Green Stormwater Infrastructure

Austin's City Hall is regarded as one of the better applications of green stormwater infrastructure. (by Thinkstock)

You wouldn't treat a gunshot wound with acupuncture, but some former members of the Flood Mitigation Task Force fear that City Council's Green Stormwater Infra­struc­ture resolution represents an inadequate response to Austin's propensity for suffering damaging flash flooding ("When It Rains It Pours," April 21).

The resolution, passed unanimously at Council's June 15 meeting after being brought to the dais by Ann Kitchen, has been hailed by advocates including Environ­ment Texas, Clean Water Action, and Save Barton Springs as a step toward fulfilling the city's Imagine Austin goal of an Integrated Green Infrastructure Plan. "Green" stormwater mitigation uses vegetation and other natural methods to manage runoff that are often less expensive than "gray" infrastructure (like pipes and sewers). Kitchen's measure primarily directs the city manager to consolidate information about GSI and improve coordination between departments. Mike Kelly with the Watershed Protection Department noted that this focus relates specifically to CodeNEXT, the overhaul of the city's land development code. "Without directing staff to change CodeNEXT, [the resolution] basically says that these things are under discussion, and we want to make sure that staff is doing a deep dive, so that as [GSI] is discussed with the public [that] people have as much information as possible," he said.

Environment Texas' Brian Zabcik identified GSI as the "most important" environmental issue to be considered in the new land use code. "CodeNEXT is going to increase density in the city by some amount, meaning that impervious cover will increase, meaning more runoff," he said. GSI "can cut runoff." Kelly added that the majority of new GSI is built in this way by commercial entities through the permitting process, whereas participation by the residential sector is "low." The resolution does direct staff to revamp Austin Water Utility's WaterWise program, which offers rebates and other tools to encourage households to make green installations on their property.

Elloa Matthews, who sat on the FMTF until its work wrapped up last year, said she sees the benefit of green infrastructure and keeps two rain barrels at her house – one in the front and another out back. But she considers the city's prioritization of this approach as a way of sidestepping the enormous but urgent project of raising the capacity of stormwater management systems citywide. "I'm not going to say that it's a bad thing," she said, "but it's like we're getting a solution to a problem we don't have." The FMTF received a case study of GSI in the Brent­wood neighborhood last year and learned that the approach significantly reduced water pollution and mitigated flooding from smaller storms, but didn't work as a cost-effective way of protecting against bigger storms. Matthews said that staff described it at the time as a "boutique" solution.

Another former FMTF member, Carol Olewin, said that GSI may be "glamorous," but that the real problems remain underground. About a quarter of the storm pipes currently under the city were built before modern design standards were adopted, and more are in need of maintenance or upgrades. Olewin said that to tackle these real infrastructure needs would necessitate a bond. "Unfortunately we suffer from 'flood amnesia,'" she said. "The importance of maintaining these systems always goes to the bottom of the list until we have another big flood."

The last bond to include drainage funds came in 2006, at $95 million, and Matthews said that the current plan for the 2018 Initial Staff Bond Recommendations propose $75 million for flood mitigation and drainage improvements. She doesn't see how it makes sense to target less money for a problem that gets worse with time. On the other hand, Zabcik said that the city doesn't just need to protect itself against the rare disastrous storm, but that it needs some defense against the much more frequent smaller storms. "The city needs to be doing both," he said. "It's not an either/or question. A green/gray mix is most effective for flood mitigation."

Olewin said she agrees that the two approaches aren't mutually exclusive, but says it's a matter of prioritization. "I think that's why it's very important who we choose to be our new city manager," she said. "Do we want to focus on mandates that will look good and sell our city, or do we focus on the needs of the citizenry?" Of course, the public will not take part in the search for the new city manager. In March, Council hired Russell Reynolds Associates to begin scouting for candidates to replace Marc Ott, but RRA won't disclose its finalist until one is selected. For now, the future city manager, and their opinion on the best flood mitigation strategy, remains a mystery.