[00:00:00] Bridget Scanlon: Welcome to the Water Resources Podcast. I'm Bridget Scanlon. In this podcast we discuss challenges with leading experts, including topics on extreme climate events, overexploitation, and potential solutions towards more sustainable management.
Today I'm pleased to have Bill Alley talk about water issues, particularly in the southwest. Bill has been the Director of Science and Technology at the National Ground Water Association since 2012.
Prior to that, you worked at the US Geological Survey serving as chief of the Office of Groundwater for almost two decades.
Bill has received numerous awards, including the Shoemaker Award for Communications in 2012. Bill, you and your wife Rosemarie have been very busy writing and publishing books over the past decade and a half, and maybe you can describe some of the topics that you've been covering and what motivated you to write these books.
[00:00:57] Bill Alley: Sure. And thanks for having me on your podcast, Bridget. Great to be here.
Yeah, so we actually started out with nuclear waste. One of my jobs when I was at the USGS was to oversee the USGS activities at the Yucca Mountain Project. So I would come home at night and tell my wife. She got interested in Yucca Mountain stories. So at one point in time she finally said, you should write a book about this, and I know what the title should be. And so she said It should be Too Hot to Touch. So not much happened for a while, but then I started digging into it and I gave her the first chapter and she told me it wasn't good for a general audience, so she told me basic number one rule is you have to make it interesting. I thought it was interesting. So she kind of got on board. She was very interested in this particular issue by that point in time and she has no science background to speak of, but she's a very good writer and very good at looking at particular items and digesting them, so we got on board with that and I was mainly motivated by, there's just so much misinformation around nuclear energy and nuclear waste, and, and we were not actually pro or con on the nuclear energy issue. It was more the waste, which no matter what your perspective is, we really need to deal with it.
So from there, when we finished that book, we thought about another one. So we did one on groundwater, the world's growing dependence on groundwater, which is titled High and Dry, although my wife later came up with a better title. Which is Groundwater: the Neglected Child of the Water World.
And after that I was on the EPA National Drinking Water Advisory Council at the time of the Trump administration came on. So I got interested in EPA and the controversies around EPA. So we did one on the The War on the EPA.
And then I was going to do one on PFAS. But Rosemarie actually identified the water recycling topic, so that was our fourth. So we've been having fun. We realized it's hard, really hard to hit a really general audience, but you can definitely communicate with a broad range of people that are involved in the water arena one way or another, which is a lot of people.
[00:03:10] Bridget Scanlon: Well, I think it's incredible and I really enjoyed reading High and Dry. I mean, what I admire about these books is that you provided the context and the history and we think everything happened yesterday, but really it takes decades for some of these things to evolve, and it's really nice how you present that.
And then also the key people that were involved in different aspects. So I would like to focus on High and Dry because many of the podcasts we've been hearing that, there's a growing dependence on groundwater and, and you deal with that very well. And even though you cover many aspects of groundwater from the US point of view, but also globally in that book, which are excellent.
I like to focus on the Southwest since there's so much concern about the Colorado River Basin,Arizona, and California. A lot of the news lately, So maybe we could start there. And I like, Rosemarie's alternative title, the The Neglected Child of the Water World, because it usually gets, second fiddle to surface water, and that gets a lot of the coverage.
So if we start with Arizona and what's been going on there in the lower Colorado River Basin, maybe you can describe a little bit. I mean, currently. They're not in too bad a shape because they had a wet winter, but they've been in droughts since two thousand. The Colorado River Basin, a long-term drought, but so, one wet winter is just not enough and it wasn't wet enough.
But currently Lakes Powell and Mead are about 30, 35% of capacity. And Lake Powell is up 35 feet from this time last year, so that's good. So maybe you can describe a little bit about how that has evolved and how that is going to possibly impact Arizona.
[00:04:59] Bill Alley: Sure. Yeah. So since 2000, the natural flow of the river I think is down about 20%. And of course it's been known for a long time that the amount of water that was allocated by the Colorado River Compact is more than the river has. I guess we're at the point where there's nothing better than a crisis. You want to take advantage of a crisis, and they surely have one in the Colorado River Basin.
So they finally brought the states to come together. Now in the case of Arizona, Arizona does have a very forward thinking program in terms of their Groundwater Management Act. In part of the state. So there were five Active Management Areas that were defined by the Groundwater Management Act back in 1980.
One of the ways in which they're very prepared is that they didn't have enough demand for the water that they were now entitled to from the river until about 2000. So they put in place a very well respected groundwater program for managed recharge for the surplus water. And they have a very well-defined permitting program. So they have for both recharge, for recharge facilities, for recovery and so forth. And they kind of look at two different kinds of recharge, direct recharge, which they call underground storage. And in lieu recharge, which is where they have groundwater savings, they call that groundwater savings facilities.
