequency as that with which 

structural flood risks would occur. Existing levee failure would force motorists to use detour routes, 

incurring additional costs for vehicle operation and opportunity cost of time. 

Considering the potential benefits based upon traffic volume for the system, while the benefits can be 

significant, raising/protecting all the bridge approaches for the system is not feasible. 

Benefits for protection of one bridge approach—the Quincy Bridge, which crosses the Fabius 

Drainage and Levee District north of St. Louis on the Mississippi River—are significant. This sitespecific, not systemic analysis, results in the possibility of a feasible project for this one bridge 

location. Multiple bridge approach protection projects in the area would increase the project costs 

significantly while increasing the overall benefits only slightly in total and spreading the benefits over 

a number of projects, making all potential projects not justified. 

Tables C-12 and C-13 in Appendix C, Economic Analysis, relate the stage/frequency/costs 

relationships for the Quincy Bridge detour cost impacts and the cost of protecting the bridge approach. 

More reliable protection for the Quincy bridge would also result in detour cost savings to the traffic 

from bridge outages at Keokuk, Hannibal and Louisiana, IA. Greater protection of the bridge 

approach through the Fabius Drainage and Levee District by means of levee improvements is far less 

costly (approximately one-fourth the cost) than a lengthy road raise project). This project appears to 

warrant further study (positive BCR indicated in Table C-13, Economic Analysis Appendix) as a nonsystemic project, given the beneficial effects of the potential regional detour cost savings which would 

accrue. 

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Discussion. During the 1993 flood even, several Mississippi River bridges were unusable due to 

flooded approach roads. These closures impeded regional transportation and created detours up to 

approximately 200 miles. Generally, bridge closures were required where access roads were 

inundated by floodwaters overtopping agricultural levees. Table C-10 of Appendix C, Economic 

Analysis, lists the bridges most susceptible to closure due to rare flood events. Depending upon 

bridge location and traffic patterns, protection of specific bridges can reduce detour costs region-wide 

(i.e., Quincy, IL bridge with Fabius Drainage and Levee District access road. See Appendix C, 

Economic Analysis). This plan is, therefore, systemic in addressing the reduction of detour costs 

throughout the study area. (Although all bridges on the Illinois Waterway and Mississippi River were 

considered, only protection of the Quincy bridge may exhibit Federal interest). 

 d. Environmental Evaluation 

(1) General Methodology. Alternative plans were evaluated from an ecosystem and 

environmental opportunities aspect in five major categories. The five categories—mitigation, 

secondary development, ecosystem restoration, nutrients and sediments—were evaluated in terms of 

acres. The evaluation approach is discussed in sections a through e, with the detailed evaluation 

analysis and results presented in Appendix A, Environmental Planning and Analysis.

(a) Mitigation. Early in the planning process, a decision was made to defer the 

development of a full-fledged Incremental Cost Analysis (ICA) until future site-specific 

feasibility studies have been performed. Accordingly, at this conceptual level of 

planning, the variability with respect to mitigation is primarily that inherent in the 

overall impact differences associated with the various alternative plans. 

To obtain a gross indication of the magnitude of habitat mitigation required under each 

systemic alternative, the environmental team determined the net change in 

levee/floodwall footprint and affected habitat acres for each plan using engineering 

design data and GIS. The total impacted acreage of open water, non-forested, and 

forested habitat for each plan was then multiplied against a generic mitigation cost per 

restored floodplain acre. 

(b) Secondary Development. By far, the most significant potential impact 

of the flood risk management systemic plans relates to induced secondary development. 

This is especially true in areas with minimal existing flood protection. Adverse effects 

of increased development include: water pollution from storm runoff, increased urban 

flooding from increased permeable surfaces, increased damages from floods 

overtopping levees, and a demand for even more structural measures. In recognition of 

this problem, Executive Order 11988 discourages Federal actions that act as an 

inducement to future floodplain development unless there is no reasonable alternative. 

While the Corps does not require compensatory mitigation for unavoidable secondary 

development effects, the minimization of such effects is an important planning priority. 

The approach to the assessment of secondary development was to document the amount 

of alternative plan lands that would be at or above a 100-year level of protection with a 

project plan in place (i.e. likely to be within the regulated floodplain) and available for 

potential development. In addition (as supplemental information), Environmental 

Chapter 5 looks at the proximity of those lands relative to two potential specific 

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development catalysts—existing river highway bridge crossings and existing major 

urban areas. 

(c) Ecosystem Restoration Opportunities. Similar to the mitigation discussion, the 

environmental team determined that the use of an incremental cost analysis (ICA) was 

inappropriate for a general assessment of habitat restoration opportunities. As an 

alternative approach, ecosystem opportunities were identified for each management 

option and alternative plan in terms of potential ecosystem restoration management 

acres, percent ecosystem restoration sustainability achieved, and ecosystem restoration 

related construction costs. 

The identification of potential ecosystem restoration locations for the various alternative 

plans and options were based on an affirmative response to a mix of questions relating 

to: 

• whether a given Drainage and Levee District site (with a flood damage reduction 

 project in place) would have less or more than a 100-year level of protection; 

• whether or not the site requires flowage easement; 

• whether or not the site has a significant degree of existing urbanization; and 

• whether or not the riverside levee would be raised in elevation. 

Next, the drainage and levee district ecosystem restoration location acres were totaled 

for each alternative plan and option. These acreages were than multiplied against an 

estimate of the percentage of those acres that might be manageable under each option to 

give a rough estimate of the total potential ecosystem restoration managed acres. 

Finally, these managed acres were then multiplied against a dollar cost per restored acre 

value derived from data developed in the navigation study. 

The environmental team did not make an estimate of operations and maintenance 

(O&M) costs. While such an O&M determination is required for reach-specific 

feasibility analyses, it was felt that insufficient information exists for a meaningful 

quantification at the programmatic level. In addition, it was recognized that the annual 

O&M costs for an ecosystem restoration project is typically minor when compared to 

the annualized construction costs. For example, the estimated annual O&M costs for 

the Swan Lake Environmental Management Program Project were less than 10 percent 

of the annualized construction costs for that project. 

(d) Nutrients Reduction. The Wetlands Initiative estimated that 38 percent of the 

lands within the 1percent chance annual (100-year) flood zone represent existing or 

drained wetlands. The nutrients analysis multiplied that percentage by the number of 

acres of potential ecosystem restoration managed lands (within levees) under each 

alternative plan to approximate the potential number of acres of wetland nutrients 

reduction opportunities. 

(e) Sediments Reduction. The method used in this analysis was to determine the 

number of tributary feeders entering each of the floodplain Drainage and Levee Districts 

identified as Ecosystem Restoration opportunities for each alternative plan in subsection 

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c. above. These values provide an indicator for the magnitude for sediments reduction 

opportunities available for addressing the sedimentation problem. 

Resource-specific impact quantifications were performed for each of the five evaluation 

categories. Table 18 shows the relationship between each study plan and the impact 

factors evaluated. In all cases, the stated impacts assumed fully implemented alternative 

plans independent of economic considerations. 

 Table 18. Plans Quantified for Specific Types of Environmental Impact

Plan Mitigation 

Secondary 

Development 

Ecosystem 

Restoration 

Opportunities 

Nutrients 

Reduction 

Sediments 

Reduction 

No Action y y y y y 

A n n n n n 

B y y y y y 

C n n n n n 

D y y y y y 

E y y y y y 

F y n n n n 

G n n n n n 

H y y y y y 

I n y y y n 

J n y y y y 

K n n n n n 

L n n n n n 

(2) Plans Quantified for Environmental Impacts. Plans B, D, E, H, I, and J were 

quantified for environmental impacts. The Comprehensive Plan alternative plans summary of 

evaluation (Table 19), displays the environmental impact findings at the systemic level. For a 

discussion and display of the results of the analysis by river reach, see Appendix A, Environmental 

Planning and Analysis. 

As would be expected, the acreages and costs for mitigation fell out proportional to the amount of 

structural features implemented. Systemically, the mitigation acres and costs from highest to lowest 

were as noted in Table 19: 

Plan B (2,721 acres at $15.2 million) 

Plan D (1,755 acres at $9.8 million) 

Plan E (1,345 acres at $7.5 million) 

Plan H (1,240 acres at $6.9 million 

Plans I and J (no mitigation acres or costs) 

As would be expected, the potential for secondary development in the floodplain increases as the 

amount of structural flood protection increases. Systemically, the plans can be ranked from lowest to 

highest potential for secondary development as follows: 

Plan J (-334,328 acres) 

Plan I (-8,776 acres) 

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Plan D (1,048 acres) 

No Action Plan (0 acres) 

Plan E (4,987 acres) 

Plan H (+215,775 acres) 

Plan B (320,037 acres) 

It should be noted that the Plan D effects could be more severe than the development acreages suggest. 

Plan D raises levees to an elevation, close to, but just shy of the regulated 100-year floodplain. This 

condition could encourage development with neither insurance nor building elevations being required, 

even as the possibility of a catastrophic flood increases. 

Obviously, plans yielding a higher number of potentially manageable acres for ecosystem restoration 

would be preferred from an environmental standpoint. The plans with the highest number of 

management acres also tended to carry a higher ecosystem restoration measures implementation cost. 

Systemically, the plans ranked from highest to lowest potential for environmental opportunities, were 

as follows: 

Plan J (807,943 potential acres at a cost of $261 million) 

Plans B and H (175,002 acres at $455 million) 

Plan E (133,889 acres at $348 million) 

Plan D (131,995 acres at $672 million) 

Plan I (9,791 acres) 

No Action Plan (no acres or costs) 

Since the nutrients reduction opportunities were calculated as a fixed proportion of the ER 

management acres—the relative ranking of the various plans was nearly the same. The plans are 

ranked from highest to lowest potential for nutrients reduction opportunities as follows: 

Plan J (307,018 wetland acres) 

Plans B and H (66,501 acres) 

Plan D (50,158 acres) 

Plan E (50,612 acres) 

Plan I (3,721 acres) 

No Action Plan (0 acres) 

The plans ranked from highest to lowest potential for sediments reduction opportunities (as reflected 

by the number of tributary feeders present) were as follows: 

Plan J (286 tributary feeders) 

Plan D (206 feeders) 

Plan H (141 feeders) 

Plan E 135 feeders) 

Plan B (124 feeders) 

Of the plans quantified, Plan J performed the best from an environmental opportunities perspective. 

This plan required the least amount of mitigation, had the least potential for secondary development, 

the highest potential for ecosystem restoration manageable acres, the highest potential for wetlands 

development, and the highest potential for applying sediment reduction features.

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(3) Plans Not Quantified for Environmental Impacts. For various reasons, Plans A, C, F, 

G, K and L were not directly quantified for environmental impacts. However, to an extent, the 

potential magnitude of impacts from these plans can be deduced. 

