[00:00:00] Bridget Scanlon: Welcome to the Water Resources Podcast. I am Bridget Scanlon. In this podcast, we discuss water challenges with leading experts, including topics on extreme climate events, over exploitation, and potential solutions towards more sustainable management. I would like to welcome Brian Richter to the podcast today.
Thank you so much for joining us, Brian.
[00:00:28] Brian Richter: It's great to be with you, Bridget.
[00:00:30] Bridget Scanlon: So Brian is the President of Sustainable Waters, which is a global organization focused on water scarcity challenges, and he promotes sustainable water use and management with governments, corporations, universities, and local communities.
And prior to that, Brian served as the Director of the Global Water Program of The Nature Conservancy. So that's where he gets a lot of his examples from his time there. So Brian has published numerous books, including Chasing Water, A Guide for Moving from Scarcity to Sustainability. And I really enjoyed reading that and I would encourage anybody to pick it up because it's chock full of really cool examples and very presentable material.
His website is SustainableWaters.org is an excellent resource for people and he sends out a blog every so often and on different topics that he's working on. So today, Brian, I thought we could start with talking about your recent work that was published in Nature Communications on the Colorado River water, and where you talk about the detailed water accounting in the river.
And then you've done so much work on environmentalflows, I think it would be great to discuss those a little. And then what I really like about your work is that you emphasize solutions a lot to various sustainability challenges. So I think we will end up talking about different types of solutions. So first, maybe let's talk about the Colorado River paper that you published recently.
I mean, that was a lot of work, a lot of collating data and pulling it all together, developing new data and all of that. I'm wondering, was there many surprises when you did that work? And, and it seemed like there was a lot of media attention to the work. And what did you garner from the media? What were they most interested in?
[00:02:23] Brian Richter: Oh, well, I want to start by saying that I felt so fortunate, Bridget, to bring together such an incredibly talented team of disciplinary specialists, and we couldn't have put together all the different facets of the, of the water accounting for the Colorado River without having people that knew how to access datasets and run models of different sorts.
So, big shout out, thank you once again to all of them. You mentioned the media. Gosh, I think that in all of my long career, 30 plus years of publishing papers and reports and all I've never had the kind of media attention that we got from this one and I think there were a couple of things about it.
Certainly there were that caught everybody's attention certainly it was that The Colorado River in, and we're speaking of the Colorado River in the Southwest, not to be confused with Texas's Colorado River, of course, the Colorado River in the Southwest has been in such a crisis now for a long time, almost going on 20 plus years, and everybody's worried about running out of water.
And so, there was already heightened attention around the river, but I think the really unique thing that we were able to do with that paper was. We were able to account for all of the river's water, which had not been done before, remarkably. So, for your listeners who don't know, the Colorado River gets consumed in its entirety before it reaches its natural delta in Mexico, in the Gulf of California.
So it's somewhat shocking that nobody had put together the whole comprehensive, complete story about where all that water goes. Thank you very much. And so that was an important contribution and some of the things weren't too novel. By that I mean that everybody knew that irrigated agriculture consumes the lion's share of the water.
And it's a little over 50% for the Colorado River. And so only less than 20 percent is going to all cities and industries. And then the other two big parts of that, of that river's pie is reservoir evaporation, which people sometimes include when they're doing the accounting for the river and sometimes don't, but it's, it's another 10%.I think it was 11%. And then the really, the part that made me very happy that we were able to include was the water that gets taken up by the natural environment. And so all along these rivers and streams throughout the Colorado river basin, there are, there is vegetation adjacent to the river, what we call riparian vegetation and wetland vegetation.
And to be honest, we got lucky that another group of researchers had just developed a very detailed complete map of all of that vegetation. And so what we were left to do is to calculate how much water was that vegetation using. And it turns out it's about 19 percent. So almost a fifth of the Colorado River's water goes to supporting nature, in essence.
And we thought that was really important. We were really happy that we can include it because we wanted to bring nature front and center into the conversations about the Colorado River and its future. So, I mentioned one la a couple other things I'll mention, Bridget, that I think attracted some media attention.
One was that in those numbers, basically the irrigated farming uses about three times the amount of water used in all the cities and industries. So, that surprises a lot of people. They don't realize, as you and I know, that so much water is going to that irrigated farming. Embedded within that agriculture, so I said about 52 percent is going to agriculture, 30, a third, 32 percent of the river is goes to two crops, alfalfa and grass hay, which we lump together as cattle feed crops.
And so a lot of the headlines that came out of this story were about how much of the river was going to feed cows for dairy and for beef production.
[00:06:46] Bridget Scanlon: Right. I mean, sometimes you hear people say turn off the faucet when you're brushing your teeth to save water and conserve water. And then they don't think about, I mean, the elephant in the room is, is what are you eating?
