Beta stung but didn’t submerge Houston – Why we shouldn’t claim victory at this time
 |
|
Philip B. Bedient
|
Sometimes, no news is good news. The day after Tropical Storm Beta moved northeastward out of Houston, the JHV checked in with Morgan Zeringue, who leads the Jewish Family Service Disaster Team, and Jewish Federation president and CEO Kari Saratovsky. Neither had received reports of home flooding along Brays Bayou.
Some of the residents who live in the neighborhoods along Brays Bayou credited the recent Brays Bayou Flood Damage Reduction Project modifications (Project Brays) for reducing the flood risk to their community. Harris County Judge Lina Hidalgo gave a press conference in which she said improvements to Brays Bayou spared “hundreds, if not thousands of structures that would have flooded” during Tropical Storm Beta. The work done on Project Brays included 21 miles of channel widening and deepening; modifications to about 30 bridges; and construction of four stormwater detention basins that can hold roughly 600 million gallons of stormwater.
However, Philip B. Bedient is less sanguine.
“We caught a lucky break in the amount and intensity of rain that fell during Tropical Storm Beta,” Bedient told the JHV. Only 10-14 inches of rain fell in Southwest Houston. A reported 11 inches fell in Meyerland. Plus, the rain came in waves, which gave many of the bayous a chance to recover somewhat.
“Beta was a big storm, but not as big as 2015 and 2016 and Harvey,” said Bedient. “Brays Bayou wasn’t challenged like it was with some of these other storms; much less rain and much less intensity. [Tropical Storm] Allison dropped, for example, 12 inches of rain in three hours and created
$5 billion dollars in damages in Houston,
$2 billion in the Medical Center, alone.
“Don’t get me wrong,” he continued. “Project Brays was a huge improvement to the bayou. It provided significant protection during Beta by knocking down water levels in the bayou several feet. But, a serious flooding problem will continue to exist in many of the areas that have been impacted by flooding in the past.”
Bedient is the Herman Brown Professor of Engineering and chair of the Civil and Environmental Engineering Department at Rice University. As director of the SSPEED Center (Severe Storm Prediction, Education & Evacuation from Disasters Center), Bedient’s job is to research protection strategies for severe storm flooding and hurricane-related surges in our Gulf Coast region.
Bedient explained that flood control, or management, involves various methods of reducing the extent of flooding or flood damages. In the past, one common method was to dig out watercourses by widening and deepening them. Another common method was to sometimes further increase the flow of water in a channel by lining it with concrete, which allows more rainwater to flow in the channel, rather than overtopping the banks and flooding adjacent land. Engineered channels have a design capacity, meaning that they can maintain the runoff from a certain intensity of storm within the banks.
The major problem associated with flooding in Brays Bayou is due to upstream development, said Bedient. Development has severely reduced the remaining undeveloped land upstream that can soak up rainwater, as well as increase the amount and speed (measured in increased runoff) of water flow.
“When Beta hit, I estimate the detention ponds helped but didn’t do nearly as much as the widening of the bayou,” said Bedient. “The pond at Arthur Storey Park worked just fine, but the other detention ponds are way upstream. We argued that we needed the land occupied by both of those old golf courses at Braeburn Valley and the old Westwood Golf course. If they had gotten both of those pieces of land and turned them into detention ponds, it wouldn’t have flooded nearly as badly in Meyerland over the years because you’re catching the water in the middle of the bayou and holding it before slowly releasing the water out of the ponds.
“By the 1990s, most of the land along Brays Bayou was developed and fully built out. There was no place to build a large pond or storage area. The result is that Brays Bayou is the most flood-prone watershed in Texas. Meyerland is a beautiful area, but it never should have been allowed to develop as it did,” he said.
There’s also the fact that we’ve experienced a series of storms that have deposited increased amounts of rainfall on Houston. Whether you believe that climate change is responsible for increasing amounts of storm rainfalls, the fact is, since Tropical Storm Allison in 2001, Harris County has experienced record-breaking storm rainfall amounts.
Rainfall amounts associated with Allison were reported as high as 26 inches in 24 hours. Allison flooded about 74,000 homes in Harris County.
The storm of July 14, 2012, dumped more than 14 inches of rain in 24 hours in parts of Harris County. In May 2015, we had the first of two Memorial Day floods. This storm dropped about 11 inches over 12 hours on the Brays Bayou watershed and the Meyerland area near Loop 610. Brays Bayou experienced the first of three major flooding events to impact the area. Eight persons died in this storm, and there were 531 water rescues.
In April 2016, we had what has come to be called the Tax Day Flood. This event was not tropical in nature, but was associated with an April cold front. The storm dumped 15 to almost 17 inches in 12 hours.
Hurricane Harvey set a national record for the amount of rainfall over a four-day period. Most of Harris County received at least 30 inches or more over this time period. An estimated 130,000 homes were flooded.
Bedient contends that in mitigation strategies, we currently are in “a catch-up game.”
“We can’t get ahead of the development and the increased rainfalls. And, we don’t have enough planning to buy sufficient land to build large regional ponds to store the water,” he said.
“FEMA is now re-mapping the old floodplains. The folks who used to be in the 500-year floodplains will be in the new 100-year floodplain. That means your flood insurance rates are going to shoot up by a factor of 4 or 5.”
It is also means, argues Bedient, that the designs of the federal projects, like Project Brays, are not based upon this revised floodplain and therefore do not fully solve the existing flooding problems. The old 100-year floodplain is used by state and federal agencies for issuing state and federal permits for sewage and water treatment plants, hazardous waste facilities, landfills, and designing state-funded and federally funded projects.
