Chapter 1 Appendix
Created by Congress in 1968, the National Flood insurance Program (NFIP) is a nonstructural approach for the prevention of flood damage. The Federal Emergency Management Agency (FEMA), an agency part of the U.S. Department of Homeland Security, administers the NFIP. FEMA's regional offices are responsible for much of the contact with local communities.
The NFIP has two main objectives:
In order to accomplish these goals, the NFIP requires the local community to adopt floodplain management regulations before flood insurance is available. The local regulations must meet the minimum federal requirements in order for the community to participate in the Program. In short, the NFIP provides insurance to people living in flood-prone areas to cover future flood damages, while regulating future development in the floodplain that might require further expenditures for disaster relief (see ).
Community participation in the NFIP is voluntary. Each identified flood-prone Community must assess its flood hazard and determine whether flood insurance and floodplain management would benefit the community's residents and economy. However, if a community chooses not to participate after the flood hazard has been identified, there are several ramifications, in addition to the availability of flood insurance, that affect property owners. By law, if a flood disaster occurs in a nonparticipating flood-prone community, no federal disaster assistance will be provided. Also, grants, loans, or guarantees made by federal agencies, such as the Small Business Administration, Federal Housing Administration, and Veterans Administration, are prohibited for acquisition or construction in identified areas.
When a community enters the first phase of the program (the emergency phase), it agrees to adopt and enforce a floodplain ordinance that meets the minimum regulatory requirements. These ordinances require the community to
For additional requirements and explanations, refer to your local ordinances. In this phase, a limited amount of federally subsidized insurance is available for all structures in the community regardless of their flood risk.
A community is eligible to enter the regular phase of the program when FEMA completes a detailed engineering study, which defines the flood hazard areas based on hydrologic, geologic, and topographic data, and produces a Flood Insurance Rate Map (FIRM). The community must adopt more stringent floodplain ordinances to enter this phase. When a community enrolls in the regular phase, more flood insurance coverage becomes available to property owners.
A Flood Insurance Rate Map (FIRM) (see ) shows the floodway special flood hazard areas inundated by 100-year flood in dark gray, floodway areas in Zone AE in dark gray with black stripes, other flood areas (Zone X) in lighter gray and other areas (Zone X) in white.
To locate a site on the map, measure the actual distance on the ground between the site of concern and an identifiable point (bridge, river channel, reference mark or other landmark). Using the map scale, convert these figures to map units and plot the site on the map. For example, the point labeled My Project is 100 feet upstream from the landmark. It is located in the Special Flood Hazard Area.
Communities use the information from the FIRM and flood profiles to regulate development in the floodplain to meet standards of the NFIP.
A flood profile (see ) is a chart showing the elevation of the water surface during a flood event at particular locations along a river or stream. Flood insurance studies determine the elevation at the cross section marks for the 10-, 50-, 100- and 500-year events. The cross section locations can be more easily seen on the Flood Insurance Rate Map (FIRM).
Communities participating in the Regular Phase of the National Flood Insurance Program (NFIP) may have a detailed Flood Insurance Study completed for them by the Federal Emergency Management Agency (FEMA). This study describes flood hazards in the community and, if done in enough detail, designates a regulatory floodway.
For purposes of the NFIP, a floodway is defined as the channel of a stream, plus adjacent overbank areas, that must be kept free of encroachment so that the 1% chance flood may be carried without substantial increases (one foot or less) in flood heights. A floodway divides the floodplain into two parts: the floodway and the flood fringe. The floodway is the area of the floodplain that must be removed to carry floodwaters so that flood damages are not increased in the remainder of the 100-year floodplain flood fringe.
The purpose of this requirement is to ensure that new development does not aggravate existing flooding conditions in the community. This objective is achieved through stringent control of development within a defined portion of the floodplain called the floodway. Within designated floodways, the community must not permit any development, new construction, substantial reconstruction, use, activity or encroachment which would cause an increase in the heights of the 100-year (base) flood.
While the floodway requirement does not automatically exclude all forms of development, it does mandate that the flooding effects of new development be calculated beforehand so that adverse effects can be avoided. In general, when confronted with an application proposing new development within a designated floodway, local permit officials should assume that the development will increase flood heights unless the applicant can demonstrate otherwise. Development proposals that are found by engineering analysis to have no effect on (or to lower) flood heights are acceptable. Such developments could include a “one-for-one” replacement of an existing structure by a building of equal dimensions and displacement; projects where a new floodway encroachment is satisfactorily offset by removal of an existing obstruction or by a compensatory excavation; or proposals where an improvement in channel flow will compensate for the adverse effect of the new encroachment. Also, depending upon the hydraulic characteristics of a particular floodway at a given site, it may be possible to design a new development project that does not increase flood heights; however, once again the burden of proof must be assumed by the applicant to document the contention of “no effect on flooding”.
WHY A FLOODWAY?
BFEs can be increased by obstructions in the floodplain. For example, if dikes are constructed on both sides of a river channel, they constrict the river’s floodplain, causing floodwaters to rise and back up, increasing flood heights upstream. To avoid the possibility of raising the BFE, the NFIP asks a community to reserve a portion of the floodplain (the floodway) nearest the channel to pass floodwater without causing a significant increase.
A significant increase has been determined by FEMA to mean a maximum one-foot rise in the BFE. This means that if all areas outside the floodway are obstructed or filled in, the BFE will not be raised by more than one foot. Any obstructions placed in the floodway then would exceed the maximum one-foot rise allowed by the NFIP regulations.
