Section 5: FEMA Policy and Procedure
Anchor: #i1002526National Flood Insurance Program
The amended National Flood Insurance Act of 1968 (42 U.S.C. 4001 et seq.) established the National Flood Insurance Program (NFIP), which requires communities--whether city, county, or state--to adopt adequate land use and control measures to qualify for flood insurance in riverine flood-prone areas.
When the Administrator of the Federal Insurance Administration has identified the flood-prone area, the community must require that, until a floodway has been designated, no use, including land fill, be permitted within the floodplain area having special flood hazards for which base flood elevations have been provided unless it is demonstrated that the cumulative effect of the proposed use, when combined with all other existing and reasonably anticipated uses of a similar nature, will not increase the water surface elevation of the 100-year flood more than 1 ft. (0.3 m) at any point within the community.
After the floodplain area has been identified and the water surface elevation for the 100-year flood and floodway data have been provided, the community may designate a floodway that will convey the 100-year flood without increasing the water surface elevation of the flood more than 1 ft. (0.3 m) at any point. Also, the community must prohibit, within the designated floodway, fill, encroachments, and new construction and substantial improvements of existing structures that would result in any increase in flood heights within the community during the occurrence of the 100-year flood discharge.
The participating cities or counties agree to regulate new development in the designated floodplain and floodway through regulations adopted in a floodplain ordinance. The ordinance should require that development in the designated floodplain be consistent with the intent, standards and criteria set by the NFIP. Failure on their behalf to enforce basic requirements can result in losing their status in the program.
The highway designer needs to be familiar with FEMA NFIP requirements because meeting them may either control the design of a facility within a floodplain or, when encroachments (any physical object placed in a floodplain that hinders flow) are proposed, necessitate considerable analysis, coordination, and expense to acquire FEMA approval of the project. Incorporate considerations concerning FEMA rules and procedures early in the project planning stages. (See Task 2200and Task 5080 of the Project Development Process Manual for more information.)
Determining the status of a community’s participation in NFIP and reviewing applicable NFIP maps and ordinances are essential first steps in conducting location hydraulic studies and preparing environmental documents. Information of community participation in NFIP is provided in the National Flood Insurance Program Status of Participating Counties, published semi-annually for each state, and available through Federal Emergency Management Agency (FEMA) headquarters and the Texas Natural Resources and Conservation Commission (TNRCC).
Anchor: #i1002568NFIP Maps
Where NFIP maps are available, their use is mandatory in determining whether a highway location alternative will include an encroachment on the base floodplain. The following three types of NFIP map are published:
- Flood Hazard Boundary Map (FHBM) -- An FHBM does not generally originate from a detailed hydraulic study, and, therefore, the floodplain boundaries shown are approximate.
- Flood Boundary and Floodway Map (FB