Plan A (Confined, 0.2 percent chance annual (500-year) protection), the most structural of the 

flood risk management plans, would likely have adverse environmental effects surpassing those of 

Plan B (Unconfined, 0.2 percent chance annual (500-year) protection). It would thus be the least 

desirable plan from an environmental standpoint. 

Plan C (with 200-year agricultural protection) would likely be intermediate in its environmental 

effects between Plans B (including 0.2 percent chance annual (500-year) agricultural protection) 

and Plan D (including 100-year agricultural protection), but closer to Plan D effects than Plan B 

effects. 

Plan F with no additional agricultural protection and its urban containment approach is judged to 

have environmental effects very similar to the No Action Plan (with no net effects). 

Plan G would have effects similar to Plan B, but slightly more adverse due to its higher allowable 

flood stage rise and reduced requirements for real estate acquisitions. 

Plans K and L, from a systemic perspective, would entail only minor changes in the environment, 

with effects not vastly different from those of the No Action Plan. 

2. Risk Informed Decision Framework (RIDF) Evaluation. 

To complete alternative plan evaluation, the Comprehensive Plan obtained assistance from the Corps 

of Engineers Engineer Research and Development Center (ERDC), located in Vicksburg, MS, in 

applying the new Risk Informed Decision Framework (RIDF) methodology that draws from current 

practice in the fields of multi-criteria (MCDA) and risk and uncertainty analysis. Multiple criteria and 

perspectives are dealt with in a transparent fashion using RIDF. ERDC is using RIDF to assist with 

the Louisiana and Mississippi coastal recovery efforts. The Southwest Division is also starting to 

apply the RIDF technique. 

 

a. Why RIDF? 

Experience since 2005 indicates that a sole focus on NED in project planning may limit the search for 

the best solution to address water resource problems. Corps plan formulation and plan selection has 

focused on the National Economic Development (NED) account for the past 24 years. Considering 

more than NED, that is the other three evaluation accounts, EQ, RED and OSE, provides additional 

information to be able to make a more informed decision and recommendation. RIDF is a technique 

that takes the complex and uncertain planning process and condenses it into a transparent, 

understandable and tractable process. 

Risk-informed decision making provides the means for structuring the analysis of decision problems 

and relevant uncertainties to support risk-informed policymaking, planning, and operations. While a 

structured methodology, RIDF is subjective based upon the input received from the participants in this 

evaluation process. 

 

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Within the RIDF, performance metrics are established to represent the multiple objectives relevant to a 

project, including those related to human health and safety, national economic development, regional 

economic development, environmental quality, among others. Risk analysis methods are used to 

evaluate the performance of alternative plans with respect to the metrics, resulting in quantitative 

values and uncertainty estimates for each metric. Multi-Criteria Decision Analysis methods are then 

used to integrate metric data with metric weights defined by stakeholders and the Corps in order to 

score, compare and rank alternative plans. 

b. Alternative Plans Evaluated using RIDF. 

The following five comprehensive plans were evaluated using RIDF. 

 

Plan Description Remarks 

Plan D ~1% (100-yr) system wide Carried forward in RIDF. 

Plan E 2% (50-yr) system side Carried forward in RIDF. 

Plan H 0.2% Cost effective buyout Carried forward in RIDF. 

Plan J 0.2% buyout Carried forward in RIDF. 

Plan M 0.2% system wide & allow up to 1’ 

induced raise on the MR&T Project. 

Carried forward in RIDF, very similar to 

Plans B & G 

c. RIDF Results. 

The Collaboration Team (CT) and Corps provided input on their weights for the evaluation accounts 

and metrics. Their overall results are displayed in the figure below. 

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98

FIGURE 4 RIDF Decision Scores by Plan and Metric

Plan selection is a group decision process from which no a single “best” solution will necessarily 

emerge. Still, multiple criteria and perspectives are dealt with in a transparent fashion using RIDF. 

Plans D and H, and to a lesser extent Plan M, emerged as the high-scoring alternative plans. These 

plans showed substantially balanced performance against multiple metrics. 

Thus, the multi-criterion decision analyses identified not only the relatively high-scoring alternatives, 

but also the abilities of these alternatives to meet multiple objectives. 

H. COMPARISON OF ALTERNATIVE PLANS – SUMMARY.

Planning step 5 is comparison of the alternative plans formulated and then evaluated. Using the 

information from step 5, the goal is to be able to select the best plan as the recommended plan in the 

next step, step 6. 

Table 19 presents a summary comparison of the alternative plans. The preceding section on Risk 

Informed Decision Framework analysis also presents the evaluation and comparison of five plans. 
Upper Mississippi River Comprehensive Plan 

Main Report 

Table 19. Summary Comparison of Alternative Plan 

No 

Action Plan A Plan B Plan C Plan D Plan 

Plan Description 

NO 

ACTION 

Confined 

500-yr 500-yr 

200-yr Ag 

 levee 

protection 

~100-yr Ag 

levee protection 

50-yr m

levee pro

Alternative Plan Evaluation By Account NED No change  H&H Yes Yes Yes Yes Ye Econ (Ann Ben) $19,169,000 $13,461,000 $12,990,000 $11, Cost (1st cost) $8,744,582,000 $5,422,082,000 $3,973,000,000 $3,715, Annualized Cost $571,538,000 $314,612,000 $230,530,000 $178, BCR 0.03 0.04 0.05 0.0EQ No change  Mitigation (Acres) 2,721 1,755  Mitigation ($) $15,200,000 $9,800,000 $7, Secondary Development (Potential New Acres) 320,037 1,048  ER Opportunities (Potential ER Managed A ) 175,002 131,995 

ER Opportunities (% Sustainability 

Achieved) 57% 43%  ER Opportunities (First Costs, $) $455,000,000 $672,000,000 $348, Nutrients (Potential Wetlands Acres) 66,501 50,158  Sediments (Potential # Tributary Feeders) 124 206 RED No change $30,381,000,000 $27,091,000,000 $22,029,000,000 OSE No change 

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100

Plan G Plan H Plan I Plan J Plan K 

Plan Description 

Allow up to 1' rise 

at Thebes; 

500-yr Ag, 

requires 10,000 

acre storage area 

in Monroe Co. 

500-year cost 

effective buyout 

Buyout 

development in 

100-yr floodplain 

No development 

in 500-yr 

floodplain; 

buyout 

development in 

Ag areas; 

remove Ag levees 

500-yr for Ag 

with regional 

critical 

infrastructure 

p

Alternative Plan Evaluation By Account NED Yes Yes Yes  H&H Yes No No Yes  Econ (Ann Ben) $13,461,000  Cost (1st cost) $6,191,830,000 $3,969,970,000 $3,187,480,000  Annualized Cost $359,276,000 $259,473,000 $184,951,000  BCR 0.05 EQ  Mitigation (Acres) 1,240 No No  Mitigation ($) $6,900,000 No No  Secondary Development (Potential New Acres) 215,775 -8,776 -334,328  ER Opportunities (Potential ER Managed A ) 175,002 9,791 807,943 

ER Opportunities (% Sustainability 

Achieved) 57% 3% 261%  ER Opportunities (First Costs, $) $455,000,000 $25,000,000 $261,000,000  Nutrients (Potential Wetlands Acres) 66,501 3,721 307,018  Sediments (Potential # Tributary Feeders) 141 No 286 RED OSE 
Upper Mississippi River Comprehensive Plan 

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I. OTHER FLOOD RISK MANAGEMENT CONCEPTS CONSIDERED.

1. Emergency Action Plan / Emergency Action Scenarios.

Members of the Collaboration Team expressed their desire for an evaluation of an Emergency Action 

Plan, on the Upper Mississippi River System, to be included as part of the Upper Mississippi River 

Comprehensive Plan. In position paper dated May 14, 2003, the Upper Mississippi River Basin 

Association (UMRBA) expresses their opinions concerning the development of an Emergency Action 

Plan. In their position paper, they state: 

“In particular, the UMRCP plan formulation process should develop and evaluate at 

least one alternative that reflects a system wide operational strategy for conveying 

floodwaters during major flood events. Such an alternative would presumably include 

such actions as strategic controlled levee overtopping, temporary levee raises, and 

minor structural modifications to accommodate the operational strategy. It would also 

include interstate and interagency agreements regarding flood fighting, which would 

address questions associated with when and where flood fighting should be focused.” 

In response to this request, the inclusion of an Emergency Action Plan as one of the alternatives to be 

evaluated in the Comprehensive Plan was considered. The initial discussions of this alternative are 

documented in the team meeting minutes of Sep 2003, which describes the proposed Emergency 

Action Plan as: 

“Emergency Action Plan. The purpose of this plan is to evaluate whether there is a more 

effective flood-fighting alternative that maximizes NED considerations while minimizing 

impacts to profiles. All urban and agricultural levee systems... with maximum emergency 

flood-fighting levee raises assumed to be 3 feet.” 

The evaluation of a series of Emergency Action Scenarios was conducted to develop a better 

understanding of the hydraulic and economic impacts of emergency actions such as flood fighting. 

Last, a proposed methodology for development of an Emergency Action Plan is discussed in the 

following section (2) Methodology for an Emergency Action Plan. 

a. Emergency Action Scenarios 

Description. An important first step in development of an Emergency Action Plan was to develop a 

better understanding of the hydraulic and economic impacts of emergency operations, flood fighting, 

on the Upper Mississippi River System. A series of four Emergency Action Scenarios were conducted 

to represent successively higher levels of systemic flood fighting. The primary hydraulic impacts of 

concern are potential increases in the computed frequency stages (i.e., 100-yr and 0.2 percent chance 

annual (0.2 percent chance annual (500-year)) flood levels) resulting from temporary increases in 

levee heights during a flood. The primary economic concern is the reduction in flood risks resulting 

from the flood fighting (presented here as the “average annual benefits” of flood fighting; which are 

computed as the reduction in “annual average damages”). 

The Emergency Action Scenario represent systemic flood fighting efforts (simulated as increases to 

levee crest elevations) conducted during a flood event. Each successive scenario offers a higher level 

of emergency protection to the modeled levee districts. Discussions among the Comprehensive Plan 

technical workgroup members established that, based on knowledge of previous emergency 

operations, the maximum raise of a levee that can be achieved system-wide, on a safe and consistent 

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basis, is 3 feet. Some communities do have the capability to increase their level of protection by more 

than 3 feet if given sufficient forewarning of impending high water. However, because of the systemwide nature of the study, all analyses were limited to a raise of 3 feet. The 3-foot rise represents all 

emergency actions, including sandbagging, flash boarding, pushing material on top of a levee and all 

other temporary measures used to raise an existing level of protection. 