[00:06:59] Brian Richter: Exactly. Exactly.
[00:07:01] Bridget Scanlon: What is the water footprint of that? We know the water footprint of beef is very high, but then the other aspect of water footprint calculations is that oftentimes it doesn't consider where the water is coming from. Yes. So if there was plenty of water to support the dairy and beef production, maybe it wouldn't be so problematic.
Yes. In semi-arid regions, and, and this, the Colorado, your recent Colorado work. It follows on your previous work where you talked about all of the alfalfa that's been grown in the Western U. S. in these semi-arid regions. And so maybe you want to comment a little bit on that, Brian.
[00:07:38] Brian Richter: Well one of the, so yes, so alfalfa is turning out to be by far and away the most dominant water user in all of the Western United States.
And it's something on the order of a, well, pretty similar to the Colorado River. It's about a third of the water is going to those cattle feed crops across the West. And that both surprises and I think disturbs or angers some people. And my quick retort to that, Bridget, is look, don't be blaming the farmers because they're growing what we want to eat and what we're willing to pay for.
It's a, it's a simple business decision on their part. In some places like the higher elevations of the Colorado River Basin, you don't have a lot of options. You can't, there's only a handful of crops that you can feasibly grow up in those higher elevations, cold temperatures. And so when a farmer's thinking about what he's going to put in his field, they're, they're thinking about what can I make the most profit off of alfalfa
And alfalfa turns out to be a pretty handy crop for that reason. And another interesting thing that we've discovered in our last couple of papers, Bridget, is that yes, so, so, so. It shocks people that we're growing a water intensive crop in a water scarce region, and that the production of alfalfa is actually going up, not down.
And so I dug into that recently to really understand that a little bit more. Well, it turns out that, so we use alfalfa for both beef production and for dairy production. Feeding cows and beef production has remained pretty stable. Americans eat an awful lot of beef four times more than the global average, but, but it hasn't changed a whole lot.
What's really driving the increases in growing alfalfa is dairy. And in particular, it's yogurt and cheese. And so I try to bring it back home when people start to get all upset or start to blame farmers about growing alfalfa. I said, well, how's your yogurt? What do you think about that cheese?
[00:10:00] Bridget Scanlon: Yeah, it's hard for people to own things sometimes.
So you compare that alfalfa, alfalfa is very flexible. Sometimes they could have been in favorable climates, they could have five or six cuttings a year. So if they don't have enough water for a short period of time or a short-term drought, they can readily adapt and not grow it for that particular time.
And contrast that, I was talking recently with Claudia Faunt in the Central Valley. They grow a lot of almonds and fruit trees and nut trees. and it takes five years for those to develop and they can't fallow them, so they buy the water and use the water even during dry periods. And so they've hardened their demand.
So I mean, there's no free lunch, it's difficult to understand all of the tradeoffs and these different things. And sometimes people say it takes a gallon to grow an almond in California and maybe it'd be better to eat beef from Nebraska or, or maybe chicken or. It's difficult to say, or maybe coconut yogurt or whatever, but then what is that, what is that doing?
What impact is that having? So it's difficult to understand all of these different tradeoffs. And for the Colorado then, I mean, it's very timely because a lot of the agreements are up for renegotiation in 2026. And so the Bureau of Reclamation and other groups are all looking at what they should develop in the future.
And you summarize very nicely the progression from the compact in the 1920s, which was a wet period and they probably over allocated the water, seven and a half million acre feet in the upper basin and seven and a half million acre feet in the lower basin, and then the Mexico allocation and stuff like that.
So has your work helped you to inform some of those groups going forward? I see decision making under deep uncertainty. There's a lot of climate uncertainty. There's the warming and increasing evaporation. So it's really difficult time, but it's important to understand the water accounting. I think that's very helpful.
[00:12:08] Brian Richter: Yes, well, a lot of people are hopeful that something magical is going to happen in those negotiations, and I, I hate to be one to throw a wet towel on those expectations, but the way that we've been managing the Colorado River, and it looks like the way that we're going to continue to, to manage the river is in a very reactive way, Bridget.
So what I mean by that is literally. Each year, by year, there are forecasts made of how much water is going to be coming down through the river system, how much water is going to be available for use, and depending upon those forecasts, and depending upon what level the big reservoirs are at, we're talking about Lake Mead and Lake Powell, the two biggest reservoirs in the United States, depending upon where their water levels at and how much we think we're going to get in the spring and the summer, they decide how much water various users are going to be cut back, that they're going to have to reduce their use.
