Looking at Water From Above: A Conversation With Jay Famiglietti

Photo by Terrence Henry/StateImpact Texas

Dr. Jay Famiglietti says groundwater in parts of Texas is depleting "at a pretty rapid clip."

The myriad issues of water and drought in Texas are often confusing. There’s the hundreds of pages in the Texas Water Plan, numerous surface water districts, and then the completely different set of rules that applies to water underground.

Trying to sort through that confusion is Dr. Jay Famiglietti, a professor at UC Irvine. He and a team of scientists, including researchers at the University of Texas at Austin, use satellites and computer models to track freshwater availability.

“I wish I could say the outlook was super-positive, but there are some real hot spots,” Famiglietti says. “Groundwater is depleting at a pretty rapid clip” in parts of Texas, and the state’s population will only continue to grow. Dr. Famiglietti will speak tonight at UT’s Environmental Sciences Institute, part of their ‘Hot Science: Cool Talk‘ series (all the info is here, it’s free and open to the public). We sat down with him to learn more about what’s happening to Texas’ water supplies, and why cultural changes may be necessary for the state’s survival.

Q: We’ve spent a lot of time looking at the drought, and when we came across this monitoring system of groundwater, it was fascinating.  You’re essentially looking from space at what’s happening with water underground. Can you explain to us how it works?

A: Yeah, it’s pretty amazing stuff. So really GRACE (Gravity Recovery and Climate Experiment) isn’t sensing water. What it’s measuring is mass. It’s a satellite that was designed to measure earth’s gravity field and how that changes over time.

So anything that has mass, exerts a gravitational attraction. So if you’re over the mountains say, compared to the plains, you’re going to have a stronger gravitational attraction over the mountains compared to a flatter region with less mass.

The way that relates to water is, the gravitational field actually changes over time. If you think about Texas, a dry Texas with no water, and then imagine covering Texas with a foot of water, it’s going to be much heavier. Water is super heavy.

And you only have to add a centimeter and a half of water to change the mass significantly enough for the satellites to record it. So what GRACE is seeing are those changes in the gravity field. But those changes in the gravity field are dominated by changes in water, water storage, water coming in from a big storm, or water leaving because of groundwater depletion.

Q: Groundwater has come up as a big issue here in Texas, particularly in light of the drought. What do you see as key management issues with groundwater?

A: Well, I think one of the biggest issues is that groundwater is a shared resource, yet it’s not managed that way. It’s basically a free-for-all. So the Day ruling supports that free-for-all mentality: It’s mine, and I can pump as much as I want and need.

And that’s only partially true. Because once you start pumping from your property, most often you’re drawing from your neighbors to replace that water. It’s a big issue we need to deal with.

Agriculture relies heavily on groundwater for irrigation. So we have to be thinking about long-term management to sustain groundwater as a resource, because we have to eat in the future.

And there’s a couple of disturbing trends we see in our data. One is the general drought trend, which has hit Texas pretty hard. In the southern part of the High Plains, the southern part of the Ogallala aquifer, which is the biggest groundwater resource in the country, is being depleted at a pretty rapid clip.

Q: Assuming Texas has more hot and dry years like it has recently, what do you see as some of the solutions on the table for the state?

A: That’s an excellent question with multiple answers.

Number one is conservation and efficiency. We’re quite spoiled in the United States. We use water quite freely and without thinking about where it comes from and what the future looks like. So public awareness and increased conservation and efficiency are a big part of the future.

One of the things that Texas may have to consider is groundwater recycling. It’s something we do in California, we actually directly recycle sewage water an inject it back into the aquifer and it becomes part of the freshwater supply

The other thing that needs to be planned for is population growth. That’s something for water managers to keep and eye on. How will climate change play out in this region? How will the future of drought play out? That has to be coupled with projections for population growth.

Q: What are we going to look back on as far as how we relate to and use water, and scratch our heads and say, ‘Wow, we really had that wrong?’

A: We do a lot of silly things with water, but when you think about domestic use, the biggest uses are really for watering the grass. It’s pretty crazy. It’s kind of nutty to drive around Southern California or Phoenix and see these green oases.

And by the way, I have a green lawn, and so do my neighbors, so I hate to preach. And making these changes is often based on how much money you have in your pocket and figure out if you’re going to recoup your investment.

One thing I should mention is that energy and water are tightly coupled. So if you’re using less energy, you’re using less water, and vice versa.

So I hope that we’ll look back at the ridiculousness of having to drive around in these huge machines. And I hope we’ll make a cultural shift away from urban and suburban landscaping and feeling like we have to have this British,  beautifully manicured garden and grass in our yards. It’s ridiculous.

 You can attend a talk by Dr. Famiglietti tonight at UT’s Student Activities Center at 7 p.m.