Floods : The Awesome Power

Suzanne Van Cooten, Ph.D – NOAA/OAR National Severe Storms Laboratory

How Is A Flood Defined?

Webster’s Dictionary

Etymology: Middle English, from Old English

flOd;

akin to Old High German

fluot

flood, Old English

flOwan

to flow

1 a :

A rising and overflowing of a body of water especially onto normally dry land; also : a condition of overflowing

flood

> b capitalized :

2 :

The flowing in of the tide a flood described in the Bible as covering the earth in the time of Noah

3 :

An overwhelming quantity or volume; also : a state of abundant flow or volume

flood

>

NATIONAL WEATHER SERVICE MANUAL 10-950, SEPTEMBER 26, 2002 Operations and Services Hydrologic Services Program, NWSPD 10-9

Any high flow, overflow, or inundation by water which causes or threatens damage.

How Is A Flash Flood Defined?

Webster’s Dictionary

A local flood of great volume and short duration generally resulting from heavy rainfall in the immediate vicinity

NATIONAL WEATHER SERVICE MANUAL 10-950, SEPTEMBER 26, 2002 Operations and Services Hydrologic Services Program, NWSPD 10-9

A flood which occurs within six hours or less of the causative event. In some parts of the Nation, the actual time threshold for an event to be considered a flash flood may be less than six hours.

How Can I Decide if it is a Flood or a Flash Flood?

Duration of Time from Precipitation Event(s) to onset of flooding Common Flash Flood Producers- Heavy Localized Rainfall, Dam or Levee Failure, Sudden Release of Water held by an Ice Jam or Debris Flow Common Flood Producers- Regional Excessive Rainfall, Mainstem Seasonal River System Flooding

Floods- An International Perspective

International Events

Windstorms (Includes Tornadoes and Hurricanes) 50 Percent of 650 Registered Events 96 Percent of Insured Loss for 2004

“

Fab Four” consisting of Charley, Frances, Ivan, and Jeanne were the “costliest combination of storms in history.” Economic Losses of 60 Billion with 30 Billion carried by Insurance Industry Jeanne was responsible for record rainfall in Haiti and Dominican Republic where 2,000 people were killed in floods and torrents of mud Ivan was responsible for 11 billion in insured losses Japan was hit by a record 10 tropical cyclones from June-October Typhoons Chaba, Songda, and Tokage produced damage in excess of 14 billion with 7 billion dollars carried by the insurance industry November- Tropical Storm Winnie produced torrential rains over the Phillipines with 750 people killed in flood waters and landslides

Floods and Flash Floods One Quarter of all Natural Events (150) January- February- Brazil Experienced its worst flood catastrophe in 15 years with 160 people dead May- Haiti and Dominican Republic 2000 people died due to flood waters and mudslides June –August Monsoon Floods in Bangladesh, India, and Nepal Bangladesh 2/3 of the country was under water for most of the time 2200 people drowned and 5 billion in economic loss June-September China River Floods Hundreds of thousands of buildings destroyed 1,000 people drowned and economic losses of 8 billion dollars

Storm Related Fatalities 1975-2004

225 200 75 50 25 175 150 125 100 0 Flood Lightning

Year

Tornado Hurricane 2004 Fatality Summary - 82 Flood , 34 Tornado, 34 Hurricane, 31 Lightning, 27 Cold, 28 Winter, 6 Heat

United States Flood Fatalities and Economic Impacts

Percent of Total Storm Related Hazard Fatalities 1975-2004

20 10 40 30 70 60 50 0 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90

Year

91 92 93 94 95 96 97 98 99 Flood Lightning Tornado Hurricane 0 1 2 3 4

30 Year Average (1975-2004) Flood = 107, Lightning = 64, Tornado = 54, Hurricane = 15 10 Year Average (1995-2004) Flood = 88, Lightning = 49, Tornado = 57, Hurricane = 21

Flood Fatality Information from NWS Hydrologic Information Center Other Hazard Fatality Information from NWS Summary of Natural Hazard Statistics

Storm Data 1995-2004 Hazards Loss

20000 18000 16000 14000 12000 10000 8000 6000 4000 2000 0 1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

Cumulative of Other Winter TS/Hurricanes Marine Flood Total Extreme Temperatures Convection 2004

With Caveats on Flood Data Economic Tabulations as outlined in

Pielke, Jr., R.A., M.W. Downton, and J.Z. Barnard Miller, 2002:

Flood Damage in the United States, 1926-2000: A Reanalysis of National Weather Service Estimates

. Boulder, CO: UCAR.