You can make it possible by, you can save groundwater by pumping surface water instead when it's available. And that's made possible really by a quantification of groundwater rights as part of the Groundwater Management Act. And just say a little bit about that Act for those areas covered.
There was no more irrigation allowed. On the urban side, they had to have a hundred year “assured water supply,” which is a little, a little nebulous and probably overcommitted in the long term, particularly in the case of climate change affecting their surface water resources. So they have a lot of water banked, not just from Arizona, but they have at least two times the Nevada's annual amount that they can have from the Colorado River Compact underground for Nevada's purposes.
[00:07:31] Bridget Scanlon: Right, right. So I mean, the original compact, the Colorado River Compact was developed in the 1920s. And that was, when you look at the rainfall, at that time, that was really a wet period. Right? A couple of decades. Right. I mean, we haven't seen that, that wet since. So it was overallocated to, because they were, they had more water then. And so that was one of the issues. And then, they have seven and a half million acre feet to allocate among the states. And California gets 4.4 million acre feet of the Colorado River Water.
And the other states, Arizona gets, is the second in Nevada gets much less. So I've, I've heard some people say the mantra that, 4.4 and no more, that they don't want California to take any more than what they're allocated. But Arizona could not take their allocation until they developed the Central Arizona Project, which was an aqueduct that they built and then delivers Colorado River water to Phoenix and Tucson and Pinal County .
So that was great, and it emphasizes the connection then between surface water and groundwater. So before Arizona got this surface water, there was a lot of groundwater over exploitation, depletion and subsidence and fissuring and other things, evidence of too much groundwater use. But then when they got the Colorado water, then they were able to irrigate with surface water, and so inefficient surface water irrigation recharges the groundwater, and then they had the spreading basins.
And so a lot of different things then. So really admired them. Of course, they're the poster child, I think for Managed Aquifer Recharge with Herman Bouwer starting that in the 1960s. They had pilot projects. It takes decades. It's almost like quitting smoking. It takes a long time to make this happen. But Arizona did a lot, right?
Yeah. And you documented that in your book
[00:09:37] Bill Alley: Yeah. And interestingly, they would not have gotten the CAP. They didn't get the CAP until they came up with the Groundwater Management Act because Congress wasn't going to fund Arizona unless they got their act together on the groundwater side. There's a whole interesting story about that, that involves Governor Babbitt and so forth
[00:09:56] Bridget Scanlon: Right. And you described that really well in the book, and it's very interesting to read that. I mean, it takes people that are extremely dedicated to make this happen. And it's not easy, but I think then also because groundwater is in the subsurface, we can't really see it. The pilot projects that they had with spreading basins were very helpful in giving people confidence that if they put it underground, it would be there for later.
So they've been doing a lot of these things over the past couple of decades. I think it has allowed them to survive the drought over the past two decades. But then also what, how do you see the future, in Arizona with the current situation? Yeah.
[00:10:43] Bill Alley: So they have a lot of water banked now they're gonna try to recover that water.
One thing to plan for it, it's another thing to do it. So one of the aspects of their program was that you didn't have to necessarily withdraw the water from the same place that you recharged it. So that gave 'em some flexibility actually. But that also potentially it's an issue.
They have to be careful in recovering water, not to over abstract in particular areas. And I think they've looked at putting some restriction on how much you can take out of any particular area. So it's not simply a matter of taking the straws and sucking on them, they've gotta manage their resource still as they recover that water.
So they are in excellent shape and some of the cities like Tucson and Phoenix are, and also in good shape. Particularly Tucson has banked a lot of water underground, and they've even banked water for Phoenix,. So they've got water in in their piggy bank, but, they'll be challenged to try to figure out how to withdraw it and without having deleterious effects in the process.
[00:11:56] Bridget Scanlon: And I guess a lot of that also depends on the geology Bill. Having suitable aquifers that you could do this coarse grain alluvial systems that would recharge readily. And then, so that's an important aspect. You have the Basin and Range system and maybe you can describe a little bit of that. And also the fact that, it is susceptible to subsidence. And those aspects.
[00:12:22] Bill Alley: Yes. So that would be another potential localized, effect if they were not careful. Yes. So the Basin and Range is most of Arizona. They have the Colorado Plateau in the northern part and then a transition area between, but the basins are basically big, deep sediment filled valleys from the mountains around them, and they provide excellent sources of groundwater, which is, and there was plenty of space created by the overdraft that took place. So there was no problem in finding space to recharge the water. You mentioned Herman Bouwer.
So that goes way back to the sixties where he was experimenting, using Soil Aquifer Treatment where you would alternate between basins with treated wastewater to basically focus on pathogens and nutrients. it was found to be very effective if you operated your basin carefully.
Right.