It's a mandated use. And so you're always just reacting year by year. And those cuts fall on different types of users in different states. Mostly in Arizona presently, but eventually in Nevada and California, and then perhaps also in what we call the Upper Basin. Colorado, Wyoming, Utah, New Mexico. For So, it's all about how much water you release out of one reservoir or the other, and how much people are going to get cut off.
What I would love to see, Bridget, is something akin to what Texas has done with water planning. And by the way, I used Texas's water planning process as an example in my Chasing Water book. And, basically, the idea is that you plan for the future. The Texas water plans are developed with a 50 year horizon and they're updated every five years.
That's quite admirable. And the reason I'm so bullish on that kind of an approach is that we're looking at a very challenging future and we need to make some long-term decisions about how we're going to allocate or reallocate. We know it's a lot less than the original allocation back a hundred years ago in the Colorado River Compact.
So they're going to have to reallocate to some degree. And I think then it's necessary to decide, how are we going to live with that? under those lower levels of water allocation. If there's less water available, how are we going to do that? And how are we going to do that in a sustainable and ecologically healthy manner, leaving enough water in the river systems?
So, I think it's way overdue for the Colorado River managers to, to develop, you If not a 50 year plan, at least something like a 20 or a 30 year plan, so that people can anticipate what the future is going to be like, so that they can draw, take some security in knowing that their water managers have a plan for how we're going to be living in the next couple of decades. And that plan, of course, needs to also take into serious account the fact that we're going to have less and less water in the coming decades because of climate change.
[00:15:38] Bridget Scanlon: Right. And so it's, you're right, it's nice to have a plan and, and California is developing the Sustainable Groundwater Management Act is forcing them to move towards more sustainable management by 2040 through all, and a little bit like Texas bottom-up approach. And so you mentioned the sector of water uses earlier, you mentioned like urban, industrial and commercial is like 20%.
So big towns like Phoenix, and then agriculture being more than 50%. So it seems like, maybe there would be some water movement from agriculture to the urban areas. And do you think that that will help? Or one thing that you wrote about recently was urban areas, their water uses. kind of decreased, even though the population has increased.
Maybe you can describe how they accomplished that. And then going forward, then how do you think these different sectors are going to interact to divide up the water? I mean, you said Arizona would be possibly the most impacted because their water rights are junior to California. So California gets 4.4 million acre feet from the seven and a half in in the lower basin and Arizona has junior water rights.
So maybe you can describe the urban water use and what's been happening with that and then what you see between urban and rural irrigated areas.
[00:17:06] Brian Richter: You bet. Yeah, so we we published a paper last year that looked very closely at water being used by cities that are dependent upon the Colorado River. And it was a startling conclusion.
Across all of those cities, on average, they had grown by 24%, which Texans are familiar with what that feels like for a lot of your big cities. That's, that's a, a very, very rapid rate of growth. Of course, that was, by the way, that was over two decades, 24% over two decades. So 2000 to 2020. Yet on average, they were able to reduce their total water use by 18%.
So it wasn't just that they held their water use stable as their populations grew, but somehow miraculously they were able to actually lower it. And I shouldn't say really miraculously. It's the biggest, the biggest factor was changing how much water we use outside of our homes and businesses. So moving away from green grass lawns that require being irrigated every other day or something like that, a lot of these big cities in the West now are financially incentivizing or legislatively requiring their residents to rip out their green grass lawns and plant some native vegetation, drought tolerant, whatever you want to call it. Xeriscaping, but far less water demanding vegetation. So when you think about the fact that it's common for western cities to use 50 or 60 percent of their total water use within the city being outdoors, focusing on trying to reduce that outdoor water use is a really, really smart strategy. So that's where most of the gains came from.
But there's other things that we continue to make progress on. Replacing old toilets. Gosh, Bridget, when I was a kid, the toilets would flush 6 gallons of water with every flush, and now they flush 1. 2 gallons. So, if you can, if you can encourage those homeowners in the older homes that still have those water guzzling toilets, and get them replaced with a more efficient toilet, it makes a big difference. In some cities, it's been 20 to 30 percent water reduction just because of replacing toilets and other old water fixtures. So, that's really important and, and that's really good news because in the Colorado River, as well as many of the other places that you and I are quite familiar with, Bridget, you mentioned the Central Valley of California, the Great Salt Lake, which has been in the headlines for being under serious water trouble right now.
All of these places are going to have to substantially reduce their total water use to bring their water budget back into balance. In other words, getting their use of water down to the level of what the reliable supplies are. And so there has to be a reduction. So the fact that cities are being able to accomplish that for the most part is very, very good news.
The same kind of progress is desperately needed in the agricultural sector. And again, because irrigated agriculture is such a big, big, It's, it's the dominant water user in the West. And so if we're going to resolve this overdraft in our water budget, we're going to have to see very substantial reductions in irrigated agriculture.