National Flood Insurance Program – FEMA Web Page 1996 1997 1998 1999 2000 2001 2002 2003 2004 1985 1986 1987 1988 1989 1990 1991 1992

Calendar Year

1978 1979 1980 1981 1982 1983 1984 1993 1994 1995

Loss Dollars Paid

$147,719,253 $483,281,219 $230,414,295 $127,118,031 $198,295,820 $439,454,937 $254,642,874 $368,216,285 $126,388,098 $105,422,538 $51,022,523 $661,668,435 $167,919,559 $353,682,166 $710,247,980 $659,092,451 $411,079,605 $1,295,481,512 $828,040,721 $519,504,541 $885,998,681 $754,823,272 $251,502,332 $1,276,439,589 $432,518,918 $759,785,550 $1,207,212,377

Types of Flash Floods/Floods

Flash Floods Intense “Quick-Burst” Rainfall Ice Jam/Debris Flows Dam Failures Landfalling Tropical Systems Floods (Prolonged Regional River System Flooding)

Rainfall – Intensity, Duration, Frequency (Antecedent Conditions) Time of Day and Season (Outdoor Activities)

Flash Flood Significant Events June 14, 1990 – Shadyside, Ohio (Evening) 3-5 Inches Of Rain In Less Than 2 Hours Fell On Saturated Soils Most Deadly and Destructive Flash Flood since 1980 15-20 Foot Wall of Water 26 People Killed- 2 Bodies Recovered 30 Miles Downstream At he Hannibal Locks and Dam on the Ohio River 80 Homes Destroyed, 250 Damaged with 6-8 Million Dollars in Damage July 31, 1976 – Big Thompson Canyon Flood, Colorado (Evening) 8 Inches of Rainfall in One Hour 139 People with 30 Million Dollars of Damage

Ice Jams

(From US Corps of Engineers Data and Web Pages) The rates of water level rise can vary from feet per minute to feet per hour during ice jam flooding. In some instances, communities have many hours of lead time between the time an ice jam forms and the start of flooding. In other cases, the lead time is a little as one hour.

For example, in March 1992, an ice jam developed at 7:00 a.m. in Montpelier, VT. By 8:00 a.m. the downtown area was flooded (Figure 2-3). During the next 11 hours, the business district was covered with an average of 1.2 to 1.5 m (4 to 5 ft) of water. The event occurred so quickly that there was not sufficient time to warn residents so they could protect their goods. Even after water levels dropped, damage related to the flooding continued as cold temperatures caused freezeup of wet objects. Damages of less than one day were estimated at $5 million (FEMA 1992b).

Israel River, Lancaster, NH Ice Jam Database US Army, ERDC, CRREL-Ice Engineering Group 72 Lyme Road Hanover, NH 03755 Phone: 603-646-4187 Fax: 603-646-4477 E-mail: [email protected]

Wednesday, March 11, 1992 6:57A

A large ice jam on the Winooski River breaks loose about the Pioneer Street Bridge and travels through Montpelier. Ice jams just below the Bailey Avenue Bridge and dams the river.

7:05A 7:15A 7:23A 7:45A

Filled with rain and snowmelt, the Winooski begins to overflow its banks along State Street and the North branch begins backing up onto Elm Street.

Water surges dramatically into low-lying areas behind Main and State Streets Radio stations are notified of a flood emergency as first warnings are issued.

Icy flood waters hit the steam heating boiler at Business on Main Street and the boiler explodes, shattering the glass storefront and destroying the basement.

7:56A 8:09A 8:30A 8:46A 9:00A

Two to three feet of water is reported in front of Days Inn on State Street where an estimated 100 people are stranded. Flood waters pout onto Main Street, stalling cars and making the road impassable. Backed-up water from the swollen North Branch flows upstream on Elm Street.

