Every city faces key challenges, and engineering often is part of the solution to those challenges. Houston and the surrounding region have faced flooding problems since the Bayou City was founded. Massive floods in downtown Houston in 1929 and 1936 could have derailed Houston’s growth. Instead, the City of Houston and Harris County officials worked with the U.S. Army Corps of Engineers (the Corps) to develop an engineering solution to Houston’s flooding dilemma.
In 1940, the Corps published a plan that called for two massive reservoirs that directed flow into Buffalo Bayou and then into a new conveyance canal going south and then east to Galveston Bay; a smaller reservoir on White Oak Bayou; and a levee on Cypress Creek that would direct water to a canal north of Houston. The Corps built the Addicks and Barker reservoirs shortly after World War II. The rest of the plan was never realized, including the additional southern conveyance channel for Addicks and Barker reservoirs.
The two reservoirs prevented major flooding of Houston for 50 years. The region was fortunate to avoid massive storms for the rest of the 20th century. Even as floodplain management regulation and national flood insurance programs increased awareness of flood risk, the Corps allowed residential development inside the reservoirs.
Inadequacies in Flood Infrastructure
In 2001, Tropical Storm Allison dumped massive amounts of rain across the Houston area. The City of Houston, Harris County and other stakeholders created a plan to address the inadequacies of the region’s flood infrastructure. Unfortunately, large parts of the plans were not implemented. In 2010, the City of Houston adopted Rebuild Houston, a plan championed by engineers, to create a dedicated funding source for drainage improvements. But the pay-as-you-go funding stream meant that the projects defined in the plan would take decades to complete. That plan is still in place. After large storm events in 2015 and 2016, a variety of organizations united to decry the lack of progress by Harris County and the Corps on flood control infrastructure.
On August 27, 2017, the largest rain event in U.S. history, Hurricane Harvey, made landfall, causing $125 billion in damage and loss of life. Many organizations that had decried progress on flood control infrastructure organized into Houston Stronger, an advocacy association.
This unique group is comprised of community organizations, business organizations, chambers of commerce, conservancies, environmental groups, and other interested groups that often disagree on development issues. But flood resiliency is a different case.
Flood Protection Plan
Houston Stronger relied heavily on the work of local civil engineering firms and experts, most of whom freely donated critical resources and time, to develop a Regional Flood Protection Plan for Greater Houston. The plan highlighted the magnitude of critical flood infrastructure projects needed to protect the region – projects that would cost upwards of $60 billion. Armed with this information, Houston Stronger urged Congress to provide federal relief funds and later worked with Harris County officials and voters to adopt a $2.5 billion flood bond in 2018.
Houston Stronger went on to advocate for state funding relief in 2019. Texas Representative Dade Phelan, Texas Senator Brandon Creighton, and others sponsored bills that provided historic state funding for projects and planning for flood infrastructure.
One of Houston Stronger’s most significant feats was developing a response to the Corps’ interim report on its Congressionally required Buffalo Bayou and Tributaries Resiliency Study. The Study was undertaken because of massive flooding caused by Hurricane Harvey upstream and downstream of the reservoirs In the interim report, the Corps assessed its responsibilities and options and concluded that the most effective options were to channelize Buffalo Bayou below Addicks and Barker reservoirs and build a third reservoir upstream. The report excluded other concepts, like installing large conveyance tunnels, due to cost. Houston Stronger members were united in opposition to the interim report and conclusions.
Houston Stronger relied on expert input from civil engineers and others to develop a detailed response to the interim report. The organization requested the Corps consider shallow depression and on-channel improvements upstream; excavation in Addicks and Barker reservoirs; and construction of a large-diameter flood tunnel to provide conveyance and avoid channelizing Buffalo Bayou. The response emphasized that tunnels are a viable option and provided updated cost information. Plus, additional storage in the existing reservoirs, along with wetland restoration and the preservation of land in upper Cypress Creek also will provide significant protection.
The four primary flood resilience components, which require additional study, are:
Construct an estimated 40-foot diameter tunnel capable of conveying floodwaters from Barker and Addicks Reservoirs to the Houston Ship Channel while avoiding impacts to water quality. Tunnel interceptors along IH 10 and Buffalo Bayou will significantly increase flood protection for Harvey-type events to neighborhoods north and south of the tunnel. A force main and expansion at the City of Houston’s East Water Purification Plant could create a new water source without adding additional cost to the project, and it would provide additional funding for the tunnel.
Components 2 & 3
Provide an additional 166,000 acre-feet of compensating storage within the Addicks Reservoir and 184,000acre-feet of compensating storage within the Barker Reservoir to offset the loss of volume on private property. The dredge material from the excavations can be used to create new topography within the reservoirs adding new ecological and recreational value while reducing transportation costs related to the disposal of dredged material.
Construct more storage in the upper Addicks watershed and expand the prairie’s natural ability to absorb, slow down, and store floodwaters in the upper Cypress Creek watershed.
Flood Tunnel Update
After submitting the report and multiple discussions with the Corps, the Corps is reconsidering the flood tunnels as a conveyance option in conjunction with the Harris County Flood Control District. The Corps also recently approved a pilot project to allow excavation in the reservoirs.
Houston Stronger also submitted an op-ed to the Houston Chronicle. The article and comments generated by Houston Stronger’s efforts influenced the Corps’ decision to reconsider the recommendations in the interim report. Houston Stronger continues to communicate with the Corps about ideas to address regional flooding.
Augustus “Auggie” Campbell is Co-Founder and Chairman of Houston Stronger and Executive Director of the Association of Water Board Directors—Texas. He can be reached at [email protected]
Natalie Chaney, PE, ENV SP, is the Municipal Services and Sustainability Team Lead for RPS in Houston, Texas. She is a former Texas ASCE V.P. Education and a participant in Houston Stronger. She can be reached at [email protected]