International Day of Forests and Water

On the March 21st, International Day of Forests, FAO HQ will host a special celebration in recognition of ‘Forests and Water’. During the event the Land and Water Division will present ‘Forests and Water in Practice’ with examples of watershed management dealing with changes in rural production processes in a framework of market-driven agricultural development.

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Watch the webcast LIVE: Monday 21 March 2016 – 12PM CET >>

 

Dry Heat

Last week, Lake Mead, which sits on the border of Nevada and Arizona, set a new record low—the first time since the construction of the Hoover Dam in the 1930s that the lake’s surface has dipped below 1,080 feet above sea level.

The West’s drought is so bad that official plans for water rationing have now begun—with Arizona’s farmers first on the chopping block. Yes, despite the drought’s epicenter in California, it’s Arizona that will bear the brunt of the West’s epic dry spell.

The huge Lake Mead—which used to be the nation’s largest reservoir—serves as the main water storage facility on the Colorado River. Amid one of the worst droughts in millennia, record lows at Lake Mead are becoming an annual event—last year’s low was 7 feet higher than this year’s expected June nadir, 1,073 feet.

If, come Jan. 1, Lake Mead’s level is below 1,075 feet, the U.S. Bureau of Reclamation, which manages the river, will declare an official shortage for the first time ever—setting into motion a series of already agreed-upon mandatory cuts in water outlays, primarily to Arizona. (Nevada and Mexico will also receive smaller cuts.) The latest forecasts give a 33 percent chance of this happening. There’s a greater than 75 percent chance of the same scenario on Jan. 1, 2017. Barring a sudden unexpected end to the drought, official shortage conditions are likely for the indefinite future.

Why Arizona? In exchange for agreeing to be the first in line for rationing when a shortage occurs, Arizona was permitted in the 1960s to build the Central Arizona Project, which diverts Colorado River water 336 miles over 3,000 feet of mountain ranges all the way to Tucson. It’s the longest and costliest aqueduct in American history, and Arizona couldn’t exist in its modern state without it. Now that a shortage is imminent, another fundamental change in the status quo is on the way. As in California, the current drought may take a considerable and lasting toll on Arizona, especially for the state’s farmers.

“We need to stop growing alfalfa in the deserts in the summertime.”

Robert Glennon, water policy expert at the University of Arizona

“A call on the river will be significant,” Joe Sigg, director of government relations for Arizona Farm Bureau, told the Arizona Daily Star. “It will be a complete change in a farmer’s business model.” A “call” refers to the mandatory cutbacks in water deliveries for certain low-priority users of the Colorado. Arizona law prioritizes cities, industry, and tribal interests above agriculture, so farmers will see the biggest cuts. And those who are lucky enough to keep their water will pay more for it.

According to Robert Glennon, a water policy expert at the University of Arizona, the current situation was inevitable. “It’s really no surprise that this day was coming, for the simple reason that the Colorado River is overallocated,” Glennon told me over the phone last week. Glennon explained that the original Colorado River compact of 1922, which governs how seven states and Mexico use the river, was negotiated during “the wettest 10-year period in the last 1,000 years.” That law portioned out about 25 percent more water than regularly flows, so even in “normal” years, big reservoirs like Lake Mead are in a long-term decline. “We’ve been saved from the disaster because Arizona and these other states were not using all their water,” Glennon said.

They are now. Since around 2000, Arizona has been withdrawing its full allotment from the Colorado River, and it’s impossible to overstate how important the Colorado has become to the state. About 40 percent of Arizona’s water comes from the Colorado, and state officials partially attribute a nearly 20-fold increase in the state’s economy over the last 50 years to increased access to the river.