[00:13:27] Bridget Scanlon: And there may be a slight reprieve from the wet winter that we have. I talked with Mike Dettinger about the atmospheric rivers and then increased rainfall this winter, and that helped with the reservoir storage and they did try a number of things then to try to manage the water.
We have a portfolio of options, which is great. But they're still not, not out of the woods. Because I mean, it seems like I've been reading recently that Phoenix is not allowing any new residential construction that depends on groundwater. I've read that, Barbara Kingsolver moved from Tucson because she said she's the author of, Poisonwood Bible and other books, because she said, we've no business living in these semiarid regions.
Mm-hmm. And she moved to the Carolinas. But, so, they're being more and more careful and, and, and they have to be. And then there was a suburb of Scottsdale and maybe, maybe you can describe what Scottsdale has been doing, and then what happened with this, suburb Yeah. No longer has access to water.
[00:14:27] Bill Alley: Yeah. So first of all, Phoenix has been growing like crazy. I mean, if you drive east of Phoenix, it's just, it goes miles and miles out from where it used to be. And there's homes going up until they've actually trying to find the hundred year assured water supply for the new development in Arizona is difficult.
I mean, there are, there are ways to obtain those from trading rights, or bringing water from elsewhere. But it's really a challenge for them. Looks like they've kind of bumped up against the limits here for at least temporarily. So Scottsdale's an interesting case because we've got a community that's next to it that's having a lot of problems.
And Scottsdale itself, has a very, good water supply, because they got involved in, they call it, they call it the Scottsdale Water Campus. And what they do is they have a very advanced wastewater treatment plant. As well as a tertiary treatment plant on this campus, and they have about 23 maybe golf courses in Scottsdale.
And they have an agreement with the golf courses who have funded their wastewater treatment plant to some degree that they provide the tertiary treated wastewater, along with some advanced treated waste water as needed to keep the sodium levels down for irrigation on the golf courses. And then when they don't, can't use the water for the golf courses, then they recharge it through dry wells. So something like 150 feet down. Well, and then it takes another couple hundred feet travel down to the water table. And because they treat the water, they're very careful in how they operate the wells, because these wells can be a problem.
And because you don't have the same ability as a well to back flush. Or a spreading pond to scrape. So, but because they've got such high-quality water, they've been able to operate these wells to provide to their groundwater system. They used to be a hundred percent on groundwater, but now they also have some surface water from CAP and water from the Salt River too.
So they have a mixed portfolio, which is a good thing for them.
[00:16:45] Bridget Scanlon: So, so that's great. So we've been talking about the Colorado River project, the CAP Central Arizona Project, which is taking water from the Colorado to Phoenix, Tucson, Pinal, and these active management areas. But, there was also the Salt River project, for managing surface water from that river basin. So they've been very act proactive about trying to manage their resources and, and, they have to be, but not every place then has access to the, the CAP water or these other surface water supplies. So places like Willcox Basin and Ranegras or other regions then that don't have access to surface water, then the groundwater has continued to decline over the past couple of decades. And so it's been very difficult in those areas.
[00:17:34] Bill Alley: Right? You have a very nice paper on that very topic. It demonstrates very clearly the advantage of the Managed Aquifer Recharge within the Active Management Areas versus the others, and they don't have that. Don't have the CAP surface water to recharge.
[00:17:51] Bridget Scanlon: So yeah, that emphasizes the importance of this conjunctive use. Then where, where we have access to surface water and I think does Arizona, it has these Irrigation Non-expansion Area (INAs), so won't allow expansion of irrigation.
[00:18:08] Bill Alley: They call them Irrigation Non-expansion Areas (INAs). And also cannot expand their irrigation acreage.
[00:18:16] Bridget Scanlon: Right, right. And I heard from somebody recently that the Palo Verde nuclear power plant was using wastewater from Phoenix, but they may not have access to that in the future because they may be marketing it to the turf grass.
And so they're looking for other sources of water to cool the power plants. So it's, it's difficult to manage all of these demands from different sectors.
[00:18:43] Bill Alley: Right. That plant is the largest nuclear power plant in the United States, and I think it's a hundred percent on using treated wastewater. Or it's cooling water, which is pretty darn important. So we’re about to see how that plays out.
[00:18:56] Bridget Scanlon: And, and you mentioned then, with the reduction in the CAP that the states that they're going to reduce the amount of water that they receive, 3 million acre feet reduction over the next three years divided between Arizona, Nevada, and California. And I think Arizona has the greatest hit. On that, and that's maybe because of water rights. Can you describe that a little bit? The water rights issue? Yeah,
[00:19:21] Bill Alley: so when the Ground Management Act was, when the agreement for CAP came in, another requirement of that was that Arizona's water would be the lower priority to California and to Nevada,.
California and Arizona had a long history of back and forth, and they had a very famous Supreme Court case that was finally settled in 1963 about how much water California had and how much Arizona had. They actually sent troops to the border at one point.
