Freese and Nichols is providing program management support to the Harris County Flood Control District (HCFCD) for the Upper Langham Creek (ULC) Frontier Program. The impact fee-based program is a proactive approach to providing required infrastructure ahead of anticipated development. The Program will allow for the orderly implementation of a wide, naturally functioning floodplain which will provide sufficient outfall depth, mitigating detention volume and conveyance capacity to support future development. It will also offer unparalleled opportunities to enhance the community through the incorporation of recreational, environmental, open space and other multi-use features.
Freese and Nichols performed detailed H&H analyses for the 16-square-mile watershed, including unsteady-state hydraulic modeling to optimize the use of both in-line and off-line detention storage volume within the system. Freese and Nichols also performed a geomorphic assessment of the 8-mile ULC corridor and designed a conceptual geomorphic channel to promote stable channel function and reduce maintenance costs, and developed water quality best management practices (BMPs) to improve stormwater runoff quality.
As development occurs within the Program area, Freese and Nichols continues to assist in modification and optimization of the Program’s two regional detention basins in order to accommodate new roadway and development projects, recreational features, and to allow for the incorporation of other amenities and aesthetic elements. For one roadway, Freese and Nichols developed an innovative “bridge” section that utilized dual arch openings, allowing the crossing to also serve as a restrictor for in-line detention within the channel, an emergency overflow for extreme events and a control structure for a detention basin downstream. The bridge section also provided opportunities for trail crossings underneath the roadway and realized cost savings by combining the roadway crossing with the control structures.
As Program Manager, Freese and Nichols is responsible for reviewing the drainage studies and design plans submitted by developers. This has been done to help ensure that the proposed improvements are compatible with the overall program and that there are no adverse impacts during interim conditions. This has required intimate knowledge of the HCFCD policies, as well as significant coordination with a number of consulting firms and land owners.