Release Rates May Be Looked At in Future
March 13, 2016
It was a dark and stormy night. Thunder boomed and heavy rain pelted the roof as a small group of us sat nervously in the middle of the rising Addicks Reservoir in far west Houston listening to the district commander of the Army Corps of Engineers tell us Addicks and Barker dams are safe.
Flanking Col. Richard Pannell last Wednesday, March 9, was a panel of officials from the Corps’ Galveston District office, as well as representatives from the Harris County Flood Control District and Granite Construction, the company awarded the $71.9 million contract to replace the leaky conduits in the 70-year-old earthen dams. The audience was a small crowd of about thirty hardy citizens who had braved the heavy traffic and heavy rain and managed to find the Bear Creek Community Center in the middle of a dark, wet forest despite the wrong address in the Corps’ public notice.
Col. Pannell made a thorough and convincing presentation of the history of the dams, the current problems, and what is being done about them. Among other work, the conduits in the two dams will be entirely replaced by new conduits in separate locations. This process will take about three years. He emphasized that the dams were in no immediate danger of failing and explained that the dams are labeled “extremely high risk” because of the potential consequences to Houston, the nation’s fourth most populous city, in the unlikely event that the dams failed.
Dams Operating Normally Despite Leaks
There were several questions about the capacity of the dams and the impact of repairs on the rate of future releases of water impounded behind the dams. The pattern of extended high releases and rapid drops has been criticized for damaging property on the bayou and killing trees and vegetation that control erosion.
After the enormous Memorial Day storm last year, the Corps began releasing impounded stormwater at 3000 cubic feet per second (cfs) for the first time. Normally the release rate is limited to 2000 cfs as measured by the Piney Point gauge. The Corps does not release water from the dams during a rain event, and the high releases began on June 1 and continued for ten days, finally dropping on June 12. The banks were already saturated from the storm, and the damage from the extended high flow was plainly visible up and down the bayou.