...Public information statement...
October 20th through 24th is California flood preparedness week! The National Weather Service forecast office for the San Francisco and Monterey Bay areas will feature a different educational topic each day during the preparedness week.
Today's topic: types of floods local to the California central coast
A flood is defined as any high flow, overflow, or inundation by water which causes or threatens damage. This usually occurs with prolonged rainfall over several days, intense rainfall over a short period of time, or when a debris jam causes a river or stream to overflow and flood the surrounding area. Other factors that can cause or worsen flooding in our area include levee or dam failure .
Flash flooding a flash flood is defined as a rapid water level rise in a stream, creek, or river above a predetermined flood level, or a rapid and extreme flow of water into a normally dry area. Flash floods can occur within hours in local streams, or in minutes on dry ground prone to ponding, after heavy rainfall begins. Flash flooding is the dominant type of flooding that occurs in the California central coast, and indeed much of California-small creeks and rivers typically respond quickly and rise rapidly during heavy rainfall events. Flash floods may also occur in minutes after a dam or levee fails, or following a sudden release of water held by a debris jam. Flash floods can even occur in areas away from the causative event. For example, an otherwise tranquil stream channel can fill quickly from an upstream rainfall event. Flash floods can catch people off guard and unprepared. You may only have a few minutes warning that these deadly, sudden floods are coming. If you live in areas prone to flash floods plan now to protect your family and property.
Dam break or levee failure flooding flooding due to failure of engineered structures, especially during the dry season is rare, but can be catastrophic and extremely dangerous. Information on dam failure or overtopping, or levee failure or seepage, is closely monitored by the Weather Service, and by federal, state, and local operators and emergency managers. In the event of potential, imminent, or occurring failure, the Weather Service works quickly to inform the public, emergency personnel, and the media of such situations and the threat they may pose. It is important to note that such failures can occur in the dry season, especially because earthquakes can happen year round. It is also important to know your risk, know where local levees, dams, or other impoundment structures are located relative to your community.
Join US tomorrow for information on debris flows and the hydrology of land burned by wildfires.
Important flood websites local NWS office: http://www.Weather.Gov/mtr
Local river forecast center: http://www.Cnrfc.NOAA.Gov
NWS mobile: http://Mobile.Weather.Gov
California flood preparedness: http://www.Water.CA.Gov/floodsafe/CA-flood-preparedness/fpw_home.Cfm
Map service center: https://MSC.Fema.Gov
US Army corps of engineers: http://www.Usace.Army.Mil/