Now you mentioned also the exchanges of water between irrigated agriculture and cities. So now that I've talked about both, it has been a strategy for cities for decades. Now we've seen a lot of transactions or trades where a city, and I'll use the example of my hometown. I grew up in San Diego, California.
They made a deal with the largest irrigation district in the country, which is in the lower Colorado, depends upon the lower Colorado River. And they said, if you're willing to conserve and not use some portion of your water rights and instead send it over to us in San Diego, we'll pay you handsomely for it.
And that's been a real boon for San Diego. It now makes up more than a third of their water supply is coming from the farmers that used to use it in the Imperial Irrigation District. The thing to bear in mind about those trades, so in terms of meeting high value, high priority water needs. urban, residential, drinking water, manufacturing, industrial, those kinds of things, which really are the mainstay of our economies.
In order to to provide water to those urban areas. One strategy, of course, is to do that kind of a trade with the agricultural water users, but that doesn't necessarily reduce the amount of water being used. And so I think that's important to understand. You're just moving it from one type of use to another.
There's no less water in total being used from the Imperial Irrigation District. It's just now that something like a quarter to a third of it is going to San Diego instead. But those kinds of, those kinds of trades are going to continue to be more and more important, particularly as we're grappling with the challenges of climate change, which is reducing the amount of river coming, the amount of water coming down a lot of our rivers.
[00:22:53] Bridget Scanlon: And I think we've heard recently about investors purchasing land near Phoenix and stuff and then selling that water to a distant municipality or developer or whatever, developing area. So I think that's been happening. And as the cities expand, you have the natural conversion of ag to urban. And as you mentioned, urban use is less.
So that, that expansion has probably reduced water use. And so if these trades and marketing and conversions can happen and actually reduce the water use also, that would be very helpful. A lot of your work, Brian, you mentioned earlier about environmental flows in the Colorado and 20 percent going to wetlands and riparian vegetation adjacent to the river.
So trying to figure out how much water you need to leave in the river to have a healthy ecosystem, how do you come up with those numbers?
[00:23:52] Brian Richter: Terrific question, Bridget. And, and one that scientists who work on those issues have been grappling with again for decades. And some of the earliest work was done way back in the 1950s.
And the concept back then, Bridget, was, it was referred to as minimum instream flow. What's the minimum amount of water you need to make sure it's trickling down the river? But we've learned a lot ecologically since that time. And so really, in the 1990s and early 2000s was a real burgeoning era of environmental flow science, where a number of us started making the case that it wasn't just the minimum amount of in stream flows that are necessary to support healthy ecosystems, but you need an occasional high pulse of water coming through the river. Sometimes you need a pretty good flood. And we've been able to articulate, been able to explain all the many ecological processes and functions and benefits that come when you have more variety, more variable flows.
That even might bear some semblance to what the historic long term ago historical flows might have been so there have been quite literally hundreds of different tools that have been developed to estimate how much, and I'm going to use this term now because it's more commonly referred to as environmental flows rather than in stream flows.
There's been a lot of different tools and methods and approaches used for, for doing those estimations, but oftentimes I'm deeply involved in one right now in the Rio Grande River in New Mexico, and we're thinking about, in each segment of the river, we're thinking about three or four or five what we call indicator species and talking through what does that species need to reproduce, to grow, to not die.
And we're coming up with some pretty nice, I would say, pretty elaborate recommendations for the specific flows that are, that are necessary to keep those ecosystems healthy. Now, the big problem that we've had to address over the last couple of decades, Bridget, is those kinds of assessments are, are pretty time-consuming and end up being pretty costly.
And so for the vast majority, I would hazard to guess, maybe 95 percent or greater of all the rivers and streams in the world, haven't had that kind of assessment done and aren't likely to in the foreseeable future. So we had to come up with some stopgap recommendations, and they aren't applicable everywhere, but we basically, after looking at the site-specific studies, the detailed studies that have been done in different parts of the world, we came up with what we called a presumptive standard.
It was what assumption can you safely make about how much water can be removed without harming, substantially harming the ecosystem. And there, it's a very conservative number. So if you're seeking a very high degree of ecological protection, you might only be able to take something on the order of 10 percent of the river's volume or flow.
If you looking for a more moderate level, still good, still great, but but a little bit more relaxed, it's something on the order of 20%. And so clearly those presumptions that those rules of thumb aren't going to work in a river where you've already lost 80 percent of the river, right? They're not going to work in the Colorado River.
So in the Colorado River, you have no other than to do those detailed, careful studies, species by species. How much of a river flood is necessary to move sediment and gravel through the system or to flush the fine material from the gravel so that aquatic insects can thrive? These are, there are myriad things in any river system that we, that we take into consideration.
