“17 Countries, Home to One-Quarter of the World’s Population, Face Extremely High Water Stress.”

Figure 1: Overall Water Risk. Source: World Resources Institute.

So says the title of a report issued recently by the World Resources Institute (WRI). Behind the florid headline lies a somewhat more complex, but still very dangerous, reality.

Figure 1 maps the overall water stress. This is a statistic that combines 13 different kinds of water risks into one summary statistic. Thus, the color coding on the map does not translate directly to a physical measure of any specific threat, but rather represents the level of threat from all combined. The report discusses the risks individually, and they can be mapped using the Aqueduct tool available at the WRI. They are:

Quantity Risks                           Quality Risks                           Regulatory Risks

Baseline water stress               Untreated wastewater           Unimproved/no drinking water
Baseline water depletion          Coastal eutrophication          Unimproved/no sanitation
Groundwater table decline                                                      Peak RepRisk country EST risk
Interannual variability
Seasonal variability
Drought risk
Riverine flood risk
Coastal flood risk

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You can see that large swaths of Africa, the Middle-East, India, and China face extremely high risk. Those who read the environmental sections of the news may recall that Chennai, India (a city of over 7 million, formerly called Madras) is currently facing a severe water crisis. This city of over 7 million people reached “Day Zero” in June, when the reservoirs ran dry, and the city water company could no longer provide water. The rich pay exorbitant rates for water that is privately trucked in from hundreds of miles away, but average people get a small allocation (less than 8 gallons per day) that is brought in by the government, and they have to walk long distances to distribution points. The temperature just now in Chennai is ranging from a low of 80 to a high of 92, and the humidity is near 90%. Can you imagine living in that heat with only 8 gallons of water every day?

Those with slightly longer memories may remember that Cape Town, South Africa, faced a similar situation last year. Reservoirs hovered at 15-30% of capacity. Had levels reached 13.5% of capacity, the water company would have turned off deliveries, and people would have had to queue for water, just as in Chennai. Heavy monsoons in the summer of 2018 partially refilled the reservoirs, and “Day Zero” has been forestalled for the time being.

In both cases, the water crises were slow motion train wrecks, building slowly over years. Mismanagement and failure to perform upkeep on the water infrastructure played a role, but the primary culprit was increased population. Cape Town’s population grew from 2.4 million in 1995 to 4.1 million in 2015, an increase of 71%. Chennai’s population grew from under 1 million in 1941 to 4.3 million in 2001, and then exploded to 7 million in 2011. These population increases represented huge increases in demand, and supplies did not keep up. In both cases, however, the crises themselves were triggered by severe drought. A drought can cause the supply of water to plummet. If a region consumes almost all of its water supply, when a drought starts, the region can very suddenly find itself in a serious shortage. If the drought persists, the region will drain its reserves, and then the taps will go dry.

Given that population continues to increase, and climate change is predicted to cause longer, more severe droughts, it is a situation we are likely to see more often in the future.

Figure 2: Baseline Water Stress. Source: World Resources Institute.

Most regions of the United States are somewhat less vulnerable to pollution and eutrophication, and have access to sanitation and treated potable water. Thus, for Figure 2, I have chosen a map of Baseline Water Stress for the Continental United States, which measures total water consumption compared to total renewable water availability. On this map, Extremely High means the region consumes more than 80% of its renewable water supply, High means it consumes 40-80%, Medium High means it consumes 20-40%, Low Medium means it consumes 10-20%, and Low means it consumes less than 10%.

The areas of higher risk tend to be in the western half of the country, which should come as no surprise. The largest area of extreme risk includes California’s Central Valley, Los Angeles, San Diego, and the Imperial Valley. That should come as no surprise to readers of this blog, I’ve reported on it many times. But extreme risk is not confined to California. There are areas of extreme risk in Arizona, Utah, Eastern Washington/Oregon, New Mexico Colorado, Texas, and Minnesota. There is even one from St. Louis to Memphis, running along the Mississippi River. In all of these locations, a partial loss of water supply would quickly throw the area into deficit.

None of these areas has faced “Day Zero” in the way Cape Town and Chennai have. But they are getting close. Drought in California a few years ago led to the imposition of mandatory water restrictions, and the 2011 drought in Texas drained the E.V. Spence reservoir to 1% of its capacity, causing billions of dollars in damages, threatening the future of Robert Lee, a nearby town that depends on the reservoir.