So they had a long history. And California, one of the main reasons for the Colorado River Compact was the upstream states were concerned about California going to have all the rights to the river. So that was a lot of instigation on the part of those of those states.
So, so this sounds like it was quite a contentious process, but they actually came to some way of trying to address their current shortages, at least over a three year period from the sounds of it and Right. And by the way, it's not just water supply, but an equal issue is, is, is electricity.
So they depend on Lake Mead and Lake Powell to generate hydroelectric. Energy, which is a base load to supplement all the solar and wind and so forth that California and others are trying to develop.
[00:20:55] Bridget Scanlon: Right, right. So they say there's about 40 million people dependent on the Colorado River water.
And California gets 4.4 million acre feet, and that goes to Imperial Valley Irrigation, but also Los Angeles and other areas. With the proposed reductions then of 3 million acre feet over the next three years. Then as you mentioned, some of these Active Management Areas will go back to groundwater, and I think the Pinal AMA, which is a heavily irrigated Active Management Area. There was some material on the web. It's clear how reliable it was, but they were originally in 2019, going to give 20 million dollars to Pinal AMA to drill deep wells. They may be about a thousand feet deep or whatever to help them deal with the reductions in the CAP deliveries. So it'll be interesting to see how that evolves over the next several years.
If they move back to groundwater, how much they have stored, how much is in the bank, how much, how long it will last them. And of course that will depend on wet and dry climate cycles and all of that sort of thing.
[00:22:06] Bill Alley: No, I think, but I'm not sure that the 3 million dollars, which the federal government's contributing about two thirds of is to buy out temporary water rights. I hope anyway that they're not gonna just pay the money and then turn around and start pumping groundwater, because that would be sort of counterproductive. So let's hope that would not happen.
[00:22:31] Bridget Scanlon: Be great because it really is a social issue with irrigators. How are they going to manage with the reduction in deliveries? And so the federal government is providing 1.2 billion over the next few years to compensate, I think for this reduction. So it wasn't clear to me how they were going to use those funds and what they would do, but that's what I'm hoping.
[00:22:52] Bill Alley: I'm kind of assuming, I don't know for sure, but I would, that would be for essentially fallowing land, taking it out of production.
And not going and drilling deeper wells. That would be super.
[00:23:03] Bridget Scanlon: And so we've been talking a lot about surface water and groundwater and how they're connected. But in your book chapter on Arizona, you describe really well how they're connected in the case example with the Fort Huachuca and the base there and, and how that planned it out. Maybe you could describe that a little bit. because.
You wrote a really nice piece on one of the myths with groundwater, how much is available versus how much is recoverable. Yeah. And you mentioned that George Bush, when he was governor of Texas, said, how much water do we have? and, and you were saying maybe that's not the right question. And so maybe you can describe that a little bit.
[00:23:44] Bill Alley: Yeah. So the San Pedro River is what you're talking about. So yeah, they had basically depleted their groundwater by about 1 or 2% of, I think 26 million acre-feet, something of that order. So it's a good example how you may have a lot of water underground, but you can't tap it all.
And we have kind of a mixed message that we give as hydrogeologists. We talk about how much of the world's fresh water is groundwater, which is huge. So that kind of gives the impression that maybe there's a lot of groundwater we're not taking advantage of, and then we try to convince people that there's many of these areas that need to be managing their groundwater a heck of a lot better than they are currently.
So, the San Pedro, is well known as a birding area in particular, it's a very important environmental area. It's in southeastern Arizona, so it's not in an Active Management Area and it has a Fort next to it. And that Fort has particular interesting characteristics of the valley there, and so they had all the incentive to try to bring the pumping under control so that they don't dry up the San Pedro River. So they formed an Upper San Pedro River partnership, I think something of that sort that would brought to stakeholders and they had a lot of meetings. And one of the more interesting aspects of that was the Nature Conservancy came up with the idea, because everybody was arguing about was the river decreasing or not, you all had a different opinion about that depending on your political stance. I think so. She organized one of the persons who deal with the Nature Conservancy organized, which was called a dry, wet, dry mapping project, which began in 1999, and they'd literally go along 40 miles or more of the river, and they break it up into different teams. And she would pair maybe, an environmentalist with a developer. So they'd pair together, so they would develop some comradery ideally over this. And, and it, it went on. It may still be going on, I don't know, but I know it went on for decades and we kind of described that whole project, which is rather unique.
And they also had another good interesting part of that project is they were developing groundwater models and they had a lot of contention and nobody would believe a groundwater model if they didn't come with the results that they wanted. So they developed amongst the stakeholders that took them step by step through the whole development of the groundwater model, so that when they were said and done, it all had some level of confidence in it, and it was a little harder to disavow the results if they didn't come out the way you wanted them to.
