The committee also recommended that each levee be individually evaluated, hydrologically and structurally, and that FEMA should inventory all levees previously credited as providing protection from the one percent annual chance flood, set priorities, and schedule communities for restudy to reevaluate the levees.
As a follow-up to the NRC report and other internal actions, in 1983 FEMA initiated a system to maintain an inventory of levees, by community name, that were accredited as providing 100-year protection on NFIP maps. In 1985, FEMA issued regulations prescribing the criteria for levee recognition by the NFIP but did not reevaluate existing levees, alter the required level of protection, or move on other nonengineering recommendations (Galloway et al., 2006). The regulations were codified as Title 44, Section 65.10, of the Code of Federal Regulations (44 CFR §65.10; see Appendix A for the text of this section) and established that to be recognized as removing an area from floodplain regulation and mandatory purchase requirements in the NFIP, a levee must provide protection at the 100-year or higher level plus a specified level of freeboard; must meet engineering design standards similar to those used by the USACE; and must be properly maintained and operated under the control of a government entity. The regulations also require that a professional engineer certify the data submitted to support a given levee system’s compliance with the structural requirements set forth in the regulation and must submit certified as-built plans of the levee. Where appropriate, a federal agency with responsibility for levee design may certify that the levee has been adequately designed and constructed to provide protection against the base flood. No provisions were made to reduce the rates for those behind levees providing less than one percent annual chance flood protection or to conduct periodic inspections, and 44 CFR §65.10 has remained unchanged since 1985.
Interagency Floodplain Management Review Committee
From April to October of 1993, the Mississippi and Missouri rivers and their tributaries inundated the surrounding floodplain, causing one of the costliest and most devastating floods in U.S. history. The flood of 1993 brought new attention to the condition of levees both within and outside of the NFIP. In 1994, a White House—based committee studying the 1993 flood reported that activities in floodplains of the United States, even with levee protection, remain at risk, finding that during the Mississippi-Missouri river floods:
• Many locally constructed levees breached and/or overtopped. Frequently, these events resulted in considerable damage to the land behind the levees through scour and deposition [of material from the river channel and the levee itself];
• Levees can cause problems in some critical reaches by backing water up on other levees or lowlands;
• The current flood damage reduction system in the upper Mississippi River Basin represents a loose aggregation of Federal, local, and individual levees and reservoirs;
• Many levees are poorly sited and [as a result] will fail again in the future. (IFMRC, 1994)
The White House study committee also indicated that the SPF flood should be the target flood for population centers and critical facilities protected by levees and that the government should require those behind levees who provide protection against less than the SPF discharge to purchase actuarially based insurance. It also found that federal agencies should ensure proper siting, construction, and maintenance of nonfederal levees. No action was taken by either Congress or the administration on these recommendations.
As a result of pressure from communities and professional organizations to improve the quality of flood mapping, the President proposed and the Congress, in 2003, authorized FEMA to undertake a 5-year billion-dollar program to modernize its maps by converting existing paper maps to a digital format and in the process, and where possible, provide new engineering analysis. As work began in 2004 on map modernization or “Map Mod,” FEMA representatives became concerned that many of the levees encountered in the mapping process might not, under review, meet the standards of 44 CFR §65.10 and, as a result formed a committee to examine the issue. In April 2005, a small internal Interim Levee Coordination Committee reported that treatment of levees in Map Mod across FEMA regions was inconsistent and that guidance should be issued immediately to ensure that appropriate