Evacuations begin of hundreds of stranded residents, workers and state employees on Main, State and Elm Street. Some wade to safety, while others are taken out by boat or by fire engines and dump trucks.

Gov. Howard Dean declares a state of emergency in the capital and closes state offices. The National Guard is called in to assist, and state police, game wardens and other public safety crews begin arriving to help in the disaster.

A Red Cross emergency shelter is set up at the gymnasium at Vermont College.

10:07A

Human chains of volunteers work successfully in frigid waters to save historic documents stored in the basement of the Pavilion Building. On Main Street, similar efforts rescue about 18,000 children's books from the basement of Kellogg-Hubbard Library and thousands of videotapes in the basement of the Savoy Theater.

Power crews shut off electricity in downtown Montpelier because of high fire and explosion hazards from leaking fuel oil and propane. Many telephone lines are out. About 200 buildings in the downtown area are flooded.

3:00P 4:57P 5:10P 5:17P 5:31P 6:13P

Backhoes and a crane move into place and begin dislodging the ice jam below Bailey Avenue Bridge.

After getting the ice flowing, a second jam occurs, sending a surge of water back up into Montpelier to cause the worst flooding of the day.

The ice jam is knocked loose again, and begins moving downstream.

Huge ice chunks grinding downriver lift and twist half the trestle railroad bridge near Bailey Avenue off its foundation, leaving it perpendicular to the rest of the bridge and pointing downstream.

The last ice clears the Bailey Avenue Bridge, and flood waters rapidly drain from downtown.

Frigid weather and blowing snow descend as downtown Montpelier is cordoned off and a curfew is set. The city remains closed until noon, Saturday, March 14, as an army of workers, volunteers & municipal crews pump basements, remove more than 650 dump truck loads of debris and repair damage.

Dam Breaks

June 1, 1889 Johnstown, Pennsylvania

20 Million Tons of Water Released Official City Records list 2,207 dead but witnesses claim more

March 12, 1928 – St Francisquito Canyon, California

William Mulholland's great St. Francis Dam broke at three minutes before midnight on March 12, 1928, sending a 180-foot-high wall of water crashing down San Francisquito Canyon and claiming approximately 470 lives by the time the floodwaters reached the Pacific Ocean at Ventura. The piano keyboard in the foreground of this photograph is an eerie reminder of the families that were caught unawares in the middle of that fateful night. The flood was the second-worst disaster in California history, second only to the San Francisco earthquake and fire of 1906 Its waters swept through the Santa Clara Valley toward the Pacific Ocean, about 54 miles away. 65 miles of valley was devastated before the water finally made its way into the ocean between Oxnard and Ventura. At its peak the

wall of water was said to be 78 feet high;

by the time it hit Santa Paula, 42 miles south of the dam, the water was estimated to be 25 feet deep. Almost everything in its path was destroyed: livestock, structures, railways, bridges, livestock, and orchards.

By the time it was over, parts of Ventura County lay under 70 feet of mud and debris. Over 500 people were killed and damage estimates topped $20 million

. ((www.USC.EDU) www.scvhistory.com

November 1977 at 1:30 AM- Kelly Barnes Dam (Rock Crib) Toccoa, Georgia Dam Failure

40 People Died (Almost 50 percent Children) In 1899 Original dam constructed of interlocking sections of timber or concrete, forming cells which are filled with earth or broken rock.

Rappaport, E. Loss of Life In The United States Associated With Recent Atlantic Tropical Cyclones. Bulletin of the American Meteorological Society. Vol 81, No. 9, September 2000.

Year Month 2004 September 2004 September 2004 August 2003 September 2001 June 1999 September 1998 September 1998 August Event Cause Hurricane Ivan Hurricane Frances Hurricane Charley Hurricane Isabel LandfallingTropical System LandfallingTropical System LandfallingTropical System LandfallingTropical System Tropical Storm Allison Hurricane Floyd LandfallingTropical System LandfallingTropical System Hurricane Georges LandfallingTropical System Hurricane Bonnie LandfallingTropical System NOAA Storm Data Total Loss 14 Billion 9 Billion 15 Billion (Est) 5 Billion 5.1 Billion 6.5 Billion 6.5 Billion 1.1 Billion NFIP # Paid Losses 28,053 6,552 3,082 19,569 30,291 18,612 8,832 2,492 NFIP Amount Paid 1,407,641,752 NFIP Average Paid Loss 50,178 Fatalities (Storm Data) 57 188,747,694 58,843,652 460,975,889 1,095,419,259 439,100,271 149,384,694 22,125,055 28,808 19,093 23,556 36,163 23,592 16,914 8,878 48 34 55 43 77 16 3

