Efforts to deal with flooding in a handful of western Harris County watersheds are taking form, but early evaluations from the federal government have drawn questions and criticisms from local groups.
The Army Corp of Engineers released an interim report Oct. 2 on a study that will look at Buffalo Bayou, Addicks and Barker reservoirs and upper Cypress Creek. The report includes a list of nine possible flood mitigation strategies-including a reservoir in upper Cypress Creek and an underground tunnel along Buffalo Bayou-along with early evaluations of their feasibility. The Corps then opened the report up to public comment.
Since the report's release, local stakeholders have been making their voices heard, pushing for the Corps to consider different strategies and calling on them to release more data from their evaluations.
Wendy Duncan, co-founder of the Barker Flood Prevention Advocacy Group, said the plans to widen Buffalo Bayou would require buyouts in the River Oaks, Memorial and Tanglewood area, which she said could draw lawsuits if properties are taken by eminent domain. Similarly, the Cypress Creek reservoir would involve using protected land in land trusts.
"I think the very big picture view of this is that the Corps has chosen what seems to be the simplest options from an engineering perspective," she said. "However, they are the absolute most difficult from a political perspective."
Col. Timothy Vail, the commander of the Army Corps of Engineers Galveston District, emphasized the report does not make any official recommendations or drawn any conclusions about what should be done.
"The report describes evaluations to date," Vail said in a statement. "It does not identify a preferred alternative nor does it make any recommendations or decisions."
The report's preliminary assessments were largely based on a cost-benefit analysis. Concepts that appeared to be early frontrunners included a new reservoir and dam structure in the Cypress Creek watershed and 22 miles of deepening and widening Buffalo Bayou, both of which would alleviate strain on the Addicks and Barker reservoirs during heavy rainfall events.
The study was launched in the aftermath of Hurricane Harvey, which caused extensive damage in Katy and the Greater Houston area and produced record levels of water in the two reservoirs in 2017. In the Katy area, upstream from the reservoirs, neighborhoods such as Cinco Ranch, Canyon Gate, Grand Lakes and Kelliwood, among others, experienced flooding due to the historic rainfall.
The construction of a new reservoir in the Cypress Creek watershed would have the capacity of roughly 190,000 acre-feet of water, would cost between $2.1 billion-$2.9 billion and prevent about $37 million in annual damages, according to the report. Meanwhile, the 22 miles of channel improvements along Buffalo Bayou-from Hwy. 6 to downstream of Studemont Street-would cost between $946 million-$1.2 billion and would prevent about $56 million in annual damages.
Several other ideas were "screened," meaning they were determined to not be as viable based on the early evaluations. Screened concepts included the use of an underground tunnel to supplement Buffalo Bayou, the excavation of the reservoirs and diverting water from the Buffalo Bayou watershed to the Brays Bayou and/or Brazos River.
Outside of the nine main concepts, the Corps is also looking into the acquisition of thousands of structures upstream and downstream of the Addicks and Barker reservoirs that could cost as much as $13 billion. The acquisitions would increase the storm water storage area of the reservoirs, but more analysis needs to be done to determine a target elevation, according to the report.
Since the publication of the report, Army Corps officials have been gathering public comments through email as well as at four virtual town hall meetings. After receiving multiple public requests to allow more time for public comment the Army Corps extended the deadline for residents to weigh in on its study from Nov. 2 to Nov. 20.
David Abraham, a flooding researcher at Rice University, said the report is a key inflection point in the study process where the Corps will use community feedback to craft a more feasible, responsive plan.
"The project sponsor does their best to hire their experts-which are going to be engineers for the most part-to develop the alternatives," he said. "If the general public is able to articulate and technically show the opportunities that should be involved ... then that has to be considered."
For the local groups that have been awaiting the study, the interim report prompted several major concerns about the early direction. The reservoir concept, if approved, would be located west of John Paul's Landing in an area known as the Katy Prairie.
Mary Anne Piacentini, president of the nonprofit Katy Prairie Conservancy, said using prairie land for a reservoir would disrupt the life cycles of various species. Piacentini also said the land provides flood control benefits in its current state, and other concepts would make more sense from a cost-benefit stand point as well. She said was surprised to see the Cypress Creek reservoir concept still under consideration at this point in the process.
In its interim report, the Army Corps detailed some of the adverse effects the reservoir concept would have on prairie land if built. The reservoir would "significantly alter and degrade more than 75% of the remaining range-wide Katy Prairie habitat and a significant portion of the actively managed and preserved remaining habitat," according to the report.
Auggie Campbell, director of Houston Stronger-an advocacy group that has drafted its own set of flooding strategies for the area-said the current proposals for the Cypress Creek reservoir and Buffalo Bayou improvements would be "very unpopular" if pursued and would potentially draw lawsuits.
Both Houston Stronger and the KPC are pitching their own ideas to the Corps about how their plans can be redirected, some of which overlap. The KPC has devised a four-pillar plan that involves expanding the Katy Prairie, making channel improvements in upper Cypress Creek, carefully excavating the Addicks and Barker reservoirs, strengthening the dam and putting in a series of smaller reservoirs in the upper Addicks watershed.
Duncan, who is also a member of Houston Stronger, said she would like to see a more incremental approach to retention upstream of Addicks.
"Because it will be very difficult politically to create the third reservoir, we believe that smaller detention and retention projects that help to control the Cypress Creek overflow that goes into the Addicks would be more beneficial," she said.
In its early evaluations along Buffalo Bayou, the Corps appears to be looking away from a concept that involves building a network of underground tunnels leading away from the reservoirs.
Initial cost estimates for the tunnels ranged from$2.2 billion-$12 billion, and the Buffalo Bayou channel improvements were determined by Corps officials to provide similar benefits at a lower cost.
However, the flood tunnel concept will continue to be studied by the Harris County Flood Control District, which is analyzing a number of potential locations in the county where they could be used, including the Buffalo Bayou corridor.
In an Oct. 28 interview, HCFCD Deputy Director Matt Zeve said the district is around the mid-point of a study that kicked off this summer to determine possible tunnel routes in Harris County. Although they disagreed with some early results, officials with both the KPC and Houston Stronger said it is crucial for the Army Corps to remain involved with the project due to the sheer scope and cost of what needs to be done.
"We understand this is a very difficult problem to solve," Piacentini said. "I think the good news is the environmental community is starting to work with the engineering community and the business community to look at problems together."
The above video is from a previous post.