California Floods: Be Aware, Be Prepared

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1 Flooding in California Do you live in California?Do you visit California? Do you know when it typically floods in California? Do you know that every county in California has been declared a federal flood disaster areaat least oncein the last 20 years? Types of Flooding California experiences manytypes of flooding: alluvial fan, debris flow, riverine, coastal, tsunami, flash, and localized floods.not every part of Californiaexperiencesevery type of flooding, but the results of each is the same: without proper preparedness, lives, homes, infrastructure and agriculture are lost, and damage to the environment and economy is likely. Preparing for devastating floods is critical. Important Facts About Floods: More people die in floods each year than in any other type of natural disaster.between 1975 and 2005, an average of 127 people died in floods each year in the U.S. Six inches of fast moving water can knock an adult off his or her feet. Six inches of water will reach the bottom of most passenger cars, causing loss of control and possible stalling. 18 inches of waterwill floatmost cars; two feet of water can float SUVs and trucks. It is extremely difficult to see how deep flood water is, so don t drive through water on the roadway. Just one foot of water can cause more than $54,000 in damages to a $150,000 singlefamily home. A home in the 100 year floodplain is almost twice as likely to suffer damage from flooding than from fire during the life of a 30 year mortgage. Statewide, $5.4 billion in crop values are exposed to the 100 year floodplain. Statewide, 1.4 million people live and work in the 100 year floodplain. BE AWARE, BE PREPARED Know your risk and take action to reduce your risk. Stay away from rising creeks, streams and rivers. Turn Around, Don t Drown.Don tdrive through water on the roadway; during floods, more people are trapped and die in their vehicles than anywhere else. Know how to leave the area quickly if you see water start to rise. Be aware of your surroundings and know your evacuation routes. Do not attempt to cross flowing water that may be more than knee deep. If you have doubts, don't cross. Have an emergency preparedness kit. (Red Cross PDF for developing a kit: 1 9/4/2012

2 Choose a family meeting place and a plan for how to communicate during an emergency. If you live in a flood prone area, consider buying flood insurance. During threatening weather, listen to local radio or TV news channels for watch and warning bulletins: o Flood Watch means it is possible that flooding will occur in a specified area. Be alert and prepared for a flood emergency. o Flood Warning means flooding is occurring or is imminent in a specified area. Move to safe ground immediately. More information about flood types and flood preparedness can be found at the following websites: My Hazards: FloodSAFE Risk Notification: Flood SMART Flood Insurance Website: National Weather Service Turn Around, Don t Drown website: Sidebar: What is a 100 Year Flood? 100 Year Flood is a shorthand expression for a flood that has a 1 in 100 chance of being exceeded in any given year. This may also be expressed as the 1% annual chance of exceedence flood or 1% annual chance flood for short. Similarly, a 200 year flood has a 1 in 200 (or 0.5%) chance of being exceeded in any given year. 2 9/4/2012

3 Alluvial Fan and Debris Flow Flooding Do you live in a mountainous area? Do you live in the foothills?do you live along the coast? If you live in or visit one of these areas, at some time you may experience alluvial fan ordebris flow flooding. Alluvial Fan Flooding An alluvial fan is a fan shaped buildup of sediment found at the base of steep mountain canyons.alluvial fan flooding is characterized by relatively shallow depths, high velocity, and moving soil and sediment, creating uncertainty aboutwhere risingwater will travel. Alluvial fan flooding is a concern primarily in central and southern California. In mid August 2004, thunderstorms in the Wildomar, Sage, and La Quinta areas resulted in alluvial fan flooding.these thunderstorms brought in monsoonal rains that inundated the areaswithin minutes. Debris Flow Flooding Debris flow floods are made up of water, mud, and debris; theycan form and accelerate quickly, reaching high velocities and traveling great distances. Debris flowsarecommonly caused by heavy, localized rainfall on hillsides where vegetation has been destroyed by fire. Debris flows can demolish homes and other structures, wash out roads and bridges and sweep away cars. In debris flow flooding, mud remains after a flood has receded, causing additional expense to remove.in January 2005, a hillside gave way in La Conchita (VenturaCounty),damaging 36 houses and killing 10 people. Impact Similar to a flash flood, alluvial fan flooding can occur with little warning. But in someinstances, weatherconditions that canlead to alluvial fan flooding are predictable, providing more time to take precautionary measures. Alluvial fan flows and debris flows can be particularly hazardous because large debris can be transported by the fast moving and densemixof slurry and boulders. BE AWARE, BE PREPARED Know your risk and take action to reduce your risk. When visiting steep mountains or foothills,be aware oflocal weather forecasts. Keep an eye on storms that appear to be moving over the mountains. Turn Around, Don t Drown. Don t drive through water on the roadway; during floods, more people are trapped and die in their vehicles than anywhere else. Be aware of your surroundings and know your evacuation routesif you see water start to rise. Have an emergency preparedness kit. If evacuating,have a plan for where to meet your family or friends and who to contact. If you live in a flood prone area, consider buying flood insurance. 3 9/4/2012

