The Harris County Flood Control District (HCFCD) and EHRA Engineering recently held a public presentation concerning Huffman-area drainage improvements. The meeting was held July 11.
“This is one of the 239 projects within the HCFCD Bond that was passed in  … It was a $2.5 billion bond issue,” said Matt Zeve, deputy executive director of HCFCD.
“The purpose of the analysis, known as bond project F-110, is to investigate multiple scenarios to reduce structural flooding,” said Jennifer Hundl, project manager of EHRA. “The study coincides with the boundaries of Huffman ISD and covers portions of the East Fork San Jacinto River, the Luce Bayou and the Cedar Bayou watersheds. Currently many streams within the area only provide a 10-year level of service. We analyzed the requirements to make the streams in the project area meet a 100-year level of service.”
Hundl explained the requirements for a 100-year level of maintenance. To provide this service, the drainage system must be able to accommodate a 13.2-inch rain over a 24-hour span without any flooding occurring within the inundation boundary.
“We conducted studies to examine the structural and non-structural tools that would be sized to contain all of the rainfall for 10-, 50-, 100- and 500-year events,” said Hundl. “The flooding source in the Huffman area turned out to be the main Luce Bayou and not the streams.”
Hundl first discussed the non-structural tools that were taken into consideration. “We examined flood plain preservation, which is the acquisition of property within the inundation boundary … This scenario does not provide a deduction in flooding. Another non-structural tool that we examined was the acquisition of impacted structures [which] focuses on structures that are at risk, but not roads or vacant land,” said Hundl.
Hundl went on to discuss the structural tools that were examined and studied. “The first structural tool examined was upstream detention, a concept based on the storage of water at or near the boundary of Harris County and Liberty County. Ninety-three percent of the water contained in Luce Bayou has contributed drainage area from outside Harris Country; this scenario would reduce flood risk. The the next tool we examined was channel modification whose concept is to provide more channel capacity to carry stormwater downstream which would result in a lesser risk of flooding. The next tool we examined was a diversion channel which would provide more storage by conveying water and diverting flows from the main stem of Luce Bayou; it would result in a reduction of flood risk with regards to the Luce Bayou main stem and it could be utilized to relieve drainage issues around FM 2100,” said Hundl.
“Two routes for water diversion were examined. These routes are conceptual at this stage, [however],” said Hundl.
The study concluded with a recommendation to amalgamate several structural tools for later implementation. “These concepts were intertwined. We recommend a combination alternative that includes channel modifications, upstream detention and a diversion channel to provide a 100-year level of service. The total cost of these recommended modifications is estimated to be $264 million,” said Hundl.
This project is still in its early stages. “The combination alternative could be built in phases as funding becomes available,” said Hundl.
“We are finalizing the feasibility stage and finalizing our recommendations which will be completed this fall. This would then move into a preliminary engineering phase. HCFCD is looking to coordinate with TxDOT on FM 2100 improvements. In the mid-term, another study will finalize the details of the PER and begin the acquisition of property for the diversion channel which needs approximately 500 acres. In the long term, we are looking to implement the master plan,” said Hundl.
For more information, visit hcfcd.org/FC110.