The Federal Emergency Management Agency’s (FEMA) Federal Insurance and Mitigation Administration manages the National Flood Insurance Program (NFIP), which is a cornerstone in the U.S. strategy to assist communities to prepare for, mitigate against, and recover from flood disasters. The NFIP was established by the Congress with passage of the National Flood Insurance Act in 1968, to help reduce future flood damages through NFIP community floodplain regulation that would control development in flood hazard areas, provide insurance for a premium to property owners, and reduce federal expenditures for disaster assistance. The flood insurance is available only to owners of insurable property located in communities that participate in the NFIP.1 Currently, the program has 5,555,915 policies2 in 21,881 communities3 across the United States.
The NFIP defines the one percent annual chance flood (100-year or base flood) floodplain as a Special Flood Hazard Area (SFHA).4 The SFHA is delineated on FEMA’s Flood Insurance Rate Maps (FIRMs) using topographic, meteorologic, hydrologic, and hydraulic information. Property owners with a federally backed mortgage within the SFHAs are required to purchase and retain flood insurance, called the mandatory purchase requirement (MPR).
Levees and floodwalls, hereafter referred to as levees, have been part of flood management in the United States since the late 1700s because they are relatively easy to build and a reasonable infrastructure investment. A levee is a “man-made structure, usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding.”5 A levee system is a “flood protection system which consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accordance with sound engineering practices.”6 Under NFIP regulations, homes and commercial buildings located in the SFHA within a participating community may be exempted from the MPR and land-use regulations when located behind a levee system that has been recognized by FEMA as providing protection against the one percent annual chance flood
1 The NFIP primarily insures residential properties (single- and multifamily homes) but does insure a smaller number of commercial properties.
2 As of December 2012.
3 As of June 2012.
4 One percent annual chance flood, base flood, and the 100-year flood are terms commonly used to describe a hydrologic event that has a 100-year (average) recurrence interval. That is, a flood that has in any year a 1 in 100 chance of being equaled or exceeded.
5 See Code of Federal Regulations, Title 44, Section 59.1 (44 CFR §59.1).
6 See 44 CFR §59.1.
event, that is, “accredited.” Certification is the technical evidence provided by a levee owner to FEMA demonstrating that the levee system meets the requirements to reduce risk from at least the one percent annual chance flood.7
Recognizing the need for improving the NFIP’s treatment of levees, FEMA officials approached the National Research Council’s (NRC) Water Science and Technology Board and requested this study. The NRC responded by forming the ad hoc Committee on Levee and the National Flood Insurance Program: Improving Policies and Practices, charged to examine current FEMA treatment of levees within the NFIP and provide advice on how those levee-related policies and activities could be improved. The study addressed four broad areas—risk analysis, flood insurance, risk reduction, and risk communication—regarding how levees are considered in the NFIP. Specific issues within these areas include current risk analysis and mapping procedures behind accredited and nonaccredited levees, flood insurance pricing and the MPR, mitigation options to reduce risk for communities with levees, flood risk communication efforts, and the concept of shared responsibility. For the full statement of task, see Chapter 1, Box 1-4. The report’s principal conclusions and recommendations are highlighted in bold in this Summary.
TREATMENT OF LEVEES WITHIN THE NATIONAL FLOOD INSURANCE PROGRAM
After the establishment of the NFIP, efforts to identify the nation’s flood hazard began. Because many flood protection works, mostly levees, had, in the past, successfully passed what had been considered a one percent annual chance flood, both local communities and contractors raised the issue of excluding areas protected by a one percent annual chance or greater structure from the SFHA. As a result, areas behind levees were not labeled on early flood maps as being within the SFHA where levees had provided or were thought to have provided protection from the one percent annual chance flood or had been constructed by U.S. Army Corps of Engineers (USACE) to withstand the one percent or higher annual chance flood.
