Flood Zones in the U.S.
Flood zones & flood zone maps: what is a flood zone, how are flood zones defined, and where can we see maps that define flood zone areas? How does location in or out of a flood zone affect the cost of flood insurance? These questions and their answers are discussed in this article.
The map shown at page top is provided by FEMA's flood map viewer and indicates (in purple) 2,655 areas within the continental U.S. for which Digital Flood Insurance Rate Map (DFIRM) data is available.
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A flood zone is a geographic or land area that FEMA (or in other countries other agencies) has defined as being subject to flooding and thus flood damage.
Buildings constructed, re-built, or repaired within a designated flood zone require additional steps to protect the building from future flood damage (or flood and storm damage) or to reduce the extent of that damage.
Depending on the type of flood zone, building owners and tenants may have flood insurance available or may be required to purchase it.
But even if your home is not located in a primary flood zone you might be smart to purchase flood insurance. (Flood maps are explained later in this article). USAA, a national financial and insurance company serving the military gives this advice:
Flood insurance is mandatory when you have a mortgage on a home in a high-risk flood area. Even if you live outside a high-risk area, don't make the mistake of assuming you'll never experience a flood. In fact, more than 25% of flood losses occur in areas considered at moderate or low risk.
Whether it's a flash flood or just a few inches from a rainstorm, water can cause massive damage to your home and belongings — and if you're not financially prepared, the effects can be devastating. The National Flood Insurance Program has teamed with USAA and other insurers to offer flood insurance. Premiums, which vary depending on where you live, start at just $129 a year.
Flood insurance is not normally provided by nor included in a standard homeowners insurance policy. Rather flood damage insurance in the U.S. is sold under the National Flood Insurance Program - NFIP. NFIP is not an agency itself but rather is an insurance program administered by consortium of private insurance companies that offer flood damage insurance under the NFIP which is in turn "run" by FEMA, the Federal Emergency Management Agency.
What this means to the homeowner is that while s/he may have purchased flood damage indurance under NFIP, a program bearing the term "national" in its name and run by a national agency, FEMA, when flood damage occurs it is a private insurance company and a private adjuster hired by that insurer who will visit the home, make a damage assessment, and offer an insurance payment.
Homeowners who are not satisified with the offering may need to hire a public adjuster, another independent agent, to negotiate in their behalf with the insurance company. As The New York Times pointed out in March 2013 in discussing dissatisfaction with flood damage coverage following 2012's Hurricane Sandy, FEMA's handling of flood insurance has been criticized for being "... very shy about taking on the insurance companies". 
Flood Zone Maps or Flood Insurance Rate Maps (FIRMS) and FIRMette documents are used to determine if flood insurance is available, optional, or required for a given property, home, or business.
Watch out: Do not enter a flooded, storm damaged,or earthquake or hurricane-damaged building if the building is still flooded or has not been determined by an expert to be safe to enter.
Basic guidelines for entering a flooded building are at Do Not Enter a Building in The Following Conditions.See BUILDING ENTRY for FLOOD DAMAGE
Shown at above left is flooding along Wappingers Creek in Dutchess County, New York. Below we demonstrate the process of finding FEMA flood zone designation maps for the area shown in this photograph.
In the U.S. flood zones and flood zone maps are defined by FEMA, the Federal Emergency Management Agency, a U.S. government Agency operating under Public Law 100-707. For purposes of emergency management FEMA divides the U.S. into ten regions for each of which FEMA maintains a coordinating office. Details and contact information for FEMA and each FEMA region are at FEMA Regional Office Contact Information & Telephone Numbers.
This article series gives action & repair priorities if your building has been flooded, or damaged by another disaster in an easy to understand guide. We describe procedures for for flood damage assessment, setting priorities of action, safe entry procedures for damaged buildings, first steps to protect a building from further damage, how to dry out the building, how to return the utilities to operation, how to clean up a flooded or damaged basement or building, how to rebuild a damaged building, and how to prepare to minimize danger and damage hazards from future disasters. We also provide special information about avoiding or minimizing mold damage in wet or flooded basements or buildings.
Flood zones are defined by FEMA in both general categories and within each of those categories in additional levels of details. The four general flood zone risk categories are:
Although not all areas of the U.S. have yet been mapped as inside or outside of designated flood zone areas, in general, and especially in coastal and high-risk areas, many homeowners or tenants can already determine whether or not their property is in fact located within a designated flood zone, and Homeowners can dispute the designation of their property as inside or outside of a flood zone. Owners whose building is listed as located in a FEMA-designated flood zone should receive a letter indicating that status.
To determine whether or not your property is within a flood zone, consult the FEMA website or FEMA-provided flood zone maps that we describe and illustrate just below.
