City crews this week launched a drainage pilot program that officials hope will delay the effects of sea level rise.
The pilot program involves a new stormwater drainage component, called a backflow prevention device. The first of the devices is being installed near English Bayou, and if the addition is successful, the city could add up to 40 more in areas south of Broadway, City Manager Brian Maxwell said.
“What we’re doing has never been done,” Maxwell said. “The manufacturer feels certain they’re going to work.”
The backflow prevention devices will be especially helpful in heavy rains, Maxwell said. In downpours, water comes down quickly and drainage systems have difficulty clearing water fast enough, backing water up the pipes, Maxwell said.
City crews had to drain any water surrounding stormwater drainage pipes before the components could be installed, and some of those pipes were more than halfway covered with water, Maxwell said.
“What we’re realizing is that our tidal inundation problem is worse than we originally thought,” Maxwell said.
The devices are part of a wider plan to address flooding as the Texas coast deals with the increasingly noticeable effects of climate change, including sea level rise.
“If it works, it’ll be really good for Galveston,” Maxwell said.
While sea level rise is an issue, the more immediate issue to be addressed is massive storms’ effects on drainage systems, said Wesley Highfield, an associate professor in the Texas A&M University of Galveston Department of Marine Sciences.
“The last round of Harvey stuff was directly related to drainage infrastructure,” Highfield said. “New drainage with a better capacity and larger lines fared better than older neighborhoods.”
“That’s where the drainage is going to be really important,” Highfield said.
Galveston uses a gravitationally-based drainage system, meaning it relies on the slope of the pipes to carry the water into channels such as bays and bayous. Galveston would likely run into problems because none of the elevation is high enough to create steep slopes, said Ben Hodges, an associate professor at the University of Texas at Austin’s Department of Civil, Architectural and Environmental Engineering.
“In places with steeper slopes, this is less of a problem,” Hodges said. “In some place as flat as Galveston, if you have a rainstorm that affects one neighborhood, you certainly could have water go backwards.”
The pilot program uses the Swedish-company Wapro’s WaStop in line check valve. The city is trying the system at no cost, but if it works, the city plans to install more at a total estimated cost of $3 million, Maxwell said.
Maxwell cautioned that the project is still a pilot and that there are no guarantees.
If sea levels continue to rise, the city will still need to find a longer-time solution to drainage problems, Maxwell said.
“We’ll solve it on the short front,” Maxwell said. “This is not a permanent solution.”
The situation has gotten dire enough that any project is worth trying, Maxwell said.
“The main goal is to do something at this point,” Maxwell said. “We don’t want to be Atlantis; we want to be Galveston.”