HISTORIC FLOODING IN TEXAS AND OKLAHOMA May 23, 2015 - and following

Walter Hays, Global Alliance for Walter Hays, Global Alliance for Disaster Reduction, Vienna, Virginia, Disaster Reduction, Vienna, Virginia,

USA USA 

RECORD FLOODING: May 23, 2015 - and following

MAY 29, 2015

• "There's so much water in Texas and Oklahoma that it's going to take quite a while for the rivers to recede," said Mark Wiley, a National Weather Service meteorologist in Fort Worth, Texas.

May 29: The confirmed death toll has now reached 24, but at least

12 people are still missing.

MAY 29, 2015

• The Colorado River in Wharton and the Brazos and San Jacinto Rivers near Houston are the focus of attention as floodwaters from North and Central Texas move downstream toward the Gulf of Mexico.

At Richmond, 30 miles southwest of Houston, where flood stage is 16 m

(48 ft), the National Weather Service expects the river to top flood stage

Friday morning and rise to 17 m (50 ft) by late Friday night or Saturday.

Forecasters say that the Colorado River at Wharton, 100 km (60 mi) southwest of Houston, could crest at 15 m

(44 to 45 ft) Saturday morning, causing major flooding.

MAY 28, 2015: REGIONAL RUNOFF SWLLS RIVERS

MAY 27, 2015: GOOD NEWS– NO F-5 TORNADO AS ON MAY 27, 1997

WEDNESDAY, MAY 27

BAD NEWS: The death toll in Oklahoma and Texas reached 19 as record rainfall continued in Texas where 37 counties have already been identified as disaster areas by Texas’ Governor GregAbbott.

WEDNESDAY, MAY 27

BAD NEWS: “The worst economic losses ever from flooding in Texas” Texas’ Governor Greg Abbott.

WEDNESDAY, MAY 27

• The flooding in Houston has affected virtually every part of the city and paralyzed some areas.

WEDNESDAY, MAY 27

• Firefighters carried out more than 500 water rescues, most involving stranded motorists on interstate highways.

WEDNESDAY, MARCH 27; HOUSTON HWY 288

HOUSTON: WEDNESDAY, MAY 27

• At least 2,500 vehicles were abandoned by drivers.

HOUSTON: WEDNESDAY, MAY 27

• 1,400 Houston-area homes have now been damaged.

CENTRAL TEXAS: WEDNESDAY, MAY 27

• Thousands of homes were also damaged or destroyed in the central Texas corridor that includes Wimberley — 744 of them in San Marcos alone---- said Kenneth Bell, emergency management coordinator for San Marcos.

TUESDAY, MAY 26

• Floodwaters kept rising Tuesday across much of Texas as storms dumped 28 cm (11 in) of rain on the Houston area, stranding hundreds of motorists and inundating the famously congested highways that serve the nation's fourth-largest city.

HOUSTON: INTERSTATE 45

HOUSTON: Some motorists were stranded on I-45 all

night, sleeping in their cars until the traffic backup was

cleared -- about 8 a.m.

HOUSTON: RESCUE OPERATIONS

SAN MARCOS: LOSS OF FUNCTION

SAN MARCOS: A RESCUE (Credit: REUTERS)

TUESDAY, MAY 26

• Meanwhile, the search went on for at least 13 people who were still missing, including a group that disappeared after a vacation home was swept down the river and slammed into a bridge.

TUESDAY, MAY 26: DEATH TOLL REACHES 14

• Several more fatalities were reported — three in Houston and one more in Central Texas-bringing to 14 the number of people killed by the holiday weekend storms in Texas and Oklahoma.

Over the May 23-25 Memorial Day weekend in the USA,

heavy rain fall, flash floods, tornadoes, and inundation occurred from the Gulf of Mexico to the Great Lakes

History was made as Texas and Oklahoma experienced

continuous periods of heavy rain, catastrophic flooding,

mass evacuations, and an urgent demand for emergency

services.

TEXAS FLOOD ZONES

37 counties in Texas were declared disaster areas by the

Governor

FLOODING

Tornadoes swept across the southern plains, destroying dozens of homes in Texas, Oklahoma, Kansas, and

Nebraska

TORNADO NEAR CHICKASA, OKLAHOMA

THE CAUSE: National Weather Service (NWS); Norman, Oklahoma

• “The widespread heavy rains were caused by a prolonged warming of Pacific ocean sea surface temperatures that results in cooler air and rain when coupled with an active southern jet stream and moisture from the Gulf of Mexico.”

