Projects & Studies
(UPDATE: Beginning June 19, a portion of the southbound lane of Dairy Ashford Road near the southwest entrance of Terry Hershey Park at Buffalo Bayou may be closed daily from 9 a.m. to 3:30 p.m. for the duration of construction, approximately seven months, weather dependent. This temporary closure is in the interest of public safety, to allow construction traffic to enter and exit the project site, but may slow traffic in the area between Memorial Drive and Briar Forest Drive. Drivers are encouraged to use caution when in this area as construction vehicles and traffic flaggers currently are present along Dairy Ashford Road at Buffalo Bayou. Construction on linear stormwater detention basins is underway in the area between Eldridge Parkway and Dairy Ashford Road on the south side of Terry Hershey Park. Safety fencing is in place marking the construction zone, which remains closed to all pedestrian and bicycle traffic. Members of the public are asked to remain clear of this area for their personal safety. Please do not try to access the construction site or approach heavy equipment.)
The Harris County Flood Control District began construction in late April 2019 on the first phase of a project to construct additional linear stormwater detention along approximately 6.4 miles of Buffalo Bayou between State Highway 6 (just east of the Barker Reservoir) and the Sam Houston Tollway. This area is within Harris County Flood Control District-owned property, acquired from the U.S. Army Corps of Engineers beginning in the 1950s specifically for flood damage reduction purposes. Harris County Commissioner Precinct 3 has constructed, operates and maintains Terry Hershey Park within this portion of Flood Control District-owned property, and the park exists in cooperation with the Flood Control District’s flood damage reduction efforts, including both existing and proposed linear detention.
Completed preliminary engineering efforts included a due diligence examination of vegetation, environmental and other factors that could impact the project’s feasibility and effectiveness. Conversations about the project with adjoining neighborhoods and organizations have and will continue to take place during construction.
From May through October 2018, the Harris County Flood Control District hosted a survey on our website to seek input from area residents as we prepare a project to add linear detention along the south bank of Buffalo Bayou. We want to thank everyone who took the time to complete the survey and offer their thoughts and observations.
Some of the most frequently asked questions and comments from our respondents can be found here and are updated as of January 2019.
The Flood Control District continues to move projects forward county-wide in response to Hurricane Harvey and other recent record-breaking rain events. Because acquiring right-of-way can be the most challenging and time-consuming aspect of any flood damage reduction project, the Flood Control District is looking first at property it already owns on which to build. The Flood Control District owns approximately 660 acres along Buffalo Bayou between State Highway 6 and the Sam Houston Tollway.
Stormwater detention is a common strategy against flooding in our region. Detention basins can be found in neighborhoods, parks, and open spaces and vary in size and appearance. Linear detention basins are gently sloped areas along the channel that are usually empty of water. During a significant rainfall event, they fill and store the excess stormwater until it is able to naturally drain off, helping reduce flooding in streets and homes.
Linear detention basins are already constructed primarily on the north side of Buffalo Bayou between Dairy Ashford Road and the Tollway. Once constructed and integrated into the surrounding property, linear detention basins exist largely unnoticed as flood reduction components and instead simply resemble a grassy, sloped feature of the landscape.
The following photos of an existing linear detention basin illustrate how linear detention blends almost seamlessly into an open space, as well as its value for holding water when needed.
An initial phase involving three linear detention compartments on the south bank of Buffalo Bayou between Eldridge Parkway and Dairy Ashford Road began in late April 2019. The exact locations of individual basin compartments were determined during the design process, taking into account construction access and existing trees and other vegetation to minimize environmental impacts such as loss of desirable habitat and wetlands. The overall project will proceed in phases as funding allows.
The addition of linear detention is one step in addressing flooding risks in the Buffalo Bayou watershed. While it would not have likely prevented flooding in Hurricane Harvey or a similar weather event, it would reduce damages from more frequent storms and would serve to increase our defenses against flooding during larger-scale rain events.