Just 3 days ago (8/15/19) the Bureau of Reclamation announced that Arizona and Nevada will experience cutbacks in their allocation of water from the Colorado River, starting January 1. As I reported just a few weeks ago, Lake Mead is actually higher than it has been for 5 years. However, the states and countries that draw on Colorado River water have finally taken the situation seriously, and a new agreement to save Lake Mead from going dry was signed earlier this year. While the old system didn’t force cutbacks until the lake was at 1,070 feet above sea level, the new agreement starts phasing them in if the surface of the lake falls below 1,090 feet. (They measure the lake by how far above sea level its surface is. The lake is nowhere near that deep.) It is projected to be at 1,089.4 next January. Arizona will see a cutback of 6.9% of their water allocation.

It is tempting to think of the extreme crises in Chennai and Cape Town as Third World events; such things could never happen here, we might think. But the trends that caused the problems in both Chennai and Cape Town are at work in Arizona, California, Texas, and all across the West: increasing population, leading to increased demand, plus longer and harsher droughts, caused by climate change. Will they lead to similar crises? Will people be surprised and wonder how things could have gotten to such a point? I guess time will tell.

Sources

Hofste, Rutger Willem, Paul Reig, and Leah Schleifer. “17 Countries, Home to One-Quarter of the World’s Population, Face Extremely High Water Stress.” World Resources Institute. Downloaded 8/11/2019 from https://www.wri.org/blog/2019/08/17-countries-home-one-quarter-world-population-face-extremely-high-water-stress.

James, Ian. 2019. “First-Ever Mandatory Water Cutbacks Will Kick In Next Year Along the Colorado River.” azcentral.
Viewed online 8/18/2019 at https://www.azcentral.com/story/news/local/arizona-environment/2019/08/15/colorado-river-water-drought-arizona-nevada-mexico-first-ever-reductions/2021147001.

U.S. Bureau of Reclamation. Reclamation Announces 2020 Colorado River Operating Conditions. Downloded 8/18/2019 from https://www.usbr.gov/newsroom/newsrelease/detail.cfm?RecordID=67383.

Wikipedia contributors, “Cape Town water crisis,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Cape_Town_water_crisis&oldid=911322360 (accessed August 18, 2019).

Wikipedia contributors, “2019 Chennai water crisis,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=2019_Chennai_water_crisis&oldid=910798196 (accessed August 18, 2019).

World Resources Institute. Aqueduct Water Risk Atlas. Maps downloaded 2019-08-18 from https://www.wri.org/aqueduct.

Missouri’s water consumption declined in 2010. The decline was smaller than the decline for the nation as a whole, and it may be due to economic factors rather than conservation.

Missouri is not one of the regions of the country where water supplies are most tightly constrained. Thus, Missouri is not under as much pressure to reduce consumption as some states are, California for instance. Nevertheless, water consumption is an important environmental variable, and it is useful to know what the trends are in Missouri.

The data for this post comes from the U.S. Geological Survey’s Water Use Data for the Nation data portal. The portal’s data for Missouri extends back to 1985.

Figure 1. Data source: USGS Water Use Data for the Nation.

Figure 1 shows Missouri’s water consumption by end use, including thermoelectric power, for 1985-2010. Missing data makes comparisons across years difficult: data for thermoelectric power is missing for 1985, and data for livestock is missing for 1985, 1990, and 1995. With those caveats, Missouri’s water consumption appears to have increased through 2005, and then declined slightly in 2010. This contrasts with national consumption, which peaked in 1980.

The decline in 2010 may represent the beginning of a trend, but before assuming that it does, recall that 2010 was during the depths of the Great Recession, and the decline in water consumption may be related to a decline in economic activity, not conservation efforts.

Thermoelectric power is by far the largest consumer of water in Missouri. Missouri’s largest power plants (Labadie, Iatan, Thomas Hill, Rush Island, New Madrid, Sioux, Hawthorne, Meramec, and Callaway) are all located on rivers or reservoirs, and they withdraw water for cooling and for making steam. Thermoelectric water withdrawals peaked in 2005 at 6,181 million gallons per day, and declined in 2010 to 5,915 million gallons per day, a decline of 4%.

Irrigation was the second largest consumer of water in Missouri. The peak year for irrigation consumption was 2000 at 1,431 million gallons per day, and it was about 2% lower in 2010 at 1,402 million gallons per day.

Figure 2. Data source: USGS Water Use Data for the Nation

Figure 2 shows Missouri’s water consumption by end use with thermoelectric power excluded. I think that thermoelectric power is not a proper end use for two reasons. First, most water withdrawn for thermoelectric power is used for cooling, and it is returned to the environment. When returned, it may cause local problems because it is hot, but generally it is not contaminated. Second, electricity is not generated for its own use, it is sold to customers for their end uses. Thus, it may be useful to understand Missouri’s water consumption with thermoelectric power excluded.