By the way, including recreational use. that's been a part of a lot of these environmental flow assessments is what kind of water level do you need during a certain time of the year? For somebody to be able to float a canoe or a kayak down it, I was, I was also kind of a, kind of a very interesting anecdote is I was involved in environmental flow assessment in India, where I think a lot of your listeners will know that one popular form of, of burial, if you will, is to place the, the deceased body on a wooden raft and light it on fire and it drifts down the river and, and immolates the body and, and the raft included.
Well, during times of the year when a lot of that is going on, it clearly introduces a lot of, a lot of material pollutants into the river that you, that you wouldn't want to have in order to have healthy water quality. And so we actually had to come up with a recommendation as to how much water needed to be going down rivers like the Ganges, in order to be able to dilute those pollutants that were coming from that activity.
So I think this illustrates the variety of things that we try to think about.
[00:29:25] Bridget Scanlon: Right. And so some of the ways that you described that you can achieve these environmental flows could be changing the, the outflow from reservoirs and stuff like that at different times. And it's nice that you emphasize it's not just low flows.
Sometimes you need high pulse flows and Mark Wentzel at the Texas Water Development Board here in Texas does a lot of work on environmental flows. And so when we're trying to find out. How much stormwater could we take from some of these rivers to support managed aquifer recharge? We go through what they say they need for environmental flows, pulse flows at this time and, and that sort of thing.
And then we figure out what's left and we're looking at the high flow. So the pulse flows are the things that would impact that the most. So it can be quite complicated, but then. I was talking to Junguo Liu from China recently, and he did some analysis in North China, and he thought that the 10 or 20 percent that you were suggesting, there they found that they could take maybe 50 to 60 percent of the flow in the rivers that they were looking at.
So I think it's quite a variable, and so maybe once more analysis. And as you say, if the river's already depleted, it's going to be tougher.
[00:30:40] Brian Richter: Yes. Well, and by the way, I'm going to be quick to point out or to say to again, give praise to Texas is blessed to have some of the best environmental flow scientists that I've worked with anywhere in the world, honestly, and the Texas agencies through what was called Senate Bill 2 and Senate Bill 3 from some years ago, provided funding and a mandate to do these kinds of assessments on, on the Texas rivers and streams. And so Texas deserves a lot of credit for paying attention to these issues. But you raise a great point, Bridget, that that's why I was careful to say that the presumptive standard of only developing or using 10 to 20 percent of the water, that's for river systems are really presently very lightly touched.
And it's also the presumptive standard, we were very clear about this, would only be something that you would want to apply as a stopgap when you, when you weren't able to do the more elaborate studies. So it's a, it's a placeholder, right? But I wanted to also illustrate your point that sometimes a little change in the current water conditions and the current river flow conditions can make a big deal.
Let me tell you the quick story about the Yangtze River in China. You reminded me of that. We did an environmental flow assessment below Three Gorges Dam and brought in 50 or 60 Chinese scientists into a workshop and the highest priority for them was to try to revive the populations of four species of carp fish, which are incredibly important.
They're the primary source of protein for people living in the Yangtze River Valley for tens of millions of people. But once Three Gorges Dam had gone in, the way that they were releasing water from that, from that reservoir wasn't suitable for those carp to reproduce. And so these biologists said, these fish respond In the spring, they set a very specific time window.
They respond when the river goes through an abrupt rise, doesn't have to last very long, maybe only 10 days. But if they experience that, that abrupt rise, they, they spawn like crazy. And, We worked with the managers of the Three Gorges Dam, got them to incorporate that, and BAM! All of a sudden we had these carp reproducing again.
So, these are great stories. It doesn't always require a wholesale change in the way water's being managed. Sometimes we just look at what simple changes can we do now? Which ones should we work toward over the next couple of years? And which ones are kind of, we need to put on kind of on the frontier of the future, that we're maybe someday we'll be able to recover this part.
[00:33:30] Bridget Scanlon: Right. Well, that's, that's fascinating. And I do remember seeing some of the museums there, they had those fish and, and, and describing what some of the issues were. And I did visit the Three Gorges is a pretty cool area. What amazed me is you can have all these farms on the sides of the gorge and, and, and they just cultivate small plots of land and it just blows your mind. They cultivate every inch.
[00:33:54] Brian Richter: Every inch. That's absolutely right. It's quite impressive. Even when you get up into the mountainous areas on the terraces, right? It's just remarkable. They really use their land pretty intensively.
[00:34:08] Bridget Scanlon: Right, right. You mentioned earlier about current concerns about Salt Lake and and Utah and I think you're doing some work there.
So do you see what's the situation there? What does it look like? Or what are the big issues in that system?