October-November 1998 Heavy Rains (Texas)

Severe Flooding from 2 Heavy Rain Events 31 Deaths (NCDC Storm Data) CDC Web Page 29 Deaths with 22 from vehicles driven into high water Approximately 1.0 (1.1 adj 2002) Billion In Damage Number of Paid FEMA Losses: 4,678 Total FEMA Claims Paid: 76,257,393 (16,301 per claim)

http://floodsafety.com/media/pdfs/texas/October98.pdf

Northern Plains Flooding –April/May 1997

NCDC Storm Data – Approximately 3.7 (4.1 adjusted to 2002) Billion in damage/costs NCDC Storm Data – 11 deaths FEMA NFIP Number of Paid Losses =7,272 FEMA NFIP Total Losses Paid = 158,401,726 Dollars ($21,782 per claim) The important factors that set the stage for potential significant flooding of the Red River and its tributaries during April 1997 included greatly enhanced snowfall during the winter and a substantial buildup of river ice throughout the northern half of the Red River. These conditions resulted from a series of major cold-air outbreaks and winter storms from September 1996 to April 1997. During this period more than 200% of normal snowfall was observed over most of North Dakota, western Minnesota and northeastern South Dakota, with 125%-200% of normal snow covering the remainder of the upper Midwest, the northern Plains, Montana and most of Wyoming This highly unfavorable March-April 1997 thaw in the Red River Basin can be put into perspective by comparing it with the very favorable or "ideal" thaw of 1994, a year in which there was only minor flooding despite record or near-record snow fall at many locations during October 1993-February 1994. The 1994 thaw featured four periods of substantial basin-wide warming during March, along with significant refreezing at night. These conditions produced a much more uniform melt of snow and river ice throughout the basin, and resulted in a substantial reduction of the winter snowpack prior to the onset of the major April warming.

The floods were then directly initiated by a highly abnormal thaw of this snowpack and river ice.

Floods – Not Only Nature’s Instruments of Change

Past Policy Decisions and How These Decisions Will Be Viewed As We Tckle Water Management Issues and Impacts in the 21

st

Century

Floods As Policy Drivers

FLOODS ON THE LOWER MISSISSIPPI: AN HISTORICAL ECONOMIC OVERVIEW Southern Region Technical Attachment 98-9 Trotter, P. , G. Alan Johnson, Robert Ricks, David R. Smith NWSFO, New Orleans/Baton Rouge, Louisiana Donnel Woods, WSO/COE, Vicksburg, Mississippi The 1927 flood left a disastrous impact upon the entire 1,250,000 mile2 river drainage. The unprecedented rainfall began over the whole basin in late summer 1926, and didn't abate until the summer of 1927. The flooding began at Memphis in the fall of 1926 and it was late August of 1927 before the last of the flood waters flowed into the Gulf below New Orleans. The levee system was decimated with over 120 crevasses (Fig. 1) and 165 million acres were inundated. There were 246 fatalities and over 600 thousand people were made homeless. The total damage was estimated at $230 million.

John M. Barry in his book

Rising Tide

has eloquently outlined the social and economic impact of that natural disaster upon the nation. As Barry points out, a major portion of the 600 thousand people made homeless was black tenant farmers which made up the labor force of the agriculture-based Delta. Those refugees were not allowed to leave and were forced to work and live on the levees that year to provide damage control. Up to that time, flood relief and river management was largely driven by economics rather than humane concern for the citizens.

Relations between diverse racial and economic groups were needlessly strained by the lack of planning and flood management procedures. Fearing that a flood in New Orleans would ruin the economic structure and investment stature of that city, bankers and commodities brokers convinced the governor to open the levee at Caernarvon 14 miles downstream. The destruction of the levee and the resulting flood inundated the two lower parishes of Louisiana displacing thousands of people and destroying the trapping, farming, and fishing industries for the following several years. Given the crevasses upstream from New Orleans, the necessity of dynamiting the levee was questionable.