Levees were divided into three categories for the Emergency Action Scenario—Urban/Industrial, 

Agricultural and Conservation. The Urban/Industrial levees received emergency response in each of 

the Emergency Action Scenarios, while the Agricultural levees receive increasing levels of protection 

in each of the successive scenarios. The Conservation levees are not raised in any of the Emergency 

Action Scenario. These levees are commonly used for wildlife refuges or other conservation purposes 

and, by design, are typically not raised during flood events. For the purposes of the Emergency Action 

Scenario, Federal, non-Federal, and private levees were treated equally. Areas currently unprotected 

were not included in the scenarios. Finally, all levee raises were uniform within each of the three 

levee categories. 

The four Emergency Action Scenario established by the Comprehensive Plan are: 

EAS 1 - Raise only the Urban and Industrial levees by 2 feet; leave Agricultural levees and 

Conservation levees at existing elevations. 

EAS 2 - Raise Urban and Industrial levees by 2 feet; raise Agricultural levees by 1 foot; leave 

Conservation levees at existing elevations. 

 

EAS 3 - Raise Urban, Industrial and Agricultural levees by 2 feet; leave Conservation levees at 

existing elevations. 

EAS 4 - Raise Urban, Industrial and Agricultural levees by 3 feet, leave Conservation levees left 

existing elevations. 

Discussion. The results of each Emergency Action Scenario for the four river reaches used in this 

study are summarized in Tables 20 and 21. The maximum computed stage increases for the 0.01 

(100-yr) and 0.002 exceedence probability (0.2 percent chance annual (0.2 percent chance annual 

(500-year) events are shown in the Table 20. The information in the table shows that: 

• there is no induced rise in frequency stage in Reaches 1 and 2 for any of the scenarios. This 

implies that induced damages are not a concern when determining emergency response priorities 

within these reaches. 

• there is no induced rise in frequency stage anywhere along the length of the Mississippi River 

or Illinois River (Reaches 1-4) caused by increasing the level of protection of only urban and industrial 

areas. 

• induced damages could be a concern for systemic agricultural levee raises in Reaches 3 and 4. 

The benefit in emergency operations is in preventing damages. Table 21 presents the remaining 

annual average damages for each Emergency Action Scenario, along with the existing condition 

damages, and the resulting benefits of flood fighting for each reach. The residual damages do not 

include induced damages, or the cost of the emergency response. The economic analysis for all 

Emergency Action Scenarios assumes that damages begin at the top of the flood fighting protection, 

unlike the existing condition, where the economic damages are assumed to begin at half the freeboard 

range. 

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Table 20. Evaluation of Emergency Action Scenarios – Induced Rise ( measured in feet)

Maximum Induced Stage Frequency Increase at 1% Chance Annual Event 

Reach EAS 1 Max. 

Ri

EAS 2 Max. 

Ri

EAS 3 Max. 

Ri

EAS 4 Max. 

Ri 1 0 0 0 0 

2 0 0 0 0 

3 0 0.4 0.7 1.1 

4 0 0.3 0.6 0.8 

Maximum Induced Stage Frequency Increase at 0.2% Chance Annual Event 

Reach EAS 1 Max. Rise EAS 2 Max. 

Ri

EAS 3 Max. 

Ri

EAS 4 Max. 

Ri 1 0 0 0 0 

2 0 0 0 0.1 

3 0 1.1 1.9 2.9 

4 0.1 0.6 1.3 1.8 

Table 21. Evaluation of Emergency Action Scenarios – Average Annual Damages

Average Annual Damages and Benefits for Alternative EAS 1 (000’s) 

Reach 

Existing Damages 

(AAD) 

EAS 1 Residual 

Damages (AAD) 

EAS 1 Benefits 

(AAB) 

 1 $3,629 $1,866 $1,763 

 2 $630 $187 $443 

 3 $9,210 $9,070 $140 

 4 $2,718 $2,220 $498 

Total $16,187 $13,343 $2,844 

Average Annual Damages and Benefits for Alternative EAS 2 (000’s) 

Reach 

Existing Damages 

(AAD) 

EAS 2 Residual 

Damages (AAD) 

EAS 2 Benefits 

(AAB) 

 1 $3,629 $,1834 $1,795 

 2 $630 $33 $597 

 3 $9,210 $3,826 $5,384 

 4 $2,718 $1,115 $1,603 

Total $16,187 $6,808 $9,379 

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Average Annual Damages and Benefits for Alternative EAS 3 (000’s) 

Reach 

Existing Damages 

(AAD) 

EAS 3 Residual 

Damages (AAD) 

EAS 3 Benefits 

(AAB) 

1 $3,629 $1,833 $1,796 

 2 $630 $22 $608 

3 $9,210 $2,933 $6,277 

 4 $2,718 $902 $1,816 

Total $16,187 $5,690 $10,497 

Average Annual Damages and Benefits for Alternative EAS 4 (000’s) 

Reach 

Existing Damages 

(AAD) 

EAS 4 Residual 

Damages (AAD) 

EAS 4 Benefits 

(AAB) 

 1 $3,629 $1,285 $2,344 

 2 $630 $3 $627 

 3 $9,210 $2,023 $7,187 

 4 $2,718 $748 $1,70 

Total $16,187 $4,059 $12,128 

b. Methodology for an Emergency Action Plan. 

The following methodology may serve as a first step in the development of an overall scheme to 

minimize flood risks during emergency conditions. 

In developing an Emergency Action Plan for the Upper Mississippi River System, it is important to 

recognize that there is a logical order of what would be protected first, and to the greatest degree. This 

ordering favors areas with the highest value property and/or critical services (infrastructure). 

Ultimately an Emergency Action Plan should reflect this logic. One expression of this ordering might 

be (from highest to lowest): 

Urban Areas and Critical Infrastructure 

High Damage Agricultural Areas 

Low Damage Agricultural Areas 

Currently Unprotected Low-lying Areas 

From the Emergency Action Scenarios that have been analyzed a better understanding has been 

developed as to where in the system flood fighting efforts result in hydraulic impacts that affect the 

level of protection of adjacent areas. Therefore, flood fighting could be restricted in those reaches 

where it creates negative impacts to higher priority areas. Additionally, where there are opportunities, 

storage areas immediately upstream of major urban areas should be identified for potential use as a 

“safety valve” to provide storage during major flood events (such as the areas identified immediately 

upstream of St. Louis in conjunction with Alternative Plan B). 

Four reasonable scenarios for Emergency Action Plan could be constructed as: 

1. flood fight to 3 feet in all urban areas; 

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2. flood fight to 3 feet in agricultural areas with significant critical infrastructure or unusually 

high damage potential; 

3. in reaches where flood fighting along the remaining agricultural levees does not have a 

significant hydraulic effect (based on the EAS runs), flood fight up to 3 feet and less in areas 

where there is an impact on hydraulic profiles, and 

4. identify areas immediately upstream of major urban areas that could potentially be used to 

provide storage during major flood events. 

To further develop this as an alternative requires that three important questions be answered: 

1. What is considered as significant critical infrastructure? 

2. What is considered as significantly high damage potential in agricultural areas? 

3. How great of a hydraulic impact (water surface rise) is considered significant? 

In order to effectively compare an Emergency Action Plan with other alternatives or Emergency 

Action Plan scenarios, quantification of the costs of flood fighting would be considered, as well as the 

induced damages resulting from the hydraulic impacts of flood fighting. 

2. Reconstruction of the Existing Flood Risk Management System

Reconstruction involves the rehabilitation of existing Federal flood control projects that are at risk of 

no longer performing as intended due to long term degradation of project features which have 

exceeded their expected service life. Reconstruction would serve to insure that the project continues 

to deliver the full flood risk management benefits intended by Congress at the time of authorization, 

but would not expand or change the authorized scope, function, or purpose of the project. The 

alternative would not involve work typically associated with the routine operation and maintenance of 

a flood control project or corrective work required due to improper maintenance on the part of the nonfederal sponsor. A Federal project would be eligible for inclusion in this alternative only if the nonfederal sponsor has adequately operated and maintained the project to Corps standards; and there are 

no outstanding maintenance deficiencies. 

Project features, for example, that may be considered as part of a reconstruction alternative include: 

concrete foundations, gravity drains, gated structures, closing structures, pumps and motors, relief 

wells and other under seepage control features, and electrical equipment. 

The age of the existing flood risk management systems and two recent detailed reconstruction analysis 

which were authorized in WRDA 2007 demonstrate the need for reconstruction on the Upper 

Mississippi River System. 

Reconstruction would be defined by elimination. Reconstruction elements would not include design 

or construction deficiencies. Design or construction deficiencies would continue to be addressed 

according to ER 1165-2-119. Further, reconstruction would only address the impediments preventing 

a project from performing as authorized after all maintenance has been accomplished by the nonfederal sponsor and any deficiencies resulting from a lack of maintenance have been addressed. 

Reconstruction would consist of addressing the major project deficiencies caused by a long-term 

degradation of the foundation, construction materials, and the engineering systems beyond their 

expected service lives and the resulting inability of the project to perform its authorized project 

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functions. In addressing reconstruction needs, the latest design standards and efficiency improvements 

can be incorporated into the project as long as the scope, function, and purpose of the project are not 

changed. 

Since reconstruction projects would not entail a change in levee elevation, no secondary development 

or induced flooding effects would be expected. 

The St. Louis District recently completed two feasibility phase level reconstruction studies for two 

urban design systems in the St. Louis Metropolitan Area. Both analysis were approved for the 

ASA(CW) and subsequently authorized for construction in the Water Resources Development Act 

(WRDA) of 2007. 

a. Wood River Levee System Reconstruction. 

The Wood River Levee System was authorized in WRDA 2007, TITLE I-WATER RESOURCES 

PROJECTS, SEC. 1001. PROJECT AUTHORIZATIONS. (20) WOOD RIVER LEVEE SYSTEM 

RECONSTRUCTION, MADISON COUNTY, ILLINOIS, as follows, “The project for flood damage 

reduction, Wood River Levee System Reconstruction, Madison County, Illinois: Report of the Chief 

of Engineers dated July 18, 2006, at a total cost of $17,220,000, with an estimated Federal cost of 

$11,193,000 and an estimated non-Federal cost of $6,027,000.” 

The purpose of the General Reevaluation Report was to investigate the existing condition of the Wood 

River Levee system in order to determine what, if any, actions are required to return the levee, pump 

stations, and other appurtenant features to a condition that ensures they continue to provide their 

intended original degree of protection into the future. EC 11-2-183 dated March 2002 provides that: 

“Older projects that are properly operated and maintained by non-Federal sponsores 

but are no longer performing satisfactorily primarily due to their advanced age may be 

considered for reconstruction. The proposed work will insure that the project 

continues to deliver the full benefits intended by Congress at the time of authorization; 

will not expand or change the authorized scope, function, or purpose of the project, 

and is not operation and maintenance typically associated with project or corrective 

work required due to improper maintenance on the part of the non-Federal sponsor.” 

