Unfiltered: Upmanu Lall
The director of Columbia’s Water Center talks with John Sabo about the inaccuracy of ‘water scarcity’ measures, how drinking water quality can get better, and why we should be very worried about aging dams…even in the United States
Can “better governance” solve the water challenges of a country like India? What’s the state of water infrastructure worldwide — and is it any better in the United States? Is climate change actually the biggest driver of water stresses today? And is the way we’re measuring “water stress” actually contributing anything to solving it?
You’ll be surprised by the answers Upmanu Lall gives to these questions. Lall directs the Columbia Water Center and is one of the world’s foremost experts in statistical and numerical modeling of hydrological and climatic systems and water resource systems planning and management. Future H2O Director John Sabo sat down with Manu to get his candid takes on some of the most pressing challenges in global water today.
John Sabo: Why does academic science still have a pervasive ‘water scarcity’ focus?
Manu Lall: It’s part of the curse of our current academia, which doesn’t think clearly about the real-world challenges. They’re informing nothing by what they do in this context.
It starts with this notion of scarcity that Malin Falkenmark and others put together [the water stress index], which is this idea that use greater than 40 percent of average annual supply indicates stress. Metrics like that do a disservice. They don’t help us understand whether we even have scarcity or not because they don’t give us knowledge of what the actual use structure of water is.
Such metrics mask who is using the water; when and for what; whether the use is consumptive or diversions; or what externalities (such as pollution) it creates on other uses. Most importantly, these metrics don’t speak to the spatial or temporal imbalances in water supply and demand in a region, and hence labeling as red regions or watersheds where average estimated use exceeds 40% of average renewable supply does not really inform a useful analysis.
For the most part, we have completely unregulated water systems around the world. No one knows what water is really being used, and we’ve made cockeyed estimates of that number instead of seriously trying to measure it and then doing this 40 percent game. This really needs to change through an accurate measurement of actual water use. There are basins that are “fully appropriated of allocated” in the U.S. West, where ecosystem services are well met by existing, high-quality river flows subject to reservoir regulation. By contrast, in monsoonal India, even in the upper catchments, in the last few decades, deforestation, erosion, sedimentation and unregulated water use have decimated ecological function, and the quality and quantity of water available for human use.
For the most part, we have completely unregulated water systems around the world. No one knows what water is really being used, and we’ve made cockeyed estimates of that number instead of seriously trying to measure it and then doing this 40 percent game. This really needs to change through an accurate measurement of actual water use.
— Manu Lall
In the last 20 or 30 years, this naïve water scarcity narrative has dominated in this field. Amazingly, even engineers have joined this scarcity narrative, rather than the narrative based on defining the situation in terms of a) the reliability with which you measure the demand that is not being met by the variable supply, and b) resilience as a frequency with which you could recover or the time it would take to recover from a deficit situation. There were a variety of measures around that people once used to define how resilient a system was, how stable it was, and how sustainable it was. All that seems to have been forgotten by the current crowd focused on scarcity metrics.
Work that Naresh Devineni and I have done on stress indices — applied to India, China, US, Korea and France — does build in some of the ideas on reliability and resilience to expose stress at different spatial and temporal scales for watersheds and political management units.(1) It still suffers from the fact that we have no real idea of actual use, and are forced to use crude estimates. In India, we found that in practice, flood irrigation application for rice paddies could dramatically exceed any estimates of consumptive use we could make using the typical biophysical equations.(2) In places in the US West, evaporative losses from surface reservoirs could be significant, and yet may not show up as “use.” And where urban water reuse is being practiced (but not reported in the USGS water use surveys), estimates of urban water use could be much higher than the effective use.
John Sabo: India — what’s holding back solutions for water there?
Manu Lall: The problem in India and in most real-world water activities is that the management a) doesn’t exist, b) is seriously flawed and c) no one is actually willing to overcome any political obstacles that are there.
The idea that climate change is the cause of water stresses in India is quite ridiculous. The Indian subcontinent has been marked by a history of severe sustained drought and flooding that dates back to the Indian epics, which were written in 2000 BC. Two to three meters of rainfall over a monsoon season can come in just 10–14 storms. Actually, the intensity of the rainfall can also be a problem. Climate dominates the nature of water- induced stresses in India, but the exacerbation of these stresses has to do much more with the dramatic increases in population, agriculture, water use, and associated flood, drought and pollution exposure than it does to climate change.
