5 ms·

As Cape Town water crisis deepens, scientists prepare for ‘Day Zero’

33 points by sdee21 9y ago

nickthemagicman 9y ago
Scary. Phoenix and So Cal aren't doing super great in this area as well.
- craftyguy 9y ago
  They only have two long-term options: 1) depopulate those regions by causing folks to leave (e.g. no longer providing water services) or 2) deploy costly (and energy-intensive) mechanisms to continue to provide water (desalination, or piping in water from some other place that will likely dry up next)
  - amluto 9y ago
    Desalination has high capital costs, but the energy usage isn't really a problem at all. A modern plant uses 2.5-3.5 kWh/m^3 [1]. My household uses something like 9 m^3 per month, so that would be about 27 kWh per month. At PG&E's rather high peak rates, that's $10/month, which is less than the marginal cost of that water. Of course, to the extent that energy costs matter, desalination plants will not use retail power at peak times. [1] https://www.amtaorg.com/wp-content/uploads/7_MembraneDesalinationPowerUsagePutInPerspective.pdf https://www.amtaorg.com/wp-content/uploads/7_MembraneDesalin...
    - henrygrew 9y ago
      are there any consumer desalination units available that one can buy and setup in their home?
      - jnwatson 9y ago
        But where do you get the salt water?
  - nickthemagicman 9y ago
    So Cal can deff run off desal plants. Esp L.A. and San diego. Phoenix and Vegas might not be a place you want to invest in real estate.
    - cr0sh 9y ago
      Arizona actually has a lot of brackish and brine well water that is non-potable. A lot of it is actually in the Gila Bend area, where people have been trying for decades to figure out something to do with it - there used to be a company that grew "desert shrimp" in ponds using the water. Later, during the housing crisis (for some reason) they tried to make a go of growing algae (in cooperation with one of our universities - maybe ASU) in the ponds by piping CO from diesel aeration pumps into the ponds - then harvesting the algae (which were high in lipids) to make biofuel. Ultimately, I don't think either of these panned out, but the water is there.
      - nickthemagicman 9y ago
        Thats very optimistic. The gila river is tiny compared to the population of Phoenix. Unless there's more water somewhere I'm missing.
markatkinson 9y ago
I live in Cape Town and I can tell you now people are freaked out and panicking. Every supermarket is sold out of water by lunch time. Driving around Cape Town you are accompanied by fleets of vehicles delivering large water tanks, and some people are straight up selling their houses, pulling their kids out of school and moving. One of the borehole companies actually now runs a weekly auction for their services and the highest bidder gets a borehole! Pretty crazy.

33 points by sdee21 9y ago

nickthemagicman 9y ago

Scary. Phoenix and So Cal aren't doing super great in this area as well.

craftyguy 9y ago
They only have two long-term options: 1) depopulate those regions by causing folks to leave (e.g. no longer providing water services) or 2) deploy costly (and energy-intensive) mechanisms to continue to provide water (desalination, or piping in water from some other place that will likely dry up next)
- amluto 9y ago
  Desalination has high capital costs, but the energy usage isn't really a problem at all. A modern plant uses 2.5-3.5 kWh/m^3 [1]. My household uses something like 9 m^3 per month, so that would be about 27 kWh per month. At PG&E's rather high peak rates, that's $10/month, which is less than the marginal cost of that water. Of course, to the extent that energy costs matter, desalination plants will not use retail power at peak times. [1] https://www.amtaorg.com/wp-content/uploads/7_MembraneDesalinationPowerUsagePutInPerspective.pdf https://www.amtaorg.com/wp-content/uploads/7_MembraneDesalin...
  - henrygrew 9y ago
    are there any consumer desalination units available that one can buy and setup in their home?
    - jnwatson 9y ago
      But where do you get the salt water?
- nickthemagicman 9y ago
  So Cal can deff run off desal plants. Esp L.A. and San diego. Phoenix and Vegas might not be a place you want to invest in real estate.
  - cr0sh 9y ago
    Arizona actually has a lot of brackish and brine well water that is non-potable. A lot of it is actually in the Gila Bend area, where people have been trying for decades to figure out something to do with it - there used to be a company that grew "desert shrimp" in ponds using the water. Later, during the housing crisis (for some reason) they tried to make a go of growing algae (in cooperation with one of our universities - maybe ASU) in the ponds by piping CO from diesel aeration pumps into the ponds - then harvesting the algae (which were high in lipids) to make biofuel. Ultimately, I don't think either of these panned out, but the water is there.
    - nickthemagicman 9y ago
      Thats very optimistic. The gila river is tiny compared to the population of Phoenix. Unless there's more water somewhere I'm missing.

markatkinson 9y ago

I live in Cape Town and I can tell you now people are freaked out and panicking. Every supermarket is sold out of water by lunch time. Driving around Cape Town you are accompanied by fleets of vehicles delivering large water tanks, and some people are straight up selling their houses, pulling their kids out of school and moving. One of the borehole companies actually now runs a weekly auction for their services and the highest bidder gets a borehole! Pretty crazy.