Once thermoelectric power is excluded, irrigation and public supply become by far the largest consumers of water in Missouri. Irrigation was discussed above. Public supply represents all water that is delivered to customers by a public water utility. Here, things get a little complex. Some domestic and industrial water consumers supply their own water themselves. These consumers represent a small fraction of the total, and are shown on the chart in red and green. Most domestic and commercial consumers, and some industrial consumers, are supplied water by public water utilities, and these are the consumers represented by the dark blue public supply category on the chart. Both irrigation and public supply peaked in 2000, and by 2010 had declined 2% and 4% respectively. Because the trend is consistent from 2000 to 2005 to 2010, I am less inclined to suspect it is a function of the Great Recession.

Figure 3. Data source: USGS Water Use Data for the Nation

Stacked column charts are great for showing categorized data over time, but pie charts show more dramatically the percentages belonging to each category in a given year. Figure 3 shows Missouri water consumption in 2010 by end use, thermoelectric power included. It shows that thermoelectric power accounted for 70% of all Missouri water withdrawals. Irrigation accounted for 17% and public supply for 10%. Together, the three accounted for 97% of Missouri water withdrawals.

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Data source: USGS Water Use Data for the Nation

Figure 4 shows the same data with thermoelectric power excluded. If one considers thermoelectric power withdrawals a non-consumptive use, then irrigation and public supply together accounted for 91% of the water consumed in Missouri in 2010.

Because of the drought in California, I have also been following water supplies out there. I will post on California’s water situation after the start of the new year.

Sources:

Maupin, M.A., Kenny, J.F., Hutson, S.S., Lovelace, J.K., Barber, N.L., and Linsey, K.S., 2014, Estimated use of water in the United States in 2010: U.S. Geological Survey Circular 1405, 56 p., http://dx.doi.org/10.3133/cir1405.

U.S. Geological Survey. 2014. Water Use Data for the Nation. USGS National Water Information System. Search criteria: Years 1965,1970,1975,1980,1985,1990,1995,2000,2005,2010; Area UNITED STATES; Catogory ALL. Data accessed 12/3/2016 at http://waterdata.usgs.gov/nwis/wu.

Water consumption in the United States declined 18% between 1980 and 2010.

Water consumption is an issue of concern in areas where water supplies are constrained. Constructing a comprehensive study of how much water is consumed in the United States is a gargantuan task, but the United States Geological Survey does it every five years. It takes several years to put together, and the report Estimated Use of Water in the United States in 2010 came out in 2014. Historical data are also available on the USGS National Water Data Information System data portal.

Data source: USGS Water Use Data for the Nation

Figure 1 shows that water consumption in the USA grew rapidly from 1965 to 1980, but since then has declined. The peak in 1980 was 430 billion gallons consumed per day and by 2010 it had declined 18% to 355. The decline occurred despite the fact that during the period Gross Domestic Product grew by 229% and population grew by 36%.

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Data source: USGS Water Use Data for the Nation

Figure 2 shows similar data, except it is separated into end uses. The shape of the trend matches the one in Figure 1. It is impossible, however, to separate water consumption by end use without either missing some that you should count, or double counting some that you shouldn’t. The result is that, for any given year, if you total the amount used by each end use in Figure 2, it won’t precisely match the amount shown in Figure 1. The disagreement is small, never as much as 5%, and often much smaller than that. It would probably matter if you were doing research, but for our purposes here, it probably doesn’t.

Figure 2 shows that more water is withdrawn for thermoelectric power (nuclear and coal-burning power plants, primarily) than for any other use. Second is irrigation. Both have decreased since 1980. I don’t know the precise reasons why, but if I had to guess, I would say that retiring nuclear and coal-burning power plants in favor of natural gas and renewable energy, improved irrigation practices, and switching to soil cover/crops that require less water were all part of the story.

Public Supply did not peak in 1980, it increased right through to 2005. That makes sense, given that population and GDP have increased. Public supply includes all water delivered by a public water utility.

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Data source: USGS Water Use Data for the Nation

I don’t consider water withdrawn for thermoelectric power to be a true end use. For one reason, it is returned to the environment and used again without much treatment. For another, electricity is not generated for its own use, it is provided to customers for their end uses. Thus, it might be useful to look at water consumption with thermoelectric power excluded. Figure 3 shows the data. Now it becomes clear just how much of our water consumption really goes to irrigation: 60-67% in any given year. And suddenly, public supply looks more significant, accounting for up to 24% of consumption. Industry has made impressive progress in reducing water consumption.

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Data source: USGS Water Use Data for the Nation

Figure 4 shows water consumption by the source of the water: fresh or saline, surface water or groundwater. By far the largest amount is sourced from fresh surface water, and the second largest amount is sourced from fresh groundwater. If dry regions of the country turn to desalination to augment their water supply, look for the saline fraction to grow.