As the program evolved, levees were required to be certified and accredited in order for the areas behind them to be mapped out of the SFHA. When a levee in a community provides less than 1 percent protection, it is not shown on a FIRM as providing protection and the flood risk is assessed as if the levee does not exist. Not recognizing levees that are not accredited on FIRMs is referred to in this report as a “without levee” analysis. An all-or-nothing approach, this either gives communities credit for a one percent annual chance levee (through exclusion from the SFHA and exemption from the MPR, etc.) or does not; that is, a levee that is not accredited is not recognized on the FIRM.
In 2003, with the support of communities and organizations to improve the quality of flood mapping, FEMA moved forward with a program to modernize maps by converting to a digital format and, when possible, providing a new engineering analysis. During “Map Mod,” FEMA officials became concerned that the levees encountered in this process might not meet the one percent annual chance standard despite being labeled as such. Affected communities, faced with the potential movement of the previously exempt areas into the floodplain and the mandatory requirement to purchase flood insurance at rates that might be the same as areas without protection, argued that some credit should be given to the presence of the deficient levees (i.e., some protection less than the one percent annual chance flood). Members of the Congress urged FEMA to discontinue use of the without-levee analysis in updating FIRMs. In agreement, FEMA is currently developing a new approach, the Levee Analysis and Mapping Procedure (LAMP), to replace the without-levee approach.
MOVING TO FLOOD RISK MANAGEMENT AND A MODERN RISK ANALYSIS
Flood risk management represents efforts to continuously carry out analyses, assessments, and related mitigation implementation activities to reduce flood risk. It focuses on assessment of flood hazards, the consequences resulting from flooding, the significance of risks identified, and the development of risk management strategies to deal with flood risk, which is gaining momentum across the global floodplain management community. Effective flood risk management requires use of the best available science in its execution. A flood risk analysis is that
7 Certification may be accomplished by a registered professional engineer or a federal agency with levee responsibilities.
analytical part of flood risk management that provides information about or quantifies consequences and probabilities of a flood event.
The current NFIP flood hazard analysis is a partial risk-based analysis used with respect to performance of levee systems, where many parts of the analysis are deterministic in fashion. A levee system that is not accredited is not considered in the analysis used to quantify flood risk, even though it provides some (potentially considerable) protection against floods. This encourages communities to construct levee systems that protect only to the one percent annual exceedance flood, enabling new development in areas with significant, but unquantified exposure to catastrophic flood risk. Thus, protection against the one percent annual chance flood event is the de facto design standard for most levees seeking accreditation in the United States, with limited attention given to the consequences (“residual risk”) should a levee fail or be overtopped. Furthermore, levee systems that only marginally meet certification standards are vulnerable to loss of accreditation status. If not properly maintained, the performance of levee systems degrades over time due to erosion, rodent damage, subsidence, and other factors. Further, the frequency and magnitude of flood hazards can increase over time due to natural and anthropogenic causes. Loss of accreditation status can be very disruptive to the affected communities in terms of safety and insurance cost.
Thus, the current NFIP approach to flood hazard analyses leads to an incomplete description of the flood hazard in many areas. This is not unknown to FEMA or relevant stakeholders, including policy makers. A more modern approach to flood risk analysis addresses problematic aspects of the without-levee analysis.8 The elements of a modern risk-based approach include:
• flood hazard analysis or an estimate of the frequency and magnitude of flooding;
• levee and other system component fragility analysis, which estimates structure performance as a function of flood levels;
• systems analysis, which includes all features that impact flooding along a levee system;
• levee breach and inundation assessment; and
• consequence analysis that estimates the damage to structures that are inundated in a flood event.
All elements of this analysis are subject to uncertainty; the evaluation of these uncertainties is also integral to a modern risk analysis.