So, yeah, it's a very interesting project. They're still, as far as I can tell, dealing with groundwater depletion in that part of, of Arizona, although recently they had a vote and the one of the basins down there, Douglas Basin, I think, now has or is developing an AMA itself. So they have now six AMAs, I believe in the Arizona.
[00:26:59] Bridget Scanlon: Right. and that's fascinating and emphasizes the importance of stakeholder involvement and oftentimes as technical scientists, we think we can just do the technical aspect and then just present the results. But that co-development that you were talking about, and that person from the the Nature Conservancy, was amazing to get, the communities and then they could see what was happening. They could watch the dynamics of these wet and dry parts of the river and how they were changing year to year, maybe related to El Nino or other things. And I think that educational aspect is huge and really admire that person for what she pulled off. I's not easy and I think we are trying to do more and more of that nowadays, but the point you make is huge.
We can only develop a small component of the groundwater. A lot of people want to know how much groundwater do we have, and it may be an irrelevant question because we can't use most of it without destroying the surface water. I mean Dick Luckey did that sort of work in Nebraska where he said, the Platte River, showed that they had reduced the base flow groundwater discharge to the streams by 50%, with this, with less than 5% development of groundwater. So those connections, the groundwater discharging to surface water and the surface water being dependent on groundwater discharge, particularly during low flow periods. And I always think of you when I think of that and then when people want to do these global assessments of how much groundwater we have, we just think …. well really, do we want to know, do we want to tell people because they can't produce most of it.
It's sort of a bit like the African study that Alan McDonald did, which was very nice and got attention to groundwater, but that they tried to emphasize there that much of that it is not accessible or recoverable. So the difference between available and recoverable groundwater without hugely negatively impacting other things like surface water or causing subsidence or other things.
So you've done it, you've been involved with the California situation for a long time, and the time that the Groundwater Management Act passed in Arizona didn't fly in California. And maybe you can describe a little bit about that. And the Sustainable Groundwater Management Act that was passed in 2014 in California.
[00:29:30] Bill Alley: Sure. Yeah. So actually in 1976 to 77 was a serious drought in California and Jerry Brown was governor at the time. The groundwater problems were certainly manifested at that point in time, but they were not able to get any kind of real legislation through to control and manage the groundwater.
Well, they passed something, but mostly it was different parts of California mainly were passing laws to forbid the export of groundwater out of their area to another area. Well, that was the main thing that was going on. So, California, not until 2014, it was the last Western state actually to have statewide legislation to manage its groundwater resources.
Now, California does have special districts like Santa Clara and Orange County that do an excellent job of managing their water and have done so for a long time. But from a state point of view, it did not. It also has 20 some areas mostly in Southern California that have been adjudicated.
So they have somebody telling them exactly how much water they can pump, but particularly the Central Valley, some other areas in California, it was becoming increasingly obvious, particularly during this drought that the time had come to try to put some breaks on and some kind of regulation of the system.
So Jerry Brown was again governor, ironically, and they passed the Sustainable Groundwater Management Act. Which is similar to Arizona’s law. There's a couple basic differences. One of the most basic is Arizona had five active management areas. California has like, almost a hundred priority basins that they have identified.
Most of those are in the Central Valley, actually, which are high and medium priority basins. And those are the ones that have to form a Groundwater Sustainability Agency and then that agency had to come up with a plan to bring their groundwater into sustainability by the year 2040.
And by sustainability, they have a number of different, I forget what they exactly call them, but they're things like land subsidence and water quality degradation, storage decline and so forth. So those are negative effects that have to be brought into more sustainable way. And they have to come up with a plan by 2040 that's gonna bring them into sustainability for 50 years. And carry it out for 50 years. Right,
[00:32:13] Bridget Scanlon: So you mentioned, that first attempt was in 76, 77. That was really extreme drought in California. I dunno if Right. That played into it. It was just a one year drought, but it was probably the most extreme drought, short term drought in California, I think a lot.
Yes. Yeah. Swimming pools were dry, et cetera, et cetera. But then you had another five year drought, 87 to 92, and. And then, so 2012 was the beginning of an extreme drought also. So 2014, when the act passed, you were in the middle of an extreme drought. And so I think that motivated people to do something.
And also I think the GRACE satellite data helped to highlight, provided a visual to people to see that, drying out. And, and so I think that was helpful also. So all of these things together help to move this Sustainable Groundwater Management Act forward. So it's a bottom up approach. so I think you described it to me recently that, but the state has a hammer. If the, the local agencies don't do a good job, then the state can intervene.
[00:33:23] Bill Alley: Right? So dall these plans have to be approved by the state. And if they don't approve 'em, And typically what they've been doing, they've submitted a lot of plans have been submitted, but many of them are marked incomplete by the state and they have to by a certain timeframe, have a plan in place that's acceptable to the state, or the state will take control of the planning process, which nobody wants.
