Why do I need to purchase insurance if there has never been a flood in the neighborhood?
The Special Flood Hazard Area is defined as the area that will be inundated by the flood event having a 1% of being equaled or exceeded in any given year. These "high-risk" zones (Zone A, AE, AH, and AO) may experience very unusual or infrequent flooding, but do have a significant risk of suffering flood damage during the normal lifespan of most buildings. Over a typical 30-year mortgage period that 1% chance per year adds up to a very respectable probability. By comparison, as of 2011, the national averages show that a typical home over the same 30-year period only has a 1% chance of being damaged by fire for the entire 30 years. Yet almost everyone willingly buys fire insurance for protection from that hazard.

Past experience is one of a number of factors used when determining flood potential. Another factor that will significantly change your flood risk over time is the amount of new development that has occurred in your watershed which will increase the speed and quantity of the storm runoff and greatly increase the extent of flooding. Inadequate levees can be very effective for smaller storm events but may fail dramatically in places when faced by a really major storm. The flood hazard areas were determined using analyses of records of riverflow, storm tides, and rainfall; information obtained through consultation with the community and topographic surveys. The Flood Insurance Study also assumes the free flow of floodwaters through bridge openings and culverts. During an actual flood event, these openings may become plugged and other areas not shown as floodprone may be flooded.

This Flood Insurance Study represents the best technical information on the current flood risk in your community.

Show All Answers

1. What is the National Flood Insurance Program?
2. What is the "new" FEMA map?
3. How do I obtain a copy of the flood hazard map for the City of San Mateo?
4. Why do I need to purchase insurance if there has never been a flood in the neighborhood?
5. Why is purchasing flood insurance important to homeowners?
6. Is flood insurance required for all structures in the floodplain?
7. What is the difference between tidal flooding and stormwater/residual flooding?
8. What other projects are needed to get my neighborhood out of the flood zone?
9. What is the City doing to help residents stuck in the flood zone?
10. Why doesn’t the City form assessment districts to fund completion of all flood related projects?
11. How do I purchase a flood insurance policy?
12. How are flood insurance premium rates calculated?
13. If my agent has questions where should he/she call?
14. What processes are available for changing or correcting the information shown on the flood hazard map when large areas of a community are affected?
15. Why is the burden of proof placed on the community or person that requests a map change?
16. What can homeowners do if they believe their homes should not be included in an SFHA?
17. Under what circumstances will FEMA waive the review and processing fee for a map change request?
18. Where can I learn more about the National Flood Insurance Program?
19. Why did a lien show up on the property report in February 2020?
20. How do I obtain a flood elevation certificate for my property?