As a result, there still will be homes near creeks and bayous that will remain at risk of flooding, even with the money being spent on federal and local improvement projects.
“You can elevate your home, but what about the people who cannot afford to do so? The solutions for Harris County are far and few between.”
Some of the residents who live in the neighborhoods along Brays Bayou credited the recent Brays Bayou Flood Damage Reduction Project modifications (Project Brays) for reducing the flood risk to their community. Harris County Judge Lina Hidalgo gave a press conference in which she said improvements to Brays Bayou spared “hundreds, if not thousands of structures that would have flooded” during Tropical Storm Beta. The work done on Project Brays included 21 miles of channel widening and deepening; modifications to about 30 bridges; and construction of four stormwater detention basins that can hold roughly 600 million gallons of stormwater.
However, Philip B. Bedient is less sanguine.
“We caught a lucky break in the amount and intensity of rain that fell during Tropical Storm Beta,” Bedient told the JHV. Only 10-14 inches of rain fell in Southwest Houston. A reported 11 inches fell in Meyerland. Plus, the rain came in waves, which gave many of the bayous a chance to recover somewhat.
“Beta was a big storm, but not as big as 2015 and 2016 and Harvey,” said Bedient. “Brays Bayou wasn’t challenged like it was with some of these other storms; much less rain and much less intensity. [Tropical Storm] Allison dropped, for example, 12 inches of rain in three hours and created
$5 billion dollars in damages in Houston,
$2 billion in the Medical Center, alone.
“Don’t get me wrong,” he continued. “Project Brays was a huge improvement to the bayou. It provided significant protection during Beta by knocking down water levels in the bayou several feet. But, a serious flooding problem will continue to exist in many of the areas that have been impacted by flooding in the past.”
Bedient is the Herman Brown Professor of Engineering and chair of the Civil and Environmental Engineering Department at Rice University. As director of the SSPEED Center (Severe Storm Prediction, Education & Evacuation from Disasters Center), Bedient’s job is to research protection strategies for severe storm flooding and hurricane-related surges in our Gulf Coast region.
Bedient explained that flood control, or management, involves various methods of reducing the extent of flooding or flood damages. In the past, one common method was to dig out watercourses by widening and deepening them. Another common method was to sometimes further increase the flow of water in a channel by lining it with concrete, which allows more rainwater to flow in the channel, rather than overtopping the banks and flooding adjacent land. Engineered channels have a design capacity, meaning that they can maintain the runoff from a certain intensity of storm within the banks.
The major problem associated with flooding in Brays Bayou is due to upstream development, said Bedient. Development has severely reduced the remaining undeveloped land upstream that can soak up rainwater, as well as increase the amount and speed (measured in increased runoff) of water flow.
“When Beta hit, I estimate the detention ponds helped but didn’t do nearly as much as the widening of the bayou,” said Bedient. “The pond at Arthur Storey Park worked just fine, but the other detention ponds are way upstream. We argued that we needed the land occupied by both of those old golf courses at Braeburn Valley and the old Westwood Golf course. If they had gotten both of those pieces of land and turned them into detention ponds, it wouldn’t have flooded nearly as badly in Meyerland over the years because you’re catching the water in the middle of the bayou and holding it before slowly releasing the water out of the ponds.
“By the 1990s, most of the land along Brays Bayou was developed and fully built out. There was no place to build a large pond or storage area. The result is that Brays Bayou is the most flood-prone watershed in Texas. Meyerland is a beautiful area, but it never should have been allowed to develop as it did,” he said.
There’s also the fact that we’ve experienced a series of storms that have deposited increased amounts of rainfall on Houston. Whether you believe that climate change is responsible for increasing amounts of storm rainfalls, the fact is, since Tropical Storm Allison in 2001, Harris County has experienced record-breaking storm rainfall amounts.
Rainfall amounts associated with Allison were reported as high as 26 inches in 24 hours. Allison flooded about 74,000 homes in Harris County.
The storm of July 14, 2012, dumped more than 14 inches of rain in 24 hours in parts of Harris County. In May 2015, we had the first of two Memorial Day floods. This storm dropped about 11 inches over 12 hours on the Brays Bayou watershed and the Meyerland area near Loop 610. Brays Bayou experienced the first of three major flooding events to impact the area. Eight persons died in this storm, and there were 531 water rescues.
In April 2016, we had what has come to be called the Tax Day Flood. This event was not tropical in nature, but was associated with an April cold front. The storm dumped 15 to almost 17 inches in 12 hours.
Hurricane Harvey set a national record for the amount of rainfall over a four-day period. Most of Harris County received at least 30 inches or more over this time period. An estimated 130,000 homes were flooded.
Bedient contends that in mitigation strategies, we currently are in “a catch-up game.”
“We can’t get ahead of the development and the increased rainfalls. And, we don’t have enough planning to buy sufficient land to build large regional ponds to store the water,” he said.
“FEMA is now re-mapping the old floodplains. The folks who used to be in the 500-year floodplains will be in the new 100-year floodplain. That means your flood insurance rates are going to shoot up by a factor of 4 or 5.”
It is also means, argues Bedient, that the designs of the federal projects, like Project Brays, are not based upon this revised floodplain and therefore do not fully solve the existing flooding problems. The old 100-year floodplain is used by state and federal agencies for issuing state and federal permits for sewage and water treatment plants, hazardous waste facilities, landfills, and designing state-funded and federally funded projects.
As a result, there still will be homes near creeks and bayous that will remain at risk of flooding, even with the money being spent on federal and local improvement projects.
“You can elevate your home, but what about the people who cannot afford to do so? The solutions for Harris County are far and few between.”