[00:34:23] Brian Richter: Yeah, well, what's happening there is common through many of the river systems and aquifers again in the western United States. And it's this phenomena, Bridget, that we allowed the local populations to become so dependent upon the available water supplies that it got to the point where we were using every drop.
I told that story about the Colorado River earlier. We use every single gallon of water flowing down that river system. Same is true in the rivers that feed the Great Salt Lake. And so you're maxing out, you're using every bit of the available water, and then climate change comes along. And climate change starts to, because of climate warming, it starts to reduce how much water is coming down those rivers that feed the Great Salt Lake, or that recharge the Central Valley aquifers, or that feed the Colorado River.
And it's come on with surprising rapidity, surprising swiftness, that a lot of these places have already lost Already, 10, 9 percent in the Great Salt Lake, the science say 10 percent in the Colorado River Basin. So we've already experienced these losses in water, and the really frightening thing is they're saying twice or three times that much going forward into the coming decades out to mid century.
So in the Great Salt Lake, the consequence of this is that the lake has been shrinking. Over decades, the Great Salt Lake has lost two thirds of its volume and half of its aerial extent. And it's stunning. I mean, we think that the consequences in the Colorado River are big. Drinking water supply for 40 million people.
In the Great Salt Lake, there are two things that I'll mention that are just mind boggling. One is that all of that exposed area around the perimeter of the lake is loaded with really, really fine particulate matter, we call it dust, very fine sands, finer than fine sand, and also some toxic materials, metals from industry in particular, that had drained into the lake and now they're sitting out there exposed.
on these salt flats on these on these exposed old lake bed where the lake used to be when the winds kick up it blows that it's very that dust is very very easily transported and it blows it right in the direction of Salt Lake city and so now you've got 0.2 million people exposed to really frightening health hazards.
I mean, the health hazards from asthma and other lung problems, all kinds of things that really, really can do a lot of damage physiologically. So that's one consequence that they, they are really, really freaked out about.
The other one I just learned about as we started to really dive in is It turns out that the Great Salt Lake is something like three to five times saltier than the ocean because there's no outlet to the Great Salt Lake. So those rivers flow in, it's a big pond, and whatever salts are in the water coming in, they just get concentrated in that big, in that big puddle. And so the lake has gotten to be, has historically always been three to five times more salty than ocean water. That means not a whole lot of things can live in it.
But one thing that does live in it and a very important economically are brine shrimp. They call them brine shrimp. They're, they're little kind of baby tiny shrimp. It turns out that their eggs are harvested and dried and then shipped literally all over the world to feed aquaculture farms. So half of the world's seafood comes out of aquaculture these days.
And so all kinds of fish, but particularly shrimp and things like that are being grown in, in these aquaculture ponds, farms. And it turns out that the Great Salt Lake supports at least a fifth of all of that aquaculture because of these brine shrimp eggs that are being sent all over the place and it supports half of all of the shrimp consumption in the United States.
So, if they don't save this lake, if they can't turn this around, if they can't stabilize it and begin to refill it, you got a human health disaster and you've got a phenomenal impact on a very important food source for all of humanity.
[00:39:03] Bridget Scanlon: Yeah, that's incredible. And when you mentioned that, I mean, I do, I remember being in China one time and, and a lot of people, because of winds and dust in Northwest China and stuff like that, a lot of people wear masks, wore masks all the time.
And I thought the funniest thing that I ever saw was at a train station one time, this guy was wearing a mask and then he took it down to have his cigarette.
[00:39:31] Brian Richter: A little irony or hypocrisy or whatever in there, huh? Yeah.
[00:39:34] Bridget Scanlon: Right. So I would like to get back, get to your book on Chasing Water because I thoroughly enjoyed it because you presented very logical way, you used an analogy with a bank account and deposits and withdrawals and things like that.
And then in the solution scape, you described. What you can do then to try to resolve spatial and temporal disconnects between supply and demand. And then because of your work with The Nature Conservancy and running the global program, you have some fantastic examples from all over the world. So, so maybe describe a little bit about the analogy with a bank account and trying to understand our water budgets and then what we can do then to resolve some of the issues that we have.
[00:40:21] Brian Richter: Great, great. Yes. And, and thanks for, thanks for bringing that up. And the book came out in 2014, but so it's a decade old now. I should have celebrated its birthday recently, I guess, but
[00:40:32] Bridget Scanlon: Time to write another one.
[00:40:35] Brian Richter: Time to, there you go. So one of the most, so we've both given so many lectures and presentations on water in our careers, right?
And for me, Bridget, I think the most common question that got asked of me, particularly if I didn't explain this very well during my presentation, is people would say, you've been talking about people running out of water and I don't understand how that happens because don't we still have the same amount of water on our planet as we've always had?