The levee district is protected by an urban design levee and is located on the left bank of the 

Mississippi River flood plain between river miles 195 and 203 above the Ohio River. The system 

includes approximately 21 miles of main line levee, 170 relief wells, 26 closure structures, 41 gravity 

drains and 7 pump stations. The district includes approximately 13,700 acres of bottomland and 4,700 

acres of hill land tributary to the bottoms. 

The major components authorized for reconstruction include gravity drainage structures, closure 

structures and pump stations. As presented in the General Reevaluation Report, March 2006, first cost 

of construction is about $16,740,000 with net benefits of $2,600,900 and a BCR of 3.13. 

b. The St. Louis Flood Protection System, Missouri. 

The St. Louis Flood Protection System, Missouri, Reconstruction Project, was authorized in WRDA 

2007, SEC. 5070, which is presented below. 

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The St. Louis Flood Protection System is located in Missouri on the right bank of the Mississippi 

River flood plain between river miles 176 and 188 above the Ohio River. The Project protects an area 

of about 3,160 acres which is mostly highly developed industrial and commercial land. 

The recommended plan, Plan 2A, as per the Reconstruction Evaluation Report, July 2005, generates 

the highest average annual net benefits ($4,967,749) and is identified as the NED Plan. The estimated 

total project cost is $14,680,000. With average annual benefits of $6,215,749, the BCR is 4.98. The 

project consists of replacing swing gates at 20 locations, permanently close gates at 13 sites, replacing 

103 existing relief wells, and adding 70 new relief wells. 

 c. WRDA 2007, SEC. 5070. 

Section 5070 of the Water Resources Development Act (WRDA) of 2007 authorizes the Secretary to 

participate in the reconstruction of about 15 projects located in southern Illinois and Missouri. The 

City of St. Louis, aka The St. Louis Flood Protection System, Missouri, Reconstruction Project, is one 

of the projects authorized in Section 5070. 

SEC. 5070. RECONSTRUCTION OF ILLINOIS AND MISSOURI FLOOD 

PROTECTION PROJECTS. 

(a) IN GENERAL.—The Secretary may participate in the reconstruction of an eligible flood 

control project if the Secretary determines that such reconstruction is not required as a result of 

improper operation and maintenance of the project by the non-Federal interest. 

(b) COST SHARING.—The non-Federal share of the costs for the reconstruction of a flood control 

project authorized by this section shall be the same non-Federal share that was applicable to 

construction of the project. The non-Federal interest shall be responsible for operation and 

maintenance and repair of a project for which reconstruction is undertaken under this section. 

(c) RECONSTRUCTION DEFINED.—In this section, the term ‘‘reconstruction’’, as used with 

respect to a project, means addressing major project deficiencies caused by long-term degradation of 

the foundation, construction materials, or engineering systems or components of the project, the 

results of which render the project at risk of not performing in compliance with its authorized project 

purposes. In addressing such deficiencies, the Secretary may incorporate current design standards 

and efficiency improvements, including the replacement of obsolete mechanical and electrical 

components at pumping stations, if such incorporation does not significantly change the scope, 

function, and purpose of the project as authorized. 

(d) ELIGIBLE PROJECTS.—The following flood control projects are eligible for reconstruction 

under this section: 

(1) Clear Creek Drainage and Levee District, Illinois. 

(2) Fort Chartres and Ivy Landing Drainage District, Illinois. 

(3) Prairie Du Pont Levee and Sanitary District, including Fish Lake Drainage and Levee 

District, Illinois. 

(4) Cairo, Illinois Mainline Levee, Cairo, Illinois. 

(5) Goose Pond Pump Station, Cairo, Illinois. 

(6) Cottonwood Slough Pump Station, Alexander County, Illinois. 

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(7) 10th and 28th Street Pump Stations, Cairo, Illinois. 

(8) Flood control levee projects in Brookport, Shawneetown, Old Shawneetown, Golconda, 

Rosiclare, Harrisburg, and Reevesville, Illinois. 

(9) City of St. Louis, Missouri. 

(10) Missouri River Levee Drainage District, Missouri. 

(e) JUSTIFICATION.-The reconstruction of a project authorized by this section shall not be 

considered a separable element of the project. 

 (f) AUTHORIZATION OF APPROPRIATIONS.-There is authorized to be appropriated 

$50,000,000 to carry out this section.

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V. COORDINATION AND PUBLIC VIEWS 

A. COORDINATION 

Coordination with various other Federal, state, local and non-governmental agencies and groups 

occurred through the Collaboration Team created in 2002. The coordination occurred through team 

meetings, teleconference calls, and electronic transmission of documents. 

The current Upper Mississippi River Comprehensive Plan Collaboration Team is presented below. 

Federal Representatives 

• Ken Hinterlong, Federal Emergency Management Agency (FEMA), Region V, Chicago, 

IL 

• Richard Leonard, FEMA, Region VII, Kansas City, MO 

• DaveEllis, U.S. Fish and Wildlife Service (USFWS), Annada, MO 

• Jon Duyvejonck, (USFWS), Rock Island Field Office, Rock Island, IL 

• Dick Steinbach, USFWS, Quincy, Illinois 

• Jon Kauffeld, USFWS, Region 3, Fort Snelling, MN 

• Tim Yager, USFWS, Region 3, Fort Snelling, MN 

• Bill Franz, U.S. Environmental Protection Agency, (USEPA)Region 5, Chicago, IL 

• Larry Shepard, USEPA, Region 7, Kansas City, MO 

• Bob Goodwin, U.S. Department of Transportation, Maritime Administration 

State Representatives 

• Gary Clark, Illinois Department of Natural Resources (DNR) 

• Arlen Juhl, Illinois DNR 

• Paul Osman, Illinois State Floodplain Management, Illinois DNR 

• Bill Cappuccio, Iowa DNR 

• Tim Schlagenhaft, State of Minnesota 

• Randy Scrivner, Missouri State Emergency Management Agency 

• Mike Wells, Missouri DNR 

• Charlie DuCharme, Missouri DNR 

• Gretchen Benjamin, Wisconsin DNR 

Non-Governmental Organization Representatives 

• Kim Robinson, Upper Mississippi, Illinois, and Missouri Rivers Association 

• Mike Klingner, Upper Mississippi, Illinois, and Missouri Rivers Association 

• Dave McMurray, Upper Mississippi, Illinois, and Missouri Rivers Association 

• Holly Stoerker, Upper Mississippi River Basin Association 

• Mark Beorkrem, Mississippi River Basin Association 

• Jennifer Frazier, American Land Conservancy 

• Michael Reuter, The Nature Conservancy 

• Owen Dutt, American Heritage Rivers 

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B. PUBLIC VIEWS 

1. Public Views. Correspondence from other Federal agencies, and state and local agencies, 

organizations and individual persons will be summarized after the June 2006 public meetings and 

based upon all correspondence received. 

A series of four public meetings was held the last week of June 2006, about a month after the draft 

Comprehensive Plan Report was released to the public. There was generally significant support for a 

reduction in flood risk in the UMRS. Some questioned the need and advisability of such a large 

expenditure. Plan G, proposed by UMIMRA, was strongly supported at the three public meetings held 

north of St. Louis, MO. Attendees at the fourth and last public meeting held at Chester, IL, located on 

the Mississippi River south of St. Louis, MO, opposed Plan G. Plan G in addition to a high level of 

protection included a 10,000 acre storage area located in the floodplain of Monroe County, IL. The 

storage area to be located in Monroe County, IL, south of St. Louis, was a major area of concern. The 

storage area would probably require fee purchase of the 10,000 acres, which local residents strongly 

opposed. 

Written correspondence in response to the public meeting including letters, emails, calls and petitions, 

was about evenly split, supporting and opposing Plan G. 

Over the nine months following the public meetings, a series of meetings was held with publics and 

representatives of the drainage and levee districts south of St. Louis, MO. In direct response to the 

meetings held and input received during this period, Plan B was the further refined and Plan M, 

presented above, was formulated. 

2. UMIMRA Preferred Plan. The major stakeholder for flood risk management in the Upper 

Mississippi River System, the Upper Mississippi, Illinois and Missouri River Association (UMIMRA), 

has indicated a strong preference for Alternative Plan G, or as a second option Plans M and H. 

Alternative Plan G would provide a systemic high level of flood protection, 0.2 % chance annual (500-

year) protection, for most areas with existing floodwalls and levees. 

Alternative Plan G, if implemented, would satisfy the WRDA authorization to “develop a plan in the 

interest of the systemic flood damage reduction...” This plan would address the planning objectives 

to 1) minimize the threat to health and safety resulting from flooding, and 2) reduce damages and costs 

associated with flooding. 

To meet the criteria of no more than a 1-foot rise in water surface profile for the 1 percent chance 

(100-year) annual flood, 9 drainage and levee districts in the area south, downstream, of St. Louis, 

would not be allowed to raise their flood protection level. Some of the floodplains of these nine 

districts may offer an opportunity to address environmental sustainability and restoration goals of the 

UMRS. If implemented, it would also address other objectives including nutrient input and 

sedimentation, bank caving and erosion reduction, and may offer the opportunity for improved 

recreation. 

Considering the evaluation of Alternative Plan G by the four evaluation accounts would result in the 

following: 

• NED – Construction cost of about $6 billion with a benefit-to-cost ratio of about 0.05. 

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• EQ – Plan G would allow unrestricted development in the protected areas. Existing 

environmental areas would be protected within the drainage and levee districts. 

• RED – Very significant regional economic development benefits of over $27 billion due 

to the jobs created, construction, prevention of loss to bridges, flood fighting, social 

disruption of the population and the areas surrounding it could be expected. 

• OSE – There are several categories considered in Other Social Effects. Aesthetics would 

be negatively impacted by Plan G, public health and safety would be improved, 

transportation systems would be protected within the leveed areas, community cohesion 

would improve, significant community growth and development would be allowed to 

occur as desired, relocations of businesses and homes would be minimized or not 

required, but there may be controversy with implementation of Plan G. 

. 

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VI. CONCLUSIONS 

General Overview. 

The need for a comprehensive, systemic plan for flood risk reduction and floodplain management 

along the Upper Mississippi and Illinois Rivers has been recognized by numerous stakeholders and in 

numerous documents and forums including the post-1993 flood reports and the regional summit 

meetings of the mid-1990’s. This recognition ultimately led to the authorization of the Upper 

Mississippi River Comprehensive Plan (Comprehensive Plan) in the Water Resources Development 

Act (WRDA) of 1999 (Section 459), which states in part that, “The Secretary shall develop a plan to 

address water resource and related land resource problems and opportunities in the upper Mississippi 

and Illinois River basins, from Cairo, Illinois, to the headwaters of the Mississippi River, in the 

interest of systemic flood damage reduction ” 

The study investigated opportunities to develop and implement a systemic approach that reduces 

cumulative flood risk costs and annual flood damages, while simultaneously providing long term 

improvements to other system values and uses (ecological, economic, recreation, transportation, etc.). 

