Is Your Marin Home in a Flood Zone?
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 likely hood 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. However, if the house is above the base elevation, flood insurance may not be required.
Where to Find Your Flood Status
There are web sites that give you government information on the flood status of your home:
- MarinMap. Click on Search By Address at the top of the page, and then enter your property address. Then check “FEMA Flood Hazards” in the left column. This is the site that most towns in Marin use for property information.
- Our Coast Our Future. Click on Flood Map. This site gives you flood information, wave hazard for waterfront areas, predictions of sea level rise, and more.
FEMA may update your home’s flood hazard status without notice. It is useful to check these maps every few years.
Should You Buy Flood Insurance?
If you have a mortgage and your home is in FEMA zone A or V, your lender will most likely require flood insurance. If you do not carry a mortgage, flood insurance is an option. There are some exceptions, for example if part of your property is in a flood zone, but your house is not.
If your home is newly designated in a Special Flood Hazard Area, you may be able to buy a Preferred Risk Policy from FEMA, at a greatly reduced rate. If your home is near a Special Flood Hazard Area, you may want to buy insurance from FEMA, available at a much lower cost, as precaution against future changes in flood maps. Please contact us to learn more about your options.
What Can You Do to Prevent Flooding?
If you live in a flood hazard zone (A or V, contact us to find out), you have options to prevent flooding:
- Install a sump pump under your house. Also, consider a natural gas powered generator in case the power goes out.
- Have sandbags ready to block the water at critical locations.
- Raise your house above the flood plane. Some cites now require this if you do a major remodel extensively or if you build a new house. It may be a small investment relative to your home’s value, and well worthwhile.
Marin County Watersheds and Flood Protection Zones
Marin County is divided into 15 watersheds and eight Flood Protection Zones. This page will help you to understand the big picture.
What is Marin Doing to Prevent Flooding?
There are many solutions completed and many underway. There is extensive information about how towns in these areas are dealing with flood control:
Zone 1: Novato
Overview of flooding in Novato
Flood control projects in Novato
Zone 3: Richardson Bay (Mill Valley, Tiburon, Sausalito, Marin City, Tamalpais Valley, and Belvedere)
Mill Valley Flood Control Plan 2021.
Flood preparedness in Belvedere.
Zone 4: Bel Aire (Part of Tiburon)
Zone 5: Stinson Beach and Bolinas
Zones 6 & 7: North and East San Rafael
Zone 9: Ross Valley (Corte Madera, Larkspur, Ross, San Anselmo, Fairfax)
Towns along the Corte Madera Creek, from Fairfax through Corte Madera to the bay, are working to provide unimpeded flow of the creek through developed areas. Creeks that drain easily are less likely to overflow. You can keep up to date with plans and ongoing programs at the Ross Valley Watershed website and the Friends of the Corte Madera Creek website.
Corte Madera Creek Watershed, courtesy of the Friends of Corte Madera Creek
Zone 10: Lagunitas and Tomales Bay (San Geronimo Valley, Lagunitas, Tomales, Dillon Beach)
