Hurricanes Propel Forward Thinking on Risk, Resilience
Climate-change issues loom larger as hurricane-ravaged regions struggle to recover
Even as hard-hit areas of two of the country’s most developed regions push for normalcy after back-to-back hurricanes in early September, policymakers and construction industry experts are weighing the longer-term implications of the damage in Houston, Florida and the Caribbean from Harvey, Irma and now Maria—and how and whether infrastructure resiliency can be accelerated and how that will affect coastal development.
“Our infrastructure is aging and deteriorating. That makes situations worse,” says Mark Abkowitz, director of the Vanderbilt University Center for Environmental Management Studies. “It will be difficult to make urban areas more resilient to flooding. In some ways we have our hands tied behind our backs because we’ve allowed development along the coast to occur. We’re going to have to chip away at this problem.”
Samuel Brody, director of the Center for Texas Beaches and Shores at Texas A&M University, noted in a 2011 book he co-authored on development and flood risk that Florida came out ahead of Texas in terms of soil, geography and planning for climate change. “We generally found Florida is better prepared and in a situation to address flooding problems, which showed up in per capita flood loss during our study period,” he says.
Hurricane Harvey’s catastrophic rainfall could be a game changer.
The lessons learned from the 40-in.-average rainfall in Houston, which peaked at 52 in., and subsequent flooding will be a guidepost for every urban area in the world that is experiencing more frequent torrents, says Edgar Westerhof, national director of flood risk and resiliency for Arcadis North America. Rather than on 100-year and 500-year events, the focus should be on “how your urban environment functions during these kind of extremes,” he says, with smarter watershed planning. Westerhof and others advocate more natural systems and flood-zone risk education.
The storm may be the tipping point to move Texas to a more holistic approach to water management. For years, the state has been studying options for a coastal protection scheme after the near miss of Hurricane Ike in 2008, but leaders have been unable to move forward and largely eschewed a region-wide approach to water management.
Westerhof says that after Harvey, “municipalities need to align their thinking and have a coastal master plan that includes drainage. It’s not just Houston or Galveston.”
Florida also has big challenges to meet. As Irma bore down on Puerto Rico, the U.S. Army Corps of Engineers closely tracked its progress, the intensity of the wind and Lake Okeechobee’s projected storm surge and elevation to determine areas of risk around the 143-mile earthen Herbert Hoover Dike. Engineers also performed a thorough inspection of the dike and prepositioned inspection teams to be available as needed.
On Sept. 5, the Corps began a pre-storm drawdown of water in Lake Okeechobee—as much as 4,000 cu ft per second west to the Caloosahatchee Estuary and 1,800 cfs eastward to the St. Lucie. The lake stage then was 13.67 ft, below the 15.5-ft elevation that triggers increased surveillance, and Irma’s track forecast cone was still very broad, but the threat to Florida was clear.
Experience with Irma has validated the caution.
On Sept. 18, the lake stood at 15.5 ft and rising, Carol Bernstein, Corps district operations division chief, told a press briefing. That elevation triggers increased surveillance and frequency of inspection because engineers expect increased seepage and piping, especially on known points of the dike, added Laureen Borochaner, engineering division chief.
On Sept. 17, inflow to Lake Okeechobee was 36,000 cfs and had added 0.16 ft to the lake’s elevation in the previous 24 hours. Conservative inspection indicates the elevation could reach 16.5 or 17 ft. “At the current rate of inflow, if there is no more rain, the level will reach its peak within two weeks,” she said.
The dike has been the focus of an active rehabilitation program to replace control structures and install cutoff walls, Bernstein said. Construction has been completed on 21.4 miles of the cutoff wall, and 35 miles remain to be built. Completion is scheduled for 2025.
While Jacksonville, Fla. did not suffer a direct hit from Irma, two neighborhoods suffered severe flooding. In one, the Riverside area, “you had high water that people had not seen in a very long time, maybe more than 25 years,” says Christopher Brown, associate professor of civil engineering at the University of North Florida. “I think the city would have to consider things like floodwalls along portions of Riverside.”
He cites their effectiveness in other cities such as St. Louis, which has a 50-ft-tall wall. A 5- to 10-ft wall would work for Jacksonville, Brown contends. “There could be a combination of walls, floodwalls, pump stations and maybe even a levee,” he adds.
But the city needs to go beyond engineering, the researcher says. “People talk about these extreme storms. We need to prepare for more of these. We used to think of them as odd combinations that don’t happen very often, but I believe the frequency is going to increase, because things like urbanization … and climate change are things we’re going to have to prepare for.”
