New details could emerge soon on the potential use of underground tunnels to carry flood water in Harris County, and officials voted May 11 to dedicate an additional $3.26 million to study efforts along Buffalo Bayou.

The new funding—requested in $1.68 chunks by Precinct 3 and 4 commissioners Tom Ramsey and Jack Cagle—will be used to build on a Buffalo Bayou and tributaries study to include the identification of flood risk reduction alternatives that also have benefits on local and regional mobility.

The move comes as Russ Poppe, the executive director of the Harris County Flood Control District, said work on the second phase of the flood tunnel study is nearing completion. An initial study phase confirmed the feasibility of the flood tunnel concept, and the second phase—which in part will identify the top three to five potential routes for the tunnel—kicked off in May 2020. The possibility of flood tunnels have been pitched everywhere from Clear Creek to Cypress Creek.

"We did look at the need across Harris County for tunnels on multiple watersheds, including in Halls, Greens, Hunting, Cypress Creek and others. We're going to present that information as we best see it," Poppe said at the May 11 meeting. "The criteria we used [will help] us identify, out of all of our tunnel opportunities, which ones make the most sense to advance first, knowing we have limited funds to do so."

The motion was supported unanimously by the court, but commissioners Rodney Ellis and Adrian Garcia both stressed the importance of making sure bayous are not left out of consideration for not having an ideal cost-benefit ratio, a metric often used in the allocation of federal funding that can result in communities with lower valued housing being passed over for funds regardless of how badly flood relief may be needed in those areas.

"The [Army] Corps [of Engineers] ... their projects are all slanted towards cost-benefit ratio," Ellis said. "I just want to make sure, as we strive to change that, we don’t just keep doing what we’ve always done."

Garcia also pressed Poppe to make sure any flood tunnel that gets a green light will not make flooding worse downstream in east Harris County. Poppe said part of the study involves looking at where and how water could be discharged from a tunnel so that it does not increase flood risk or cause erosion.

County dollars going toward the study are being supplement with federal Community Development Block Grant funds. The Army Corp of Engineers screened the use of a flood tunnel in an preliminary report released on Buffalo Bayou last fall, prompting criticism from number of groups who called for a tunnel to be reinserted as an option. However, HCFCD officials said their own studies into a tunnel have been continuing unimpeded.

Although questions still remain to be answered, Ramsey said he believes the flood tunnel for Buffalo Bayou has the potential to address the needs along that bayou while also providing relief elsewhere in the county.

"This is certainly better than channelizing Buffalo Bayou; this is certainly better than building a third reservoir," he said at the May 11 meeting. "There’s got to be a first tunnel somewhere ... the two big reservoirs out there are a place to start."