U.S. Using Less Water Than It Did 35 Years Ago
The United States is using less water than during the peak years of 1975 and 1980, according to USGS water use estimates for 2005. Despite a 30 percent population increase during the past 25 years, overall water use has remained fairly stable.
So what else do we know--and not know--about water use in the U.S.? Learn from a USGS scientist and partners, and hear what they're going to talk about at a water use briefing on Capitol Hill.
David Hebert: Hello everyone and thank you for joining us for another episode of the USGS CoreCasts. I’m Dave Hebert and today we’re going to be talking about how water is used around the United States. The USGS has just released its latest water use report which offers a comprehensive picture of how we divvy up our water resources in this country and how that mix of uses changes depending on what part of the country you’re in.
We will also be talking a bit about what we don’t know about water use and how we might improve that knowledge. So I’m joined here by Bob Hirsch from the USGS’s National Research Program, and then on the phone we have Dave Naftzger, executive director of the Council of Great Lakes Governors, and Sue Lowry, interstate streams administrator for the Wyoming State Engineer’s Office. Thank you all very much for joining me.
Dave Naftzger: Thanks for having us.
Sue Lowry: You’re welcome.00:52
David Hebert: All right, Bob, what does this water use report tell us?
Bob Hirsch: We put our water sue reports once every five years to tell us where we stand in terms of how people are using water all across the United States. We give national totals, but we also divvy it up – look at how it’s used on a basis of states and – what we find in this report, which is keyed on the year 2005, is that really water use has been quite stable across the United States over the last, actually several decades, since at the mid-80’s. The nation withdraws about 410 billion gallons per day for all types of uses of water.01:33
That’s actually a decrease of about 5% since 1980, and on a per capita basis, actually decrease of about 27% since its highest levels in 1980 and we break it down into the major use categories. I could go ahead and talk primarily about the top 3 because 3 uses really constitute the greatest – the vast majority of the water use in the country. People are often surprised to learn that the single largest use of water in the United States is for cooling up power plants – whether they’re cold fired or nuclear – and that is about 49% of the total amount of water that’s withdrawn from rivers and streams and ground water in the nation as for thermoelectric cooling at about 200 billion gallons a day.
02:20And the second greatest use is for irrigation. Now, that’s 31% of the total and I would make contrast between irrigation use and thermoelectric. A lot of the thermoelectric use is water that’s withdrawn, heated up a little bit and then discharged into the environment or re-circulated in a plant and not really consumed, where as in irrigation a fairly large amount of that water is consumed, that is to say lost to evapotranspiration.02:49We’re seeing a slight amount of decline occurring in the amount of irrigation occurring in the nation; more so we’re seeing – the irrigation of course is very concentrated in the western United States, but interestingly, it’s really been increasing in the east in the last couple of decades, about 50% more irrigation water use occurring in the east today than it was two decades ago, whereas the west is pretty much equivalent to what it was a couple of decades ago.03:20The third category is public supply which is the kind of water used that many citizens think about most – more than any, and that’s the water supply to our homes, if we’re on a public water supply, to our schools, to our stores, our government buildings, our recreational facilities, and all the things around our cities and towns. That’s about 11% of the total water use in the nation, about 44 billion gallons a day, but it’s a very important part of the total and it is rather expensive to deliver because it’s treated to a very, very high standard, whereas those first two categories could take water of much lesser quality.04:01
So we spend a lot of money and we spend a lot of energy, frankly, on our public water supply. Public water supply withdrawals continue to increase the use of water and public supplies is up about 2% since the year 2000, but in fact when we compare that use of water in public supply to the number of people that are being served by those public supplies, we’re actually seeing that demand is decreasing on a per capita basis. So it’s – those are some of the really major findings of this report.
David Hebert: Thank you. And do we know if this info is being used across the country by states and other localities responsible for managing water?
04:41Bob Hirsch: What we do know is that it’s one of the most frequently requested reports that we produce about water in the United States. We probably don’t know as much as we’d like to know about exactly how people utilize the information, but I think it’s a very important part of providing citizens and public officials with some really valuable context to understand how things are changed overtime and how different regions of the country are different from each other in terms of their water using behavior.05:14David Hebert: And along those lines, I’d like to jump to you, Dave and Sue, on the phone for perspective outside the USGS. Sue, let me start with you. Could you tell us what part of the country you represent?05:24
Sue Lowry: Sure, I’d be glad to. I actually work for the Wyoming State Engineer’s Office, so we are the agency that administers water right. Of course, here in the west, water rights are important. Without a water right, you are not legally able to pull water from a stream or a ground water valve.
