As Hurricane Season Begins, ‘Green’ Flood Control Finds Support in Texas (With Accompanying ASPN Interview)
As greater Houston seeks protection from the next Hurricane Harvey, using natural features like prairies and sand dunes to control water is gaining purchase.
HOUSTON— With the 2019 Atlantic hurricane season under way as of June 1, Texas has taken a major step toward improving its flood defenses by passing a bill to tap into the state’s savings—the aptly nicknamed Rainy Day Fund—for a sum of $1.7 billion. The move comes almost two years after Hurricane Harvey deluged Texas in August 2017, killing 68 people and causing an estimated $125 billion in damage statewide.
Texas lawmakers passed Senate Bill 7 in late May, and it now awaits the signature of the state’s Republican governor, Greg Abbott. For municipal governments around the state, small and large, the bill’s passage means an influx of money through grants and loans that will unlock cost-sharing federal dollars for as-yet-unspecified resilience schemes.
Houston Mayor Sylvester Turner and Harris County Judge Lina Hidalgo wrote to Abbott and other senior state politicians in January urging them to free up some of the reserves. A spokesman for Turner said last week that the mayor advocated for the Rainy Day funds “because of massive return on its investment for flood projects.” For FEMA Public Assistance projects, such as repairing buildings and parks and replacing equipment, local governments will get $9 for every $1 spent. For FEMA Hazard Mitigation Grant projects, the state will get $7.50 in federal aid for every $2.50 it spends.
A chance to push for green infrastructure
With its loyal support for the oil and gas industry, it’s not often that the Texas legislature gives conservationists anything to cheer. But the text of Bill 7 cites “construction and implementation of nonstructural projects, including projects that use nature-based features to protect, mitigate or reduce flood risk.” Environmental advocates see a chance to push for green designs in a state better known for exploiting natural resources than preserving them.
Lawmakers still envision a significant role for traditional “gray” engineered solutions, such as pipes, levees, drainage channels, and retention basins. But Laura Huffman, state director for The Nature Conservancy, thinks politicians are “recognizing that green infrastructure can scale just like gray infrastructure,” she said.
“So we could do things as small as pocket prairies in a neighborhood—which could be restoring a vacant lot, a parking lot, a front yard—and that actually can do a lot for helping to manage the ‘flashy’ parts of flash floods,” said Huffman. “And you can scale that strategy out to a city and a regional level.”
Making landfall as a Category Four hurricane, Harvey flooded more than 154,000 homes in Harris County, which encompasses Houston. The region did not wait for the state legislature to take action. Exactly one year after the storm made landfall, Harris County voters approved a $2.5 billion bond measure to finance more than 200 flood-control projects. Several dozen contracts with engineering firms have since been approved, for repairs, upgrades, and analysis. Some of the bond-measure funds went to buyouts.
Buyouts make slow, ad-hoc progress
One of the most obvious strategies is to buy and demolish high-risk homes in floodplains to create absorbent green spaces—and Harris County had the largest buyout program in the nation even before Harvey. Since the storm, thousands of property owners have volunteered for buyouts.
But resilience through buyouts is harder and more complex than it sounds. “The traditional buy-out approach is typically initiated in a reactionary, ad hoc manner—after flooding has already done its damage. This creates a checkerboard pattern of vacant lots,” said a Nature Conservancy report released in February that advocates more proactive and clustered buyouts.
Also, local governments using federal money cannot force out homeowners to achieve clustering. A spokesperson for the Harris County Flood Control District said its buy-out program has always aimed to avoid “checkerboarding,” but it must follow FEMA guidelines, and buyouts must be voluntary.
The slow speed of the process can persuade frustrated homeowners to stay in their homes after all. According to Harris County figuresfrom May, out of the 4,000 homeowners who have opted for buyouts, 1,100 are now approved (at a cost of $310 million) and 450 cases are under way; only 322 homes have been purchased. Meanwhile, more than 100,000 homes are estimated to remain in flood-prone areas.
Heavy engineering’s weak spots
On a much larger scale, the U.S. Army Corps of Engineers manages two giant flood control reservoirs and dams in west Houston and is planning a coastal “spine” or barrier for Texas that could cost up to $31 billion. The fate of similar heavy, gray infrastructure in Louisiana may be a cautionary tale.
Following Hurricane Katrina, the Army Corps built a $14 billion system of levees, pumps, gates, and flood walls to protect New Orleans. It was completed last year, 13 years after the storm. But the Corps revealed in April that the defenses will cease to provide their intended degree of protection as soon as 2023 because of sea-level rise and subsidence. The Corps is now considering using sand dunes in place of levees in Texas because of their smaller environmental impact, the Houston Chronicle has reported.
The complexity of Houston’s challenge is illustrated by the Buffalo Bayou, which flows through Houston from west to east. Thousands of homes flooded when the Army Corps deliberately released water from the reservoirs rather than risk potentially even more disastrous uncontrolled inundations. One west Houston neighborhood known as the Energy Corridor still bears the scars but is searching for solutions.
On a recent morning, builders worked on a new house on the north side of the bayou, its foundations elevated about six feet above ground, unlike its unfortunate older neighbors. Opposite, two yellow excavators rumbled along neatly sloping banks, their back-up warning beeps audible over twittering birds. A few days prior there was a dense covering of sycamore and pine trees; now, razed trunks laid piled in the clearing.
The flood-control district is slicing slivers of forest to fashion mostly-bare grassy slopes into a basin that will hold stormwater—although almost certainly not enough to prevent flooding if another Harvey hits, the district acknowledges.
“Engineering companies want to do the most expensive thing they can do,” complained Susan Chadwick, executive director of Save Buffalo Bayou, a local advocacy group. Her group argues that chopping down trees and vegetation reduces the land’s stability and potential to absorb water and capture pollution; adds to repair and maintenance costs; and has a negative impact on residents’ wellbeing.
The detention project feels like a compromise between natural and artificial flood-control techniques. “After Harvey, they needed to bring some stuff off the shelf and show they are ready to do something,” Chadwick said. She is skeptical that a city that used concrete to conquer swamps, marshes, and prairies can learn to restore green spaces—or just leave them alone.