On April 22, Arizona held a public meeting to prepare for an eventual shortage declaration, which could come as soon as this August. The latest rules that govern a shortage, established in 2007 by an agreement among the states, say that Arizona will have to contend with a 20 percent cut in water in 2016 should Lake Mead fall below 1,075 feet, which will decrease the amount available to central Arizona’s farmers by about half. At 1,050 feet, central Arizona’s farmers will take a three-quarters cut in water. At 1,025 feet, agriculture would have to make due largely without water from the Colorado River. That would probably require at least a temporary end to large-scale farming in central Arizona. Below 1,025 feet, the only thing Colorado River states have agreed to so far is a further round of negotiations. In that emergency scenario, no one really knows what might happen. More

 

The US is heading for a ‘megadrought’ if climate change continues at this pace

The long and severe drought in the US southwest pales in comparison with what’s coming: a “megadrought” that will grip that region and the central plains later this century and probably stay there for decades, a new study says.

Thirty-five years from now, if the current pace of climate change continues unabated, those areas of the country will experience a weather shift that will linger for as long as three decades, according to the study, released Thursday.

Researchers from Nasa and Cornell and Columbia universities warned of major water shortages and conditions that dry out vegetation, which can lead to monster wildfires in southern Arizona and parts of California.

“We really need to start thinking in longer-term horizons about how we’re going to manage it,” said Toby R Ault, an assistant professor in the department of Earth and atmospheric sciences at Cornell, one of the co-authors. “This is a slow-moving natural hazard that humans are used to dealing with and used to managing.”

Megadroughts are sustained periods of sparse precipitation and significant loss of soil moisture that span generations, about 10 times as long as a normal three-year drought.

Tucson had less than 80 percent of its normal rainfall for long stretches in the 1990s. If that were to last for two decades, “that’s a megadrought,” Ault said.

Based on climate models the researchers used for the study, there is an 80 percent chance that such an extended drought will strike between 2050 and 2099, unless world governments act aggressively to mitigate impacts from climate change, the researchers said.

North America’s last megadroughts happened in medieval times, during the 12th and 13th centuries. They were caused by natural changes in weather that give megadroughts a 10 percent chance of forming at any time.

But climate change driven by human activity dramatically increases those chances. “With climate change, the likelihood of a megadrought goes up considerably,” Ault said.

The other writers for the study were its lead author, Benjamin I Cook, a research scientist for NASA’s Goddard Institute for Space Studies, and co-author Jason E Smerdon, a research professor at Columbia’s Lamont-Doherty Earth Observatory. The report was published Thursday in the journal Science Advances.

“We got some exciting, thrilling and important research,” said Marcia Kemper McNutt, a geophysicist and editor in chief of the journal Science. “We are facing a water situation that hasn’t been seen in California for 1,200 years.”

At the study’s presentation, Ault had a word of caution. Weather conditions can vary, climate impacts can be mitigated, and the warnings of the study might not come to pass. A single El Niño weather pattern in the West could interrupt periods of prolonged drought.

Smerdon said the researchers went back over a thousand years’ worth of data to look at conditions that caused drought in North America and observing patterns in tree rings to determine wet and dry periods.

After 2050, there is “overwhelming evidence of a dry shift,” he said, “way drier than the megadroughts of the 1100s and 1200s.” The cause, Smerdon continued, “is twofold, reductions in rainfall and snowfall. Not just rainfall but soil moisture and changes in evaporation that dry out the soil much more than normal.”

The research is newly published, but its findings are not dramatically different from similar studies in the past. Beverly Law, a specialist in global change biology at Oregon State University’s College of Forestry, co-authored a study of megadroughts three years ago.

It showed that a drought that affected the American West from 2000 to 2004 compared to conditions seen during the medieval megadroughts. But the predicted megadrought this century would be far worse. Law said Thursday’s study confirmed her previous findings.

“We took the climate model and compared” two periods, 2050 to 2099 and 1950 to 1999, she said. “What it showed is this big, red blotch over Southern California. It will really impact megacities, populations and water availability.”

Law is also co-author of an upcoming study commissioned by the U.S. Geological Survey about forest mortality later this century, and the preliminary findings are disturbing, she said.

According to predictions, the amount of precipitation in Arizona will be half of what it was between 1950 and 1999.

“We have drinking water to be concerned about,” she said. “That area’s really vulnerable.” More

 

Arctic snap will ice Northern states, whipped down by ‘bomb cyclone’

(CNN)The ice man cometh. And does so early this year, after a former Pacific typhoon flew up toward the Arctic and rammed the jet stream.

