§2318 Flood Plain Management

Summary

The Secretary must leave out some buildings and floodplain changes when adding up the benefits that justify Federal flood control projects. New or greatly rebuilt buildings put in the 100-year floodplain after July 1, 1991, whose first floor is below the 100-year flood level (unless the building is needed for water activities), cannot be counted. In counties that are mostly in the 100-year floodplain, the same rule applies for buildings put in the 10-year floodplain after July 1, 1991. The Secretary also must exclude buildings that end up in those floodplains because someone added a constriction after July 1, 1991. For nonstructural flood projects, benefits must be calculated like for structural projects and must avoid double counting. By January 1, 1992, the Secretary must report to Congress about raising the non‑Federal share of costs in areas where new buildings or constrictions were added after the community joined the National Flood Insurance Program. The Secretary must issue rules, with FEMA, within 6 months after that report and define key terms. Projects with a final Chief of Engineers report sent to the Secretary before the end of that 6‑month rule period, but no later than July 1, 1993, are not covered. Defined terms: new or substantially improved structure — a building newly built or largely rebuilt; constriction — something that narrows or blocks the floodplain; 10‑year floodplain — area with a 1-in-10 chance of flooding each year; 100‑year floodplain — area with a 1-in-100 chance of flooding each year.