A number of Corps studies completed since the Flood of 1993, provided the foundation for evaluation 

of a comprehensive systemic plan for flood risk reduction. 

The Upper Mississippi River Comprehensive Plan provides a possible framework to go forward with 

flood risk reduction by interested Federal, state and locals interests. In total, eight alternatives were 

evaluated in detail ranging from reconnection of the floodplain through buyouts to various levels of 

increases in the level of protection, up to a systemic 500-year level of protection. 

Two significant events occurred during the period of preparation of the draft report in 2005 that served 

to refine the study approach and analysis. First, two severe hurricanes, Katrina and Rita, hit the 

southern United States. The hurricane experience, in addition to the lessons of the Flood of 1993, 

resulted in a reexamination of approaches to flood risk management and flood mitigation, changing 

some perspectives and increasing the emphasis on risk informed decision making rather than relying 

on more narrowly defined economic decision criteria. Secondly, during the development of the report, 

the Corps of Engineers issued several engineering circulars, emphasizing collaborative approaches to 

planning and reaffirming the assessment of plans based on all four accounts: NED, EQ, RED and 

OSE. 

The lessons learned from the 1993 Flood and Hurricanes Katrina and Rita were incorporated into the 

UMR Comprehensive Plan, including the recognition that flood risk management is a shared Federal, 

state and local responsibility and any future improvements will need support from all interests. To 

assist in providing a framework for complex decision making, the project team and stakeholders 

utilized a Risked Informed Decision Framework (RIDF). RIDF is a planning tool which incorporates 

risk and uncertainty information into the decision process. One outcome of the process highlighted 

the importance of public health and safety. Prior to implementing RIDF, while Other Social Effects 

were considered, the analysis focused on net NED benefits in the selection process. However as 

indicated above, both the 1993 Flood and Hurricanes Katrina and Rita demonstrated that using the 

NED results as the primary decision tool does not adequately address public health and safety, 

especially in the event of infrequent floods. 

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Evaluation of the project alternatives revealed very low National Economic Development benefits and 

high RED (state and local) benefits. In addition the impacts of the OSE and EQ accounts were 

considered as part of the evaluation. To meet the legislative requirement to develop a systemic plan 

for flood protection, it is clear that a collaborative partnership of Federal, state and local interests is 

necessary. The Corps can bring technical expertise (hydraulic, hydrologic, economic, environmental, 

and engineering) to such a collaborative partnership as well as coordinatation with existing Corps 

programs (Upper Mississippi River And Illinois Waterway System Navigation Environmental 

Sustainability Program (NESP); the Environmental Management Program (EMP); Illinois River Basin 

Restoration, Sec. 519 (Illinois 519)); and other environmental programs to help prioritize and locate 

environmental projects that benefit the Upper Mississippi River System. 

As the Comprehensive Plan was limited to the Mississippi and Illinois River floodplain, about 4,000 

square miles, rather than the entire watershed, there exists the possibility of performing watershed 

analysis on major tributaries in the future. 

Conclusions 

Systemic Flood Risk Management. 

The existing flood risk management systems currently prevent 95-97% of the potential average annual 

flood damages on the system. However, the Flood of 1993 and Hurricanes Katrina and Rita have 

clearly shown that even low residual risk may not meet the Nation’s expectations with regard to public 

health and safety. If there would be an overtopping of a levee or floodwall, a catastrophic loss could 

result. 

None of the comprehensive, systemic flood damage reduction plans that were evaluated had net 

positive NED benefits. For the eight plans evaluated, benefit-to-cost ratios (BCR) were below 0.1. 

Initial analysis indicated NED benefit-to-cost ratios of greater than one for a project addressing critical 

transportation facilities (e.g. bridge approaches, etc.). 

Environmental Quality (EQ) opportunities exist within the Upper Mississippi River floodplain. 

Coordination between other Corps programs (NESP, EMP and Illinois 519) and the Comprehensive 

Plan could encourage wetland and conservation in areas that would also result in flood risk reduction. 

Existing conservation areas located in the Upper Mississippi and Illinois Rivers floodplain may be 

impacted by the rise in water surface profiles if a systemic flood risk management plan is 

implemented. 

Implementation of a large, systemic flood risk reduction plan would result in significant regional 

economic benefits. The Tennessee Valley Authority estimated that every dollar spent on 

comprehensive flood risk reduction (i.e., 500-year level of risk reduction for urban areas and 100-year 

or greater level of risk reduction for agricultural areas - Plans A, B, D, G, H or M) would generate as 

much as $5 in increased gross regional product for every dollar expended. Also, employment could 

increase by more than 20,000 jobs annually in the five-state Upper Mississippi Valley Region 

resulting from upgraded levee protection provided by the full implementation of a comprehensive 

flood risk reduction plan.

Other Social Effects (OSE) benefits for public health and safety and displacement would occur if a 

systemic alternative plan were implemented.

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From a stakeholder view, the results of applying the Risked Informed Decision Framework (RIDF) 

indicated a preference for a comprehensive plan with a high level of risk reduction for the entire Upper 

Mississippi River System. 

Plans B, G, H and M are all similar in providing a high level of flood risk reduction. Plan H includes a 

cost comparison. For Plan H, the construction cost of increasing the system height, typically raising a 

levee, is compared to the cost of acquisition of the district, and the cost effective option, either the 

levee raise or acquisition, then becomes a part of Plan H for that site. Any district could choose not to 

be a part of the plan and then the district would stay “as is” or find other resources to improve the 

existing level of protection. Of the existing flood damage reduction systems, 37 systems should be 

further evaluated using a cost comparison methodology. 

A Regional or National oversight group (e.g., the Mississippi River Commission or an interstate 

group) would provide assistance to the states and local drainage and levee districts to implement a 

comprehensive flood risk management plan. This oversight would provide a regular review of the 

water resources problems, needs and opportunities in a collaborative framework working with other 

Federal, state and local agencies and non-governmental organizations, stakeholders, and the interested 

public. This oversight group would be the catalyst to address the problems and needs collaboratively. 

The Corps could assist by bringing its leadership and expertise in technical areas (e.g., hydrology and 

hydraulics, economic and environmental analysis, and engineering) to bear in addressing the changing 

problems, needs, and opportunities of the region. The Corps could also help coordinate environmental 

programs, including NESP, EMP, and Illinois 519, to provide greater priority for projects benefiting 

flood risk reduction, navigation, bank caving, and erosion, watershed nutrient and sediment 

management, recreation needs, and other purposes. 

Reconstruction. 

The Upper Mississippi River Comprehensive Plan recognized the importance and benefit of the 

existing flood damage reduction systems in place. Due to the average age of the last major 

construction upgrade, over 45 years, and condition, the existing flood risk reduction systems need to 

be evaluated to determine the feasibility of reconstruction. Reconstruction could insure that the 

systems continue to provide the billions of dollars in benefits for the foreseeable future. The average 

year of last construction upgrade of the agriculture systems on the Upper Mississippi and Illinois 

Rivers was 1940, making the last system major construction upgrade, on average, over 65 years old. 

The reconstruction effort would focus on a feasibility phase level of evaluation of the system 

components including pump stations, gates, closures, and supporting infrastructure. Further, 

reconstruction would address, if necessary, the current frequency water surface profiles and the height 

of the existing protection systems to determine if the systems have to be raised to maintain the 

authorized level of protection. 

Critical Infrastructure – Transportation. 

Preliminary analysis of costs and benefits for the protection of one location crossing the Mississippi 

River indicates that the protection may be economically justified from an NED account evaluation, the 

traditional Corps evaluation account. A systemic analysis of the Upper Mississippi and Illinois Rivers 

for critical transportation infrastructure (e.g. bridge approaches, railroad infrastructure, etc.) using all 

four evaluation accounts may indicate that protection of the transportation infrastructure is worthwhile 

at several locations to insure that the transportation system continues to function during a significant 

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flood event. The result of this analysis may indicate where priority plan implementation could occur 

to reduce the flood risk to critical transportation systems. During the Flood of 1993, major east 

west transportation arteries (roads and railroads) were severed causing significant delays and 

major rerouting of goods and individuals. In many cases the rerouting was in excess of 100 

miles. If a flood similar to the Flood of 1993 were to occur today, the container traffic 

disruption from the west coast to the major distribution center in the Chicago area would have 

national ramifications. The reduction of flood risk for this critical transportation infrastructure 

would fit within the total system plan. 

Systemic Hydrologic Analysis of the Upper Mississippi River System. 

The UMR Comprehensive Plan successfully developed a set of tools capable of analyzing the 

hydraulic, economic and environmental effects of systemic flood damage reduction alternatives. 

The hydrologic body of knowledge of the Upper Mississippi and Illinois Rivers has dramatically 

increased as a direct result of the previously completed Flow Frequency Study and the Comprehensive 

Plan. The systemic modeling is a useable product for the future if maintained. It allows the 

determination of system-wide hydrologic impacts from actual and proposed changes. This modeling 

has the potential to substantially change the way this river system is managed. 

Specific findings of the hydraulic analysis of alternatives include: 

• The levees above Lock and Dam 19 at Keokuk, Iowa (study reaches 1 and 2) can be 

systemically raised without causing more than a one-foot increase in the 1 percent annual chance (100-

year) flood profile anywhere within reaches 1 and 2. 

• Likewise, the levees on the Illinois River (reach 4), river mile 0.0 to 160.0, can be raised 

without causing more than one foot of rise in the 1 percent annual chance (100-year) flood profile. 

• Several flood risk reduction measures (levee setbacks, realignments, and removal of bridge 

obstructions) have only a very localized reduction of water surface profiles. 

• Any raises to levees immediately above the confluence of the Missouri and Mississippi 

Rivers, or south of St. Louis on the Mississippi River, where limited non-leveed floodplain exists, 

would increase flood heights more than one (1) foot. The existing levee alignment in these areas will 

not allow significant flood risk reduction improvements. 

Emergency Action Scenarios. 

Members of the Collaboration Team expressed the need for an evaluation of Emergency Action 

Scenarios for the Upper Mississippi River System to be included as part of the Upper Mississippi 

River Comprehensive Plan. The evaluation of a series of Emergency Action Scenarios, temporary 

raising of levees during a flood emergency of up to three feet, was conducted to develop a better 

understanding of the hydraulic and economic impacts of emergency actions such as flood fighting. 

Hydrologic analysis of a series of scenarios concluded that: 

• There is no induced rise in frequency stage in Reaches 1 and 2 for any of the scenarios. This 

implies that induced damages are not a concern when determining emergency response priorities 

within these reaches. 

• There is no induced rise in frequency stage anywhere along the length of the Mississippi River 

or Illinois River (Reaches 1-4) caused by increasing the level of protection of only urban and industrial 

areas. 

