If you went out for a walk along Lady Bird Lake on Tuesday afternoon you might have noticed the water level was lower than usual. Muddy stretches of bank extended farther toward the center of the lake. The smell wasn’t great.
Lady Bird Lake’s water level fell by about 2 feet.
The Longhorn Dam holds the lake in. Austin Water said one of the dam's nine floodgates got stuck open, allowing water to keep flowing downstream. The utility said the cause of the dam failure is under investigation.
Austin Water said contractors installed a temporary structure called a “stop log” Tuesday night to block the flow. It said the fix will be in place for a few months until permanent repairs are done.
This is at least the third time water levels have dropped noticeably in the last six months. In October, the utility said, ants got into an instrument panel, breaking parts of the dam and allowing water to flow out.
Online data from the Lower Colorado River Authority, which controls water flows upstream, also show lake levels dropping by over a foot on Dec. 10.
The floodgates at the Longhorn Dam have been an issue for some time, and the city has struggled to find a long-term solution.
The dam was built in 1960 to create a water reservoir for the Holly Power Plant. Back then it was managed by Austin Energy. While the power plant is gone, the dam still helps regulate water flows downstream and keeps Lady Bird Lake at a more or less constant level year-round.
After flooding in 2013, the dam changed hands; it's now under Austin Water’s management. A 2014 report by the Watershed Protection Department found the gates were outdated and the dam needed major repairs and upgrades.
Some work has been done to the 60-year-old equipment in the last several years. The city said Tuesday’s malfunction happened while dam upgrades were underway.
KUT has asked the utility if the gate that broke has had any repairs in the last 10 years and what work has been done to address the issues raised in the 2014 report. It did not respond before this story was published.
Austin Water and the Lower Colorado River Authority are working on gradually refilling Lady Bird Lake to its usual level.