FEMA provides an online tool that produces a Letter of Map Change that can provide a document certifying the updated status of your building in (or out of) a flood zone.
In 2013 the U.S. Federal Emergency Management Association (FEMA) released new flood zone maps for the United States indicating that areas to be designated as at high risk for flooding and flood damage have been substantially extended.
The new flood zone maps consider recent weather changes associated with global warming, recent storms and storm damage such as Hurricane Sandy that flooded and damaged parts of the Northeastern U.S. in 2012, but not anticipated increases in the frequency and severity of storms and related floods.
As we expect global warming and its effects on the frequency and extremity of weather events to increase, one might interpret the new flood zone maps as conservative in estimating the level of flood damage risk faced by building owners and occupants in the coming decade or longer.
For the New York City area alone, in January 2013 the New York Times reported that the number of homes within designated high risk flood areas was doubling, adding an additional 35,000 homes and businesses into the updated FEMA flood zone map data.
At above-left is the FEMA Flood Zone Map obtained by searching for Oriental Boulevard, in FEMA's New York City Flood Zone Map. We found the free online maps helpful but distressingly blurry with illegible details. The printed maps that can be ordered from FEMA are completely legible, detailed, can be zoomed-in to read details, and cost $4.00 for a print form or $2.50 for an on-line map.
We purchased the online version of the FEMA map above. The procedure produces a nicely detailed 16MB map as a xxx.png file - the map image.
At left we include an excerpt from that map demonstrating the level of detail that can be displayed, in this case for Oriental Boulevard in Brooklyn, NY.
For purposes of determining flood insurance rates under the National Flood Insurance Program (NFIP), and because homes and businesses located within high risk flood-zone designations can be required to obtain and pay for flood insurance, the new maps won't take effect until 2015.
However people re-building structures damaged by Hurricane Sandy in 2012 will want to consider additional flood proofing measures both because of increased flooding risks and because of the impact of NFIP insurance requirements and NFIP insurance premiums.
The same Times article gave a flood insurance premium example explaining that owners of a home located in a designated flood zone and built with a "half basement" whose floor is four-feet below ground level might have to pay twenty-two times as much for flood insurance as a structure built three feet higher than the anticipated flood line or level.
In the U.S. flood zone maps are provided by FEMA and are easily accessed through the FEMA Map Service Center - search the FEMA website at https://msc.fema.gov for "Flood Maps" or ask for help from your FEMA Regional Office.
It is possible to search flood zone maps by the actual property address, by searching FEMA's product catalog, or by ordering a map from FEMA. To find the flood zone map for any area simply area in the United States just enter the address in the search window for this page.
FEMA's flood zone maps can be viewed online (zoom-in for a usable map) and can also be purchased from FEMA in print form. As FEMA's website advises, you'll have to be patient to wait for your flood area map to load.
Finding the exact flood zone map details surrounding your exact property using FEMA's online maps can be a little difficult unless you have first found your own address or property on a more legible Google Map or other map.
As a test we searched for an arbitrary address known to be near a creek and low area subject to flooding in Dutchess County, New York. Searching for 1 Willowbrook Heights, Poughkeepsie, NY 12603, produced the map shown at below left [click to enlarge].
Zooming in on the flood map using the FEMA web page ZoomWin tool (not the Zoom In tool which was not helpful) produced he second image (below right) on which the local Dutchess County airport served as a landmark. We zoomed on the map area that we knew contained the street of interest - Willowbrook Heights - marked in red and pointed-to by a large orange arrow on each map. The colored markings are our additions and are not provided by the FEMA flood zone map tool.
The detailed FEMA flood zone map at above if you enlarge it, shows helpful details such as local dams, footbridges, and the elevations in feet above the flood plain.
[Click to enlarge any image]
For now you might find as we did that the most useful flood zone map you can produce from FEMA's data is made by zooming in on the map and then using a screen save utility to keep the image that you produce.
FEMA provides a FIRMette tool that can be used to make a detailed map showing the area of interest, on a Flood Insurance Rate Map (FIRM). Before buying a map, try using the FIRMette tool - there is no cost.
Watch out: we found that FEMA's FIRMette tool and page were not quite working (January 2013) and could not be induced to actually produce a useable detailed map of our area of interest. The image below is as far as we could get before the FIRMette hung. An easy workaround for this problem is available by selecting the map purchase option from the FEMA maps options. If you accept electronic delivery of a map document the cost is just $2.50.
Continue reading at ELECTRICAL SAFETY for Flood Damage Inspectors or select a topic from the More Reading links or topic ARTICLE INDEX shown below.
Or see 9 STEPS to REPAIRING YOUR FLOODED HOME - Flood damage assessment, building entry safety, repair priorities
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