The Harris County Flood Control District (HCFCD) completed the Cedar Bayou Flood Risk Reduction Study (FRRS), which was funded as part of the 2018 Bond program. This study involved an investigation of the existing flood hazards in the watershed and identified potential future drainage improvements aimed at mitigating flooding and flood damage. While the focus is to improve existing areas with identified flood hazards and damages, future growth in the watershed will be considered with planned improvements which are beneficial in the long term. Included in the study are the Cedar Bayou main tributary (Q100-00-00) and 18 of its tributaries that were deemed as priority, including Q128-00-00.
This study also focused on evaluating long-term flood risk reduction strategies for the watershed while outlining an initial phase of improvements that could provide benefits in the short-term. The long-term proposed solution consisted of a large regional stormwater detention basin (approximately 120 acres in size which would provide approximately 511 million gallons of storage volume), channel improvements to widen/deepen Q128-00-00 upstream, and structure improvements to increase the capacity of existing bridges/culverts. The short-term recommendations include acquisition of right-of-way (ROW) for future improvements, and the initial construction of the regional stormwater detention basin.
The implementation of the long-term proposed solution would be phased as funding becomes available, with the estimated total cost for the ultimate solution equal to roughly $60 million.
The project benefits include:
- More effective channel conveyance to contain future 100-year flows.
- Removal of inundation of up to 17 structures downstream of US 90 in the 100-year event.
- Removal of inundation of approximately 1,169 acres and 4.5 miles of road in the 100-year event,
- An estimated reduction of $1.1 million in damages.