The stream has whipped south, dragging down frigid air from Canada over the northern Plains and Mountain States and the Upper Midwest, according to the National Weather Service.

It is already plunging temperatures below freezing there and will hammer them into the teens and single digits in many places by midweek, even lower in others.

Great Falls, Montana, will shiver at 9 below zero on Tuesday night.

It’s the coldest weather of the season, the weather service said.

Minneapolis could soon get a foot of snow, the service said, with the Minnesota city experiencing below-freezing temperatures that could last for eight days.

Let it snow

The snap is forecast to lay down the first broad layer of wintry snow, flurries, sleet or ice — long before winter starts — from Montana down to Nebraska and over to Wisconsin.

It will accumulate in inches in the northern Rockies, northern Plains and Great Lakes.

People farther south will also shiver. “Much of the nation east of the Rockies is expected to see a major pattern change by the beginning of the work week,” the weather service said.

The western Dakotas are also forecast to get significant snow.

Lows will drop to freezing in Kansas City late Monday, then into the 20s a night later. The snap will stop short, leaving much of the Deep South and Southwest in a fall-like warm zone.

Rain is expected to hit Chicago and Milwaukee on Monday and Tuesday, with a few snowflakes mixed in, according to the service on Sunday afternoon.

Courtesy of Nuri

Residents in the northern United States can thank a whopping tropical cyclone in the Pacific Ocean for the wintry blast.

The remnants of super Typhoon Nuri rolled up north over Alaska’s Aleutian Islands on Friday, kicking off the ripple of Arctic air in the other direction.

Nuri is now the strongest known Northern Pacific cyclone on record, according to the National Weather Service Ocean Prediction Center.

Its remnants plowed into cold air adding violent energy as it went north, similar to what Superstorm Sandy did in the Atlantic two years ago. That earned it the weather moniker “bomb cyclone. More

 

 

30 Percent of Singapore’s Water Supply is Currently Met by Recycled Water

The South-east Asian island country has a population of 5 million residing on less than 750 square kilometers of land. Whilst known for its strong economy, Singapore is lacking one essential asset — water.

Water security has long been a national priority in Singapore as half of its current water supplies are imported from neighboring Malaysia. “We are preparing for the day that should the water agreement expire, we should be ready to fulfill our own needs,” says Chew Men Leong, Chief Executive of the Public Utilities Board.

The agreement with Malaysia is due to expire in 2061, so the country has time to be ready.

Singapore’s strategy for a hydrated nation is four-fold: as well as importation, it includes desalinization plants, efficient catchment of rainwater and recycling of sewage.

Rainwater is collected through a network of drains, canals, rivers, storm water, collection ponds and reservoirs with the aim to catch water across two-thirds of the country. But the real hope lies in the membrane technology to treat wastewater known as ‘NEWater’, created by the country’s public utilities board.

Through a four-step series of barriers and membranes, wastewater is made free of solids, microorganisms, and contaminants resulting in potable water supplies for use by humans and industry.

After one decade, the technology meets 30 percent of Singapore’s water needs, with plans to triple volumes by 2060.

“The level of quality we receive from the Public Utility Board meets and exceeds the expectation,” explains Jagadish CV, CEO of Systems on Silicon Manufacturing, where the water is used in their processing of silicon wafers. “We are using the water three times before we let it into the drain,” he says.

The demand by industry is being further met by a new collaboration with Japanese firm Meiden that will supply factories with recycled industrial water. One and a half Olympic-sized swimming pools of water are currently filtered and treated every day.

The goal is to more cost-effectively treat industrial waste streams in the long run.

Professor Asit Biswas from the Lee Kuan School of Public Policy feels other countries should follow the example set by Singapore and even the current standards can be improved to eventually re-use every last drop of water. More

Source: CNN


 

 

Jamaican’s Cautioned Against False Sense Of Water Security

THE RAINS have returned, bringing with them relief from drought conditions that plagued the island during the summer, but Jamaicans must guard against a false sense of water security.

