Harris County Flood Control District Begins Project to Complete Willow Waterhole Stormwater Detention Basin

The Harris County Flood Control District has begun the final phase of construction to complete the Willow Waterhole Stormwater Detention Basin, a major component of Project Brays designed to reduce flooding risks in the Brays Bayou watershed of south Harris County.

The Harris County Flood Control District has begun the final phase of construction to complete the Willow Waterhole Stormwater Detention Basin, a major component of Project Brays designed to reduce flooding risks in the Brays Bayou watershed of south Harris County.


On May 23, 2017, Harris County Commissioners Court awarded an approximately $11.7 million construction contract to low bidder Serco Construction Group LTD for this final phase of the basin project. Work on this phase began in June and is expected to be completed in August 2018.


Construction on the Willow Waterhole basin originally began in 2004 on what are now 292 acres near South Main Street/U.S. 90A and South Post Oak Road. The basin is located on Willow Waterhole Bayou, a channel formally identified as HCFCD Unit D112-00-00. The basin’s interconnected set of six compartments, when complete, will hold approximately 1,865 acre-feet, or nearly 608 million gallons, of stormwater that might otherwise flood homes and businesses. The basin site has already become a popular community asset, hosting numerous public concerts and events, and with park features, trails and a pavilion sponsored by other governmental entities and community organizations.


The current construction project will involve expanding and deepening Compartments 1 and 6 of the basin (the two compartments north of South Willow Drive) by excavating more than 50,000 cubic yards of material; constructing inflow/outflow weirs to connect those compartments to the bayou; installing larger box culverts; adding two road crossings under South Willow Drive to interconnect various compartments; realigning and installing 7,750 square yards of concrete channel lining along the bayou; and adding a control structure.


A stormwater detention basin is a large excavated area connected to a bayou or channel and designed to temporarily store potentially damaging excess stormwater until after the threat of flooding has passed, and the stormwater can safely drain back into the bayou or channel. The concrete control structure will help direct the flow of stormwater from Willow Waterhole Bayou into the basin so that it functions most efficiently.


Construction equipment will access the work area via South Willow Drive. The contractor will use heavy construction equipment such as dump trucks, backhoes and bulldozers. Motorists are urged to be alert to truck traffic when passing near construction access points. The project will require temporary closures and detours and other changes at the Chimney Rock and West Bellfort intersection, and along South Post Oak and South Willow Drive to allow for construction.


The basin is part of the Brays Bayou Federal Flood Damage Reduction Project, known as Project Brays. Project Brays is a multi-year, $480 million cooperative effort between the Flood Control District and the U.S. Army Corps of Engineers. Project Brays includes the widening of 21 miles of Brays Bayou from the Houston Ship Channel to Fondren Road and from West Houston Center Boulevard to State Highway 6; the replacement or modification of 32 bridges to accommodate channel modifications; and excavation of four stormwater detention basins that will hold a collective 3.5 billion gallons of stormwater. Project Brays information can be found at www.projectbrays.org.
The Willow Waterhole basin has been designed by the Flood Control District to enhance the environment.  The compartments retain a permanent pool of water year-round and have been planted with thousands of wetlands plants to improve stormwater quality. The Flood Control District also has planted thousands of trees and native plants, which support the Flood Control District mission while also providing additional habitat for birds and other wildlife.


For more information on the Willow Waterhole Stormwater Detention Basin project, please visit www.projectbrays.org. To ask a question or comment on the project, please call Harris County Flood Control District's Project and Study Information Line at 713-684-4040 or the Project Brays Information Hotline at 713-316-4820.

About the Harris County Flood Control District
The Harris County Flood Control District provides projects that reduce flooding risks and damages, with appropriate regard for community and natural values. With more than 1,500 bayous and creeks totaling approximately 2,500 miles in length, the Flood Control District accomplishes its mission by devising flood damage reduction plans, implementing the plans and maintaining the infrastructure.