The modern risk-based analysis offers several advantages. It would provide an in-depth technical evaluation of flood hazards and directly account for the performance of levee flood protection systems whether accredited within the NFIP or located within an NFIP community. It would account for all features of the flood protection system (levees, gates, other structures) that significantly affect flood risk, as long as they meet minimum design, operation, and maintenance standards. Hence credit could be given for establishing flood insurance rates for flood protection systems that do not protect to the one percent annual chance standard, but at the same time provide some level of protection. In other words, the modern risk-based approach acknowledges that risk across a floodplain varies across the landscape. It has the impact of softening, but not eliminating, the one percent annual chance decision line.
Also, a risk-based approach would estimate flood risk for lands protected by levee systems that do protect to the one percent annual chance standard or higher. In these circumstances, the risk analysis results would inform communities of the flood protection system limitations and potential vulnerabilities, the actual flood risk being faced, and inform flood insurance ratings. Risk analysis results would also differentiate between protection provided by one percent annual chance levees and 0.2 percent levees. It would be able to recognize difference between low areas behind levees and higher ground. It would also provide guidance to the communities for development of new regulations that would encourage floodplain management. The NFIP should move to a modern risk analysis that makes use of modern methods and computational mapping capacity to produce state-of-the-art risk estimates for all areas that are vulnerable to flooding.
8 In this report the term “modern” is used to indicate characterization and analysis of risk using the best science available to the risk management field.
Levee Analysis and Mapping Procedure
The LAMP approach is based on sound algorithms and is a reasonable first cut at dealing with the potential contributions of levees that do not meet the standards for protection against the one percent annual chance flood. LAMP represents a response to the issues raised by members of Congress that, given funding and personnel constraints, will likely take several years to fully implement. However, it represents a diversion from the need to move the NFIP to a modern risk-based analysis. Because it would be highly unlikely for the NFIP to move forward concurrently with implementation of LAMP and development of a modern risk-based approach, a move to LAMP would simply postpone the inevitable need to move the NFIP to the risk-based foundation that other agencies and nations have already endorsed. FEMA should move directly to a modern risk-based analysis for dealing with areas behind levees and not implement the Levee Analysis and Mapping Procedure (LAMP). Should a decision be made not to implement LAMP, dealing with the current situation is still necessary; interim steps are proposed in Chapter 4 of the report.
INSURING PROPERTIES BEHIND LEVEES
Flood insurance is an essential part of the NFIP used to address catastrophic loss potential from floods. It provides a method for prefunding (usually over time) the adverse consequences of potential flood losses. FEMA evaluates the flood risk of policyholders and determines rates for the “full-risk” class through a balance of factors including the extent and type of flood hazard, the base elevation of the insured structure and the structure type,9 the contents location (first floor, second flood, etc.), and whether or not the community participates in the Community Rating System (CRS)10 that provides discounts for communities that actively manage their flood risk.
The notion of actuarial soundness in the context of the NFIP is somewhat subtle and elusive because of the differences between a government-run program with mandated discounts, no profit requirement, no significant interest income, and reliable, significant borrowing power and the private sector from which the notions of actuarial soundness arose and are routinely applied. The major structural drawback to the fiscal soundness of the NFIP is not actuarial unsoundness due to inappropriate or inadequate rate-setting methodology or inadequacies, but rather the fiscal unsoundness caused by not being able to apply actuarial principles uniformly across all classes. The NFIP mandated “discounted risk” class was anticipated to eventually decrease substantially over time, and this has indeed been the case.11 Still, there are a substantial number of discounted policies in the NFIP. The difference between the full-risk premium for a discounted policy and the discounted premium for the policy is revenue lost to the NFIP (this lost revenue is not compensated for in any other part of the premium structure). FEMA is legally unable to raise premiums in a manner sufficient to allow the NFIP to be financially sound or to build a contingency reserve fund sufficient to pay for a catastrophic future loss. Without this ability, the NFIP is destined by law not by actuarial methodology inadequacy to run short of money in the long run, with occasional dramatic shortfalls. Furthermore, repetitive loss properties continue to drain the fiscal soundness of the NFIP. The NFIP is constructed using an actuarially sound formulaic approach for the full-risk classes of policies, but is financially unsound in the aggregate because of constraints (i.e., legislative mandates) that go beyond actuarial considerations. The Biggert-Waters Flood Insurance Reform Act directs adjustment of fiscal practices to move the NFIP to a more fiscally sound approach.
