Underground tunnels proposed for Houston flooding

HOUSTON – The flood control district for the Houston area is considering a proposal to build massive underground tunnels to drain floodwaters from bayous across the county.

Harris County Flood Control District officials said the idea could be a bold solution to alleviating the chronic flooding that has plagued the Houston area, including during Hurricane Harvey.

The project could cost several billion dollars and take several years to complete, the Houston Chronicle reported . It would build a network of deep tunnels to carry water from several of Houston’s waterways, so that they’d be able to keep a 100-year storm event within their banks.

A 100-year storm event refers to rainfall that has a 1 percent chance of occurring in any given year. It usually ranges from 12 to 14 inches in a 24-hour period. During each of the last three years, Houston has experienced a 500-year flood, which has a 0.2 percent chance of happening in any given year.

“What the flood control district has been doing for decades doesn’t occur fast enough or it doesn’t have the benefits that the public really wants,” said Matthew Zeve, director of operations at the flood control district. “We’ve been challenged to try to think of new ideas and new strategies and this is an answer to that challenge.”

He said the tunnel project would displace and disrupt far fewer people than other methods of reducing the flooding risk, such as widening bayous and buying out homes in especially flood-prone areas.

Commissioners will vote Tuesday on whether to pursue a feasibility study to assess the tunnel proposal. It’s estimated that the study would cost about $400,000 and be completed by October.

Republican Rep. John Culberson, of Houston, said he’s “encouraged” that the district “is thinking outside the box.”

“It certainly seems like this type of project could be partially funded by FEMA hazard mitigation grants and, perhaps, through other federal sources, as well,” he said.

A spokeswoman for Gov. Greg Abbott said it’s too early to comment on the proposal.