Sao Paulo’s Reservoirs are Drying Out When they Should Be Filling Up

It’s the rainy season for Brazil. But, thus far, adequate rains have not come.

A persistent high pressure system has lingered over Brazil. A blocking high of the kind that has now become so common with global temperatures spiking to more than +0.8 C above 1880s averages — thickening heat domes and granting these powerful weather systems an ever greater inertia. A set of circumstances that has set off a plethora of very severe droughts ranging the globe since the early 2000s.

During early 2015, Brazil’s own persistent atmospheric block re-strengthened over an Amazon whose water re-circulating abilities have been crippled by a combined deforestation and ever more prevalent wildfires. Ever since late December, the high has warded off cold front after cold front. The result is a terrible extension of the worst drought to impact Brazil in at least 80 years.

Southeast Brazil Drought January 11

(No rain in sight in the NASA MODIS satellite shot for Southeast Brazil on January 11, 2015. During a typical day in January, the wettest month for Sao Paulo, the satellite map should be filled with clouds and storms. Not so for 2014 and 2015. Image source: LANCE-MODIS.)

During December, this dogged weather system kept rainfall totals below average — at about 80 percent typical amounts for that time of year. But by January, the high had strengthened and only very weak rains had fallen over Southeastern Brazil with most other areas remaining dry. Now, drought appears to be re-establishing a strong grip as weather forecasts call for the typically strong January rains to be cut in half.

The ongoing drought has had serious and widespread impacts throughout Brazil — curbing production of everything from soybeans and sugarcane to coffee and cattle. But the worst impact has been to the water supplies of one of Brazil’s most populous regions — the Sao Paulo megalopolis. There, an unofficial water rationing has been in place since early 2014. A rationing that has hit Sao Paulo’s least advantaged residents the hardest.

Key Reservoir Drying Out When it Should Be Filling Up

Over the past six years, water levels for the Cantareira reservoir have been in free-fall. By 2014, an 80 year drought pushed already falling water levels radically lower. As an emergency measure, officials added dead pool volume — a level usually below municipal water inlets — to the reservoirs stated reserves. This move coincided with shifting water levels lower.

But the action only bought time for the failing reservoir as month after month of drought continued.

Dead Pool Volume Included

(Water losses from the Cantareira Reservoir since 2009. What this ominous graphic shows is that rainy season failure was not isolated to last year’s epic drought. It is instead part of a six year event that may well represent an ominous trend. Image source: Brazil Water)

By austral spring of 2014 (October), the Sao Paulo water system was again under dire threat. Water levels at the Cantereira reservoir fell to below 6% percent before officials diverted water from other sources and allowed use of water below even already lowered levels. This new arrangement moved water inlets deeper into the drying reservoir. An action that essentially dropped Canteriera outlets to city water supplies into the mud.

These emergency actions by city and water planners added another few percent to the radically diminished water supply. Hopes remained that rains would return with the wet season starting in November and that levels would rise enough to make it through the next summer.

But with rains remaining weaker than normal throughout November and December, water levels kept falling when they should have been rising. By early January, reservoir levels had again fallen to below 7 percent.

On Monday January 5, 2015 the level of Sao Paulo’s Cantariera reservoir was at 6.9% capacity. Today, just one week later, the same reservoir measured 6.5%.

9 Million Facing Lack of Water, Millions More at Risk

In total the Cantareira reservoir serves 9 million residents in Sao Paulo. These are mostly middle and lower class neighborhoods. And if the current weather situation continues, that reservoir could be empty come the start of the dry season in April. Such a situation would force an even more extreme water rationing on a state that has now become famous for water scarcity.

Unfortunately, Cantareira isn’t the only Sao Paulo reservoir under threat. In total, 5 out of 6 reservoirs representing the lion’s share of all water for more than 20 million people are now at 39 percent capacity or below.

The Sistema Alto Tiete — a smaller reservoir serving about 4 million Sao Paulo residents — is not far behind Cantareira. For as of today volume in this reservoir stood at 11.3 percent capacity. A third and fourth reservoir system — Rio Claro and Sistema Alto Cotia — now stand at 27.5% and 30.% capacity respectively. Together these two systems serve another 2 million people. The Guarapiranga reservoir, at 39.2 percent capacity as of 1/12/2015, serves another 4 million people.

