F-43 Channel Conveyance Improvements for Adlong Ditch Q128-00-00

F-43 Channel Conveyance Improvements for Adlong Ditch Q128-00-00

Recent Action

December 1, 2020 - Harris County Commissioners approved $1,200,060 for planning stage engineering services in support of this project.

June 30, 2020 - Harris County Commissioners Court authorized the Flood Control District to accept a preliminary engineering report to analyze alternatives to achieve flood reduction goals in the Cedar Bayou Watershed.

May 19, 2020 - Harris County Commissioners Court approved updates to project details in the 2018 Bond Program List. Update reallocates funds to new Bond ID F-123 to support the Cedar Bayou Bond Implementation Management (BIM) Project Funding.

April 28, 2020 – Harris County Commissioners Court authorized and initiated this project.

Project Description

This project will improve channel conveyance to reduce flooding risks along the Cedar Bayou tributary, formally identified as Unit Q128-00-00.


Q128-00-00, also known as Adlong Ditch, is a tributary to Cedar Bayou watershed near the northeastern corner of Harris County, downstream of US 90.


This project is in the PRELIMINARY ENGINEERING stage. This effort will result in more detailed recommendations for flood damage reduction projects and an implementation strategy for those projects in the form of a preliminary engineering report (PER).

Bond Project Listing

Bond Project F-43 is a “Local Only” project, meaning that the project will be funded entirely from the 2018 Bond Program without any funding partners. The Bond Project List includes an allocation for this project of $23 million.

Q128 Study:

The Harris County Flood Control District completed the Cedar Bayou Flood Risk Reduction Study (FRRS), which was funded as part of the 2018 Bond program. This study investigated the existing flood hazards in the watershed and identified potential future drainage improvements to mitigate 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 evaluated long-term flood risk reduction strategies for the watershed while outlining an initial phase of improvements that could provide short-term benefits. The long-term proposed solution consisted of a large regional stormwater detention basin (approximately 120 acres in size, providing 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 included acquisition of right-of-way (ROW) for future improvements and the initial construction of the regional stormwater detention basin.

The long-term proposed solution is anticipated to be implemented as funding becomes available, with the estimated total cost for the ultimate solution to equal roughly $60 million. The project benefits include:

  • More effective channel conveyance to contain future 100-year flows.
  • Removal of the 100-year floodplain from up to 17 structures downstream of US 90. 
  • Removal of the 100-year floodplain from approximately 1,169 acres and 4.5 miles of road. 
  • An estimated reduction of $1.1 million in damages.

Virtual Community Engagement Meeting

The Harris County Flood Control District held a virtual Community Engagement Meeting for the Channel Conveyance Improvements for Adlong Ditch. The purpose of this meeting was to inform residents about the status of the Channel Conveyance Improvements for Adlong Ditch project and share project information.

Date: Wednesday, May 25, 2022
6:30 p.m. - 7:30 p.m. 

Presentation Presentacion (esp) Virtual Meeting Video Summary