Prolonged Rains Conceal Full Hurricane Harvey Destruction
As reports trickled in of sinking streets, collapsed bridges, flooded refineries and overtopped dams, engineers, contractors and government officials remained focused on saving lives during the continuing disaster of Hurricane Harvey in Texas before assessing the damage of the storm and subsequent flooding.
“What is happening in Houston is a life-changing event for our entire community,” said Carol Ellinger Haddock, the city’s acting director of public works and a board member of the American Society of Civil Engineers at ENR press time on Aug. 29. “Seventy-two hours in and we are still actively rescuing people stranded on roofs and in homes with water. Recovery will take years.”
With a reported death toll at 14, threats to life, property and infrastructure continue. South of Houston, one levee holding back the Brazos River was breached on Tuesday, and officials urged residents to evacuate. Jeff Linder, a Harris County meteorologist, said one trillion gallons of water—enough to run Niagara Falls for 15 days—fell on the county in the four days after then-Hurricane Harvey came ashore on Aug. 25 and became a tropical storm that moved inland and stalled over Houston. Many areas of America’s fourth-largest city received 40 in. of rain, with an additional 7 in. to 13 in. possible by Sept. 1. Federal Emergency Management Agency chief Brock Long said in an Aug. 28 press conference that 30,000 people were expected in shelters and 450,000 would seek federal aid. He pledged to help Texas “find a new normal.”
“The situation in Houston is dire,” David Singleton, CEO of Houston-based subcontractor Griffin Dewatering. “We are unable to get to many sites where we have active dewatering occurring. Many projects have been impacted. The city is literally impassable at this point.” John Marshall, vice president of Houston builder Satterfield & Pontikes Construction, adds, “We have experienced the full range of impacts, from minor to severe.”
Rivers in central to south Texas were continuing to rise and were expected to crest on Aug. 30 and 31. Several cities south of Interstate 10 issued mandatory evacuations, including Missouri City, Sugar Land, Rosenberg and Bay City, near the Brazos River. That waterway was set to reach 57 ft on Aug. 31—equivalent to an 800-year flood.
Exacerbating the flooding were the unexpected releases by the U.S. Army Corps of Engineers from the Addicks and Barker reservoirs in attempts to prevent breeches. The Corps owns and operates the reservoirs, which were built in the 1940s to prevent flooding in downtown Houston and the Houston Ship Channel.
Portions of I-10 Still Flooded
The Texas Dept. of Transportation still was surveying road conditions, with many roads, including portions of I-10, still flooded. The agency reported more than 500 flooded roads, with some washed out and at least one bridge said to have collapsed. Marc Williams, deputy DOT executive director, told the Weather Channel that floodwaters and storms have to subside before road repair can begin. “The time and duration [of restoration] is something that is outside of our control right now,” he said.
On Aug. 29, the Texas Dept. of Environmental Quality had just begun to assess damage to drinking-water and wastewater plants and survey potential chemical releases from Superfund and other industrial sites. “Our folks are en route,” says Andrea Morrow, a spokeswoman. “It’s a moving target.” As of noon on Aug. 29, at least five wastewater treatment plants were inoperable because they were flooded, had no power or were damaged in the storm. Several water districts have issued precautionary “boil water” advisories.
The Federal Railroad Administration declared a state of emergency that ceased operations on Houston’s light-rail system, Amtrak and Class 1 freight railroads; area airports remained closed. All but one of the state’s ports were closed and were expected to remain shut until at least Aug. 30, hampering shipments of the nation’s fuel supplies.
Bechtel, which is constructing a liquefied-natural-gas terminal in Corpus Christi for Cheniere Energy, uncovered only minor cosmetic impacts from the storm that came ashore late on Aug. 25, according to Cheniere. The company did not shut down LNG production at its Sabine Pass facility, west of Houston.
“Across our projects and Houston office, we continue to evaluate the current weather conditions and heed the advice of the local authorities before reopening for normal work activities,” said Bechtel spokesman Mat Ovenen. A Fluor Corp. spokeswoman says, “Our project sites in the affected areas are also closed,” but she declined to identify specific projects or whether they sustained flood damage.
Energy Facilities Offline
Several refineries and other energy production facilities were off line as of Aug. 28, including Exxon Mobil’s Baytown facility on the Houston Ship Channel, the second-largest U.S. refinery. In a statement, the firm said noted that, at Baytown, extreme weather and flooding caused “operational issues,” which were not detailed.
“I think that the final magnitude of the storm has not yet been defined, and the enormity of it will be incredible,” adds Bob Pence, chairman of Ft. Worth-based infrastructure engineer Freese and Nichols.
According to Pence, the firm’s municipal clients took precautions, including lowering lake and water retainage-structure levels to accommodate the rainfall. In addition to flood damage, he noted that cresting rivers will affect “slope and foundation stability of the road networks” and levee stability. Pence says the firm has been tapped by FEMA for flood assessment work and expects similar assignments from local clients.
ASCE President Norma Jean Mattei said the group is in close communication with Houston leaders “to evaluate what can be done to improve the resiliency of infrastructure as Houston rebuilds and what lessons we can learn to enhance public safety in future events wherever they may occur.”
The U.S. Dept. of Energy reported that, as of early Aug. 29, 18% of offshore oil production was still not on line following the storm and that more than 270,000 customers throughout Texas were without power.
Power restoration dates had yet to be determined in the areas with the greatest damage from the storm, including Matagorda County, Rockport, Port Aransas, Fulton, Woodsboro, Port Lavaca, Lamar and Bayside. Utility CenterPoint Energy said it would be unable to address outages in downtown Houston until floodwaters had receded and electric infrastructure dried out. The utility said that, in some areas, “we are proactively taking service off the grid to avoid long-term damage to our electric infrastructure under water.”