Risk-based insurance pricing is key to efficient and equitable financial transfer of the risk. With a modern
9 Condominium, single- or multifamily home, residential or commercial use, number of floors, with or without a basement, ventilated crawlspace, etc.
10 FEMA’s Community Rating System (CRS) is a voluntary incentive program that encourages floodplain management activities exceeding the minimum NFIP requirements.
11 The discounted risk class applies when (1) a structure was built before the flood insurance maps were available, that is, a “pre-FIRM” structure or built before December 31, 1974; (2) a structure was built in a V zone before 1981 and before maps that consider wave height were adopted in setting flood insurance rates; (3) a structure is in an AR or A99 zone for levees in the course of reconstruction or construction (and so their current actuarial risk does not correspond to their current risk charge); or (4) the policyholder participates in a group flood insurance policy. Currently, approximately 20 percent of NFIP policies are discounted policies.
risk-based analysis, a gradation of probabilities that can differ from property to property even within the same geographic area or flood zone can be applied. Rate setting for properties behind levees, accredited or not accredited, should be improved by using a modern risk analysis method employing advances in hydrology, meteorology, and geotechnical engineering to more precisely calculate the probability of water inundation levels and the associated damage estimates throughout the area behind the levee in a graduated fashion. This will replace the current approach and more appropriately reflect the risk.
The Mandatory Purchase Requirement
When the NFIP was established, property owners could purchase insurance voluntarily. In 1973, given the limited voluntary purchase that had taken place to that date, the mandatory purchase requirement (MPR) was implemented to ensure that the exposure of the federal government through mortgages on properties within the SFHA was covered by insurance, thus decreasing the financial burden on the federal government for uninsured losses. Although the MPR applies to properties within the SFHA that hold a federally backed mortgage, apart from those behind accredited levees, the NFIP encourages all those living in areas subject to flooding to purchase insurance.
The effectiveness of the MPR can be explored by examining the percentage of those living within the SFHA who have insurance (i.e., market penetration) and the percentage of those living within the SFHA with a federally backed mortgage who have insurance (i.e., MPR compliance). Review of studies indicate that national market penetration in the SFHA is between 30 and 50 percent and national MPR compliance is between 50 and 78 percent. The more recent and more detailed information indicates that penetration and compliance are likely closer to the lower values in both ranges.
The development of market penetration and compliance estimates are confounded by several factors including varied structure type across assessment (single-family homes versus all residential structures), whether or not the structure owner carries a mortgage, and whether or not the structure is insured with a federal lender. Regardless, national market penetration and compliance studies call into question the efficacy of the MPR. The current policy of mandatory flood insurance purchase appears to be ineffective in achieving widespread purchase of NFIP flood insurance policies. To date, relying on federal supervisory agencies to oversee and lenders to require purchase has not achieved widespread compliance with the MPR. Extending the MPR to areas behind levees where there are large numbers of structures, incomplete determination of flood risk, and varied evidence supporting its effectiveness is imprudent. At this time, there is no sound reason to institute mandatory purchase of flood insurance in areas behind accredited levees.
A perception exists that if the NFIP simply sold more policies, the program’s fiscal issues (e.g., debt to the U.S. Treasury) would be solved. However, simply adding new policies does not automatically improve the program’s fiscal soundness. Adding new polices could lower the program’s overall risk if the policies increased the program’s diversification of risk acquired through those policies. However, adding new policies very well may increase the NFIP’s overall risk through concentration of policies in, for example, high-risk areas such as the SFHA. Furthermore, adding new policies would also increase the program’s exposure to risk accumulation, or the additive risk of multiple events occurring at the same time. If NFIP policies continue to be concentrated in the same high-risk areas around the country, the diversification of risk and the fiscal soundness of the program will remain relatively unchanged.
