Texas is a land of extremes. Some of the biggest hats, trucks and guns I’ve ever seen were in Texas. I once ordered a chicken-fried steak so large that it spilled over the edge of my plate. And the weather…well…entire books have been written about it. It’s as extreme as it gets.
When it rains, it really rains. The thunder and lightening are so severe they sends shivers down your spine. The tornadoes are so frightening you’ll be having an overdue conversation with Jesus while sitting in your bathtub wearing a bicycle helmet and holding mattress over your head. Trust me. I’ve been there.
And when it doesn’t rain, it really just does not rain — for months at a time. When my family lived there, the relentless summer heat made us feel like we were trapped in an oven, and that the only way to escape was to drive for hours to a cooler climate. It got so bad that by mid-summer, even the dog didn’t want to go outside. By the end of the season, when the heat finally ‘broke’ and dropped to the more ‘tolerable’ low ‘90’s, well, then it was too ‘cold’ to go to the neighborhood pool.
This past year has been a prime example of the extremes that define Texas. The seasonal rains of spring and fall that typically provide the wet bookends for the hot, dry Texas summers, failed to materialize, resulting in a drought as big as the state itself. While Texas is no stranger to drought, the last year has literally been a killer. It’s been the driest twelve-month period on record since the state began keeping track of rainfall in the 1890’s.
The impacts are startlingly troublesome. Towns are truly being sucked dry as their limited water supplies are siphoned away. Livestock is being evacuated to greener pastures, or even worse, it is dying from the stress…or abandoned to eventually suffer the same fate. While lake and groundwater levels fall at alarming rates, fires rage across the parched landscape, burning thousands of acres…and thousands of homes. The state has already lost half of its cotton crop. Total economic losses are currently estimated to exceed $8 billion.
Unfortunately, drought is unavoidable. It is both a natural part of the ups and downs of climate, and it is also one that is becoming a more frequent visitor, in response to human-induced climate change. More and more we are seeing that it is clearly overstaying its welcome. The greater southern U. S. is in the grips of a long-term ‘dry’ that has climate experts wondering whether drought is already becoming the new normal for the mid-latitude regions of the world — a typically semi-arid to arid, more desert-like state, where already scarce rainfall is becoming even more so.
This poses a tremendous challenge to regional water managers because, let’s face it, we love to live in dry climates. Some of the fastest growing regions of the world are also the driest. And since these regions are dry, their water supplies are typically dominated by groundwater. For example, in my home city, semi-arid Irvine, CA, we rely on local groundwater to provide half of the city’s water supply.
The problem is that in regions like Irvine, and Las Vegas, and a good half of Texas, most of that groundwater, once used, is not coming back, at least by natural means. These are dry places, where by definition, it does not rain, so there are limited opportunities to replenish groundwater supplies. Unless you’re sitting on top of 10 underground Lake Meads, which most places are not, then long-term reliance on groundwater in arid and semi-arid climates is unsustainable: we’re using it at a far greater rate than it is being replaced. When drought kicks in, and what little surface water that might be available disappears, we are forced to rely even more heavily on groundwater — for use in our homes, to grow food, and for our businesses and industry — accelerating the disappearance of this finite resource.
In short, the human response to drought is to increase groundwater use. It’s our money in the bank so to speak, that we’re saving for a not-rainy day. But in the dry parts of the world, this will accelerate the depletion of our aquifers. When we factor in more frequent drought due to climate change, and continued global population growth, well…you get the picture. An already overstressed resource will be pushed, in many places, to the brink.
We see this all over the world, and right now, we’re seeing it in Texas. And unless we adopt new management paradigms, this critical component of our water supply and oft-assumed hedge against drought, will slowly but surely disappear, in some places, much faster than others.
I’m sorry to be the one to have to tell you this, but, praying for rain, while spiritually soothing, well, is just not going to help. We need a strategy. We need to ask ourselves the tough questions about whether we are sufficiently prepared to endure the increasing wrath of drought in the future. To be honest, I’m not really sure that we are.
For example, here’s a fundamental hydroscience and water management question to which society must demand an answer. Exactly how much freshwater do we have?
The truth is, we don’t know. Not in Texas, not in the U.S., and really, just about anywhere else on the map.
What we do know is our storage and delivery capacity, but that’s a different thing. I’m talking about how much water we have stored in our rivers, lakes, reservoirs, and groundwater aquifers, and of that, how much is potable. It’s a rather fundamental number that we simply just don’t know. Please take a moment to ponder the situation that our technologically-advanced civilization finds itself in: how in the world can we ever manage our water sustainably unless we know how much we actually have?