PRELIMINARY IMPACTS

• The central part of Texas was hit hard, especially San Marcos and Wimberley, near the Blanco river – which crested at 13 m (40 ft) the highest level since 2010.

• At least 2,000 residents were forced to evacuate their homes.

CENTRAL TEXAS: IMPACTS

• 1,000 homes were damaged in San Marcos, Wimberly and other communities in Hays County, a fast-growing area between San Antonio and Austin, the capital.

WIMBERLEY

OVER 2,000 EVACUATED

CENTRAL TEXAS IMPACTS

• Rivers rose so fast that whole communities woke up on Sunday morning surrounded by water.

CENTRAL TEXAS IMPACTS

• The Blanco River crested at a height more than double its flood stage of 4 m (13 ft), swamping Interstate 35 and forcing closure of parts of the busy north-south highway.

DALLAS AREA IMPACTS

• Dallas faced severe flooding, with the Trinity River expected to crest near 13 m (40 ft) on Monday (25th).

SEVERE WEATHER IN DALLAS AREA

In Johnson County, just outside Dallas, residents had to cope with the third flood in four

weeks, a rare small earthquake, and a mile-wide tornado that

touched down.

NORTH TEXAS

• The Red and Wichita rivers also rose far above their flood stage.

OKLAHOMA: Oklahoma City set a new monthly rainfall total this weekend – 45 cm (18.2 in) through Saturday, beating the

previous mark of 35 cm (14.5 in) set in 2013.

FLOODING

LOW DEATH COULD RISE

• At least three people have died, but, at least 12 are missing in Texas and Oklahoma.

Forecasters predict more storms through Monday that will likely

hinder rescue and recovery operations and exacerbate the

already overwhelmed waterways and saturated

grounds.

LOCATION MAP

FLOODSFLOODS

YOUR YOUR COMMUNITYCOMMUNITY

YOUR YOUR COMMUNITYCOMMUNITYDATA BASES DATA BASES

AND INFORMATIONAND INFORMATIONDATA BASES DATA BASES AND INFORMATIONAND INFORMATION

HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS

•HAZARD MAPS•INVENTORY•VULNERABILITY•LOCATION

RISK ASSESSMENTRISK ASSESSMENT

RISK

ACCEPTABLE RISK

UNACCEPTABLE RISK

FLOOD DISASTER RISK FLOOD DISASTER RISK REDUCTIONREDUCTION

•PREVENTION/MITIGATION•PREPAREDNESS•EMERGENCY RESPONSE•RECOVERY and RECONSTRUCTION

POLICY OPTIONSPOLICY OPTIONS

FLOOD HAZARDS (AKA

POTENTIAL DISASTER AGENTS)

• TOO MUCH WATER DISCHARGED WITHIN THE DRAINAGE SYSTEM TO BE ACCOMMODATED NORMALLY IN THE REGIONAL WATER CYCLE

• EROSION

• SCOUR

• MUDFLOWS

RISK ASSESSMENT INTEGRATES RESEARCH AND SCIENTIFIC KNOWLEDGE GAINED FROM

“FLOOD DISASTER LABORATORIES,” WITH

EMERGING TECHNOLOGIES AND THE

COMMUNITY’S POLITICAL PROCESS.

RISK ASSESSMENT INTEGRATES RESEARCH AND SCIENTIFIC KNOWLEDGE GAINED FROM

“FLOOD DISASTER LABORATORIES,” WITH

EMERGING TECHNOLOGIES AND THE

COMMUNITY’S POLITICAL PROCESS.

LOSS OF FUNCTION OF STRUCTURES IN FLOODPLAIN

FLOODSFLOODS

INUNDATION

INTERACTION WITH HAZARDOUS MATERIALS

STRUCTURAL/CONTENTS DAMAGE FROM WATER

WATER BORNE DISEASES (HEALTH PROBLEMS)

EROSION AND MUDFLOWS

CONTAMINATION OF GROUND WATER

CAUSES OF RISK

CAUSES OF RISK

CASE HISTORIESCASE HISTORIES