Upon implementation of a modern risk analysis, insurance rates will more accurately reflect flood risk behind a levee. If the insurance rate goes up, it indicates that the property is at more peril than previously understood to be; if the insurance rate goes down, it indicates the property is at less peril than previously understood to be. Thus, FEMA’s moving to a modern risk-based analysis and pricing premiums accordingly will have an impact on NFIP policy purchase. (The Biggert-Waters Flood Insurance Reform Act directs full, risk-based premiums and elimination of certain discounts, also promoting a change to the NFIP that affects policy purchase.) More accurate pricing and more information created by a modern risk analysis has the potential to prompt additional policy purchase. Property owners would be more favorably inclined to buy flood insurance if individual risk is well known and understood and insurance rates are priced to match the probability of flooding and financial impact of flooding events. This includes areas behind levees, both accredited and not accredited, in the SFHA at large, and also non-
SFHA areas. It is likely that if a lender has more information through a risk-based analysis, the lender is more aware that requiring flood insurance purchase is in line with its fiduciary responsibility. However, this premise is challenged by nuances in risk communication principles, specifically, that awareness does not necessarily lead to actions to mitigate risk.
As the use of risk-based pricing becomes widespread, the thinking behind the necessity of the MPR in the SFHA may change, along with the decision of waiving the MPR behind an accredited levee. A modern risk-based analysis has the potential to impact the purchase of flood insurance, diversify the NFIP’s exposure to flood risk, and generate a fiscally sounder program. Once the risk-based approach has been put in place and matures, FEMA should review and study the necessity of the mandatory purchase requirement behind levees and throughout the SFHA.
IMPLEMENTING FLOOD RISK MANAGEMENT STRATEGIES
There is some level of risk to all locations within the floodplain. The magnitude of that risk is a function of the flood hazard, the characteristics of a particular location (e.g., elevation, proximity to the river or coast, and susceptibility to fast-moving flows and surges), measures that have been taken to mitigate the potential impact of flooding, the vulnerability of people and property, and the consequences that result from a particular flood event. The initial risk to an area is represented by the area’s characteristics without consideration of mitigation and risk transfer measures and the vulnerability of the population. Mitigation and risk transfer measures reduce the overall risk to some degree, but it is impossible to completely eliminate risk, resulting in residual risk.
A flood risk management strategy identifies and implements measures that reduce the overall risk. Available measures include structural (levees, dams, pumps, etc.), nonstructural (elevation, relocation, etc.), and risk transfer methods, that is, insurance. In developing a flood risk management strategy, those responsible judge the costs and benefits of each measure taken and its overall impact in reducing the risk. Levees represent one method of reducing the impacts of flooding on a community or a region.
There are varied circumstances that dictate flood risk behind levees. These circumstances can include anything from proximity to the coast, local climate, population growth, existing infrastructure, to community preparedness. Some risk scenarios are associated with long time horizons, such as flooding associated with climate change, and might be less perceptible to the at-risk community compared with, for example, a design deficiency in a levee discovered during the Map Mod process. The importance of climate change and population growth is further highlighted when considering the future impact on the size of the nation’s floodplain, both geographically and in terms of population, and the corresponding number of insurance policies needed in the floodplain.12 Complicated scenarios arise as communities grapple with unique situations. A mix of flood management mitigation and risk transfer measures tailored to the risk of a particular community is the most effective flood risk reduction strategy. There is a clear need for a comprehensive, tailored approach to flood risk management behind levees that (1) is designed and implemented at the local level; (2) involves federal and state agencies, communities, and households; (3) takes into account possible future conditions; and (4) relies on an effective portfolio of structural measures, nonstructural measures, and insurance to reduce the risk to those behind levees.