A final Sao Paulo reservoir — the Sistema Rio Grande — serves about 2 million residents and remains just above 70 percent capacity.

If current forecasts for January hold and February-March follow present trends, then all these reservoirs with the probable exception of Sistema Rio Grande will be under threat entering the fast approaching dry season. A situation that would put nearly 20 million residents under severe threat of losing municipal water services.

UPDATE:

In addition to Sao Paulo, recent reports show that 93 cities have rationed water services to ever-broadening populations. In total, more than 3.9 million people are estimated to have had their water rationed. In some cases, water has been cut off to broad areas for as long as five days.

This official water rationing began last year. But this year’s rationing is broader in scope with water cut offs, which were at first limited to isolated rural zones, now stretching into larger urban population centers.

As mentioned above with Sao Paulo, this water rationing is occurring during the rainy season when water supplies should be building. However, with rainfall totals for Brazil this summer far less than the historic average and with a continuation of the worst drought in more than 80 years, most reservoirs show dropping levels when they should be filling.

In total, what we see for Brazil is a sad example of what a combination of climate change and deforestation can do to a previously water rich region. Bad management in the face of this crisis and instances of climate change denial are exacerbating an already desperate situation there.

UPDATE:

The Cantareira reservoir fell to 6.4% capacity on 1/13/2015 — a 0.5% loss in just 8 days. System losses at this rate bring the reservoir to zero in about 100 days. However, the current capacity, due to very low level of water outlets  may not be fully useable. In addition, rainy ends in April at which point levels would be expected to drop more precipitously.

Links:

Brazil’s Water Supply, Crops Still at Risk

In Brazil, Two Car Washes Have Wildly Different Experiences of the Same Drought

Drought Menaces Brazil’s Coffee Crop

Drought Vamps Up Brazil’s Cattle Prices

LANCE-MODIS

Off-Season Drought Makes 93 Brazilian Cities Cut off Water

Hat Tip to Andy in San Diego

Hat Tip to Colorado Bob

Hat Tip to TodaysGuestIs

A Sao Paulo Resident Vents Frustrations Over Unfair Water Distribution and Mis-Managed Resources

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Reservoir at 5 Percent Capacity: Climate Change to Leave Sao Paulo’s 20 Million Without Water By November?

Suffering from its worst drought in over 84 years, the city of Sao Paulo is in the midst of a crisis. For as of this weekend the city’s primary reservoir — the Cantareira — had dropped to just 5 percent capacity putting millions at risk of losing access to water.

The fall prompted the city’s governor — Geraldo Alckmin — to again ask for permission to draw emergency water supplies from below flood gates to alleviate catastrophic losses from the Cantareira and ensure water supplies to the region’s 20 million residents. The move would tap a river system that feeds two other states also facing water shortages — Rio de Janeiro and Minas Gerais.  But the draw is only a temporary stop gap and, without rain, the Cantareira will continue to fall — bottoming out sometime this November.

cantareira-reservoir-sadesp-sao-paulo-brazil-february-2014

(Dam and section of Cantareira Reservoir high and dry under incessant drought conditions. Image source: Linhas Populares.)

Don’t Use the ‘R’ Word

The Cantareira provides water to nearly 50 percent of Sao Paulo’s residents. But ever since February of 2014 the multi-year long drought, a drought that has featured less and less seasonal rainfall over time, has triggered reduced water access by city and state residents.

Those living within areas served by the Cantareira have been treated to increasing periods of dry taps — being forced to go for longer and longer without available water supply. The intermittent lack of water service has put a strain on businesses and residents alike with many people living in Sao Paulo being forced to abstain from washing, cooking and brewing. For now, water for drinking can be stored during times when the faucets flow. But that time could come to an end all too soon without a change in the weather.

“Sometimes I have no water for two days, then it comes back on the next day and the day after that, I have no water again,” said Zeina Reis da Cruz, a 55 year old resident of one of Sao Paulo’s lower income neighborhoods in a September 25 interview with The Globe and Mail.