So that is a hammer that they have here. And the other interesting thing is there could be multiple sustainability plans. They have all these basins and there's multiple sustainability agencies breaking up parts of these basins, so they have a lot more complicated situation. It makes it easier to get the local involvement, but it's a much more complicated process.
And Arizona really had the Arizona Department of Water Resources, it was developing that made a play major role in developing their plans. And so this is a little more chaotic process. A lot of people have criticized 2040 as too late, but if you look at Arizona, their plans were to the year 2025. So they're still working towards theirs, which they call safe yield.
So it takes quite a while to go through the entire process for these sort of locally driven planning processes.
[00:34:45] Bridget Scanlon: And, and one of the interesting things about having 100 priority basins and so many local agencies that multiple, groups may be counting on the same water, so they may be double counting, triple counting. And so they're going to have to coordinate and, and to make sure, and it may be the state will, will review that and, and oversee that so that they, they're not all thinking that they get this water or whatever.
[00:35:11] Bill Alley: Yes, the Public Policy Institute of California, I think has been tracking this to some degree. And as you might imagine, they have a lot more water planned for example, for recharge than they have source water available. So supply sides ideas are a lot more palatable to people than the demand side. So they have a very heavy emphasis on the supply side and there's definitely a lot of double counting going on.
[00:35:43] Bridget Scanlon: Well, California is a very interesting state. I mean, they developed the State Water Project and the Central Valley Project, these big pipeline systems transporting water from the humid North region where you have most of the water, 70, 80% of the water, but you have most of the demand in the semi-arid region to the south.
So those projects were developed in the early to mid-last century. They provide water during wet years. And so then in Central Valley where they grow a lot of our food and vegetables for the US, they switched from maybe 70% surface water during wet periods, to maybe 70% groundwater during droughts.
And without that surface water, they would've been in much worse shape. So this conjunctive management is very important, but also it, it takes a lot of energy to transport all that water from the north to the south.
[00:36:42] Bill Alley: Yeah. And particularly for the state water project over the Tehachapi Mountains, and this is an amazing percentage of the state's electricity just to pump that water up over the hills.
[00:36:53] Bridget Scanlon: And I think, yeah, I think you were mentioning one of the things that would constrain over exploitation of groundwater is subsidence and the impact on these on canal systems and changes in grade that may preclude some of that water transport. Do you think that's a a big thing that will constrain over exploitation?
[00:37:16] Bill Alley: I think that that has been a big factor in sort of motivating because the canals differential subsidence has a big effect on the canals. So you need them to have a certain gradient to them, and the subsidence really messes with that. And it turns out there's a lot of areas in California that had land subsidence.
In fact, in more recent years, it was newer areas that they hadn't actually discovered until somebody did some InSAR and discovered that they had these other areas that were actually quite a bit of subsidence going on. Right.
[00:37:51] Bridget Scanlon: Yeah, and I really admired the US Geological Survey, and the Department of Water Resources for their groundwater models and the monitoring data that they pull together and synthesize and use them in developing these models to understand how the system has been evolving, how it's responded to climate, to changes in water demand and stuff. So that's been very helpful. And you mentioned the synthetic aperture radar data that, Michelle Sneed the Claudia Faunt looking at and finding areas where they had expanded irrigation, where there was no surface water and, seeing groundwater or, subsidence where they didn't even anticipate it from their long-term ground-based monitoring.
So that was extremely interesting. So the satellite data comes in handy at different times, right? Yeah. Yeah. So, I mean, trying to develop sustainable management. Then, we have supply and demand so we can increase supplies. And you mentioned that that's what people usually prefer to do. Increase supplies. Reduce demands, store more water like we've seen in Arizona, in surface reservoirs or in groundwater or transport water, which we've seen in California. So going forward with these Sustainable Groundwater Management Act in these districts, there's a lot of emphasis on Managed Aquifer Recharge. Right. And how do you think that's going to evolve?
[00:39:21] Bill Alley: Well, I think managed aquifer recharge is a very key component to how they solve the problem. Particularly a lot of interest in wet periods, particularly, in flood MAR, taking advantage of the massive amount of water that sometimes flows through California.
So the state has recently put in practice sort of a temporary permitting program where you can get 180 day permit, temporary permit, or even a five year potentially temporary permit to recharge excess water. It's flowing through these canals because there's a whole lot of legal aspects that certainly crop up when you try to do that.
So they've been trying to play catch with this huge amount of water that's flowing through the state right now to capture as much as they possibly can. But that aside, I think just regular managed aquifer recharge projects will be more and more of those will be seen in throughout California.
Right. There's a lot now, but there'll be a lot more probably.