Meanwhile, cities, utilities and construction professionals are scrambling to recover and be ready for the next big one—in this still unfolding hurricane season and others in the future.
Houston Mayor Sylvester Turner appointed on Sept. 14 former Shell Oil Co. president Marvin Odum as the city’s chief recovery officer. Turner says he wants Odum, leader of Shell’s recovery after Hurricane Katrina, to recommend bold moves that position Houston to be ready for the next storm.
Likewise, Harris County administrative county judge Ed Emmet has said all options are on the table to improve flood control in the fast-growing area. For now, the region is focused on recovery and drainage projects already in planning stages.
County road crews worked 24/7 shifts to repair in days an inundated highway that normall would have taken weeks.
Texas Gov. Greg Abbott (R) also has set up a task force to determine how to rebuild the state, led by John Sharp, Texas A&M University chancellor. “We are working to get before the task force to provide input of the previous planning and needs for the Houston area,” says Bob Pence, chairman of Texas design firm Freese & Nichols, which helped bring the flooded Beaumont, Texas, water supply system back to operation.
To restore power that was lost to as many as 7.8 million Southeast customer accounts, utilities have mustered thousands of workers and implemented strategies for hardening that they learned from their Northeast peers during Superstorm Sandy in 2012.
Daniel P. McQuade, AECOM Group construction services president, says “one of the most critical enablers of a faster and more effective recovery from storms such as Harvey and Irma is thorough preparation of active construction sites.”
He says crews lowered sections of tower cranes and expedited concrete pours of all open decking on its sites. Even so, partial collapses occurred at three south Florida tower sites not linked to the firm.
Jamie Cook, construction sector analyst for Credit Suisse, says most investor calls to the firm last week focused on financial impacts on public firms and their projects in storm-affected areas. She said affected firms “have the ability to declare a force majeure event for a named storm for projects currently under construction.” Forecaster Global Insight predicts the economic impact of both storms totaling at least $300 billion.
"Immediate impacts from the storms could include unscheduled downtime, and perhaps an uptick in FEMA orders. Expectations regarding the medium term (6-9 months) should be managed, however, as true reconstruction will probably not commence in earnest until insurance recoveries start to trickle in, said Brent Thielmann, construction sector analyst for D.A. Davidson Co. in a Sept. 19 investors' note. "The long term impact of the storms will be felt for years, but will be difficult to differentiate from fundamental demand, particularly in Houston, which is already the nation’s largest homebuilding market. Short-term E&C and heavy materials suppliers operating in these regions will see negative impacts, although interestingly no companies reduced annual guidance."
Some energy-patch observers predicted more project start delays in the hard-hit Gulf Coast region.
Matt Zeve, Harris County flood control operations director, said the county is working with federal, state and local agencies to secure money to repair storm damage and fund some of the backlog of $1 billion in capital improvement projects, now progressing at just $60 million a year, some of which are cost-shared with the Corps of Engineers. Zeve says agencies are also developing a comprehensive buyout program to purchase homes that have repeatedly flooded or are in high-risk areas. He says the effort could include buyouts of reluctant homeowners.
Federal assistance and funding will be critical in providing relief, recovery and reconstruction assistance to Texas, Florida and other areas hit by the still-unfolding stream of hurricanes.
“We have always designed ourselves to be able to meet two of these disasters and do them at once, and I think FEMA prides itself on doing the same. But when you throw three or four together, that’s when you have to be very innovative,” Army Corps of Engineers Commander Lt. Gen. Todd Semonite told ENR in an interview Sept. 19.
He says the Corps has deployed 350 people to Harvey-affected areas, and now has 122 in the U.S. Virgin islands awaiting Hurricane Maria, “riding through a Cat 5 storm only because we know … we have to respond very fast when it comes to power generation, temporary roofs and debris removal.”
The first in what is expected to be a series of emergency disaster-relief measures is providing $15.3 billion to agencies working in storm-battered regions. The measure, which President Trump signed on Sept. 8, provides $7.4 billion each to the Federal Emergency Management Agency for disaster relief and to the Housing and Urban Development Dept. for community development block grants that can be used for infrastructure.
The legislation also extends the flood insurance program through Dec. 8; authorization had been set to expire on Sept. 30. Sen. Bill Nelson (D-Fla.) said in a Sept. 10 TV interview that Congress will take up a second disaster relief bill in mid-October and Tom Bossert, Trump’s homeland security adviser, told reporters in a Sept. 11 White House briefing that one or two additional follow-up measures could follow.