Yes, India needs better water governance. But “governance” is also an annoying word because it’s a cover for people who don’t do anything. Sometimes it’s not governance, it’s stupidity or kicking the can down the road.
— Manu Lall
Population pressures definitely contribute because, over most of India, we now have three crops a year, as opposed to one or two crops when I was living there. The time the land stays unused in many parts of the country between crops averages less than ten days.
Another problem is that you have free electricity for pumping groundwater in India. You have canals, which were built with some of the largest dams in the world behind them. And there are no charges for water from the canal. The people who release water from the dams can give you records of what was released, but no one knows where the hell the water goes. And there are laws that say that the water belongs to the tailenders, so in some cases water goes to the tailenders, and then you end up with waterlogging in these areas because the soils are clayey, and flood irrigation is practiced. There’s all this water coming down and it has nowhere to go. So: mismanagement beyond belief, in a way.
In the urban setting, most cities in India get two to four hours of piped water supply on a daily basis. This intermittent supply poses a health hazard, since the ability to control bacterial and virus populations under control in the pipe system is compromised. The supply is limited, not as much by source water constraints, but by the enormous amount of physical and economic leakage in the pipe systems, which are not maintained in part due to inadequate revenue to cover the sheer size of the maintenance issues, as well as the high energy costs to operate the systems. Private tanker deliveries thrive in places where the situation is worst.
Yes, India needs better water governance. But “governance” is also an annoying word because it’s a cover for people who don’t do anything. Sometimes it’s not governance, it’s stupidity or kicking the can down the road.
John Sabo: You say that the state of dam infrastructure is “precariously weak,” not just in India but also in the U.S. What’s going on?
Manu Lall: Maintenance in India is often poor — but maintenance in the U.S., once you get away from the federally owned properties, is shockingly also very weak.
In both countries at the moment, we have aging dams and aging levees. We have 88,000 dams in the U.S. that are taller than 15 meters. Their median age is 67 years. They were designed for 30- to 50-year lifespans. The likelihood that several of these might fail in a cascading chain from upstream to downstream is super-high because a lot of them have lost much of their capacity through sedimentation over time, and the material properties of many of them (which are concrete or even earthen) have deteriorated to the point of instability.
Climate change is making this situation progressively more concerning. We don’t have thinking on how to deal with this. Putting out more and more papers on what the year 2100 might look like in terms of floods and droughts is popular. Coming up with solutions is not as popular.
The U.S. Army Corps and the U.S. Bureau of Reclamation, which are the two national organizations with the most authority to deal with water issues, have not done any planning work or a national look at the problem at least since 1960, which is remarkable. At Columbia, we started the America’s Water Initiative seven years ago, recognizing that we needed to just dive into the research — that there was no funding for it, so let’s just do it. The organizations responsible for it are not doing it. They’re obsessed with climate change as well, but not the solutions to it. Once a dam fails or something significant happens related to a dam failure, the agencies will move very quickly to address it.
Climate change is making [aging dam infrastructure] progressively more concerning. We don’t have thinking on how to deal with this. Putting out more and more papers on what the year 2100 might look like in terms of floods and droughts is popular. Coming up with solutions is not as popular.
— Manu Lall
When I’ve talked about this at AGU and other forums, the answer I am given is: water is local, so why are you trying to look at the whole country? But money is not local. The money to plan major infrastructure projects in the U.S. historically has come from the Federal Government, and in the future it may come from private sources as well. So, if we think that the states of Utah or Arizona are single-handedly going to be able to do planning and fund what needs to be done, without interacting with other adjoining states, it is unlikely, and I just don’t think the money is there at the very local level.
John Sabo: Why do you think point-of-use sensors are a critical part of the answer to improving U.S. drinking water infrastructure?
Manu Lall: We are averaging around 840 main pipe breaks per day in the U.S. In 1950, our annual average was pretty close to that number. This is another aging infrastructure disaster issue. Every time a pipe breaks, there’s a boil-water notice, there’s a shutdown, and then there’s a subsequent contamination. The investment in water infrastructure in the urban setting has gone primarily to centralized treatment systems. Yet, if you look at the cost structure, 80 percent of the capital and operating costs is in distribution and not in treatment.
We are averaging around 840 main pipe breaks per day in the U.S. In 1950, our annual average was pretty close to that number. This is another aging infrastructure disaster issue.