• Induced damages could be a concern at some locations for systemic agricultural levee raises in 

Reaches 3 and 4. 

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Potential Follow-on Studies 

The Comprehensive Plan efforts pointed to the need for several follow on studies. The first three 

follow-on studies are specifically recommended in the next section. The fourth study would assist in 

identifying the expected flood risk throughout the Upper Mississippi River System in a useable and 

understandable way to the general public, a key factor in reducing flood risk. 

1. Cost shared feasibility phase reconstruction analysis should be undertaken. This 

reconstruction analysis would be accomplished on individual flood risk management 

systems to evaluate whether rehabilitation on the aging infrastructure is needed and 

justified to assure that the existing system provides benefits in the future. This 

reconstruction analysis and FEMA Flood Insurance Rate Map development are two 

immediate examples using the results of the hydrologic modeling in Follow-on Study No. 

3. 

2. A systemic analysis of critical transportation systems should be performed to determine 

the feasibility of protecting river approaches for land based systems, highways and 

railroads. 

3. The hydrologic modeling for the Upper Mississippi River System should be maintained 

and updated as changes occur and new data is available. This would make the modeling 

and its results available to all Federal, state and local agencies in the future and would 

allow new tools to be incorporated as available. Existing information used to evaluate 

project benefits is, on the average, over 30 years old. Updating this information would 

provide decision-makers and the public with better quality data upon which to manage the 

system on a long-term basis. Also, The Flood Flow Frequency (FFF) study did not 

complete the GIS mapping of the Illinois River from Mile 42.0 to 90.0, and this should be 

completed. 

4. Development of a methodology to clearly convey the flood risk for the Upper Mississippi 

River System should be undertaken using a combination of technology tools, such as a 

geographic information system (GIS), and a series of river gages, so the public can relate a 

specific location to the expected flood risk. 

5. To close data gaps in our understanding of the river system, investments should be made 

in GIS-based computer modeling, a second generation Habitat Needs Assessment, longterm sediment monitoring, and pilot Projects for evaluating wetlands creation using 

existing agricultural drainage districts as a potential management tool for nutrients control 

and reduction. 

6. As the Comprehensive Plan was limited to the Mississippi and Illinois River floodplain, 

about 4,000 square miles, rather than the entire watershed (185,000 square miles), there 

exists the need of performing a watershed analysis on individual tributaries. 

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VII. RECOMMENDATIONS 

This Upper Mississippi River Comprehensive Plan is prepared in response to the Congressional 

directive contained in Section 459 of the Water Resources Development Act of 1999. While this 

report presents a Comprehensive Flood Risk Management Plan in response to Congressional direction, 

additional authority to implement the Comprehensive Plan is not being recommended nor requested at 

this time based upon the NED evaluation of alternative plans. Specifically, the congressional language 

required the development of a comprehensive plan for systemic flood damage reduction in the upper 

Mississippi and Illinois River basins. While none of the plans evaluated were feasible based on net 

National Economic Development (NED) benefits, decision makers may desire information beyond 

NED to ensure that their decision meets the needs of the Nation. Therefore, in an effort to be 

responsive to the congressional directive, the best performing of the plans evaluated was identified 

based upon consideration of the four evaluation accounts, NED, EQ, RED and OSE, using both 

traditional economic analysis and risk informed decision framework analysis techniques. 

Plan H, while not economically feasible when evaluated by NED guidelines, has been identified as the 

best performing plan of those alternative plans evaluated. Plan H includes a cost effectiveness 

consideration. For Plan H, the construction cost of increasing the system height, typically raising a 

levee, is compared to the cost of acquisition of the district, and the cost effective option then becomes 

a part of Plan H for that site. Any district could choose not to be a part of the plan and then the district 

would stay “as is” or find other resources to improve the existing level of protection. However, it 

should be noted that Plan H has not been thoroughly vetted with the public and stakeholders. In 

addition, the following factors should be considered by decision makers. 

a. Implementation of Plan H would provide a significant increase in the level of risk 

reduction for the Upper Mississippi River System (UMRS). 

b. There is likely to be limited Federal interest, based upon current guidance, in plan 

implementation by Federal agencies. 

c. Regional or national oversight (e.g., the Mississippi River Commission) would be 

required to ensure the plan functions as a system over the implementation and operation 

phases of the project and project priorities are established to reflect the changing systemic 

needs. 

d. The States of Illinois, Iowa, and Missouri need to agree on the plan and plan 

implementation to insure the plan is acceptable. The Corps could provide facilitation and 

technical support to this effort. 

e. If Plan H were implemented as a comprehensive, systemic flood risk reduction plan for 

the Upper Mississippi and Illinois Rivers, significant additional technical analysis in all 

areas would be required before final plan design and implementation could be initiated to 

insure all potential impacts are adequately addressed. 

Continued collaboration between Federal agencies, state agencies, and stakeholders, may establish a 

comprehensive approach to flood risk reduction and floodplain management leading to consensus 

building for the UMRS. This would then allow other Federal and non-Federal agencies to bring to 

bear their authorities and capabilities toward implementation. 

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ACRONYMS AND ABBREVIATIONS 

AAB average annual benefits 

AAD average annual damages 

BCR benefit-to-cost ratio 

CRP Conservation Reserve Program 

E.O. Executive Order 

EAP Emergency Action Plan 

EAS Emergency Action Scenarios 

EQ Environmental Quality 

ENR Engineering News-Record 

EOP Environmental Operating Principles and Implementation Guidance 

ER Engineering Regulation 

EWP Emergency Watershed Protection Program 

EWRP Emergency Wetlands Reserve Program 

FEMA Federal Emergency Management Agency 

FFS Flow Frequency Study 

FMRC Floodplain Management Review Committee 

FMRC Floodplain Management Review Committee 

IDC interest during construction 

MR&T Mississippi River and Tributaries 

NED national economic development 

NER National Ecosystem Restoration 

NRCS National Resources Conservation Service

NGO Non-governmental Organizations 

OSE Other Social Effects 

RED regional economic development 

RM river mile 

SAST Scientific Assessment and Strategy Team 

TVA Tennessee Valley Authority 

UMIMRA Upper Mississippi, Illinois and Missouri Rivers Association 

UMRBA Upper Mississippi River Basin Association 

UMRCC Upper Mississippi River System resources management 

UMR-IWW Upper Mississippi River-Illinois Waterway 

WRDA Water Resources Development Act 

WRP Wetlands Reserve Program 

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REFERENCES 

Economic Impact of the Recreation on the Upper Mississippi River System. US Army Corps of 

Engineers Technical Report – EL-95-16. Waterways Experiment Station, 1995. 

Floodplain Management Assessment of the Upper Mississippi River and Lower Missouri Rivers and 

Tributaries. U. S. Army Corps of Engineers, 1995 

Natural Disaster Survey Report: The Great Flood of 1993. U.S. Department of Commerce, National 

Oceanic and Atmospheric Administration, 1994 

A River That Works and a Working River. McGuiness, Dan. The Upper Mississippi Rover 

Conservation Committee, 2000. 

Sharing the Challenge: Floodplain Management into the 21st Century (Galloway Report). Interagency 

Floodplain Management Review Committee, Washington, D.C., 1994 

Taming the Upper Mississippi River: My Turn at Watch, 1935-1999. William H. Klingner, P.E., 

P.L.S. Petterchak, Janice. Legacy Press, Rochester, IL. 2000 

Upper Mississippi River Comprehensive Basin Study, Appendix G—Fluvial Sediment. U. S. Army 

Corps of Engineers, 1969 

Upper Mississippi River System Flow Frequency Study. U. S. Army Corps of Engineers, 2004 

Upper Mississippi River System—Ecological Status and Trends of the Upper Mississippi River System. 

U. S. Army Corps of Engineers, 1995 

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GLOSSARY 

100-year flood: a term commonly used to refer to the one percent chance annual flood. The 100-year 

flood is the flood that is equaled or exceeded once in 100 years on the average, but the term should not 

be taken literally as there is no guarantee that the 100-year flood would occur at all within a 100-year 

period or that it would not recur several times. 

500-year flood: a term commonly used to refer to the 0.2 percent chance annual flood. The 500-year 

flood is the flood that is equaled or exceeded once in 500 years on the average, but the term should not 

be taken literally as there is no guarantee that the 500-year flood would occur at all within a 500-year 

period or that it would not recur several times. 

acre-foot: a unit measure of volume equal to one acre covered to a depth of one foot; often used to 

describe reservoir capacity or the amount of water flowing past a point in a river over a specified time 

period. one acre-foot equals 43,560 cubic feet, or 326,70tl gallons 

actuarial rates: insurance rates determined on the basis of a statistical calculation of the probability 

that a certain event would occur. Actuarial rates, also called risk premium rates, are established by the 

Federal insurance administration pursuant to individual community flood insurance studies and 

investigations undertaken to provide flood insurance in accordance with the national flood insurance 

act and with accepted actuarial principles, including provisions for operating costs and allowances. 

aggradation: the process of filling and raising the level of a streambed by deposition of sediment 

agricultural levee: a levee for which the majority of benefits are derived from protection of 

agricultural lands 

backwater lake: a lake connected to a river at its downstream end that tills principally from the rise 

of the river rather than from inflow from the lake’s drainage area 

backwater: a) a rise in upstream water level caused by an increase in flow downstream; b) an 

upstream water level rise caused by obstructions downstream, such as ice jams or debris 

bank stabilization: use of structural measures such as rock, concrete, or other material to stabilize 

channel banks against movement and erosion 

bankfull stage: at a given location, the maximum elevation to which a river can rise without 

overflowing its banks (See flood stage.) 

base flood: a florid of specific frequency and used for regulatory purposes. The NFIP has adopted the 

“100-year” flood as the base flood to indicate the minimum level of flooding to be used by a 

community in its floodplain management regulations. 

basin: a region or area drained by a river system. Also, the total land area that contributes runoff to 

any given point on a river or stream; often called a watershed. 

biotechnical engineering: channel or bank modification techniques that use vegetation in innovative 

ways in contrast to traditional bank sloping and riprap protection 

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bluff line: a steep headland or cliff which in some topographical settings defines the edge of a 

floodplain 

bottomland hardwood: tree species that occur on water-saturated or regularly inundated soils. 

classified as wetlands, these areas contain both trees and woody shrubs 

channel modifications. flood stages can be reduced by improving flow conditions within the channel 

and increasing the stream’s carrying capacity. Methods generally used to obtain improvements of 

channels include straightening to remove undesirable bendways, deepening or widening to increase 

size of the waterway and clearing to remove brush, trees, and other obstructions. 

collaborative approach: a commitment to working collectively to solve complex, inter-related 

concerns. A collaborative effort requires more than consultation, coordination, and seeking public 

input. 