Hope River in dry season

So says Director of the Climate Studies Group Mona Dr Michael Taylor, who is supported in his caution by Herbert Thomas, deputy managing director of the Water Resources Authority.

Taylor, a physicist, urges Jamaicans to be mindful not only of the El Niño phenomenon that promises a return to the dry spell towards the end of this year and into next year. They need, too, he warned, to be cognisant of climate change, which will see the island experiencing longer and more severe dry spells over the long term, as well as flooding incidents.

“As El Niño peaks, we might revert to dry conditions somewhere between the end of the year and early next year, but as it declines, we are susceptible to the reverse, which is flooding, when the early rainfall season kicks in,” he said.

“So the point is, we have to figure out how to be resilient to these swings in extremes from drought to flood within the course of a year, and these kinds of swings will become more and more the norm under climate change,” the scientist posited.

This is borne out by research done over the last two to three years by the Climate Studies Group for the Planning Institute of Jamaica.

That research, Taylor said, looks at climate scenarios up to 2040, with a focus on projections for temperature and rainfall.

“The temperature will continue increasing about one degree up to 2040, and that is further from where we are now. We have warmed by about one degree over the last 50 years. What that really translates into is, the number of really hot days is increasing every year and the number of really hot nights is also increasing and will continue to increase,” he said.

“Rainfall will continue with this form of variability, which is a yearly swing between drought and flood conditions, but by 2040 will show the beginning of an overall long-term drying trend. This means that, from 2040 onward, even though we will get rain, we will get less overall rain,” added Taylor.

The solution, he said, is a comprehensive look at water security, something Government is attempting to tackle, with work ongoing on a new water policy that takes account of climate impacts.

“We need to be concerned about water capture, water storage, water access, conservation, efficiency, and using science to help us to better plan for these kinds of extreme variations,” the head of the physics department at the University of the West Indies said.

Thomas agreed, noting that the island’s long-term water security will depend on a comprehensive plan, informed by the new water policy now nearing completion, and with both private citizens and Government working in concert.

“Some people like to stand under the shower and sing. Cutting out things like those [is important]; you would be surprised to know the amount of water you waste that way,” he told The Gleaner recently.

Retrofitting for conservation

In addition, Thomas said Jamaicans might have to look at retrofitting their homes and offices to include features such as low-flush toilets and faucets that use less water for showers. This, while the island looks at alternative energy sources in order to reduce the overall cost of getting water to the areas where it is needed.

Checks with communications manager at the National Water Commission, Charles Buchanan, revealed that current electricity cost for water stands at some of $500 million monthly.

Beyond that, Thomas said there is the need to look at rainwater harvesting and the comprehensive use of wastewater, to which the water policy also gives attention.

“For example, the treated sewage out at Soapberry, there is the thinking that some of the water could be used in St Catherine areas for agriculture and, therefore, the water normally used for agriculture could be freed up for domestic use in Kingston,” he noted.

“And there are other things … . You might have to consider a double-plumbing system so you separate grey water (water from bathroom sinks, tubs and washing machines, etc) from black water. Grey water you can use to flush toilets and water lawns,” Thomas added. More

 

Wastewater recycling, part of the solution to water shortage?

After the report on mountaineering and my experiences on the ascent to Mount Aconcagua, I return to the subject of water, and the opportunities and challenges in recycling it.

In earlier posts here I wrote about a very sophisticated system of wastewater recycling in Singapore, which turns it back into drinking water.

And at this year’s Singapore International Water Week, the Californian Orange County received the highest recognition, for a scheme where perfectly treated wastewater is pumped back into underground aquifers, to be later pumped up again as drinking water. It also serves as a barrier to seawater intrusion.

These two examples, especially Singapore, are probably the most far-reaching examples I know of achievement in water recycling.

Places like San Diego, hit by a drought, are now re-considering again the idea to follow the Singapore example, despite some opposition from civil society. So, to what extent is it possible to scale up these kinds of activities globally; is there potential for wastewater to contribute in a substantial way to closing the gap of some 300 cubic kilometres between the level of water withdrawals and sustainable supply?