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Data source: USGS Water Use Data for the Nation

One final chart: these stacked column charts are good for showing categorized data over time, but they don’t show the categories for any given year as powerfully as does a pie chart. So Figure 5 is a pie chart showing water consumption in the USA by end use, thermoelectric power included, for 2010. It very powerfully shows that almost half of all water withdrawn in the USA that year went into nuclear and coal-burning power plants. About 1/3 of it went for irrigation.

In the next post I’ll look at water consumption in Missouri. I’m going to take a week off for the holiday, however, so it will appear in January.

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Sources:

Bureau of Economic Analysis. Current Dollar and Real GDP. National Economic Accounts. Downloaded 12/4/2016 from http://www.bea.gov/national/index.htm#gdp.

Maupin, M.A., Kenny, J.F., Hutson, S.S., Lovelace, J.K., Barber, N.L., and Linsey, K.S., 2014, Estimated use of water in the United States in 2010: U.S. Geological Survey Circular 1405, 56 p., http://dx.doi.org/10.3133/cir1405.
U.S. Census Bureau. Part II. Population of the United States and Each State: 1790-1990. Downloaded from http://www.census.gov/population/www/censusdata/Population_PartII.xls.

U.S. Census Bureau. 2011. Table 1. Intercensal Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1, 2010 (ST-EST00INT-01. Downloaded from http://www.census.gov/popest/data/intercensal/national/nat2010.html.

U.S. Geological Survey. 2014. Water Use Data for the Nation. USGS National Water Information System. Search criteria: Years 1965,1970,1975,1980,1985,1990,1995,2000,2005,2010; Area UNITED STATES; Catogory ALL. Data accessed 12/3/2016 at http://waterdata.usgs.gov/nwis/wu.

Two-thirds of the world’s population lives under severe water scarcity at least 1 month of the year, according to a study published in Science Advances. That’s 4 billion people. Nearly half-a-billion face severe water scarcity all year round.

The study’s authors divided the globe into small squares, roughly 50 kilometers on a side. Within each square, they calculated the ratio of the demand for water divided by the supply available. Ratios above 1.0 indicate areas where demand exceeds supply. Ratios below 1 indicate areas where supply exceeds demand.

Source: Mekonnen & Hoekstra, 2016.

There are a number of ways to consider water scarcity. One would be an annual summary – how does the average yearly demand compare to the average yearly supply? Figure 1 shows the data, with dark red areas having the biggest water deficit, and dark green areas having the biggest water surplus. One could guess the areas of greatest water deficit: the world’s great deserts. If there are surprises here, it is how much of the globe is red. Close to home, the size of the red area in North America is surprising, and a bit daunting.

(Click on chart for larger view.)

Source: Mekonnen & Hoekstra 2016.

Annual averages may not be the best way to consider water scarcity, however. In regions with monsoonal weather patterns, like India, Africa, or California, there may be copious water during part of the year, and severe dryness during other parts. Figure 2 shows the number of months per year that the water ratio exceeds 1.0, that is, the number of months demand exceeds supply. Dark red equals 12 months, or the whole year. Green equals 0 months, or none of the year. You can see that many of the same regions experience a water deficit for at least 6 months per year. Look at North America – how much of Canada, Mexico, and the United States experiences a water deficit a significant portion of each year! And it includes some surprising areas, such as Florida, Georgia, the Carolinas, Arkansas and Louisiana, etc.

Source: Mekonnen & Hoekstra 2016.

Finally, one can look at water scarcity seasonally, as shown in Figure 3. The top map shows the data for winter, the second map for spring, the third for summer, and the fourth for fall. There are regions of the world that experience water scarcity year-round, like the Sahara Desert and Saudi Arabia. But if you look at China/Central Asia and North America, you can clearly see a seasonal pattern. In these regions, water scarcity is at its highest in spring and summer.

It is hard to locate Missouri on these maps, it would appear to straddle the line between water surplus and water deficit. I know of no similar studies that address the situation here in more detail. In previous posts I’ve seen no sign that the state as a whole faces a significant water deficit: neither flow on the Missouri River nor statewide precipitation seem to be declining.

If your region of Missouri faces a significant water deficit, or if you know of a study of statewide water supply, why not comment and let us know? Thanks.

Source:

Mekonnen, Mesfin, and Arjen Hoekstra. 2016. “Four Billion People Facing Sever Water Scarcity.” Science Advances. 2016, 2. Downloaded on 2/13/16 from http://advances.sciencemag.org/content/2/2/e1500323.