To reduce the flood risk to those behind levees, FEMA should encourage communities to develop and implement multimeasure risk management strategies for areas behind accredited levees. This strategy would contemplate the full range of foreseeable flood scenarios involving levee overtopping or failure and future conditions. The development of new risk management analysis tools will facilitate the identification of risks and suggest feasible approaches to dealing with the risks to those behind levees.
Development and maintenance of supporting policies affecting the portfolio of mitigation measures are both critical and effective floodplain management strategies. In the case of levees, the principal regulatory document that establishes the procedures for inclusion of levees in the program is Title 44 of the Code of Federal Regulations, which contains several parts pertaining to levees in the NFIP. There is a need for revisions to this document that address the handling of embankments (i.e., railroads or existing roads) in a levee system, provide a unique
12 Hydrologic nonstationarity associated with environmental change makes these uncertainties even more complex.
designation for areas behind accredited levees on FIRMs, require actions to verify to FEMA that an accredited levee maintains integrity, and expand requirements for maintenance to ensure the carrying capacity of the river channel.
A modern risk analysis and effective flood management strategy options require knowledge of the location, condition, and ownership of levees. Currently, the majority of the knowledge of the extent of levees in the United States is at the federal level. The USACE’s National Levee Database (NLD) is the biggest single resource for levee data in the United States and currently includes more than 2,500 levees and associated structures (also known as levee systems) totaling more than 14,500 miles in length, catalogued in digital format. The FEMA Mid-Term Levee Inventory (MLI) database, designed to complement the NLD, contains data on 5,100 miles of NFIP-accredited levees and an additional 24,700 miles of other levees identified by FEMA.
There is currently no method to determine whether a levee in the NLD is also in the FEMA MLI except through a one-to-one comparison of certain levee characteristics. Because some data elements in the two inventories are different, USACE and FEMA have been attempting to manually look for overlaps, but have yet to complete the effort. A preliminary analysis by both agencies indicates that approximately 3,400 miles of levees, or 66 percent, may be operating under oversight of both agencies. There is a reasonable understanding of the number of federally owned and operated levees in the country, although opportunities for improvement exist. Efforts to inventory levees at the state level vary widely, with the majority of the states not having levee inventories. The definition of what constitutes a levee also varies widely in inventory efforts, ranging from structures built under federal and state supervision to other structures, such as embankments, highways, railroads, irrigation water and supply canals, that work to reduce flooding. A comprehensive inventory of the nation’s levees, along with a consistent definition of a levee, is needed to ensure public safety and develop appropriate floodplain management strategies. The states have an important role in inventorying the number of levees within their respective borders. This information can then be combined with a federal inventory to create an accurate assessment and inventory of the nation’s levees.
Development of appropriate strategies for risk communication is part of the overarching formulation of flood risk management strategies. Challenges associated with the public perception of flood risk need to be considered when developing risk communication strategies, including:
• The meaning of the 100-year floodplain and, to a lesser degree, the one percent annual chance flood is often misunderstood.
• Awareness of risk does not always lead to actions to reduce or mitigate risk.
• People assume that flood control structures are “safe,” with no need to take additional actions to mitigate risk.
• Experience with floods matters and influences the actions that residents and communities take to mitigate the impacts.
• People will seek advice from friends, family, and neighbors on the determination of risk and actions to reduce flood risk.
• Personalizing risk on the basis of the experience and feelings is more likely to motivate behavioral action than simply providing technical information about risks and consequences.
Communicating the concept of residual risk behind a levee presents an additional challenge. Furthermore, the variety of levee-related stakeholders, including several federal agencies with different roles and responsibilities who are sources and recipients of risk information, adds additional complexity. So, rather than one entity confronted with the challenge of communicating risk to the public, levee-related flood risk communication efforts face the challenge of presenting unified, effective communication among all the governmental agencies, as well as between agencies and the public.