And so what I came to understand, what I talked about in my book is that we're taught about the global water cycle, right? And water is constantly being recirculated and evaporating off fresh moisture, evaporating off of the great oceans and going up into clouds and moving across the landscape and, and coming down as rain or snow anyway.
And so that was really, really hard for people to understand. And I said, okay, but you, so I have to tell my students, forget about that for a minute. Forget about that global water cycle for a minute, because what's important to you is not how much water is available in the world. You're not going to be able to tap the Congo River in Africa for your water needs in your home.
Instead, and the water that's available to you is what is close enough to be accessible at an affordable price. Okay. So, so that, that kind of drives what our local water account is. And so I scratched my head for a while to come up with, okay, so what metaphor in our other, the rest of our daily lives can, can we relate this to?
And I, and I, in the book I came up with the, with the bank account, with the checking account. And I said, when you think about your local water account, and of course it's shared by other members of your local community, so all of the users of water from that particular local account, it's your local river or your local groundwater aquifer.
Those are the water accounts I'm talking about. If you are using water, meaning writing checks, faster than you're making deposits, which is recharge of an aquifer, replenishment of a river, then what happens to your account? It goes down, right? You're spending more than you're, than you're depositing.
Well, your bank balance goes down. And that's what happens with our water accounts. The, the groundwater aquifer level goes down, the river dries up, the lake dries up or shrinks in the case of the Great Salt Lake. And so that's, that's basically, it doesn't need to be any more complicated than that in order for people to just grasp That's how we run out of water.
That's what we call water scarcity. Water scarcity is not a pure reflection of aridity, of having low levels of rainfall. It's the relationship between how much water is being replenished and how much you're using. And so if, if you're using all of that available water or close to it, you're in a, you're in a condition of water scarcity.
So by the way, I've recently started to use more often. I start using the metaphor of, and maybe this will work for some of your listeners even better, of a bathtub. So you got a bathtub faucet coming in, you got a drain going out. If the drain's going out faster than the faucet is coming in, then the level of your bathtub goes down.
So, use whatever is easier for your metal fixture there. So, yes. So, I, in the book, I tried to outline, as simply as I could, before we started recording, I said to Bridget that I tried to write the book in a way that my parents could understand it. So every sentence was kind of a test for me. It's like, will mom and dad understand what I'm saying here?
So I tried to write in very simple, clear, plain terms. I talked about the different ways that we access water. In other words, how, how, how, for our, when I said our water supply or our available water, what influences that? Or how do we access that? And it's sometimes like, well, you stick a pipe, pipe in the river, you stick a well down in the groundwater.
It may be that you build a reservoir to capture water during a wet season so that you've got some water left over for the dry season. It may be that you'll import water, that you stick your, stick your reach out and into a, perhaps, miles, tens of miles, in some places on the planet, it's now a thousand miles away and you book, then you pull water into your local water account.
Various things. People are desalting ocean water and desalting salty groundwater to make it suitably fresh. So I talk about these ways that, that we, access and build our local water supplies. And then you mentioned, and then I, it's very, very important to me. I've come to be frustrated over the, over the term of my career, that so much of science is documenting the demise of the world and not enough of it posing what the available solutions are, are, or what the logical solutions, policies might be.
And so in the book, I lay out seven sustainability principles, which are rules to live by. And by the way, one of the most important ones is be as conservative as you possibly can and invest in water conservation programs. But then I tell a lot of stories as you're suggesting about how various strategies have been deployed in order to either further build your water supply or, in my mind, more importantly, reduce how much water your community or your farming area needs.
[00:46:28] Bridget Scanlon: Right. I used the same analogy many years ago. I was trying to get funding from the World Bank, and so I was talking to a bunch of economists, and so the only thing I could think of was a bank account. Maybe some of the young people these days don't really understand what a bank account is or what a check, a check is.
So maybe the bathtub, but I'm not sure they take baths either.
[00:46:55] Bridget Scanlon: So it's getting more and more difficult to communicate. Do you mean
[00:46:56] Brian Richter: my debit card?
[00:47:00] Bridget Scanlon: But it's a nice way to present the material because, I mean, it's easy for us to understand deposits and withdrawals. So input and output and then what you're left with is the balance or the change in storage.
So how can you, what sort of solutions can you have? You mentioned conservation, reduced demand, reduced the outputs. And so you were talking about the cities doing that with the, changing their outdoor watering and irrigation, irrigating lawns, trying to forget that they're not living in the UK and it's actually the semi arid Southwest.
Yes.
[00:47:35] Brian Richter: Yes.
[00:47:36] Bridget Scanlon: And then increasing supplies. I don't know. Wastewater reuse, water capture, desal, San Diego, I think. Do they have desal, I think, or?