Estimates show close to 300 cubic kilometres of wastewater is generated by municipalities per year (average 2003-12). This is the equivalent of some 50% of global average annual withdrawals for household use.

Part of the other 50% of withdrawals not counted as ‘wastewater’ may well be lost in leakage in pipes (in some countries this accounts for up to 70% of the water withdrawn by the municipal water supply schemes). Another part could be ‘used’ through evapotranspiration in lawns and gardens, etc.

As the table below shows, only about half of this wastewater is actually collected and treated, but less than 10% of the treated wastewater is directly reused.

Table 1: Municipal wastewater generation and treatment data 2003-2012, country groups by income per capita

Source: FAO aquastat

 

To get an idea of how municipal water could contribute to closing the gap between withdrawals and sustainable supply, let me go through the water supply chain.

The first step would require a better understanding of what happens with the 50% of municipal water apparently ‘disappearing’. Where this is down to leakage, governments have to set the right incentives so municipal water authorities address the issue.

One way proposed by the 2030 Water Resources Group (2030 WRG) in South Africa, which has been implemented by the government there, is to measure both water delivery and water intake, and to pay a premium to the schemes where the difference (i.e., water unaccounted for) gets smaller.

According to 2030 WRG cost-curve estimates, the cost savings would by far exceed the necessary spending to reduce the leakage.

As part of my proposals for targets within the water goal for post-2015 sustainable development, I suggest primary treatment of all wastewater by 2030 – an idea I will come back to in a later post.

So, what happens with 285 km³ of estimated wastewater generated, and what needs to be done? We will first have to increase collection, particularly in economically deprived areas, to make sure wastewater is collected and available for proper treatment.

Actually, only 36% of the world’s population has a sewage connection; this leaves 4.6 billion people unconnected. According to a WHO study, initial investment to set up a sewer connection is about USD 170 per capita; so the investment cost to connect them would be somewhere close to USD 800 billion. The annual cost of capital, repayment and operating cost is estimated at USD 1 per m³.

Next: treatment of both the up-to-now untreated collected – and the newly collected – wastewater. Estimates amount to USD 0.35 per m³. A big part of this cost is energy, an often forgotten link in the water-food-energy nexus framework.

And last but not least: less than 10% of treated wastewater is used directly. This can and must be increased. Direct use is, for instance, the Singapore approach, bringing treated water back to consumers as so-called ‘NEWater’.

Another example is Australia: around 1.4 cubic kilometers of municipal wastewater are treated, of which 0.4 cubic kilometers are used directly, mostly in agriculture.

At Nestlé we have a similar approach. All our factories treat wastewater (in fact the first wastewater treatment plant in the group was built in the 1930s, so we understood the need for this very early) and as much of this treated wastewater as possible is used directly.

At the same time, we should keep in mind indirect use, even though it’s often difficult to measure. Treated wastewater is returned to rivers and then often withdrawn again and treated further for human consumption.

One might, for instance, assume that a significant part of the water in the River Thames, once it reaches London, is treated wastewater from communities further up the river. Increasing the share of direct use of wastewater should clearly be encouraged – in a form accepted by local communities.

So, all in all there are some significant opportunities to use treated wastewater as a resource, helping to close the gap between freshwater withdrawals and sustainable supply. But these opportunities need to be carefully evaluated, to make sure they are fully accepted, but also cost and energy effective when compared to other solutions. Via Peter Brabeck-Letmathe – Linkedin More

 

Drought apocalypse begins in California as wells run dry

(NaturalNews) Water wells in central California have begun to run dry, reports the LA Times. (1) “Extreme drought conditions have become so harsh for the Central Valley community of East Porterville [that] many of its residents dependent on their own wells have run out of water.”

Tulare County has confirmed their wells have run out of water, and so far hundreds of homes have no running water.

According to the LA Times, rumors are also spreading that Child Protective Services officials will begin taking children away from families who have no running water, although the county claims the rumor is false.