community assistance program (cap): the program established by the Federal emergency 

management agency and intended to assure that communities participating in the NFIP are carrying 

out the flood loss reduction objectives of the program. The cap provides needed technical assistance 

to NFIP communities and attempts to identify and resolve floodplain management issues before they 

develop into problems requiring enforcement action. 

community rating system (CRS: a program developed by the Federal emergency management 

agency to encourage—by use of flood insurance premium reductions—community and state activities 

that go beyond the basic NFIP requirements; the CRS gives communities credit for certain activities to 

reduce flood losses, facilitate accurate insurance rating, and promote the awareness of flood insurance 

confined: flows are confined between the levees in the river channel and overbank area or between 

the levee on one bank and the bluff on the opposite river bank. Flood waters are not allowed to 

overtop any levee. It is assumed for analysis purposes, that levees would be raised as needed to keep 

the flood waters out of the levee areas, confined to the river. 

conservation tillage: practices that reduce cultivation of soil, leave a protective vegetative layer on 

the surface, and thereby serve to reduce or minimize soil erosion 

crest: the highest water level at a given location during a flood event 

crop rotation: growing crops in a cropping sequence designed to provide adequate residue for 

maintaining or improving soil condition 

cubic feet per second (CFS): the rate of flow (see discharge) past a given point, measured in cubic 

feet per second. One cubic foot of water equals approximately 7 1⁄2 gallons. 

cumulative impacts: the impacts on the environment that result from the incremental impact of an 

action when added to other past, present and reasonably foreseeable actions; cumulative impacts can 

result from individually minor but collectively significant actions taking place over a period of time 

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dam: a structure built across a waterway to impound water. Dams are used to control water depths 

for navigation; or to create space to store water for flood control, irrigation, water supply, hydropower 

or other purposes. The function of reservoirs is to store water when streamflow is excessive and to 

release it gradually after the threat of flooding has passed. 

debris: objects such as logs, trees and other vegetation, building wreckage, vehicles, shopping carts 

or dead animals carried by water in a flood (or by wind, as in a hurricane or tornado) 

degradation: a process of lowering the level of a streambed scour and erosion 

design flood: the maximum amount of water for which a flood control project would offer protection. 

selection is based on engineering, economic and environmental considerations 

dike: in most areas of the U.S., an earthen or rock structure built partway across a river for the 

purpose of maintaining the depth and location of a navigation channel. In others areas the term is used 

synonymously with levee. 

discharge: rare of flow in a river or stream measured in volume of water per unit of time. (See cfs) 

drainage tiles: short lengths of perforated pipe made of clay, concrete, or plastic installed in soil to 

remove free water for the purpose of crop production. 

drainage area: total land area from which water drains to a point on a river; the Upper Mississippi 

River drainage area comprises 23 percent of the land area of the 48 contiguous united states. 

dry detention: a dry detention area is an area that can supply temporary storage of water for a given 

time in an area that is normally dry. Usually the outflows are unregulated. 

easement: typically reimbursing a land owner to restrict the possible use they can make of the 

property. There are generally two easement types: 

flowage easement: a permanent easement that grants to the government the right to 

overflow, flood and submerge land lying above a certain elevation. Generally restricts the 

property owner from utilizing the property for anything other than agricultural uses. Typically 

no structures would be allowed within the limits of the flowage easement, without prior 

approval of the government. 

conservation easement: a permanent easement that restricts development on a specified 

tract of land. Typically used to restrict an owner from developing the property for more 

intensive uses, such as commercial or residential development. 

ecosystem: biological communities (including humans) and their environment (or watershed) treated 

together as a functional system of complementary relationships, including transfer and circulation of 

energy and matter 

ecosystem integrity: maintenance of the structural and functional attributes characteristic of a 

particular locale or watershed, including normal variability 

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ecosystem management: management of the biological and physical resources of an ecosystem or 

watershed in an attempt to maintain the stability of its structural, functional, and economic attributes, 

including its normal variability 

emergency spillway: see spillway

emergency: any instance for which, in the determination of the president, Federal assistance is 

needed to supplement state and local efforts and capabilities to save lives and protect property and 

public health and safety or to lessen or avert the threat of a disaster in any part of the United States 

encroachments: activities or construction within the floodway, including fill, new construction, 

substantial improvements, and other development, that may result in au increase in flood levels 

environmental assessment: an examination of the beneficial and adverse impacts on the 

environment of a proposed action, such as a water resources project, and alternative solutions 

Executive Order 11988: the floodplain management executive order (E.O.), issued in 1977, 

specifying the responsibilities of the Federal agencies in floodplain management. E.O. 11988 directed 

Federal agencies to evaluate and reflect the potential effects of their actions on floodplains and to 

include the evaluation consideration of flood hazards in agency permitting and licensing procedures. 

Federal Interagency Floodplain Management Task Force: the task force established in 1975 to 

carry out the responsibility of the president to prepare for the congress a unified national program for 

floodplain management member agencies are the Department of Agriculture, Department of the 

Army, Environmental Protection Agency, Federal Emergency Management Agency, Department of 

the Interior, and the Tennessee Valley Authority 

Federal trust resources: as applied in this report, these resources include migratory birds, federallylisted threatened and endangered species and species that are candidates for listing, interjurisdictional 

fisheries and wetlands. Such resources are protected by international treaty, and/or Federal law in 

recognition of their ecological and/or commercial significance. 

field borders: a strip of perennial vegetation established on the edge of a field. it involves plantings 

of herbaceous vegetation or shrubs 

flash flood: flood with a very rapid rate of rise that is caused by intense rainfall. during flash floods 

the time between peak rate of rainfall and peak flow is very short 

flood/flooding: a general and temporary condition of partial or complete inundation of normally dry 

land areas from the overflow of river and/or tidal waters and/or the unusual accumulation of waters 

from any source 

flood control structures: structures such as dams, dikes, levees, drainage canals, and other structures 

built to modify flooding and protect areas from flood waters 

flood discharge: the quantity of water flowing in a stream and adjoining overflow areas during times 

of flood. It is measured by the amount of water passing a point along a stream with a specified period 

of time and is usually measured in cubic feet of water per second (cfs). 

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flood frequency: the frequency with which a flood of a given discharge has the probability of 

recurring. For example, a 100-year frequency flood refers to a flood discharge of a magnitude likely 

to occur on the average of once every 100 years or, more properly, of a magnitude that has a onepercent chance of being equaled or exceeded in any year. Although calculation of possible recurrence 

is often based on historical records, there is no guarantee that a 100 year flood would occur at all or 

that it would not recur several times within any 100-year period. 

flood hazard: the potential for inundation that involves risk to life, health, property, and natural 

floodplain values 

flood hazard mitigation teams: teams consisting of representatives of the 12 Federal agencies that 

signed an interagency agreement to provide technical assistance to states and communities for 

nonstructural flood risk management measures. The teams are typically employed after each major 

flood disaster declared by the president to provide technical assistance and guidelines to communities 

and states affected by the disaster. 

flood insurance rate map (FIRM): an official map of a community on which the Federal emergency 

management agency has delineated both the special hazard areas and the risk premium zones 

applicable to the community. FIRMS typically identify the elevation of the one-percent chance annual 

flood and the areas that would be inundated by that level of flooding; they are used to determine flood 

insurance rates and for floodplain management. 

flood insurance: the insurance coverage provided through the national flood insurance program 

flood of record: the highest flood historically recorded at a given location 

flood-pulse advantage: the amount by which fish yield is increased by a natural predictable flood 

pulse 

floodplain management regulations: zoning ordinances, subdivision regulation, building codes, 

heath regulations, special purpose ordinances that cover, for example, floodplains, grading, and 

erosion control and other regulation to control future development in floodplains and to correct 

inappropriate development already in floodplains 

floodplain management: a decision-making process whose goal is to achieve appropriate use of the 

nation’s floodplains. Appropriate use is any activity or set of activities that is compatible with the risk 

to natural resources and human resources. the operation of an overall program of corrective and 

preventive measures for reducing flood risk, including but not limited to watershed management, 

emergency preparedness plans, flood control works, and floodplain management regulations. 

floodplain resources: natural and cultural resources including wetlands, surface water, groundwater, 

soils, historic sites, and other resources that may be found in the floodplain and that provide important 

water resources, living resources (habitat), and cultural/historic values 

floodplain: low lands adjoining the channel of a river, stream, watercourse, lake, or ocean that have 

been or may be inundated by floodwater and other areas subject to flooding 

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floodproofing: the modification of individual structures and facilities, their sites, and their contents to 

protect against structural failure, to keep water out, or to reduce the damaging effects of water entry. 

there are many different flood proofing measures to consider including seepage control, wet and dry 

floodproofing and elevating or raising a structure or roadway. 

flood stage: a site-specific river level at which flood damage may start to occur; usually at or above 

the top of the riverbank. flood heights are often measured relative to the florid stage elevation. (See 

stage). 

flood storage pool: a volume of space in a reservoir reserved for storage of flood water 

floodwall: reinforced concrete walls that act as barriers against floodwaters thereby helping to protect 

floodprone area. Floodwalls are usually built in lieu of levees where the space between developed land 

and the floodway is limited. 

floodway: the channel of a river or other watercourse and the adjacent land areas that must be 

reserved to discharge the base flood without cumulatively increasing the water surface elevation more 

than a designated amount. The floodway is intended to carry deep and fast-moving water. 

flow diversion: a flow diversion allows the movement of floodwater from one area to another by 

means of an alternate route. A by-pass channel is an example of flow diversion. 

flowrate: rate of flow (discharge) at a specific location in a river or floodplain 

freeboard: a factor of safety usually expressed in feet above a flood level for purposes of designing 

flood protection facilities and for floodplain management. Freeboard tends to compensate for the many 

uncertain factors that could contribute to flood heights greater than the height calculated for a selected 

size flood and floodway conditions, such as wave action, bridge obstructions, and the hydrological 

effect of urbanization of the watershed. 

gated outlets: conduits, such as pipes or box culverts, in which mechanical gates are placed for the 

purpose of controlling the discharge 

geographic information system (GIS): a computerized system designed to collect, manage, and 

analyze large volumes of spatially referenced and associated attribute data 

greenway: a protected linear open-space area that is either landscaped or left in its natural condition. 

it may follow a natural feature of the landscape, such as a river or stream, or it may occur along an 

unused railway line or some other right of way 

high energy erosion zones: areas on the floodplain, such as the location of a former channel, that are 

subject to extensive scour and sediment transport during overbank flows 

hinge-control points: points in slackwater navigation pools where the water level is used as an index 

to establish gate settings at navigation dams for maintaining navigable depths 

hydraulics: the science dealing with the mechanical properties of liquids that describes the specific 

pattern and rate of water movement in the environment 

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hydrology: the science dealing with the properties, distribution, and circulation of water on and 

below the surface of the land and in the atmosphere 

improved flood forecasting/warning. reliable, accurate, and timely forecasts of floods and flood 

stages can be coupled with timely flood fighting and evacuation to save lives and reduce property 

losses. The Federal government has traditionally provided the leadership in developing and operating 

flood forecasting systems. The National Weather Service has the primary responsibility for 

forecasting on the Upper Mississippi River System, with support from the u.s. army corps of 

engineers. 

interjurisdictional fisheries: fish and shellfish resources whose habitat includes waters shared by 

two or more states 

land treatment measures: measures used to reduce runoff of water to streams or other areas; 

techniques include maintenance of trees, shrubbery, and vegetative cove~ terracing; slope stabilization 

grass waterways; contour plowing; and strip farming 

land use/construction regulation: reduce flood risks by using land use and construction regulations 

to control development in the floodplain 

levee: a linear earth embankment used to protect low-lying lands from flooding. a levee extends from 

high ground adjacent to a floodprone area along one side of a river to another point of high ground on 

the same side of the river. As options, existing levees could be raised in place, set-back, realigned, 

partially degraded or removed. Using the area behind a levee for floodwater storage to reduce the 

flood peak is another example of an option using levees. 

lock: a structure adjacent to a dam or in a canal to allow passage of vessels from one water level to 

another. The lock consists of a chamber with gates at either end, in which water is raised or lowered. 