4 More information about flood types and flood preparedness can be found at the following websites: My Hazards: FloodSAFE Risk Notification: Flood SMART Flood Insurance Website: National Weather Service Turn Around, Don t Drown website: 4 9/4/2012

5 Riverine Flooding Rivers, Creeks and Streams Do you have a stream, creek or river in your neighborhood? Do you visit streams, creeks or rivers on vacation? If you do, then you may be exposed to riverine type flooding. Riverine Flooding Riverine flooding occurs when rivers, streams and lakes overflow their banks. This includes flooding caused by levee failure and channel erosion.areas adjacent to local streams and creeks can also experience flooding as a result of excessive runoff from heavy rainfall and accumulation of water flowing over broad flat areas.of particular concern in Californiaare the deep floodplains of the Central Valley, which are subject to periodic riverine flooding.riverine flooding can be widespread, with floodwaters persisting for several hours to days, weeks or more. Impact Riverine flooding usually allows time for communities to take measures to protect life and property. The dangers from riverine flooding likely involve inundated structures and roadways, and electrical shock from downed power lines. In January 1997, riverine flooding in the Central Valley damagedmore than 23,000 homes and businesses;destroyed many thousands of acres of agriculture lands, roads, bridges, and flood management structures; and nine people died. In 2006, flood damage to the City of Napa and surrounding communities totaled approximately $115 million dollars; 1,200 homes and 250 businesses were damaged. BE AWARE,BE PREPARED Know your risk and take action to reduce your risk. Stay away from rising creeks, streams and rivers. Pay attention to local weather forecasts. Know how to leave the area quickly if you see water rising. Remember Turn Around, Don t Drown.Don t drive through water on the roadway; during floods, more people are trapped and die in their vehicles than anywhere else. Be aware of your surroundings and know your evacuation routesif you see water start to rise. Have an emergency preparedness kit. If evacuating, have a plan for where to meet your family or friends and who to contact. If you live in a flood prone area, consider buying flood insurance. 5 9/4/2012

6 More information about flood types and flood preparedness can be found at the following websites: My Hazards: FloodSAFE Risk Notification: Flood SMART Flood Insurance Website: National Weather Service Turn Around, Don t Drown website: 6 9/4/2012

7 Coastal Flooding and Tsunami Dangers Do you live work or vacation along the California coast? Do you know the risk of tsunamis in Californiais real? Know your risk, know your role and take action to reduce your risk. Coastal Flooding Storms can cause flooding through a process known as storm surges, which is when ocean waves are significantly larger than normal. If a storm event corresponds with a higher than normal tide, extensive flooding can occur. Winds blowing in an onshore direction (from the sea toward the land) can cause the water to pile up against the coast,overtopping natural and manmade flood protection structures like sea walls. Coastal communities, especially low lying stretches of Southern California, are highly susceptible to this hazard. Tsunami Dangers Although many people think of a tsunami as a single, breaking wave, it typically consists of multiple waves that rush ashore like a fast rising tide with powerful currents. Tsunamis can travel much farther inland than normal waves.tsunamis are triggered by earthquakes, volcanic eruptions, underwaterlandslides and onshore landslides in which large volumes of debris fall into the water. All of these triggers can affectcalifornia.some come from across the globe; for example, the March 2011 earthquake in Japan brought an 8 foot wave into Crescent City harbor, destroying much of the harbor.some of these triggers happen close to our coastline. If a tsunami causing disturbance occurs close to the coastline, a resulting tsunami can reach coastal communities within minutes.coastal communities, especially low lying stretches of northern California are highly susceptible to this hazard. Impact The impact from coastal flooding by either storm surges or a tsunami can be devastating. More than 600,000 Californians live within a quarter of a mile of the coast.in addition to the significant number of people at risk of coastal flooding and tsunamis, coastal urban centers provide considerable support for California s economy. Lives, homes, businesses and infrastructure like roads, railways and industrial areas are all at risk of coastal flooding, with massive potential for social and economic loses. In 2006, a tsunami caused approximately $20 million dollars in damage to Crescent City harbor.the repairs were not yet completed when the March 2011 tsunami caused approximately $12.5 million dollars in additional damages to the harbor. BE AWARE, BE PREPARED Know your risk and take action to reduce your risk. If you live in a flood prone area, consider buying flood insurance. Be aware of local weather forecasts andwarnings. 7 9/4/2012

8 Know how to reach high ground quickly. Be aware of your surroundings and know your evacuation routes. Look for evacuation routes and signs. Have a preparedness kit. If evacuating, have a plan for where to meet your family or friends and who to contact. Remember Turn Around, Don t Drown.Don t drive through water on the roadway; during floods, more people are trapped and die in their vehicles than anywhere else. Have an emergency preparedness kit. If you live in a flood prone area, consider buying flood insurance. More information about flood types and flood preparedness can be found at the following websites: My Hazards: FloodSAFE Risk Notification: FEMA s Flood SMART Flood Insurance Website: NOAA s StormReady/Tsunami Ready 8 9/4/2012