— Manu Lall
Replacing main pipes and sewers costs between $500,000 to $1.5 million for a mile. In Newark, New Jersey, up to 40,000 kids between 2012 and now may have been exposed to lead in the water and have a high blood-lead concentration. Now they want to replace the lead service lines, and the governor is considering a $2 billion bond to cover it. This bond still doesn’t cover treatment required for pharmaceuticals or a variety of other contaminants in the water that are on the list of concern for the EPA but not being dealt with at the moment.
People should have an ability to have sensors right at their point-of-use, which will tell them extensively whether or not any of the chemicals that they could be concerned about are in what they are about to drink.[6] The Flint and the Newark stories really are about that. It’s not about lead; it’s about the fact that people were consuming lead ongoing until someone pointed that out.
Having sensors at the point of use is critical, and they exist now. Something that used to cost $150 per grab sample to test your tap water, and you’d wait a week for the lab result, can now be done for a fraction of that cost and in real time. That is an essential step. Who’s going to pay for it is an open question, but it also opens up doing wastewater reuse in places where scarcity is of interest, since you could then assure that the reuse water is safe to drink or use.
John Sabo: How important will distributed approaches to the drinking water infrastructure crisis be going forward?
Manu Lall: Currently, in places facing scarcity, people have been doing additional treatment to wastewater at a wastewater treatment plant, and injecting it into an aquifer. This has fairly expensive energy costs, especially in places where people don’t want to accept direct drinking of treated wastewater.
On the other hand, for a system at a neighborhood, household or building scale that treats wastewater to drinking water, and within which you could also do rainwater harvesting and have point-of-use sensors, you are basically agnostic as to the source of water because your system can treat it all the way through locally and monitor the quality. The treatment is more expensive, but the reduction in the piping costs and the pumping costs could more than offset that in most places.
It won’t work everywhere. Rainwater harvesting in a 100-story building in Manhattan is not going to supply that building’s water. But we’ve done an analysis across the country at the county scale, looking at census estimates of the typical roof area for residences and home occupancy in that county. And it turns out that if you target 70 percent reuse of rainwater-harvested water and a modest amount of storage each for dirty water and clean water (modest meaning about two cubic meters on each, that you could easily house in a basement of the house or even outside), you pretty much make it everywhere except in Arizona and New Mexico and some parts. And even there you would make it if you increase the storage.
I’m not advocating that rainwater harvesting becomes the solution to our infrastructure issues — just to make the point that you could do it. We thought that big infrastructure with high capital costs and higher operating costs was giving us economies of scale, and it didn’t. Compared to building ten small dams, building one large one has economies of scale. But in the urban setting, if you rethink it, this is where you end up.
At a time when our infrastructure is suffering from age and needs replenishment, we have to make bold investments in this direction, or suffer from inability to overcome sunk costs invested in inferior, unsustainable options.
— Manu Lall
But moving the idea of distributed local water infrastructure forward is hard because, just as with solar and wind energy, utilities want to fight you on this because they think it takes away from their current investments. And they’re right. But at a time when our infrastructure is suffering from age and needs replenishment, we have to make bold investments in this direction, or suffer from inability to overcome sunk costs invested in inferior, unsustainable options. Distributed elements can be added on in an as- needed basis in areas where pipes are already failing and need replacing, and in new urban developments. Distributed infrastructure for storage and treatment does not imply the lack of centralized management. In fact, it strengthens the need for a centralized structure for the synthesis and data mining of information from a vast number of sensors for better control and proactive management or pre-emptive maintenance.
John Sabo: Can we do aquifer storage and recovery at scale?
Manu Lall: It’s really quite challenging. It’s very useful in California, for instance, to reduce salt-water intrusion if you’re pumping water further inland. The first challenge is that if you want to infiltrate it by gravity, you now are looking at building a large pond, which will slowly let the water go into the ground. If you do that, you do lose quite a bit of water to evaporation and eventually the soil underneath that pond starts becoming saline.
India is all now gung-ho about aquifer storage and recovery. I just don’t see that happening easily.
— Manu Lall
More challenges arise if you want to pump it into the aquifer. First, you need to expend additional energy. Second, if the chemistry of the water that you put in is different from that of the water in the aquifer, which it always is, you can set up some interesting reactions. In Arizona in one case, when they pumped the water out to start using it again, it looked like milk.