[00:40:22] Bridget Scanlon: Right, right. I visited Arvin Edison Irrigation District many years ago, and they've been doing it since the sixties. When they have surface water, they have these spreading basins and stored underground, and then during drought they have a large number of wells and they're pumping 24/7, 365 to provide water during the drought periods, and it's just amazing what they do.
I really like your quote in the Arizona chapter of your High and Dry book. where you mentioned, Steinbeck's quote, and they'd never failed that during the dry years, the people forgot about the rich years, and during the wet years, they lost all memory of the dry years. And it was always that way.
And so I think what we are trying to do is solve, resolve this temporal disconnect between having too much and too little, right? Oftentimes people talk about water scarcity, but it's managing these extremes, I think is the real challenge. And the spreading basins, they take a lot of surface area, so by flood managed aquifer recharge, then they're flooding agricultural fields during the winter and then taking account of the recharge that happens from that and doesn't seem to negatively impact, nut trees or, or things like that. So that's really beneficial. And of course there's plenty of space in those depleted aquifers.
[00:41:45] Bill Alley: They also have lots of space and I think the idea actually was instigated by a particular farmer who just decided he was going to divert some water, flood waters onto his nut trees. And see what happens because he was in big trouble, so he might as figured, might as well try it. And it worked out just fine.
[00:42:03] Bridget Scanlon: Yeah, that's amazing. And then we mentioned increasing supplies to reach sustainability and so California by the coast, a lot of interest in seawater desal. And then wastewater reuse and recycling. You lived in San Diego for many years, and so they have a big desal plant there. And maybe you can describe that a little bit and then maybe we can talk about wastewater reuse, recycling.
[00:42:29] Bill Alley: Yeah, so they have the largest seawater desal plant in the Western Hemisphere in North County, north of San Diego, which supplies water to the county for the most part. It's been successfully run so they can fill their demand and supply issues. Some promised to buy so much of that water over a certain period of time. They also have a large scale effort to do water recycling as part of their drinking water supply, and they're working on that right now, which in a long, long time they've been trying to get that in place. It's actually, interestingly enough, driven by the fact that they have a wastewater treatment plant owned by the City of San Diego. That's not up to regulations. But it would cost them a fortune to make it so that it fully met EPA standards. So there's kind of a tradeoff. If they treat all this water, then they're reducing the problem and it's a sensible solution, although an expensive one. Controversial over time for San Diego.
[00:43:27] Bridget Scanlon: Right.. And so maybe you can describe a little bit about what would be required for the wastewater recycling, what level of treatment, and then Sure. And then they put it in spreading basins or the seawater barrier or how they manage.
[00:43:42] Bill Alley: Sure. Typically for groundwater augmentation, and California finally passed sort of their regs for groundwater augmentation, maybe back in 2014 or sometime around then, they require for injection wells that the water be treated by what they call fully advanced treatment or FAT, which is a specific process of microfiltration, followed by reverse osmosis, followed by UV and advanced oxidation processes. So they, they have a whole treatment train that they have specifically, and then you've got to add things back to the water at the end so it doesn't corrode all your pipes.
Now in the case of San Diego, they are using a surface water reservoir, which, and it's a small one, so they've added two levels of treatment, biologically activated carbon and ozone to the front end of their process. So they have five major ways of treating the water in the process for their planned plant, which they're currently working on right now.
They're hoping to have it up by 2025. I think it's been moved up a little bit to 2026, or maybe beyond. So they have specific treatment processes. If you're doing injection wells, you need that high quality water to maintain your injection wells and they all have always done it that way. The spreading basins have been more, Orange County uses that process, the advanced treatment, the FAT process I described for both their spreading basins and for their well injection. Los Angeles does more tertiary treatment for their spreading basins, although they have more recently have a advanced waste water treatment plant for a lot of it. But there's a lot of water recycling potable reuse going on in California for using groundwater for an environmental buffer in particular. And a few that really don't have groundwater resources like San Diego turn to the surface water as an alternative.
[00:45:35] Bridget Scanlon: So is there much direct potable reuse and what are the regs related to that?
[00:45:40] Bill Alley: Yeah, so there's a lot of plans for that. So there's only one place in the United States, Big Spring, Texas, that actually does direct potable reuse and has for some time. There was also a temporary project that went on in Wichita Falls, Texas under emergency basis. They now do indirect, but California's actually working on regulations for direct potable reuse. A lot of their plans for expansion in the LA region, for example, working with the Metropolitan Water District, California involved the idea that they would at some point be doing some direct potable reuse where they treat the water and inject either into a normal drinking water treatment plant or directly into the drinking water lines, if you will. And so they're working on regulations due this year, I believe. Other states include Colorado. Florida, probably Texas too are working on direct potable reuse.