THE CONCEPT OF THE FLOODWAY
DETERMINING A FLOODWAY
The “wall” could be fill, structures, a levee or physical obstruction. When the imaginary obstruction has constricted flood flow enough to raise the Base Flood Elevation one foot, the limits of the obstruction define the boundary of the floodway.
In the past, these boundaries were placed on a Flood Boundary Floodway Map (FBFM). Since FBFMs are no longer printed, they are now placed on the Flood Insurance Rate Map (FIRM) provided to the community along with the Flood Insurance Study.
Normally, floodway boundaries are determined by computer model applying the equal degree of encroachment rule. The rule requires that the quantity of floodwaters conveyed on both sides of the watercourse be reduced by an equal percentage when developing the encroached floodway boundary.
This rule is based on the legal need to treat similarly situated property owners in a similar manner. In practice, the rule is not always followed due to many factors, including property ownership, topography, existing development patterns and comprehensive land use plans. Any of these factors may justify modifications to the equal degree of encroachment rule. As such, FEMA generally works closely with a community in identifying boundaries to make sure the floodway that is defined meets NFIP standards and community needs.
When reviewing permit applications in the floodway, the floodplain administrator must determine the extent of development. In some cases, it is apparent that the proposed development will cause no change in the existing topography (for example, a playground). However, in most cases, the administrator will NOT be able to determine whether the development will cause a rise in base flood elevations.
When the floodplain administrator is uncertain, the permit applicant must prove to the community that the proposed floodway development, along with similar future development assumed by the equal degree of encroachment rule will cause no increase in the BFEs. The applicant must use a registered professional engineer to analyze the development plans and assess how the BFEs will be affected. Unless this analysis proves the development will cause no rise in the BFE the permit application must be denied.
Structures existing in a floodway prior to the floodway identifications are “grandfathered in” but are subject to NFIP regulations. Any substantial improvements to such structures, however, must be in compliance with the standards.
ALLOWABLE FLOODWAY USES
What is Flood Insurance?
The National Flood Insurance Program (NFIP) was created to provide affordable flood insurance to property owners in flood-prone areas and promote good floodplain management so future developments will not suffer damage from flooding. The NFIP is administered by the Federal Emergency Management Agency (FEMA) and carried out by local community administrators.
Who Can Buy Flood Insurance?
Flood Insurance can be purchased by anyone in a community participating in the NFIP, whether or not their property is in the floodplain Flood insurance is voluntary unless required as a condition of a mortgage.
Where Can I Buy Flood Insurance?
Any licensed property or casualty insurance agent can sell flood insurance.
What Does It Cover?
Any walled and roofed structure can be insured from direct loss caused by the general condition of flooding. Flooding is defined as a general and temporary condition of partial or complete inundation of normally dry land by the overflow of water, or; the unusual and rapid accumulation of runoff of surface waters from any source .
What About Basements?
For flood insurance purposes, a basement is defined as having its floor subgraded on all sides. The NFIP limits flood insurance coverage in basements and in areas below the lowest elevated floor or an elevated building. Items covered include:
Items not covered include:
How much does it cost?
Depending on if your community is in the Emergency or Regular Phase of the program, each policy premium differs.
FACT: Most homeowners insurance policies do not offer protection against flood damage.
FACT: Ninety percent of all disasters in the U.S. are flood related.
FACT: You are four times more likely to experience a flood than a fire if you live in a high risk flood zone, or Special Flood Hazard Area (SFHA).
FACT: Flood insurance is available through the federal government’s National Flood Insurance Program (NFIP), which is administered by the Federal Insurance and Mitigation Administration, a part of the Federal Emergency Management Agency. Flood insurance can be purchased through any licensed property/casualty insurance agent or through many private insurance companies that are now writing flood insurance under arrangements with the FIMA.
FACT: Flood insurance is required by law. Congress passed the Flood Disaster Protection Act of 1973, and the National Flood Insurance Reform Act of 1994 mandating at all federally insured or regulated lenders require flood insurance for mortgages and other loans on buildings and manufactured (mobile) homes located in SFHAs.
FACT: Almost any building with at least two walls and a roof may be insured if it is principally above ground and located in a community participating in the NFIP. Coverage is also available for buildings under construction.
FACT: The average premium for an NFIP flood insurance policy is $300 per year for approximately $85,000 worth of coverage. For those not in an SFHA, but still exposed to a risk, there is a low cost policy referred to as the Preferred Risk Policy, available for as little as $106 per year. Nearly one-third of our claims come from these lower risk areas.
FACT: Flood insurance is available for buildings in communities that have agreed to adopt and enforce sound floodplain management practices. Currently, there are over 18, 000 communities participating in the NFIP throughout the United States and our overseas territories.
FACT: While there are more than 3 million flood insurance policyholders, estimates are that of flooding.
FACT: Businesses may also be insured through the NFIP.
FACT: Contents of insurable, fully enclosed buildings may be covered by a separate policy, making flood insurance available to renters, too.
FACT: There is normally a 30-day waiting period between the time flood insurance is purchased and the time coverage is in force.
The following are the principal features of Increased Cost of Compliance (ICC) coverage: Note all references are to the Standard Flood Insurance Policy Endorsement Number One.
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Page last updated: December 20, 2017