Photo: Flickr user Norm Lanier.

A new report provides an exhaustive look at potential flood fixes and how to understand each.

Mayor Sylvester Turner called it a "defining moment" when City Council approved new floodplain development regulations Wednesday. "Can we undo what was done with Harvey? No. But can we build looking forward? Yes," Turner told the council.

Under the new regulations, new development will have to be built two feet above the 500-year flood-plain. A significant step, the regulations are just one flood mitigation tool on the table, in addition to buyouts and talk of a third reservoir, among other proposals. A new exhaustive report from the Greater Houston Flood Mitigation Consortium, which includes the Kinder Institute for Urban Research, details how these and other projects and proposals fit into what should be a balanced approach that aims to both reduce flooding vulnerability as well as the impact of flooding. Though the report does not include recommendations, it does frame how to evaluate a wide array of flood mitigation strategies and considers everything from drainage to buyouts and infrastructure.

Across all these areas, a few takeaways emerge to guide decision-making and help the public make sense of the many ideas being floated.

Proposed projects or changes should have a clear goal.

"Instead of just saying we need a third reservoir," said Kyle Shelton, director of strategic partnerships for the Kinder Institute and one of the researchers involved in the Consortium report, "you need a third reservoir for what outcome? What are you trying to protect?" Indeed, plans for a third reservoir pre-date Hurricane Harvey and as currently conceptualized, said Bill Fulton, director of the Kinder Institute, it "will mostly protect undeveloped land that developers are wanting to develop rather than existing structures and residents." 

That doesn't mean a third reservoir can't be made to do something different. "The third reservoir that was talked about in 2014 and 2015 is about allowing more development, is that what we want it to do," said Shelton. "Or do we want it to prevent flooding in Cypress Creek? Or do we want it to be about actually helping Addicks and Barker?" That extends beyond just the third reservoir to all mitigation strategies being proposed. "If we’re going to do buyouts, what is the goal? Removing people from harm’s way? Creating buffer zones," asked Shelton. "The report shows there is a need for specificity. We don’t get the best answers if we just say, 'Here’s this nondescript solution.'"

Solutions need to be transparent and participatory

Building on the findings of the Kinder Institute's report on buyout best practices, the Consortium report emphasizes a need for public engagement across multiple strategies. Whether it's improved risk communications, better flood risk mapping or alternative tools that allow neighborhoods to articulate what's important to them and includes social and environmental impacts beyond a strict cost-benefit analysis, there's a need for better public engagement. In the case of buyouts, for example, the report notes, "extensive case management and adequate relocation assistance should accompany buyout efforts, and plans for these programs should be vetted by an entire community, not just targeted homeowners."

Source: Greater Houston Flood Mitigation Consortium.

Prioritize equity

Equity concerns extend across most flood mitigation strategies and include making sure that evaluations include more than an economic cost-benefit approach. But one particular contribution from the report is a breakdown of projects by watershed. Within those there are wide variations in funding and standards. "I think one of the most important things that this document does is talk about every single watershed and highlight the equity needs around that," said Shelton. So, he said, "Addicks and Barker are already 100-year flood control measures, but there are other watersheds whose projects are just engineering to a 10-year flood. They’re not solving for the same flood events." 

Infrastructure doesn't just mean channels 

That the built environment contributes to flooding is not surprising but the report highlights particular pinch points that likely cause flooding. "Much of the flood problem on Little White Oak is related to culverts and channels built in conjunction with the original construction of Interstate 45, such as the constriction point at the culvert under Interstate 610 that appears to increase flooding in Independence Heights," according to the report. "These issues can be addressed as part of the planned North Houston Highway Improvement Project to address flooding along Little White Oak."

Evaluate old projects on the books

"There are five watersheds in Harris County with a combined population of over 2.9 million that have ongoing federally-funded projects: Brays, Hunting, White Oak, Greens Bayous and Clear Creek," according to the report. "These projects will reduce flood risk in their respective watersheds, however, it is important to note that their completion will not eliminate flooding in these areas." Planned projects should be evaluated alongside proposed ones to ensure that the above goals are met. For each watershed, the report examines those projects.

What such thorough analysis makes clear is that a variety of strategies is needed. There is no one fix. "My own personal view," said Fulton, "is that you have to watch out for the idea that there’s a magic bullet that will solve all these problems. Every billion spent on that is a billion you don’t have for other stuff."