Why LCRA won't use Lake Buchanan to fill Lake Travis

KXAN's Chief Meteorologist Nick Bannin spoke with the Lower Colorado River Authority's Vice President of Water John Hofmann about their water management practices.

AUSTIN (KXAN) -- While the drought has improved dramatically over the last few months, our lakes have seen split results. Lake Buchanan has risen considerably, whereas Lake Travis, home to a lot of water recreation, hasn't risen by nearly as much.

KXAN's Chief Meteorologist Nick Bannin spoke with the Lower Colorado River Authority's Vice President of Water John Hofmann about their water management practices.

KXAN Chief Meteorologist Nick Bannin: So how unusual is it for Lake Buchanan to be so much more full than Lake Travis?

John Hofmann, LCRA's Vice President of Water: You know, this is one of the big questions we get. Lake Buchanan is one of two water supply reservoirs in our system along with LakeTravis, and those are the two that we look to for our water supplies. And so the answer is, it's somewhat unusual for Lake Travis to be a little bit lower than what Buchanan is. You know, Lake Travis has a larger contributing watershed and generally it gets more rainfall, but the rains that we got in May fell mainly over the northernmost part of our watershed and the upper mainstem of the Colorado over the San Saba River watershed and up toward Brownwood, and so that flows directly into Buchanan.

Bannin: Now this next question we have been getting a lot as well, so hopefully this answers so many people at home. Why don't you fill Lake Travis with water from Lake Buchanan?

Hofmann: We manage the reservoirs with the primary purpose of water supply. And in doing that we want to keep your storage as high as possible within the system, because that allows us to be able to supply all of our potential water needs from there. So that's the reason why we want to try to keep storage up as high in the system as we can. It's also the most arid part of the watershed, and the part of the watershed that traditionally receives the lowest amount of inflows into the system. Having said all that, we're going to rely more heavily on Buchanan to meet our stored water needs, under the storage conditions that we're in right now, because it has the most supply.

Bannin: And then people see this all the time. They know we're in drought. They know, Lake Travis doesn't have a lot of water, at least compared to where we would like it to have. And yet they see the water releases going downstream. Why are you releasing water from the Highland Lakes during drought?

Hofmann: Sure, it's the question that we get most often. And the reality is in the summertime, we move water throughout the system every day to satisfy the different demands that we have for water. So you have cities, power plants, and industries that are all using water released from Buchanan and Travis, because remember, those are our two water supply lakes and it ends up coming down through Mansfield Dam is that last control point. The fact is, if we didn't move water through Mansfield Dam every day, cities like the city of Austin and Pflugerville and others couldn't meet their needs. In fact, the city of Austin has two intakes on Lake Austin, two of the three and intakes that they have. So when I explain this to people that generally, you're able to say, 'oh, okay, I understand it now,' because many of our utilities in our region here get their water supply diverted out of Lake Austin, but it's sourced from Travis and Buchanan.

Bannin: And there's some ecological reasons too, right? Keeping water flowing?

Hofmann: Of course, yeah. There's always the issue that we have with respect to, we want to make sure that we maintain a healthy ecosystem within the Colorado River Watershed, both the river itself and the bigger ecosystem that depends on it.

Bannin: Now, a lot of people moving to this area, we're going longer periods, perhaps between drought and deluge, how can you ensure that we're meeting our future water needs?

Hofmann: You know, that the the answer is that we're going to have to think differently about how we use water starting with our landscapes. The idea that you can either do all conservation or do all new water supplies. Really, you have to do conservation every day and think about conservation just as a normal part of life and living in Central Texas and we'll have to continue to look for additional supplies for our region as well.