David Hebert: And how about you, Dave, what part of the country do you represent?05:47
Dave Naftzger: Sure. I represent the Great Lakes St. Lawrence River Basin and it’s a very vast resource that stretches from Minnesota to Quebec and also it includes parts of eight states and two provinces. It’s a very water-rich area, about 20% of the world’s surface fresh water is in the Great Lakes Basin and it’s home to about 35 million people.
David Hebert: Starting with you, Sue, could you each talk about how you’ve been using USGS water data and water use data?
06:14Sue Lowry: Sure. Again, I think the water use report is good for that 20,000 foot level, if you will. There’s certainly other more day-to-day, real time information that is gathered by other program from the USGS that we utilize for making water distribution decisions, which of course are done on a much smaller timescale. But I think the – one use, just as an example, that the Western States Water Council wanted to look at how each of the state might estimate what their water demands would be and in what sector demands would be by the year 2030.06:57So we utilized trying to ask each of the western states to make that kind of an estimate of what their use would be 30 years, 25 years and to the future. And we try to use the same categories or sectors of use that the USGS uses in their report so that there would be consistency across the states because, as Bob mentioned, there is a lot of difference in the individual reporting programs that the states might have and trying to compare those can be quite difficult. So in cases where we could get as much consistency, that’s what’s important, and certainly, the USGS report is kind of a standard, if you will.07:38
David Hebert: OK. Thank you. And how about you, Dave. Have you been using water use data in the Great Lakes area?
Dave Naftzger: Well, in a variety of different ways. One of the principal uses for the Great Lakes States and the provinces has been the consumptive use coefficients. Most of the water use is not measured in terms of the specific quantity that will be consumptively lost as a result of a specific use. So consumptive use coefficients are used broadly to get an estimate of how much water is being returned to the source and how much is being lost. That’s been very important for some of the broader management efforts that the states and the provinces have been undertaking, looking at the sustainable usage of the overall resource.
08:32David Hebert: OK. Thank you. Let me go back to you in talking about some of things we’d like to be able to do that maybe we’re not doing now. First of all, you had said that this report was for the year 2000, 2005. Why is it that our latest water use report only goes up to 2005?
Bob Hirsch: Right. As I mentioned, we’re very reliant on the states for this information and as is appropriate, the states each have their own schedule by which they collect information in various manners in which they collect it and they report on different schedules and some states may report several – you know, very quickly, others more slowly, some may do it on the zeros and the fives, other may do it on the threes and the eights or whatever. And because we’re trying to collect the information from all 50 states, we’re kind of constrained by whoever is the latest on to report rather than when the bulk of them can report.
And I know it’s frustrating to people, and in fact a number of actually very well known experts on water in non-governmental organizations and other agencies get very impatient and put in a lot of phone calls to some of us about, “When is that report coming out?” They’re really, really anxious to see it and so we’re as frustrated as anyone by the fact that it doesn’t come out in a terribly timely manner.
So that’s one of the kinds of things that we’d like to improve. And frankly, and as the National Academy of Sciences recommended to us, is that we need to try to move to more of what I would call water use science as opposed to more of just a simple accounting practice. The better use for example of remote sensing information which can tell us a lot about irrigation and how much water is being applied, how many acres it’s being applied to, and other ways. And frankly using economic information to help us track back to the water information.
So a variety of statistical and economic and remote sensing techniques really being brought into the game.
David Hebert: What are some of the big things that we hear at the USGS don’t know that we’d really like to know about water use?
Bob Hirsch: Well I think both of the other speakers on the call here, they’ve put their finger on it and that is consumptive use that there is – in many uses, certainly in irrigation but even in our homes. For example, water that we take which goes right back in and infiltrates into the soils and on into our aquifers, into our ground water system and perhaps back out to the streams and it’s just in knowing what you have available, it’s critically important that you know what that consumptive use amount is.
