Flooding effects push back dam upgrade
U.S. Army Corps of Engineers projects that work could be finished by fall 2019
When record flooding submerged parts of Houston in April, the Addicks and Barker reservoirs near the Energy Corridor were among the most impacted structures.
Weeks later, that impact can still be felt as long-anticipated renovations to the reservoirs’ dams have been pushed back by months.
A $72 million overhaul to the dams, which are more than 70 years old, had begun in April before the flooding. Now, the contractor in charge of construction, Granite Construction Co., won’t be able to begin assessing the restoration process again until sometime in July after both the Addicks and Barker reservoirs are finished draining.
The contractor “was doing pretty good before the rain hit,” said John Long, resident engineer at the U.S. Army Corps of Engineers Galveston District, which oversees the reservoirs. “We won’t know for sure how long the delay is until we do an analysis.”
In 2009, the district self-labeled the dams as “extremely high risk” for flood control based on technical problems that might cause dire consequences if the dams were to fail during a major storm.
West Houston saw between 12-17 inches of rain during the Tax Day floods, and water from the downpour quickly rose in the reservoirs, eventually spilling into nearby streets and residences.
Despite experiencing record-setting levels of water, both reservoirs held their ground during the flooding, according to Rick Villagomez, the renovations project manager.
“The dams did not experience any damages when rains hit,” Villagomez said. “We continue now to monitor the dams, and to our knowledge, there is no issues with the structures themselves.”
Even now, the normally dry Addicks reservoir remains approximately 20 percent full while the Barker reservoir is at about an equal percentage of capacity, according to Ralph Steiner, the area engineer at the district.
The dams protect an estimated 1.2 million Houstonians by taking in excess water from Buffalo Bayou.
This isn’t the first time the construction project has been delayed. Construction should have begun in September 2015 after the district approved a construction contract with Granite Construction. Delays occurred then as the district awaited notice to proceed from the federal government, which is funding the developments.
The delays will cause construction costs to rise, Long said.
“Yes, (the delays) are frustrating, but we have it within our contract to deal with this situation,” Long said. “The contractor is taking great steps to mitigate costs; so we are not expecting large cost increases.”
The renovations include developing new intake towers, cutoff walls and downstream filters.
Since 2009, the district has implemented interim measures while it waited to begin renovations. The measures included constructing a granular filter around the ends of the outlet structure, which gives the dams added strength, and installing additional lighting for inspection and monitoring.
As it awaits to see when the major renovations can begin again, Granite Construction has been handling light maintenance throughout the dams, Villagomez said.
The dams were constructed after catastrophic floods in both 1929 and 1935. The more recent large flooding events in 2009, 2015 and this year have tested the aged dams’ limits.
The renovations were scheduled to be completed around May 2019 but will now be pushed back to a September 2019 finish, Steiner said.
And that’s if the weather plays nice in the unpredictable swamp that is Houston.