With all plans implemented, Harris County’s Zeve said that he expects flooding would be lessened in the event of a major rainfall, but not completely eliminated. “Engineers can do anything, but no engineering criteria is designed for 40 inches of rain,” he says. Houston is drained by hundreds of creeks and several bayous. Ditches, roads and highways are designed to carry runoff to those creeks. But over the years, development in Houston and Harris County has left fewer and fewer places for the water to go.
“It’s just taking water off your property and putting it somewhere else, and there are fewer somewhere elses,” says Vanderbilt’s Abkowitz, also a professor of civil and environmental engineering. “It’s basically promoting flooding.”
Development also fragments natural drainage systems and has covered prairie land that could absorb as much as 11 in. of water within the first hour of a rainfall, says Texas A&M’s Brody.
Retired Army Lt. Gen. Robert Flowers, former Corps of Engineers commander and now a now senior advisor at Dawson & Associates, says a lot will hinge on whether Houston can gain money from Congress up front like New Orleans did after Hurricane Katrina.
“Now that we have had biblical events —a lot of it is centered around funding, you can be really creative around what you can do,” says Stephen Costello, Houston’s director of resiliency, also known as the city’s flood czar.
Zoning, however, won’t be one of those things. Houston, the self-professed “city with no limits,” doesn’t have zoning, and Costello says that won’t change. Costello says zoning would have just resulted in a zoned city that flooded.
Houston may reexamine ordinances that set criteria for parcel development. The city is responsible for water from rooftops to bayous. In 2010, it implemented a program to upgrade drainage infrastructure and roads. Costello says there is only so much the city can do. The drainage basin, the area’s creeks and bayous, are managed by the county flood district.
Additionally, two Corps of Engineers reservoirs built in the 1940s, Addicks and Barker, proved inadequate during Harvey and the Corps had to release water into neighborhoods to prevent worse flooding and potential dam failure.
“You are never going to be able to bring risk to zero,” says Corps chief Semonite. “These reservoirs were built around 70 years ago, to be able to handle a certain load. This particular storm far exceeded what was ever in those reservoirs in the past. ” He adds that “you have to manage the risk to figure out what … governments can afford when it comes to flood control, and compliment that through zoning, smart development, insurance programs and all those other pieces.”
A plan for a third reservoir has been discussed for years, and has gained new interest since Harvey.
The county has a no-impact policy that prevents Houston from building projects that will add more water to the bayou. Yet a 2016 report that examined Houston’s 2010 “Rebuild Houston” program to improve drainage and roads says that the city’s construction of below-grade roads to carry stormwater to the bayous is having an impact.
“The current criteria encourages streets to be lowered in elevation resulting in more frequent flooding of roadways, at deeper flood depths, for longer durations,” according to the report. “The current criteria produces a flawed and false sense of security. This criteria can typically only be achieved when a false assumption is made that during the storm event, the downstream bayou, stream, tributary or open channel is basically empty. This is not a likely occurrence.” Designing to a 1-in-100-year standard within a flood plain also has proven woefully inadequate in Houston.
A study published just days before Harvey found that FEMA’s 100-year floodplain maps failed to capture 75% of the flood damage from Hurricane Ike in 2008, Tropical Storms Erin in 2007 and Allison in 2001, and two rainstorms in 2006 and 2009.
Jim Blackburn, co-director of the Severe Storm Prediction, Education and Evacuation from Disaster Center at Rice University in Houston and a professor of civil and environmental engineering, suggests that until the standards are changed to reflect the most recent storms, engineers should look to the 500-year flood standard. But even then, he says, the onus is on engineers to look beyond standards when designing new infrastructure and buildings.
“A Texas engineer’s first obligation is to protect the public. At what point do engineering ethics require you to speak out when a client refuses to acknowledge that climate change is happening,” he says. “At what point do you refuse to design to an old standard that has repeatedly shown to be inadequate?”
Texas A&M’s Brody says Houston’s flooding is a symptom of a resiliency breakdown, adding that there must be a look at the broader region and a systemic review of the entire system. “I am hopeful,” he says. “I have to be optimistic that this is an opportunity to make a change.”
By Pam Radtke Russell and Debra K. Rubin, with Tom Armistead, Tom Ichniowski, Scott Blair, Mary B. Powers, Tim Grogan, Jeff Rubenstone and Louise Poirier