As a result of the devastation, the Flood Control Act of 1928 was passed. Levee and reservoir maintenance and management was placed in the hands of the Army Corps of Engineers (COE), with cooperation among levee boards, river commissions and emergency management officials.

Rising Tide: The Great Mississippi Flood of 1927 and How It Changed America John M. Barry

NOAA Historical Photo Collection

FEMA/NOAA Aerial Photos

How Do I Get The Information?

Outlooks Product

Flood Potential Outlook

Identifier

___ESF___ (example)

Source

WFO

Description

• • • • This product is issued when conditions indicate that significantly heavy precipitation will cause or aggravate flooding. It is issued with a 36-hour or greater lead time. It includes: Area affected Time frames Discussion of hydrologic and meteorological factors and conditions Information on projected watches and warnings Excessive Rain Outlook NMCGPH94E NCEP • • • • This product is issued when conditions indicate that significantly heavy precipitation will cause or aggravate flooding. It is issued with a 36-hour or greater lead time. It includes: Area affected Time frames Discussion of hydrologic and meteorological factors and conditions Information on projected watches and warning

Watches Product Identifier

Flood Watch ___FFA___ (example)

Source

WFO

Description

• • • • • • This is used to inform cooperating agencies and the public about the threat of flooding. It covers precipitation, snow/ice melt, and dam break conditions. It Includes: Area affected Time frames Conditions Extent of hazardous conditions possible Potential severity Call-to-action statement

Statements Product

Flood Statement

Identifier

___FLS___ (example) River Statement River Ice Statement ___RVS___ ___RVI___

Source

WFO WFO WFO

Description

This product is issued to update and expand the information in a Flood Warning (FLW, see below). The Flood Statement may be used in lieu of a warning if flooding is forecast, imminent, or existing and presents no threat to life or property. The statement is used also to terminate a Flood Warning.

This product provides daily river stage forecasts and/or information about ice jams and ice movement that does not warrant a Flood Warning or a Flood Statement. It is used also to communicate conditions such as low flows, chemical spills, etc.

This product can contain numeric and/or narrative information on river ice conditions.

Advisories/Warnings Product

Flood Warning

Identifier

___FLW___ (example)

Source

WFO

Description

This product normally specifies crest information and is issued for specific communities or areas along rivers where flooding has been forecast, is imminent, or is in progress.

Discussions Product Identifier

Hydrometeorological Discussion ___HMD___ (example)

Source

RFCs

Description

• • This product summarizes the current hydrometeorological situation, general trends of the RFC's hydrologic forecasts, and flood potential for the • entire RFC area. The types of conditions monitored include: Areas where Quantitative Precipitation Forecasts (QPFs) indicate significant potential for rainfall causing runoff Rivers that are already above flood stage Areas where soil moisture is above normal due to recent excessive rainfall • • Areas covered by a significant snowpack that could readily melt in changing meteorological conditions such as a rain-on-snow event or a heat wave Areas where frozen ground could generate dangerous runoff with • moderate rainfall Areas where ice jam breakups could potentially produce backwater flooding or dam-break-like flood conditions

Fatality Trends and Multi-Agency Education Programs

Nearly half of all flash flood fatalities are automobile related.

Water weighs 62.4 lbs. per cubic foot and typically flows downstream at 6 to 12 mph.

When a vehicle stalls in water, the water's momentum is transferred to the car. For each foot water rises, 500 lbs. of lateral force are applied to the car.

But the biggest factor is buoyancy. For each foot that water rises up the side of the car, the car displaces 1500 lbs. of water. In effect, the car weighs 1500 lbs. less for each foot water rises.

Two feet of water will carry away most automobiles.

http://www.nws.noaa.gov/om/water/tadd/

Questions?

Suzanne Van Cooten, Ph.D

Research Hydrometeorologist NOAA/Office of Oceanic and Atmospheric Research National Severe Storms Laboratory 1313 Halley Avenue Norman, OK 73026 Office Phone (405) 366-0536 E-Mail: [email protected]