Change In Flood Zones

Floodplain boundaries have changed over the years and as a result, the flood maps for the City of Sunnyvale have been revised. Last year, the Santa Clara Valley Water District (SCVWD) completed a flood study along Lawrence Expressway and Calabazas Creek.  At that time, FEMA approved interim flood maps. All the flood protection improvements are now completed and FEMA has approved the final flood maps with an effective date of May 18 , 2009.  The current flood maps can be viewed from the following link:

Sunnyvale Flood Map

Please note, the maps will provide general information about flood zones. For more information please refer to the following Flood Zone streets listing staring with:

 A-E- F-K - L-P - Q-Z

Origin of Flood Zones

In the past, insurance companies did not provide flood insurance because one major flood could bankrupt an insurance company. Comparing flood chances against fire risk, the 1% per year chance of a flood is higher than the risk of fire; also, fire damage happens usually in a single area and can be covered as it occurs, which is not true of floods.

In order to make flood insurance available, Congress started the National Flood Insurance Program (NFIP). This insurance was made available only on a community basis, and the community wishing to have flood insurance had to join the NFIP and enforce the federal regulations with local ordinances. The NFIP was placed under the jurisdiction of the Federal Emergency Management Agency (FEMA) and its Flood Insurance Administration (FIA). Thus, FEMA is the agency that decides what areas are in which flood zone. FEMA/FIA issued the first Sunnyvale Flood Insurance Rate Map in 1983. The FIRM is the official designator of the Flood Hazard Areas in the city.

All of Sunnyvale that is not in a Special Flood Hazard Area is in the "X" zone, which is described as an area of moderate risk of flooding (roughly speaking, outside the 100-year flood but inside the 500-year flood limits). Thus, all of Sunnyvale has been determined to be subject to some risk of flooding, and it is inaccurate to say that a given property is "not in a flood zone" simply because it is not in a Special Flood Hazard Area. The special flood construction rules are not applicable to structures in an "X" zone, and flood insurance is not federally required, though it is available at rather attractive prices.

Special Flood Hazard Areas (SFHA)

FEMA designates certain types of zones as Special Flood Hazard Areas (SFHA). These are the zones that start with an "A" and, roughly speaking, correspond to the limits of the 100-year flood for that area. Although the 100-year boundary was chosen as the SFHA limit, property located just outside this boundary is almost equally at risk as one just inside it. First, though, we need to clarify the meaning of the term "100-year flood." Strictly speaking, a 100-year flood is the flood expected to occur with a probability of one percent per year. This means that over a long, long period of time this type of flood will occur, on the average, every one hundred years. Of course, flooding could happen twice in one year or several hundred years apart. But, statistically speaking, the flood zones remain as shown on the flood maps, even in times of drought.

An A0 zone is a zone where the 100-year flood is expected to cause sheet flooding between 1 to 3 feet.

In an AE zone the base flood elevation has been determined, and will vary from location to location. For instance, if an area is at about three feet above sea level and the flood plan is determined to be 8 ft., the 100-year flood would reach a height of five feet above the ground.

Structures within Special Flood Hazard Areas are subject to several special requirements. The most important of them for homeowners are: a federal regulation requiring that all federally-backed loans be protected by flood insurance, and the requirement for lowest floors of new or substantially improved structures to be elevated above the predicted flood level. So, if you have been required by your mortgage lender to obtain flood insurance, chances are this is required by the Federal Government.

The SFHA areas are defined on the Flood Insurance Rate Map (FIRM) for a community. The FIRM panels for Sunnyvale are available for viewing in Public Works at City Hall, or Public Works can give you that information over the phone or by letter ((408) 730-7415).

Ultimately it is the lender's responsibility to require flood insurance on a property, and if your lender insists you are in a SFHA there are only two ways out of an insurance requirement: paying off the loan or getting the property removed from the SFHA.

There are only two ways to get out of the SFHA:

1. FEMA can publish new maps and your property no longer shows as being in a Special Flood Hazard Area; or

2. You can request that FEMA issue you a Letter of Map Review (LOMR) which states, in essence, that the data used to create the maps was in error with respect to your specific property which is high enough to no longer be considered in a Special Flood Hazard Area. You'll have to prove this to FEMA, and that requires hiring a surveyor.

FEMA reports that about one-third of its claims payments are for structures that are not within a Special Flood Hazard Area. When creating its flood maps, FEMA does not take into account very localized conditions that might create a flood hazard, such as inadequate storm drains. These areas are "X" even though they may have a more than "X" chance of flooding.

More information is obtainable from the Federal Emergency Management Agency/Federal Insurance Administration consultant, Computer Services Corporation, at 800/638- 6620.

For more information about the NFIP, ask your insurance agent or company, or call the NFIP's toll-free number at 1-888-call-flood, ext. 445.

For additional information regarding floodzones, please note the following websites provide useful information:

FEMA www.fema.gov

Santa Clara Valley Water District www.valleywater.org

List of Flood Zone Streets starting with:

 A-E- F-K - L-P - Q-Z