It begins: the collapse of California's water aquifers

With this news, it is now official that the collapse of California's water aquifers has begun. With each passing month and year, more and more wells will run dry across the state as California plummets into the desert conditions from which it once sprang.

Extreme drought now covers 82% of California, according to the National Drought Mitigation Center. (2) Fifty-eight percent of the state is in “exceptional drought.”

During the unfolding of this drought, California farmers and cities have siphoned unprecedented volumes of water out of the state's underground aquifers. This is called “fossil water” and it can take centuries to regenerate. Once this fossil water is used up, it's gone.

35-year “megadrought” may be on the way

“The southwestern United States has fifty percent change of suffering a 'megadrought' that lasts 35 years,” reports the Daily Mail. (3)

“They say global warming has meant the chance of a decade long drought is at least 50 percent, and the chances of a 'megadrought' – one that lasts up to 35 years – ranges from 20 to 50 percent over the next century.”

One scientist is quoted in the story as saying, “This will be worse than anything seen during the last 2,000 years and would pose unprecedented challenges to water resources in the region.”

Unless politicians become magical wizards and figure out a way to create water out of nothing, what all this really means is that cities of the American southwest will not be able to support present-day populations. A mass migration (evacuation) out of the cities will be necessary sooner or later.

California's water deficit will lead to ecological and economic collapse

In an almost perfect reflection of California's state budget deficits, the state is also running an unsustainable water deficit. It is a mathematical certainty that when you remove far more water from the aquifers than is being replenished, the amount of water remaining in those aquifers will eventually reach zero.

This “zero day” water reality is still psychologically denied by most Californians. If the reality of this situation were widely recognized, California would be experiencing a glut of real estate inventory as millions of homeowners tried to sell their properties and evacuate the state. The fact that the real estate market has not yet collapsed in California tells us that Californians are still living in a state of denial about the future of their water supply.

Even as California's water supply collapses by the day, local farmers and towns have few options other than drilling for more water. “Drill! Drill! Drill!” is the mantra of the day, creating an 18-month backlog for well drilling companies. Each new well that's drilled must seek to go deeper than the previous wells which are running dry. It's a literal race to the bottom which can only end in catastrophe.

Then again, a willful acceleration toward catastrophe is merely a sign of the times when it comes to human civilization. There is almost no area in which humans have ever achieved balance: not in fossil fuels, metals mining, fossil water exploitation, debt creation, industrial chemical contamination, ecological exploitation or even global population. It's almost as if the human race is determined to destroy itself while racing to see who can achieve self destruction first. More

 

ADB Spotlights Pakistan’s Water Assessment and Management Plan


News: ADB Spotlights Pakistan’s Water Assessment and Management Plan

ADBSeptember 2014: The Asian Development Bank (ADB) has published a report titled ‘Water Balance: Achieving Sustainable Development through a Water Assessment and Management Plan – The Case of Federally Administered Tribal Areas (FATA), Pakistan.' The report presents the case of the development of the FATA Water Assessment and Management Plan, outlining elements necessary in such assessment, and emphasizing that inefficient and unsustainable management of development initiatives result from lack of information about water availability and cause watershed degradation.


Integrated water resources management (IWRM) was used as a core approach in the development of possible activities to promote the sustainable use of water resources in the FATA region. While noting much of the data used is historical, the report emphasizes that climate change is likely to alter current water availability patterns, and calls for integrating hydrological forecasting and climate change models into the assessment.


The report includes sections on: background; project area; assessing surface water availability; assessing groundwater; assessing water consumption; water balance model; water management plan; and conclusions. [Publication: Water Balance: Achieving Sustainable Development through a Water Assessment and Management Plan – The Case of Federally Administered Tribal Areas (FATA), Pakistan]


Read more: http://water-l.iisd.org/news/adb-spotlights-pakistans-water-assessment-and-management-plan/


Peak Water

There is a lot of water on planet Earth – 326,000,000,000,000,000,000 gallons (329 trillion gallons), or 1,260,000,000,000,000,000,000 litres. About 70 percent of the planet is made of oceans and 98 percent of all the water on earth is in the oceans. That’s a lot of water.