And you can’t measure that by simply going to the pump or the meter or what-have-you that says what’s coming into the home or onto the farm, but it really involves a lot of the scientific measurement of what’s happening in the soils and in the aquifers and in the drains and the streams downstream. And we – there’s a lot of potential and the states have been making use of this potential and using remote sensing capabilities including particularly the USGS Land Satellite and its thermal band which is an excellent way to tell the amounts of water that are being used and the acreages on which it’s being done.
David Hebert: On October 30th, all three of you are going to be talking about this report and about other water use issues at a USGS Congressional Briefing on Capitol Hill in Washington, D.C. Sue, starting with you, can you just tell us a little bit about what you’re going to be presenting at this briefing?
Sue Lowry: Sure. I mentioned the Western States Water Council which is an arm of the Western Governors Association. Our council just completed a report back to the governors on what is the outlook for sustainable water use in the west as we’ve seen huge calculation growth, a lot of what we termed “egg to urban transfers”, the well water rights that has been attached with irrigated lands are then changed for municipal supply to meet the needs of growing populations in growing cities. So I think we’ve seen the way the west uses water certainly changed over the last 20-30 years and documents like the USGS’s water use report, then it shows us again about bigger scale, how those changes have occurred.
So I think that’s a big part of what we’re trying to look at and also how the states can be more consistent in how they report and gather the water use data that really is the basis for the report and use some of these new technologies like the thermal band above mentioned and just get those data collected more quickly and more consistently across the west.
David Hebert: OK. Thank you. And how about you, Dave, what are you going to be talking about at the briefing?
Dave Naftzger: It’s been a very exciting time to be involved in water policy in the Great Lakes region over the past few years. New interstate compact following many years of work just became a law last year. I serviced the executive director for the compact council, so we’re in the process of putting in place a new water management framework for the region. An important part of that is an improved and renewed effort to getting at how we collect water use information and how we’re applying it.
Over the past 12 months or so, we’ve had a major effort and USGS has been one of our partners to look at the development of new water use information protocols. Really spelling out in detail a common framework for how the states in the provinces will get water use information from water users, how they will share it with one another and how that will be packaged and made publicly available not only to help informed decision making by the states in the provinces, but for a whole variety of other applications as well.
We need better tools to assess individual and accumulative water use impact. This will help us to improve our water supply information and our water budget. We need better impact assessment tools which will help us to monitor or predict forecast. We need a better understanding of our ground water and surface water in our action. Gauging and modeling can help and be a part of that. And more fundamentally, we need to strengthen the partnership that we have among the states in the provinces with the scientific communities so that we can all work together on this sustainability agenda that the governors had been very active in challenging us all to be a part of.
David Hebert: Thank you, Dave. And how about you, Bob, what will you be addressing at the briefing?
Bob Hirsch: I’ll be giving the perspective I often talk about, and that is water of course is very vital to our economy, whether it’s the electricity we use or industrial production. It’s incredibly important to the nation’s food production and very important to our welfare of citizens, but at the same time, I think we need to make people - help people understand that the water use is a choice at the level of individual farmers, industries. Government has a role particularly in some of the regulations that are imposed upon various kinds of industries and sectors that have resulted in major changes in the way that water is used.
Economic forces of prices and energy cost, et cetera, affect water use. And making choices at all levels – the individual up to the federal government level – really depends on good information. And that’s what we’re trying to do here is provide a basis of information and really try to foster the idea that there is a science to water use and need for understanding of that so that all the people involved in water planning can have the best possible plans and projections of how much water is going to be available, how much water is going to be needed for various uses to really provide for our economy and then provide for our environmental well-being all at the same time.
So I’ll pain some pictures of some of the major changes and the choices that our society has made in recent decades about water use.
David Hebert: All right. Well, thank you very much. It has been very informative and I hope you’ve compelled to our listeners to learn more, not only about our water use nationwide, but also in their own backyard.
Dave Naftzger: Thank you.
Bob Hirsch: Thank you.
David Hebert: And thank you to all of you out there for listening. You can take a look at the water use report for yourself at pubs.usgs.gov/circ/1344. And you can find other USGS water use information at water.usgs.gov/watuse. For more on USGS congressional briefings, visit usgs.gov/solutions and you can get this and other USGS CoreCasts as well as transcripts and related resources at usgs.gov/corecast.
CoreCast is a product of the US Geological Survey, Department of Interior. Until next time, I’m Dave Hebert. Thank you so much for listening and have a wonderful day.