[00:47:48] Brian Richter: They recently, within the last 10 years, they built the largest desalination plant in North America. Yeah. Right. So, so San Diego is a good example where they're, where they're using, I call the different ways of, of balancing your water budget is tools in the toolbox.
And San Diego is, is kind of a standout there. They're really have a very diversified water portfolio where they're deploying all of those strategies.
[00:48:13] Bridget Scanlon: Right. And then the temporal disconnects between floods and droughts, like we're seeing more and more of these climate extremes. So trying to store water from the period of excess to the, the drought periods.
And I think traditionally we've stored it in surface reservoirs, but now we're looking more and more at depleted aquifers. And Lenny Konikow estimates that about, we've got about a thousand cubic kilometers or a thousand close to a thousand million acre feet of storage space that we have depleted in the past.
Yes. And so that's a reservoir that we could partially refill through managed aquifer recharge. And I think the Sustainable Groundwater Management Act in California is targeting that approach in different ways.
And then you mentioned transporting water. I guess the big California's done that north to south.
State and federal projects and, and China more recently with the South to North water transfers. But you've got a wealth of examples from South America, from India, and from all of your travels in Africa and stuff. And so it's a delightful book. And I would encourage the readers because it's, he wrote it for his parents so anybody can understand it.
And I think it. really well put together and very helpful. And, and you're right. You get tired of hearing all about we're in deep trouble, but trying to figure out potential solutions, I think is, is very important and to, to try to explain those to people. So, I mean, what are your thoughts about the future?
There's a lot happening. Are you optimistic about the future? I mean, I think your detailed water accounting of the Colorado. We need those data in order to make, we need to understand the problems and how things are happening right now if we want to make appropriate solutions. So data availability has been increasing and people pulling data together, harmonizing data and satellites and all that sort of thing.
So I'm wondering what your thoughts are going forward.
[00:50:09] Brian Richter: Yes, I was chuckling a little bit under my breath there, Bridget, because I oftentimes get asked by my friends, they said, aren't you pessimistic? Aren't you afraid of what the future is going to be for water? We're running out of water everywhere and the climate's changing and in, in this sort of thing.
And my response, and it's an, it's a, it's an honest one is. I remain optimistic because we presently manage our water so poorly, which means, which means that we have a lot of room for improvement. And that margin of improvement can, can get us out of trouble in an awful lot of places. I mentioned that it's, it's, it's a, it's almost weird to me that right now in, in many of the water stressed places in the world where they're experiencing water shortages, It's a difference of 20%.They need to reduce their water use by 20%. Well, you think about it, if you're not using really, really careful, conservative, efficient water use practices, you can easily make up that much and maybe even more to, to be, to start building a buffer into the, into a changing climate future. So I am very optimistic about that.
And I think it's, I think it's both the adaptability of human behaviors, that we are capable of change. Unfortunately, it takes a pretty bad crisis, but, but we are capable of it when we're got our backs against the wall. And you mentioned the technological advances that applies to both the science where we're understanding things so much better, so much more accurately, but also things like the technologies of desalination of safely being able to recycle our waste water after we've used it, being able to capture the storm water, the water that's running off the streets and the roofs and used to just get run into our rivers and, and cause unnatural flooding in our rivers. And now we're learning how to capture some portion of that storm water and putting it, as you said, Bridget, putting it underground, storing it in aquifers so we don't have to build a big reservoir on the surface that comes with its own associated environmental problems in most cases.
So, yes, I think there's, I think there's a lot of, there's a lot of room for improvement. Otherwise, I have to tell you, I wouldn't be doing what I'm doing and I would just throw up my arms and give up.
[00:52:38] Bridget Scanlon: Right. I think that's interesting what you say about there's a buffer there because we're, we're doing so poorly at the moment with management.
And so that gives us a buffer to improve the situation. I think the analogy could be like, if you were already dieting yourself to death and you're still trying to lose more weight, there wouldn't be much buffer, but we've got a lot of buffer there. And so, so that's good. And, and I think as we move forward. And so, as we move forward, we will have to be cognizant of the solutions that we propose and, and the energy requirements of those and the greenhouse gas implications, and also the impacts on food production, because, as you said early on, irrigated agriculture is the dominant user, and so, So food security and energy implications, all of those sorts of things.
Well, I really appreciate your time today, Brian, and I encourage the listeners to read your book and also many of the papers that you have been publishing recently, trying to enlighten us on, on the different issues and, and harmonizing so much data and bringing new data to the front. Thank you so much for your time.
[00:53:43] Brian Richter: I really enjoyed it, Bridget, and thank you for the excellent questions. It was a great conversation.