Only 2 percent of all this water is fresh drinking water but most of that is locked up in the polar icecaps and glaciers – approximately 80 percent (or 1.6 percent of the planet’s water). Another 36 percent is in underground aquifers and wells and roughly 0.036 percent of our fresh water supply is found in lakes and rivers. That still leaves thousands of trillions of gallons for drinking. (Source: Environmental Science, howstuffworks)

But is that enough fresh drinking water for a population which is growing exponentially? Every second, four babies are born and two people die. In the time it will take to write this article, 20,000 people will have joined the human race.

‘Peak Oil’ has been extensively written about for many years “but the real threat to our future is peak water,” wrote Lester R. Brown, president of the Earth Policy Institute, in the summer of 2013 in theguardian. “There are substitutes for oil, but not for water. We can produce food without oil, but not without water.”

“The concept of “peak water” and its implications for the U.S. economy are less well explored and understood.” says Dr. Peter Gleick, President of the Pacific Institute. His April 2010 paper (Peak water limits to freshwater withdrawal and use) sparked such interest that the term “peak water” was chosen by The New York Times as one of their 33 “Words of the Year” for 2010. Gleick outlines three different definitions of “peak water”:

Peak Renewable Water. Most water resources are renewable, in the form of flows of rainfall, rivers, streams, and groundwater basins that are recharged over relatively short time frames. Renewable, however, does not mean unlimited. When human demands for water from a watershed reach 100% of renewable supply, we can’t take any more, and we reach “peak renewable” limits.

For a number of major river basins, we have reached the point of peak renewable water limits, including the Colorado River in the United States. All of the water of the Colorado (indeed, more than 100% of the average flow) is already spoken for through legal agreements with the seven US states and Mexico and in a typical year river flows now often fall to zero before they reach their ends. This is true for a growing number of rivers around the world.

Peak Nonrenewable Water. In some places, water comes from stocks of water that are effectively nonrenewable, such as groundwater aquifers with very slow recharge rates or groundwater systems damaged by compaction or other physical changes in the basin. When the use of water from a groundwater aquifer far exceeds natural recharge rates, this stock of groundwater will be depleted or fall to a level where the cost of extraction exceeds the value of the water when used, very much like oil fields. Continued production of water beyond natural recharge rates will become increasingly difficult and expensive as groundwater levels drop, leading to a peak of production, followed by diminishing withdrawals and use.

This kind of unsustainable groundwater use is already occurring in the Ogallala Aquifer in the Great Plains of the United States, the North China plains, parts of California’s Central Valley, and numerous regions in India. In these basins, extraction may not fall to zero, but current rates of pumping cannot be maintained. Worldwide, a significant fraction of current agricultural production depends on non-renewable groundwater. This is extremely dangerous for the reliability of long-term food supplies.

Peak Ecological Water. Water supports commercial and industrial activity and human health, but it is also fundamental for animals, plants, habitats, and environmentally dependent livelihoods. By some estimates, humans already appropriate almost 50% of all renewable and accessible freshwater flows, leading to significant ecological disruptions…the term “peak ecological water” refers to the point where taking more water for human use leads to ecological disruptions greater than the value that this increased water provides to humans.

Running Out of Water

The story of “Peak Water” is increasingly coming to the forefront in 2014 as large portions of the American mid-west are suffering through the worst drought in the last hundred years. Drinking water supplies from the tap have dried up in many communities forcing authorities to provide bottled-water rations and water for bathing and home use.

Tom Philpott writes in Mother Jones that the water crisis is much worse than previously known. Homeowners and farmers are having to drill deeper wells to harvest dwindling groundwater reserves. California has declared a drought emergency and imposed mandatory restrictions on water use with the levy of heavy fines for wasting water on non-essential activities – watering lawns and driveway, washing cars. National Geographic reports that:

Groundwater supplies in our major western aquifers — the Central Valley, the southern Ogallala and now those that underlie the Colorado River Basin – are disappearing. We simply pump out more water than is being naturally replenished, and as a result, groundwater levels are falling rapidly…..The American West is running out of water. More