DL sent this NYT article on Montevideo, Uruguay, running out of drinking water. As usual, the poorest are suffering, but the city also risks depopulating and collapsing, as solutions are too slow or expensive to implement in time to deal with the crisis. The “plan” is for rain to bail them out, but that’s not much of a plan.
Most people know that farmers use far more water than cities, and that urban landscaping uses a lot of water (more than half, in hot cities), which allows for “painless” cutbacks in those uses during droughts, and reallocation to drinking. But that’s also not much of a plan.
Cities instead need to be far more proactive, i.e.,
- Maximizing groundwater storage, and restoring/protecting the quality of that groundwater.
- Recycling wastewater as a new supply.
- Identifying multiple sources of water, hopefully from uncorrelated sources (so one drought does not reduce all of them at once), and storing water in multiple ways (under ground, in reservoirs, in snowpack).
- Not replying on technological “solutions.” Desalination is the most popular, but it’s not available in the short term (portable units are too small to supply a city) and unsustainable in the long term. Riyadh houses 5 million in a high-altitude desert far from the ocean, but it’s one of the only countries foolish enough to live in constant danger of losing its water supply.*
- Rebalancing water uses away from agriculture and towards ecosystems (which keep cities habitable) and drinking water. In watersheds shared with cities, farmers should immediately reduce their use of groundwater (with a goal of “net zero” over time), and prepare to lose access to their surface water.
My one-handed conclusion is that cities, which are uninhabitable without drinking water, take immediate and dramatic steps to secure themselves against the increasing and inevitable risks of droughts.
*Saudi Arabia, the third highest A/C user in the world (after the US and China), uses around 600,000 bbl oil per day in summer for A/C [pdf]. That’s around $50 million per day, or $1.30 per citizen.