AUSTIN (KXAN) –With much wetter weather expected this weekend than the region has seen for a while, the Lower Colorado River Authority said it is monitoring rainfall and inflows into the Highland Lakes, ready to move floodwaters downstream through the series of dams on the Highland Lakes if necessary.

The Highland Lakes are a chain of manmade lakes built between 1935 and 1951 on the Colorado River northwest of Austin. The lakes were built to protect communities from flooding events, generate hydroelectric power and provide a reliable water source. ​When it rains heavily over the Highland Lakes watershed, the Colorado River and connected streams swell, which sends the runoff into the Highland Lakes, per the LCRA.  

The two largest lakes are Lake Travis and Lake Buchanan, and now are only 44.1% and 60.7% full, respectively, according to Water Data for Texas. When it rains upstream of Lake Buchanan, that freshwater flows unobstructed into Lake Buchanan, where is stored using the Buchanan Dam.

Lake Travis is the only designated flood pool, and because the water is so low right now, LCRA said there is plenty of space to store flood water. And even if Lake Travis becomes full, LCRA said there is another 776,000 acre-feet of dedicated flood storage available. 

Diagram of Highland Lakes (KXAN)

While all of the dams in the basin were built to manage floods, the Mansfield Dam at Lake Travis was built to hold back floodwaters and temporarily store them in the lake, per the LCRA.

LCRA advises people in the region that if it needs to open a floodgate, the flows downstream will be much faster than usual. “We urge anyone by the lakes to be extremely cautious and to take action to protect people and property,” it said in a release. KXAN will update you if LCRA decides to open floodgates, but members of the public can also monitor LCRA’s social media accounts.

Travis County is still under drought conditions and it is unclear whether our stormy weekend will affect that situation. You can monitor rainfall, lake levels and stream flow on LCRAS’s hydrometer.