In Marin, heavy rains and runoff into our creeks can cause flooding in nearby neighborhoods. If the bay tides are high, the streams drain slower and flooding can be more severe. Areas that are prone to flooding in Marin are areas along creeks and low areas along the bay. There have been only a few years of serious flooding in Marin. However, the increase in sea level and heavy rain storms have increased the risk.

 FEMA FLOOD MAPS, NEW IN 2016 AND 2017

The Federal Emergency Management Agency (FEMA) publishes “flood maps” (FIRMS or Flood Insurance Rate Maps) that show the flood risks, if any, of every property in Marin. FEMA has defined flood hazard zones by the likelihood of flooding in the next 30, 100, 500 years, and so on:

B, C, and X zones have low chances of flooding and usually do not require flood insurance.

A and V zones (also known as Special Flood Hazard Areas or SFHAs) have a high risk of flooding in the next 30 years. Flood insurance may be required for properties in these zones.

Much of the flood zone determination has to do with the number of feet a house is above a base flood plane (or elevation). Each community determines this elevation. It may be, for example, 9 feet. This sometimes results in a situation where part of a property is in the flood zone and part is above the flood zone. If the house is above the base elevation, flood insurance may not be required.