Navigation lock and dams normally do not store flood water. 

lower Mississippi River basin: the portion of the Mississippi River basin that drains into the 

Mississippi River from its confluence with the Ohio River to the Gulf of Mexico. 

lower Mississippi River: the reach of the Mississippi River from the confluence of the Ohio River at 

Cairo, IL, to the Gulf of Mexico 

low profile berms to protect environmentally sensitive areas: an area protected by a low frequency 

(example a 10-year) embankment to protect the area from frequent, seasonal flood events that 

negatively affect the ecosystem management objectives of the area 

major disaster: any natural catastrophe or, regardless of cause, any tire, flood, or explosion in any 

part of the United States which, in the determination of the president causes damage of sufficient 

severity and magnitude to warrant major disaster assistance under the Robert T. Stafford Disaster 

Relief and Emergency Assistance Act. 

middle Mississippi River: the reach of the Mississippi River between its confluence with the 

Missouri River at St. Louis, MO, and its confluence with the Ohio River at Cairo, IL. 

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mitigation: any action taken to permanently eliminate m reduce the long-term risk to human life and 

property and the negative impacts on natural and cultural resources that can be caused by natural and 

technological hazards. 

mitigation lands: lands acquired to offset adverse impacts of water resource (or other) projects 

National Wetlands Inventory Project: wetlands mapping on a national basis performed by the U. S. 

Fish and Wildlife Service to provide scientific information on the extent and characteristics of the 

nation’s wetlands and consisting of detailed maps and status and trends reports. 

natural resources and functions of floodplains: include, but are not limited to, the following: 

natural flood and sediment storage and conveyance, water quality maintenance, groundwater recharge, 

biological productivity, fish and wildlife habitat, harvest of natural and agricultural products, 

recreation opportunities, and areas for scientific study and outdoor education 

navigation channel: the channel maintained in a body of water for the purpose of assuring a depth 

adequate for commercial vessels 

nonstructural measures: a term originally devised to distinguish techniques that modify 

susceptibility to flooding (such as watershed management, land use planning, regulation, floodplain 

acquisition, floodproofmg techniques and other construction practices, and flood warning) from the 

more traditional structural methods (such as dams, levees, and channels) used to control flooding 

one-percent chance annual flood: a flood of a magnitude that has a one-percent chance of being 

equaled or exceeded in any given year. Often referred to as the 100-year flood or base flood, the onepercent chance annual flood is the standard most commonly used for floodplain management and 

regulatory purposes in the united states. 

open river: the Mississippi River downstream of the last locks and dam located at Granite City, IL, in 

the St. Louis Metropolitan Area. This is immediately downstream of the confluence of the Missouri 

and Mississippi Rivers. The Mississippi River is free flowing with no locks and dams located further 

downstream needed to insure a nine-foot channel depth for navigation. 

permanent evacuation: permanent evacuation of developed areas subject to inundation involves the 

acquisition of lands by purchase, the removal of improvements, and the relocation of the population 

from such areas. Lands acquired in this manner could be used for unprotected agriculture, parks, or 

other purposes that would not interfere with flood flows or result in material damage from floods. 

permanent vegetation: perennial vegetation such as grasses, shrubs, and trees which provides cover 

to soil and prevent erosion. 

Principles and Standards/Principles And Guidelines: “The Principles and Standards for Planning 

of Water and Related Land Resources” is a presidential policy statement issued in September 1973 

that established a framework for improved planning for the use of water and related land resources 

baaed on the objectives of national economic development and environmental quality. the “principles 

and standards” were revised and issued in 1983 as the “economic and environmental principles and 

guidelines for water and related land resources for implementation studies. ” 

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Quad Cities: the metropolitan area comprised of the cities of Davenport and Bettendorf, IA, and 

Rock Island and Moline, IL 

recurrence interval: the average interval in which a flood of a given size is equaled or exceeded as 

an annual minimum 

regulatory floodplain: the area adjoining a river, stream, lake, or ocean that is inundated by a 

regulatory flood. I riverine areas the floodplain usually consists of a regulatory floodway and 

regulatory flood fringe (also referral to as a floodway fringe). in coastal areas the floodplain may 

consist of a single regulatory floodplain area or a regulatory high-hazard area and a regulatory lowhazard area. 

regulatory floodway: the area regulated by Federal, state, or local requirements to provide for the 

discharge of the base flood so the cumulative increase in water surface elevation is no more than a 

designated amount (not to exceed one foot as the minimum standard set by the national flood 

insurance program) 

relocation/acquisition/buy-outs: structures are removed from the floodplain most often using 

acquisition or buy-outs of the structure which reduces future flood risks 

repetitive loss: a flood-caused loss of more than $1,000 to a repetitive loss structure 

repetitive loss structure: a structure for which two or more losses of more than $1,000 (building and 

contents combined) have been paid since 1978 

riparian ecosystems: distinct associations of soil, flora, and fauna occurring along a river, stream, or 

other body of water and dependent for survival on high water tables and occasional flooding 

riparian vegetation: hydrophytic vegetation growing in the immediate vicinity of a lake or river 

riparian zone: the border or banks of a stream. Although this term is sometimes used 

interchangeably with floodplain, the riparian zone is generally regarded as relatively narrow compared 

to a floodplain. The area is typically subject to frequent, short duration flooding. 

risk: the probability of being flooded 

rock closing dams: in reaches of rivers where multiple channels are formed by islands, rock dikes 

that span the side channel, generally where it departs from the main channel, are called rock closing 

dams. They serve to direct flow to the main channel. 

scour hole: erosional holes developed as a result of breached levees. Locally called blow, blew, or 

blue holes. 

scour: process of eroding surface soil by flowing water which results in gullies in the landscape. 

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Section 409 Hazard Mitigation Plan: a plan prepared as required by section 409 of the Robert T. 

Stafford Disaster Relief and Emergency Assistance Act of 1988 by any jurisdiction that receives 

Federal disaster assistance. 

sediment and debris basin: retention structure constructed on or adjacent to a watercourse to store 

sediment and debris 

side channel: a stream or channel to the side of the major channel or stream. 

slackwater navigation dam: a dam placed across a river for the purpose of creating water depth 

sufficient for navigation. The term slackwater refers to the relatively low velocity in the navigation 

pool compared to an open river. 

slough: a swamp, march, bog or pond as part of a bayou, inlet or backwater 

spillway: a feature of a dam allowing excess water to pass without overtopping the dam. Usually a 

spillway functions only in a large flood. 

stage: the height of the water surface in a river or other body of water measured above an arbitrary 

datum, usually at or near the river bottom 

standard project flood: a very large (low frequency) design flood standard applied to the design of 

major flood control structures and representing the most severe recombination of meteorological and 

hydrological conditions considered reasonably characteristic of a particular region 

strip cropping: growing crops in a systematic arrangement of strips or bands along a contour 

structural measures: measures such as dams, reservoirs, dikes, levees, floodwalls, channel 

alteration, high-flow diversions, spillways, and land-treatment measures designed to modify floods 

substantial improvement: any repair, reconstruction, or improvements of a structure, the cost of 

which equals or exceeds 50 percent of the market value of the structure either before the improvement 

or repair is started or if the structure has been damaged and is being restored, before the damage 

occurred 

substantial damage: the amount of damage to a structure caused by flooding that may be sustained 

before certain regulatory and flood insurance requirements are triggered. As defined in NFIP 

regulation, a building is considered substantially damaged when the cost of restoring the building 

would exceed 50 percent of the market value of the structure. 

tailwater: the reach of stream or river located immediately below a water control structure such as a 

dam. In contrast, headwater is the term applied to the pool immediately above a dam. 

terrace: a raised bank of earth having vertical m sloping sides and a flat top used to control surface 

runoff 

timed use of off-channel (behind levee) storage: critical usage of “off channel storage” was 

considered when the elevation of the storage areas was overtopped. The critical overtopping 

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elevations of these units were adjusted up and down to determine a reasonable optimum condition 

during the alternative analysis. It is hard to predict when to use “off channel storage” but the approach 

that was used considered a range of possibilities over the frequency curves. 

unconfined: unconfined for the Comprehensive Plan means allowing no more than a one foot water 

surface profile rise. The river is no longer confined between the levees or levee and bluff. With a one 

foot rise, the analysis lets river flows overtop leveed areas to insure no more than the one foot water 

surface profile rise.

upper Mississippi River basin: the portion of the Mississippi River basin that is above the 

confluence of the Ohio River. it includes the Missouri River basin. 

upper Mississippi River: the reach of the Mississippi River from its confluence with the Missouri 

River at St. Louis, MO, upstream to its headwaters at outlet of lake Itasca in Minnesota. 

watershed: a region or area contributing ultimately to the water supply of a particular watercourse or 

water body 

wetlands: those areas that are inundated by surface or groundwater with a frequency sufficient to 

support and, under normal circumstances, does or would support a prevalence’ of vegetative or aquatic 

life that requires saturated or seasonally saturated soil conditions for growth and reproduction. 

Wetlands generally include bottomland hardwoods, swamps, marshes, bogs, and similar areas such as 

sloughs, potholes, wet meadows, river overflow, mud flats, and natural ponds. 

wetlands restoration: the restoration and/or creation of wetlands in the floodplain to provide 

floodwater storage which may have an impact to frequent, smaller flood events. Numerous 

environmental opportunities are available in these areas. 

wing dikes: rock wing dikes or darns, closing dams, wood pile dikes, and bendway weirs are types of 

channel training structures used to divert river flows toward a single main channel used for navigation. 

Generally constructed perpendicular to flow, and constructed to various submergent of emergent 

elevations, these structures usually function most effectively at lower flows.