Here’s another one. Could we have seen this coming? While the current Texas drought has been characterized as having started a year ago, our data suggests that the decline has been going on for much longer – three years or more. Could these data, from the University of Texas-based NASA GRACE satellite mission, which give a more holistic picture of changes in total water storage (that is, all of the snow, surface water and groundwater in a region), have provided an early warning?
Take a look at this figure (courtesy of Sean Swenson at the National Center for Atmospheric Research) for the river basins that drain from Texas into the Gulf of Mexico. The red dots are the monthly values of the change in total water storage (relative to the average of the 2002-2011 time period shown) in, well, most of Texas. That’s the change in storage of nearly all of Texas’ water. Right there. On the left. The line connecting the dots gives us a picture of how total water storage increases and decreases with the seasons, and how some years are wetter or drier than others.
A few things about this chart stand out. First is that the total water storage in Texas has been in decline since 2008, and even as far back as 2005. The second is that there has been an overall decline of total water storage, as shown by the straight red trend line, for as long as the GRACE has been collected, since 2002. And third, the drought of the last two years has dropped water levels to the lowest they’ve been in the last 9 years of the GRACE record, with 18-month declines nearly as great as those in the 2005-2007 drought.
This behavior is mimicked in a second chart, shown below, which includes not only the Texas drainages, but the Rio Grande and the Arkansas-Red basins as well. With information like these available today, it’s hard to imagine how it is that we’ve found ourselves caught so off guard. Note to Texas water managers: I urge you to take a closer look at how the GRACE data can help you with the difficult task of providing a reliable water supply to a region that is subject to such great extremes.
Finally, we need to ask ourselves how can we better prepare for the increasingly dry future that Texas and other regions around the globe may be facing. There are in fact many ways, but the key is early recognition of drought conditions. A major step in this direction comes from NASA’s contribution to the U.S. Drought Monitor, led by UT grad Dr. Matt Rodell. Matt and his team work with Drought Monitor group to integrate the GRACE data into its assessments. If these charts are any indication, including GRACE data in the Drought Monitor could provide a season or more of advanced warning of the potential for worsening drought, potentially saving billions of dollars and hundreds of human and animal lives.
Better monitoring of surface and groundwater resources is another essential step for managing groundwater resources under extreme conditions. Groundwater withdrawals, in particular, are poorly tracked. In fact, in most states, Texas included, landowners have the right to unrestricted groundwater pumping from beneath their property. This is a holdover from a time when there were far fewer people around, and little to no understanding of how the water cycle functions.
In the modern world, we now understand that aquifers are shared resources, and that when one person pumps groundwater freely, the entire, commonly-owned supply is depleted. One person’s actions affect everyone else’s water availability.
Now consider the implications of tens, or hundreds, or thousands of landowners behaving this way. Unfortunately, this is exactly the situation we’re in, in Texas, in California, and around the world, including the major aquifers in places like India and China, where groundwater levels are falling at alarming rates. Much like gun control, another holdover from the pioneer days, I don’t expect much change in water law in Texas or the rest of the United States. Although Texas has created a number of Groundwater Conservation Districts, their power appears limited and is often challenged. Water rights are exceptionally contentious, with billions of dollars at stake. However, that does not change the need for enhanced groundwater monitoring and new thinking on modern-era, enforceable water law.
There are a host of other ‘droughtbuster,’ strategies, including water recycling, desalination, more realistic water pricing, conservation, and far greater efficiencies in agriculture, the greatest use of water resources on the planet. Of course we all need to eat, but better crop selection and more efficient irrigation and water reuse on the Nation’s farms has the potential to save vast volumes of water within the United States. Anita Hamilton’s recent article in Time provides an excellent summary of our portfolio of options.
Drought is an insidious phenomenon with the potential to become the norm in much of the southern tier of our country, as well as in many of the arid and semi-arid regions of the world. It’s time to move beyond praying for rain and other “Hail Mary” emergency measures like eleventh-hour pipelines. The technology is in place to significantly modernize operational water observation systems for greatly enhanced water management. Current and future satellites, combined with better ground-based monitoring, can tell us how water storage is changing. With some effort we can figure out how much water we actually have in the ground. All of these data can be ingested into modern Hydrologic Information Systems (pioneered by Prof. David Maidment at UT Austin) and advanced computer models, with the potential to better predict water availability far better than ever before.
All it takes is the vision and the commitment on the part of our environmental and elected leadership.
What are we waiting for? Please tell me it’s not a rainy day.