Despite an ongoing and growing failure to provide water services, the city refuses to use the word ‘rationing.’ Such an admission of failure would have weighed heavily on Alckmin’s re-election campaign (Alckmin was just recently elected to a new term as governor). Instead, irate citizens and businesses making calls to utilities are simply told that there is nothing wrong with the water supply and to wait until the water comes back on.

Regardless of politically-motivated denials, water rationing is the most accurate way to describe what many Sao Paulo residents have been experiencing for 9 months now under a regime of systemic drought that just grows steadily worse with time.

Climate Change Spurred by Deforestation, Worsened By Atmospheric Heating

The great forest of the Amazon provides a rich source of water for both Brazil and surrounding countries. It captures as much as 80 percent of the tropical atmosphere’s heavy moisture load and re-circulates it locally – providing ongoing and consistent rains. A critical means of replenishing regional water sources.

But, over recent decades, a combination of clear cutting and human-spurred warming of the climate have been adding severe stresses to the Amazon. During the period of 2000 to 2010, the great rainforest lost 93,000 square miles of wooded land alone to clear cutting. By 2014, government restrictions had brought down the rate of loss to around 2,300 square miles per year, but by this time warming-related impacts to the Amazon were looking even more dire.

As the 2000s progressed, it was becoming ever-more-clear that a heating climate driven by human fossil fuel emissions was taking an increasing toll. For, during recent decades, the Amazon has been warming at a rate of around 0.25 C every ten years — about twice as fast as the global climate system. The added heat increased evaporation, pushing soil moisture levels below critical thresholds.

Drought Map South America

(It’s not just Sao Paulo, most of South America is showing ongoing rainfall deficits. Map provided by NOAA shows percent of normal precipitation received by South America this summer. Note the severe drying over much of the Amazon Rainforest and broader South America coupled with drought over Sao Paulo. Image source: Climate Prediction Center.)

This loss has, in turn, increased the prevalence of forest-destroying understory fires. And, according to a 2012 NASA study these understory fires have been burning away the Amazon at the rate of more than 30,000 square miles every ten years for nearly two decades. By late this Century, business as usual fossil fuel emissions and related warming of 4 degrees Celsius is expected to destroy about 85 percent of the Amazon, resulting in widespread desertification of a once-lush region.

Today, this period of initial drying caused by a human heating of the atmosphere appears to be putting the stability of Brazil’s most populous city at risk.

A Major Humanitarian Disaster

Typically for October, Sao Paulo receives between 80 and 100 mm of rainfall. So far this month, the number is approaching zero. Long range forecasts bring that total to just above 50 mm through the end of the month — about half the usual rainfall. Very dry for a month that is supposed to be the start of Sao Paulo’s rainy season, a period that usually runs from October through March. A rainy season once fed by a now greatly endangered and increasingly moisture-impoverished Amazon rainforest.

It would take a massive rainfall to replenish Sao Paulo’s reserves. The kind of rain event that would result in widespread devastation should it emerge. Now, city officials appear to be holding out for any rain to tip the scales on their swiftly shrinking water stores.

But if the worse happens. If this year is a repeat of last year which saw a parched rainy season. If the rains of October and November continue to delay or do not emerge at all, then Sao Paulo faces a terrible event. A complete drying out of its largest water store and a complete cut-off of water supplies for millions of residents.

It’s like Paulo Nobre, director of the Center for Weather Forecasting and Climate Studies at the National Institute for Space Research in Brasilia, recently noted:

“It will be a real humanitarian disaster if it happens. We are 20 million people: You can’t bring water on trucks for 20 million. So they are praying that rainfall will come – but it may not rain so much.”

Links:

Sao Paulo Water Supply at Risk in Extreme Drought

Unprecedented Drought Puts Sao Paulo Water Supply at Risk

Brazil Drought Crisis Deepens in Sao Paulo

Climate Conditions Determine Amazon Forest Fire Risk

NOAA’s Climate Prediction Center

Reversal of Fortune: Amazon Deforestation Increased by 28 Percent Over Past Year

Amazon Could Shrink by 85% Due to Climate Change

Sao Paulo Weather Forecast

Linhas Populares

Impacts of Deforestation

(Hat tip to Andy)

(Hat tip to Colorado Bob)

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