LA: Importing water on sinking land

Clara writes*

In LA, there hasn’t been a “Day Zero” just yet. They are, however, only 8 places away in global ranking from achieving that. The birthplace of “Waterworld” and home of its cherished stars might well soon host its own real-life version of a dystopian future. Not only is it 9th globally in water-stress levels, but on the national level, it takes the crown.

Los Angeles imports 85% of its water supply from other parts of the state. It feeds on four aqueducts: the two Los Angeles Aqueducts, the Colorado River Aqueduct, and the State Water Project’s California (West Branch) Aqueduct that brings water from the North over the Tehachapi Mountains and into Southern California. LA also depends on local groundwater from the San Fernando Valley aquifer.

Importing so much of its water is a major issue not only for the reasons that it leaves other regions and ecosystems with less water. LA also depends on groundwater, even when often faced with the challenge of this water’s pollution. Groundwater may only represent 11% of usage on average but during dry season, and even more so in long-lasting droughts, groundwater reliance shoots up. This reliance hides a larger problem: land subsidence. Though LA city itself may be safe from sinking or rising sea-levels, the same is far from true for its outskirts and surrounding areas. The over-drafting of aquifers has, despite the presence of recharge pumps, resulted in worrying rates of subsidence due to the collapse and compaction of subsurface structures.

Sinking land is undesirable because the subsidence damages infrastructure such as the California aqueduct. Sinking land has already reduced its carrying capacity by a full 20%. The Los Angeles Aqueducts have also suffered from the combination of subsidence and uplift.

In addition to problems of supply flows, LA’s supplies are also endangered by heavy agricultural water consumption. California’s sunny climate allows a plethora of water- and sun-intensive crops to be grown. The most abundant crop is alfalfa. Why should anyone care for a simple grain, you ask? At 65%, the colourful grass is responsible for a majority of the land use, and water use with it. It is grown as high quality fodder for the state’s dairy industry. In addition to the impact of the agriculture, domestic consumption, though negligible relative to the former, attains levels between 295 and 510 litres per person (ranging from downtown LA to Beverly Hills, respectively) for domestic use daily. These levels are, independent of agriculture, too large when compared to cities such as Amsterdam, a city with, notably, far less water-scarcity.

Los Angeles, with its 4 million water-hungry residents, is over-dependent on imported water, which it is also condemning by encouraging land subsidence under its various aqueducts.

Bottom line: If Los Angeles does not adjust its consumption of water, management of aquifer use and improve resilience of aqueducts, it will be running head first into a irreversible case of water scarcity.

* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Author: David Zetland

I'm a political-economist from California who now lives in Amsterdam.

4 thoughts on “LA: Importing water on sinking land”

  1. Hi Clara! That’s a nice blogpost and your introduction immediately caught my attention. You talk about a lot of different issues that are nonetheless all related to one another and you explain that very well. I only have two questions: I am wondering whether there is a specific reason why so much water is lost due to evaporation. Is it because of the way it is stored? I would also like to know when the Californian state started taking legal actions. Is it a recent development or has the state tried before to address the issue and was unable to do so effectively?

    1. Hi Xenia, thank you for your comment! I think it is mostly due to the hot and dry climate of the desert-ish state of California that so much evaporates. When they have many stagnant reservoirs, which they do, it increases that phenomenon even more. the legal action is quite recent from the late 2000s/beginning 2010s. I do not know enough currently about how much action was taken to address the faulty storage or wastage of water but they have indeed tended to ignore that and focus on maintaining the performance of importing mechanisms that easily solved all their demand (but thus displacing scarcity elsewhere in the state).

  2. Hi Clara! You described the situation very comprehensively. However, I was wondering why Los Angeles has such high water-stress levels compared to other cities in other states in the United States. Is it just geographical or does the policy differ a lot from that in other states? Does California have less restrictions on water consumption? Is it just because of the water-intensive crops? If California produces these water and sun- intensive crops because the climate is suitable for it, I would think California also exports a lot of virtual water. If the agricultural sector is incentivized to use less water and thus less water-intensive crops, will the agricultural sector in other places not start producing these water-intensive crops in order to meet the demand for them?

    1. Hi Sasja! Thanks for your thought-provoking comment. I’m not entirely sure why it is so bad compared to other desertic areas of the United States. I think it is very closely tied to geography, yes. California is not only quite dry and hot, but it also has mountains to deal with in terms of transporting (importing) water and more importantly perhaps, it is exposed to many natural disasters such as fires, earthquakes, landslides, and volcanic eruptions. Along with the very high population numbers, the high demand these have and the high demand of economic/industrial activity in the area, it causes a demand far exceeding what they actually have at hand (thus the imports).
      You make a really nice point about the exported virtual water and the displacement of the problem if they stopped due to demand for these crops. Perhaps that is true, but perhaps also, growing these crops would then happen in places a bit more suited to them. Also possible: prices would simply rise due to lowered supply until long-term adjustments can be made by the global agricultural community to produce more of these crops again.

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