This map shows where linear detention (shaded areas) exists on the north banks of Buffalo Bayou today, between Dairy Ashford Road and Wilcrest Drive.
TREES & VEGETATION
Construction of linear detention along Buffalo Bayou likely will require the removal of some trees and vegetation to achieve maximum results. In October 2017, the Flood Control District began tree and vegetation surveys within approximately 177 acres of Flood Control District property between State Highway 6 and the Sam Houston Tollway. The goal of the survey was to provide data needed to catalog existing vegetation and aid in evaluating potential future flood damage reduction projects. Results of the ongoing vegetation survey will be used to minimize removal of any desirable vegetation.
The 2017 survey was intended to complete and update a similar 2014 survey that included approximately 77 acres on the south side of Buffalo Bayou between North Eldridge Parkway and Wilcrest Drive. Additionally, the project will utilize other previous study efforts, including the Charting Buffalo study, as a starting point for identifying the linear detention basin compartments. Previous studies identified environmentally sensitive locations along Buffalo Bayou that will be avoided in this current effort.
The Flood Control District understands that Buffalo Bayou and Terry Hershey Park are special places for many Houstonians. The above-mentioned studies, surveys and other efforts are being made to ensure candidate space is developed in the most thoughtful and effective way possible.
The first phase of project construction included site preparation to mark and protect vegetated areas and trees being preserved during excavation. This was completed in April 2019. The next step is clearing trees and vegetation in the immediate detention compartment construction area and along construction access pathways. Construction then moves to excavation and removal of soil from the linear detention compartments.
Plans for the area include preserving a tree buffer where possible between the detention compartments and adjacent private property, and also preserving some trees and vegetation at the water’s edge.
On March 21, Harris County Precinct 3 relocated 17 trees from the project area to John Paul Landing Park.
Post construction, the area will be folded into the Flood Control District’s Tree Planting Program where we consistently plant from 12,000 to 15,000 trees per year. Existing linear basins within this stretch of Buffalo Bayou feature rolling slopes, native grassy meadows, forested areas and grass banks, and are integrated with Terry Hershey Park trails. A plan for tree replacement will be coordinated with Harris County Precinct 3, which is responsible for maintenance of Terry Hershey Park. It should be noted that the Flood Control District will not design or install recreational features as part of this effort.
IMPACTS FOR LOCAL LANDOWNERS AND PARK VISITORS
In August of 2017, the Flood Control District began communications with landowners who have property bordering the area where additional stormwater detention is being considered. Issues of encroaching fences, fixtures and other personal property are being handled on a case-by-case basis. Impacted landowners have received additional correspondence to discuss encroachment as it relates to their property and are encouraged to reach out to the Flood Control District with questions.
Construction will temporarily impact park and/or trail access. Notification signs about the construction and related temporary park closures went up March 19 in the project area. All closures necessary for public safety reasons are marked and were announced in advance on this webpage.
- Buffalo Bayou from State Highway 6 to what is now the Sam Houston Tollway was straightened, regraded and cleared in the 1940s by the U.S. Army Corps of Engineers, removing many of its original meanders. Since then, trees and other vegetation have naturally grown along this area, giving it a natural appearance. Vegetation also covers man-made mounds created from the placement of material excavated during channelization work.
- The Flood Control District acquired the property beginning in the 1950s from the Corps.
- In 1993, the Flood Control District and Harris County Precinct 3 signed an agreement creating Terry Hershey Park, which integrates the property's primary flood damage reduction purpose with recreation. Harris County Precinct 3 is responsible for trail maintenance and other recreational amenities.
- In the late 1990s and early 2000s, the Flood Control District constructed a series of linear stormwater detention basins on the north side of Buffalo Bayou within Flood Control District lands and Terry Hershey Park. The basins are located mostly between Dairy Ashford and the Tollway. Normally dry, they feature rolling slopes, native grassy meadows, forested areas and grass banks.