India is all now gung-ho about aquifer storage and recovery. I just don’t see that happening easily. When you have an intense monsoon rainfall, where are you holding that water so that you can even pump it up? You still need large storage at the surface and then you’re pumping it down. That’s essentially the challenge with aquifer storage.
John Sabo: Is climate change everything now in water narratives and policy? If not, what’s its proper role?
Manu Lall: I started working on climate change in 1988, and I was one of the authors of the early IPCC reports. Climate change has to be a factor for planning and design of new infrastructure and design of release policies and so on.
What is an issue is when people use it as a cover for everything else. The fundamental driver of both climate change and water scarcity is increasing population and higher per capita use of every resource. Climate change is not the root cause but a symptom of our unsustainable population growth and consumption trajectory.
The argument some in the water community are making is: “Hey, we don’t get any attention, so we need to latch onto climate change as a way to get resources for us to do something.” That’s wrong.
— Manu Lall
Take Cape Town’s recent water crisis, culminating in Day Zero. Some people stated that this was at least a 10,000-year drought and that proved it was due to climate change. I wondered: is it really possible that somebody can do that sort of a calculation? I was able to find the rainfall records for Cape Town going back to the 19th century, and I then essentially converted that to stream flow coming into the reservoirs that they had, and then did an analysis of what the recent drought looked like and what were the past droughts relative to the designed release from their reservoirs.
Bottom line: this was a 50-year drought. The 10,000-year story is because somebody decided to take the data starting in 1974, when the last big drought ended just before. If you look at the record all the way through, there are three droughts that are comparable to the recent one in terms of overall severity of shortage.
So why did the water shortage happen? It turns out that the reservoirs system was originally designed for municipal use. They had an abnormally wet period from 1970 to about 2010, 2015. Somewhere around 2010, the government — seeing that the reservoirs were always full — decided to start giving some of the reservoir water to the agricultural sector as well. And as the drought progressed, they didn’t curtail any supplies to anybody. So it’s not a surprise that you got a Day Zero, and then Day Zero was broken because the farmers finally said: “Oh, well, you know, we’ll be nice guys to you and we won’t take any more water.” Incredible.
The argument some in the water community are making is: “Hey, we don’t get any attention, so we need to latch onto climate change as a way to get resources for us to do something.” That’s wrong. They should address how they’re going to do demand management and how they’re going to do ecological resource management.
John Sabo: Final question: how important are corporations as leaders for water sustainability?
Manu Lall: Politicians don’t act on their own, for the most part. They often follow corporations. So one key to getting positive action by governments is for citizens to push corporations toward better behavior on climate and water. Water risk has been in the top five risks for the World Economic Forum since about 2010. The food and beverage sectors, mining and energy, and the construction industry are all much better versed in water issues in watersheds than your average politician or bureaucrat would be. [10]
Corporate leaders are pushing change on two fronts: first, pushing their own companies to do well, and second, by becoming evangelists for water sustainability. The second trend is more interesting and I’ve seen it in India, the U.S., Brazil and Chile. The next crossover might be corporations paying for the entire water infrastructure for the city they’re based in. In India, Jamshedpur is the only city in the country with 24/7 water supplies that meet Western standards. And it’s a city where the Tata companies have a lot of manufacturing. It could well be that, in terms of water, the dynamic will shift to where we become essentially corporate citizens.
(1) See the following papers:
America’s water risk: Current demand and climate variability. N Devineni, U Lall, E Etienne, D Shi, C Xi. Geophysical Research Letters 42 (7), 2285–2293
Assessing chronic and climate‐induced water risk through spatially distributed cumulative deficit measures: A new picture of water sustainability in India. N Devineni, S Perveen, U Lall. Water Resources Research 49 (4), 2135–2145
China’s water sustainability in the 21st century: a climate-informed water risk assessment covering multi-sector water demands. X Chen, D Naresh, L Upmanu, Z Hao, L Dong, Q Ju, J Wang, S Wang. Hydrology and Earth System Sciences 18 (5), 1653
Sustainable Development of Water Resources: Spatio-Temporal Analysis of Water Stress in South Korea. S Kim, N Devineni, U Lall, H Kim, Sustainability 10 (10), 3795
(2) See https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2014WR015402
For more information about ASU Future H2O’s work and research on creating opportunities for global water abundance, visit our website and subscribe to our newsletter.