9 Flash Flooding What is a flash flood? How can you avoid getting caught in a flash flood? Is it safe to drive through a flooded street? Know your risk, know your role and take action to reduce your risk. Flash Flooding Flash floods are the number one weather related killer in the U.S. because they can roll boulders, tear out trees, and destroy buildings and bridges quickly. A flash flood is a sudden, rapid flooding of low lying areas typically caused by intense rainfall. Flash floods can also occur from the collapse of a man made structure or ice dam.rapidly rising water can reach heights of 30 feet or more. Although floods can occur throughout the year, California srainy season usually lasts from November to April. This is when the chance of heavy flooding and flash flood risks is greatest. Impact Flash flooding is particularly dangerous because people attempt to drive through rushing water or down a flooded road. Six inches of water will reach the bottom of most passenger cars, causing loss of control and possible stalling.it only takes two feet of water to lift a car or SUV and once a vehicle becomes buoyant, the water can easily push it sideways or roll it over, trapping those inside and washing them downstream. Drivers should remember this simple saying: Turn Around Don t Drown, and practice safe driving during flood events. On August 15, 2004, flooding destroyed several miles of roadway along Highway 190 and Route 127 in Death Valley, resulting in the death of two people and an estimated $20 million in damages. Flash flooding causes more than $2 billion in property damage each year in the U.S. BE AWARE, BE PREPARED Know your risk and take action to reduce your risk. Keep alert for signs of heavy rain, thunder and lightning, both where you are and upstream. Know how to reachhigh ground quickly if you see or hear rapidly rising water. Do not attempt to cross flowing water thatmay be more than knee deep. If you have doubts, don't cross. Remember Turn Around, Don t Drown.Don t drive through water on the roadway; during floods, more people are trapped and die in their vehicles than anywhere else. If your vehicle stalls, abandon it and seek higher ground immediately. Do not drive around a barricade. Barricades are there for your protection. Turn around and go the other way. During threatening weather listen to local news channels for watch and warning bulletins: 9 9/4/2012

10 o Flood Watch means it is possible that flooding will occur in the specified area. Be alert and prepared for a flood emergency. o Flood Warning means flooding is occurring or is imminent in the specified area. Move to safe ground immediately. Listen to the weather forecast. Be aware of your surroundings and know your evacuation routes. If evacuating, have a plan for where to meet your family or friends and who to contact. Have an emergency preparedness kit. If you live in a flood prone area, consider buying flood insurance. More informationabout flood types and flood preparedness can be found at the following websites: My Hazards: FloodSAFE Risk Notification: FEMA s Flood SMART Flood Insurance Website: National Weather Service Turn Around, Don t Drown website: /4/2012

11 LocalizedFlooding Do you live in or visit urbanized areas? If so, you probably have experienced, or will experience, stormwaterflooding. Know your risk, know your role and take action to reduce your risk. Stormwater Flooding Localized flooding occurs in both urban and nonurban areas during or after a storm.any storm, particularly slow moving, steady rain storms, can overwhelm drainage systems.when the system backsup, pooling water can flood streets, yards and even the lower floors of homes and businesses. Even less intense storms can cause this type of flooding when leaves, sediment and debris plug storm drains. Localized flooding poses most of the same problems caused by larger floods, buttypicallyimpacts fewer people and affects geographically smaller areas.flooding of this type tends to recur year after year.the aftermath can meancostly damage to homes and property.in many cases, stormwaterflooding can easily be avoided by keeping stormdrains clear of debris, so the stormwater system can function properly. Impact Stormwater flooding frequently causes property damage and traffic congestion.keeping stormdrains clear of leaves and debris so the system can perform its task is the responsibility of residents and business owners. BE AWARE, BE PREPARED Know your risk and take action to reduce your risk. Be aware of your surroundings and know your evacuation routes. Keep your storm drains free of debris. If your property is prone to flooding, have sandbags, plastic sheeting and other floodfighting materials on hand. Remember Turn Around, Don t Drown.Don t drive through water on the roadway; during floods, more people are trapped and die in their vehicles than anywhere else. Have an emergency preparedness kit. If evacuating, have a plan for where to meet your family or friends and who to contact. If your property is subject to localized, stormwater flooding, consider purchasing flood insurance. More information about flood types and flood preparednesscan be found at the following websites: My Hazards: FloodSAFE Risk Notification: /4/2012

12 Flood SMART Flood Insurance Website: National Weather Service Turn Around, Don t Drown website: /4/2012

13 California Flood Preparedness Week: Daily themes and known activities Monday Oct. 15 th : Opening Day focus all 7 risk categories, preparedness Tuesday Oct. 16 th :Alluvial Fan and Debris Flow Flooding Wednesday Oct. 17 th Slow, Riverine Flooding Thursday Oct 18 th :(Great shake out Marine, coastal and tsunami flooding) Friday Oct 19 th :Flash Flooding Saturday Oct 20 th :Urban, stormwater, local flooding (rake leaves, clearing storm drains) (Event at the Home Depot on Howe Avenue with Safely Out Program, ads on Clear Channel) 13 9/4/2012