During a Virtual Community Engagement Meeting on June 16, the Harris County Flood Control District released the final report of its Phase 2 Study of the Feasibility of Constructing Storm Water Conveyance Tunnels. The primary presenter was Scott Elmer | HCFCD Asst. Director of Operations, who was joined by Tommi Jo Scott | Engineering Project Manager for the Q&A session. A recording can be viewed at https://www.hcfcd.org/Z-08.
The Phase 1 study, completed in September 2019, had concluded at a conceptual level that tunneling could be applied in Houston’s soil conditions, and that tunnels could move enough water to make a difference.
The Phase 2 study included rainfall/runoff modeling, past flooding data, and the identification of high-risk “flood damage centers” to establish criteria for the location of tunnels, that together with other approaches, would potentially provide the greatest benefits. The report proposes 8 tunnel systems affecting 11 different bayous. Tunnels would range in capacity from 7,260 cfs to 12,020 cfs, and, with some exceptions, would generally follow along the channels of existing bayous. A summary table of the tunnels’ lengths, diameters, and underground depths appears at 34:09 in the video and on pages 7-3 and 7-4 of the 1860-page Phase 2 Final Report.
Public comments will help to shape the much more detailed Phase 3 Study, which will begin in spring of 2023 and is expected to take 3 years. The public comment period runs through Sept. 30. Submit your comments online at https://www.hcfcd.org/Z-08. Updates will be posted on the HCFCD website.
