16 February 2015

Some thoughts on water shortages in São Paulo, Brazil

JM emails:
I would really appreciate a blog post on any insights you may have on Brazil's current water situation. [We received a letter] from water authorities stating that São Paulo is running out of water and there is no plan B, written "in large friendly letters." A few things that I've picked up on the situation:
  1. Southeast Brazil is in a severe water shortage and it's the "worst drought in 80 years...."
  2. If it's this bad now in rainy season, I assume things will get worse in dry season.
  3. Around 40% of São Paulo's water supply is unaccounted for (local news, but I don't have any official sources). Leaks are a major problem (I see roads torn up all the time with water utility employees hunting for leaks), but so is the "free" water use.
  4. 90% of Brazil's power generation is hydroelectric. I know Brazil can buy some power from neighboring countries, but I don't think it's near enough to compensate if the water level continues to drop. All eggs in the hydroelectric basket? Paraguay might be worse, since it depends on just the dam at Iguassu Falls for nearly all power generation.
  5. I believe the letters like the one I received are inciting the opposite of the desired behavior, and many people are filling buckets of water to prepare for low or no water pressure.
  6. Some discount programs have been created, such as "lower consumption by 30% and lower your water bill by 50%!" But, prices have not been raised and few efforts to curb illegal use have been implemented.
  7. Water rationing has limited effects because nearly everyone maintains a "water box" above the home or apartment complex. When the water is off, consumption comes from the box, which is simply refilled when the water comes back on. Local news has stated that water authorities are considering "five days off two days on" in order to reach the desired consumption level.
I could be wrong on some of the specific stats above, but that's what I've gathered from local news sources and this really isn't covered internationally. You mentioned Brazil briefly in your AMA on Reddit, but considering the situation is getting quite dire, maybe you could weigh in with more details, if you're familiar. Last, any suggestions for a resident? For example, how real is the impact? Is this a hoard as much bottled water as possible scenario? Any ideas on when water shortages typically lead to unrest?
Well, JM, you've got a pretty good handle on the situation, from my perspective, but let me comment with my opinions of what's going on. (I've never been to SP, so I'm just flying by pants here...)
  • Natural droughts can have must larger impacts when people are already "using" a large share of ecosystem capacity, esp. if we are withdrawing stored water. It seems that SP depends on rainfall for hydropower. The lack of sufficient groundwater (or surface) storage is disconcerting
  • High rates of stolen and leaked are consistent with incompetent or corrupt utilities -- esp. if they get paid to "repair" leaks
  • Yeah, 90 percent if pretty high. Always good to have diverse energy sources
  • Buckets are a short term solution, storage tanks as well. Then comes people with wells and access to tanker water deliveries, but the real long term solution is to live within annual precip with a buffer of 1-10 years (depends on weather cycles). I guess SP is outside those bounds, probably b/c it's more popular to deliver what people demand at a minimal (and risk increasing) price/cost of service. 
  • You're right -- higher prices and a crackdown on theft would be useful... about 3 years ago. Nobody wants to see the poor cut off when managers' failures are already manifest -- remember Detroit!
  • Water rationing could be replaced by higher prices, but that assumes (1) water meters and (2) high enough prices. As you can see with the boxes, people are clever enough to get around superficial responses (rationing rarely works...)
In terms of suggestions, I say:
  • Store two liters/person/day of drinking water for 20 days (40lts/person) and -- probably -- switch to bottled water, as it's tough to maintain quality when the pipes are filling/emptying at various pressures all the time.
  • Yes, there will be unrest, but what will people do? Attack the dam? They can't insist that more gas be burned (i.e., for energy shortages), so it should dissapate or fall on unlucky merchants. Keep an eye on local desalination (if any) and bottled water plants in terms of scaling up/breaking down, etc.
Anyone else got something to add?

Bottom Line: Poor governance can be hidden for awhile, but when the tide goes out, everyone sees who's got no pants on.


  1. Unfortunately, the situation that J.M. describes looks very like the one that prevails throughout most of India. Based on my extensive experience there, however, I would suggest one significant correction. Those rooftop "Water Boxes" do not represent a clever response to shortages. Underground storage pumped to private rooftop storage containers represent a near necessity to anyone (who can afford them) when faced with intermittent supply by the local municipality. Furthermore, there presence usually indicates that the local authorities have been fooled into thinking that they are saving water, money and energy when in fact they usually have increased all three.

    I'll be glad to share with you more detailed analysis of the pros and cons of intermittent (anything less than 24/7 supply) vs. continuous supply but essentially the presence of those boxes shows that the local authorities have resorted to rationing by hours per month of service instead of repairing leaks, installing meters and implementing an effective tariff system.

    Based on our experience we found that intermittent supply:
    (1) led to increased energy consumption because of the need for homeowners to pump the water up to those boxes;
    (2) led to increased contamination because those who can afford it, install suction pumps in an effort to extract more water from the water supply lines and consequently end up literally sucking raw sewage in through the myriad of cracks in the supply lines and delivering it right to their homes;
    (3) Required more water because not only did they fail to repair those leaks but in many cases the homeowners end up throwing away the "old" water in the storage containers when new water becomes available.
    (4) Required more money because whatever small amount the municipality saves is more than offset by increased costs to the homeowner to pay for extra pumping and for treating the now contaminated water;
    (5) Created a far more regressive system than would have been caused by a system with meters and tariffs (including lifeline rates for the first thousand gallons per month) because only the higher income families can afford the extra pumps, storage tanks and treatment systems. Furthermore, in those situations where the families can not afford this extra equipment, the real cost is even higher because then they need to take off time from work, come home and fill every spare bucket on those occasions when the water is turned on.


    David Foster

  2. The largest global cities (50 with 1.5B people) move 504 billion litres of water a day a distance of 27,000km from 41% of the global land surface. This is drawing water from the rural areas that need water for food production and processing. Already 25% of these cities are water stressed with US$4.8 trillion in economic activity at risk.
    Stormwater, free rainwater falling on global cities should be captured. It causes huge costs from flooding and processes to dispose it into the sea. The amount, unaccounted for, could be 1000M Ml valued at, say US$1trillion/yr. Utilising this untapped water resource, creates
    • New and additional water for cities, sourced from rain from within the cities.
    • Releases limited rural water for use for food production and processing.
    • It's value covers the costs of the technologies needed to recover and use this water.
    • These costs can be shared with other water needs and so reduce the overall costs.
    • Technologies to manage this water are available and will get increasingly more efficient.

    Currently urban stormwater is treated as a liability not an asset: it causes flooding and traffic chaos, transports pollutants, degrades waterways and stormwater drains are expensive. Rainwater falling on Australian cities is 5.4 billion cubic metres/yr. 2.5 b cm/yr falls on soft (vegetation) surfaces and this will keep plants alive. This will be crucial for greening the cities, but more water will needed for drought. The rest falls on hard services and is recoverable; 2.9 billion cubic metres/yr valued at $6.2 billion/yr of new water is available. The design requires integration of existing technologies for the capture, storage, cleaning and distribution of stormwater into plans to increase the availability of water for NSW food. A 25 year stormwater plan could revolutionise water for Sydney.


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