[00:46:36] Bridget Scanlon: One of your book chapters in your water recycling book on San Diego is fascinating. Describing the evolution of that way back and people toilet to tap and how the yuck factor and all this. It takes a lot of communication skills and bringing the people on board and the education and everything to get people to accept this.
[00:46:59] Bill Alley: Right, right. Yeah. They had went through a long process of that. It got killed once because it got involved in mayor or in county city council elections, and then it resurfaced later on. And mainly because it was driven by this treatment plant. They had to deal with the treatment plant. Do you wanna spend $2 billion to upgrade a treatment plant for limited impact, if any really? Or recycle the water and create an additional water supply for the region, and it's really nice closing the loop on these things.
[00:47:26] Bridget Scanlon: And then maximizing, reuse, and increasing water supplies. Can you describe a little bit about the relative energy demands of wastewater recycling versus. Sea water desal and yes. How they compare.
[00:47:42] Bill Alley: Yeah, so the numbers are variable around, I think maybe a half to a third, cost for the recycled water to the desal water.
It's a lot cheaper. It's also economically viable compared to imported water. So if you're sitting in Orange County, the cost of imported water might be twice what it costs to run the wastewater through their advanced treatment processing. And recharge it in the groundwater system. So because the energy costs are large relative in California, or the transport of water, either from the Colorado River or from Northern California, actually recycling is very, economically positive. The benefit cost rates is greater than one.
[00:48:29] Bridget Scanlon: Yeah. Yeah. And you mentioned it briefly earlier, the sustainability also needs to consider groundwater quality. And I think it was interesting in Tucson when they had the CAP water and they put that directly into their pipe system, that they mobilized the stuff in their pipes. It wasn't compatible, a bit like Flint (Michigan) but then they put it into the groundwater so that they would avoid. So those issues. So water quality is also a very important thing in arsenic mobilization and so to be careful how we manage these things in terms of water quality.
[00:49:03] Bill Alley: Yes. That was an interesting case where basically CAP water was a different salinity than the water they've been pumping and eroded their pipes in parts of the city and created all kinds of problems. But now they do, they recharge what they, I think they have a law that you have to have use groundwater. So they take the CAP water and they recharge it into basins around the city, and then they pump it back out.
[00:49:26] Bridget Scanlon: I can, I think some of the politicians were wearing orange shirts because the iron that was mobilized. Oh really? I know. So somebody was telling me that it was quite a, quite a deal at the time.
[00:49:38] Bridget Scanlon: So we've been talking a lot about a lot of different things and I think the message that comes through is that we need a portfolio of options to manage water within the context of climate extremes, increasing demand.
And so how, how do you see the future for states like Arizona and California going forward? You're really trying hard to manage the resources and are you optimistic about whether they're you able to pull it off.
[00:50:05] Bill Alley: Yeah, if you look historically, we typically don't run out of water in place in the cities, but not for very long. So we get a warning as humans and then we try to work our way back out of it. And I think that's the case here. We have a lot, there's a lot of technologies out there and a lot of approaches that can be used and, and there is a lot more attention given the water recycling and storm water, how you can, how we can manage storm water better for water supply as well as manage groundwater and surface water.
I think there's really. It's starting to kick in. The people understand the need to manage their surface water and groundwater collectively. I, I'd give the example of Cape Town South Africa, which everybody knows had their so many days till they were going to run out of water and they fortunately didn't, but it really woke 'em up.
South Africa had managed aquifer recharge in the north part of the city, but it kind of decayed over time. One of the oldest managed recharge systems around the world. The city engineers were so focused on surface water that they just never took advantage of that resource.
And since that time, they've done a lot of planning and they're not going to have that happen again if at all possible. So they're looking at multiple sources and managing their surface water and groundwater conjunctively and on and so forth. So there's a wakeup call that sometimes comes.
[00:51:30] Bridget Scanlon: Yeah, I was talking to Karen Villholth recently and she mentioned the Atlantis project. Maybe that’s what I was mentioning. Yeah. Referring to, yes. And they also started to develop more groundwater. Yeah. They were completely dependent on surface reservoirs, and so started to develop their groundwater supplies. They had a temporary seawater desal. So the thing is you don't want to rely on one single thing, and then you have to have a portfolio of options and maybe some may be more expensive than others, but it's going to be very important insurance for water reliability in extreme situations. So I think cities and other groups are becoming more aware of that. So, I really appreciate your talking with me today. Our guest today is Bill Alley. He's the director at the National Ground Water Association and he has written a number of books that we've discussed that he mentioned at the beginning of the podcast with his wife Rosemarie. And we've been focusing mostly on his book called High and Dry, which is fabulous and I would encourage people to read it and also many of these other books.
Thank you so much, Bill, for taking the time to discuss these topics with me.
[00:52:40] Bill Alley: Thank you, Bridget. My pleasure.
