Six Things to Know About Flooding in Ross Valley

Creek levels are still relatively low and the ground isn’t especially saturated with water (Kentfield has accumulated 7.91 inches of rain since the beginning of July, according to the National Weather Service), so while flooding is far from imminent, the approaching winter storms present an appropriate occasion to brush up on local flood information. Especially since Ross Valley has had two "100-year" floods in the last 30 years. 

Here’s some tips from the Town of San Anselmo website with Ross Valley flooding basics. We have already published tips on preparing your home for a storm, so make sure you check those out too.

 

IT’S MORE LIKELY TO FLOOD WHEN… 

• The ground is completely saturated (usually after 10-12 inches of rain has accumulated in the season) and a high percentage of the falling rain becomes runoff

• The lakes are full and are spilling water from spillways

• Six inches or more of rain falls in a 10 to 12 hour period

 

WHAT TO DO IF IT FLOODS

• If you are indoors, listen to a battery-operated radio for news (see resources below) and evacuate immediately if told to do so. If you have internet access, we will try to keep you updated on Patch.

• If you are outdoors, climb to high ground and stay there. Avoid walking through any floodwaters. Fairfax residents told to evacuate should go to the Fairfax Pavilion.

• If you are in a car, don’t drive through a flooded area and if your car stalls, abandon it immediately.

 

FLOOD TERMINOLOY

A Flood Watch is issued whenever flooding is considered a possibility (but is not certain or imminent). 

A Flood Warning is issued to warn the public that flooding is occurring or is imminent.

 A Flash Flood Watch indicates that flash flooding is a possibility in or close to the watch area.

 A Flash Flood Warning signifies a dangerous situation where rapid flooding of small streams or urban areas is imminent or is occurring.

An Urban and/or Small Stream Flood Advisory alerts the public to flooding which is generally only an inconvenience (not life threatening) to those living in affected areas.

 

WHAT THE SAN ANSELMO FLOOD HORN SOUNDS LIKE

When flooding appears to be imminent, San Anselm town staff will sound the flood horn with five blasts, a pause, five blasts, a pause, and five more blasts.

When you hear the flood horn, do not go to flood prone areas.  Seek higher ground.

 

SIGNS OF LAND MOVEMENT

• Doors or windows will jam for the first time

• New cracks will appear in plaster, tile, brick, or foundations

• Outside walls, walks, or stairs will begin pulling away from the building

• Slowly developing, widening cracks will appear on the ground or on paved areas

• Bulging ground that appears at the base of a slope

• Water that breaks through the ground surface in new locations

• Fences, retaining walls, utility poles, or trees that tilt or move

If you notice any of these signs on your property, you may need professional assistance. Call 911 if you feel the situation is life threatening.

 

RESOURCES: PHONE NUMBERS AND WEBSITES TO HAVE HANDY

Emergency ONLY: 911

San Anselmo 24-hour Emergency Information Line: 258-4632

San Anselmo Police Dept. Info and non-emergencies: 258-4610

Fairfax Police Department: 453-5330

Ross Valley Fire Dept.: 258-4686 

Department of Public Works: 258-4616

PG&E: 1-800-743-5002

Cal Trans (roads): 511 

Weather Forecast: (831) 656-1725

Ross Valley Schools: 454-2162

Humane Society: 883-4621

Ross Valley Sanitary District sewage spill reporting emergency line: 259-2949 

Local AM and FM Radio Stations:  KCBS 740 AM, KGO 810AM, KTID 100.9 FM & 1500 AM KQED 88.5 FM, 1610 AM

Creek Depth Gauge for Fairfax Creek and San Anselmo Creek 

San Anselmo web site

San Anselmo Flooding and Storm Resources

Fairfax disaster information

County of Marin web site 

National Weather Service: (A great resource for current warnings, watches, and forecasts)

 

See what else is on San Anselmo - Fairfax Patch:

• Powerful Storms Heading Our Way - Is Your Home Ready?
• Cyclist to Pedestrian: ‘I Should Really Run Into You Right Now’
• San Anselmo Pursues Grant for Memorial Park Flood Detention Basin

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