Historically, there has been little information about hazards associated with levees available to local communities, other than Flood Hazard Boundary Maps and FIRMs that reflect only the flood hazard area (the area flooded by the one percent annual chance event). However, this is changing with continued efforts to communicate flood
risk behind levees, largely with nonregulatory products.13 To be effective, risk communication efforts need to be anchored in several principles:
• delivered at the local level;
• tailored to individual households, communities, and other stakeholders;
• delivered from a credible and trusted source;
• long term;
• have consistent, correct, and nonconflicting content;
• encourage or motivate some behavior;
• account for the values of target audiences or communities;
• employ multimodal networks; and
• provide repeat messaging.
FEMA and others involved in risk communication at all levels should incorporate contemporary risk communication principles in the development of flood risk communication strategies and implementation efforts.
It appears that risk communication efforts surrounding NFIP levees have an advantageous window of attention during three situations: (1) after a flood disaster, (2) through the mapping programs, and (3) when a community participates in FEMA’s CRS program. It also appears that during these three situations, in particular situations 1 and 2, considerable confusion and controversy or considerable success in communicating risk can occur. FEMA should communicate flood risk through a collaborative approach that works with and provides strong support to local communities.
SHARED RESPONSIBILITY IN MOVING TO FLOOD RISK MANAGEMENT
Several federal agencies, state and local governments, and other stakeholders play important roles in managing the nation’s flood risk. Federal roles are dictated by their legislated authorities and presidential guidance. As such, coordination challenges exist. Collaborative and coordinated efforts that share responsibility for levee-related flood risk across the federal, state, and local levels are not as robust as they could be. Increased coordination and cooperation among and between governmental agencies, state and local entities, and the public at large would result in increased effectiveness of and improved efficiency within the NFIP, and would improve the nation’s approach to floodplain management and treatment of levees. Promising developments do exist, but more progress is necessary. A coordinated, national approach that shares responsibility across federal, state, and local entities is necessary to appropriately manage the nation’s flood risk behind levees.
FEMA and USACE are challenged by different approaches to risk analysis. The technical and programmatic differences between FEMA and USACE as they relate to the evaluation of flood hazards and levee systems have been and continue to be an issue that compromises interagency communication and causes confusion and frustration in the local communities that work with the agencies and in the public that is being served. FEMA and USACE should jointly develop a common, risk-based approach to levee assessment in a timely manner and apply this approach to all levees assessed by the two agencies. This includes a joint methodology, procedure, and where feasible, the sharing of models and other risk analysis tools.
The utility of levee-related flood risk communication developed and communicated at the federal level is challenged by uncoordinated messaging. One federal message using consistent terminology, transparent data, and open discussion and decisions about the determination of flood risk is critical to inform the affected communities who, in turn, communicate and manage risk at the local level. FEMA should assume a leadership role in providing direction for research, development, and release of flood risk communication products and maps.
13 The committee interprets regulatory flood risk communication products as FIRMs and nonregulatory products as all other FEMA products that communicate leveerelated flood risk.
This report provides advice on the current treatment of levees within the NFIP. Key to this advice is the transition of FEMA to a flood risk management approach and the use of a modern, risk-based analysis of flood risk. This transition will, no doubt, be challenging. New or revised regulations, procedures, and training systems will need to be established, and clear, consistent messaging to those affected by the new approaches is critical. A modern risk analysis will bring about changes in insurance ratings and modify current perceptions of risk. Communicating flood risk in general and flood risk behind levees will require close collaboration among all levels of government and within governmental agencies. There are currently legal challenges and more will most likely arise. The appropriate balance between public and private investment will continually be considered. Despite these challenges, the advice in this report is provided to move FEMA’s NFIP toward floodplain management anchored in a modern risk-based analysis, a move that is increasingly recognized as imperative in the floodplain management community.