Did the US hit peak water in 1970?

Is peak water 40 years old?

Everyone is aware of the dangers of peak oil, but peak water is just as, if not more, devastating. The planet's fresh water supply is a precious resource and the rate at which the industrialised world consumes it is always increasing. As such, there is a fear, as with oil, that eventually extraction rates hit a peak and it's only downhill from thereon-in.

Staff at the Pacific Institute however have made a disturbing discovery - that the US hit 'peak water' in 1970... and nobody noticed.

US Infrastructure has written in the past about the US rate of water consumption and as such, the timeline of hitting peak water has fluctuated from 'it's already happened' to 'it could happen in 30 years time'.

With any finite resource, hitting a peak consumption point is always a possibility and according to the analysis, "Peak Water Limits to Freshwater Withdrawal and Use", performed by the Pacific Institute, for the US and its water supplies, that time has come and gone.

According to Ars Techica, the report states that "there are some significant differences between petroleum and water (consumption). For oil, using it involves a chemical transformation that won't be reversed except on geological time scales. Using water often leaves it in its native state, with a cycle that returns it to the environment in a geologic blink of an eye. Still, the authors make a compelling argument that, not only can there be a peak water, but the US passed this point around 1970, apparently without anyone noticing."

The staff made their case in three ways, showing how the US water supply has hit limits in terms of its usage.

1. Peak renewable water (for sources that rapidly replenish, like river basins or snow melt): Citing the Colorado River as an example, the report states that since 1960, essentially no water has reached the ocean. "Although actual water use is governed by a series of interstate and international agreements, these simply serve to allocate every drop of water. Similar situations are taking place in other river basins, such as the Jordan."

2. Peak non-renewable water (such as the use of aquifers that replenish on time scales that make them closer to a finite resource): The report states that aquifers in the US, such as those in Ogallala and Central Valley, are being drained at a greater rate than they are getting refiled. It is expected that these supplies will eventually tail off.

3. Peak ecological water: Here other waters sources, such as major rivers, are used as a primary source. Essentially this idea is not tolerated because of the "potential economic impact of eliminating the use of the waterway, and because we're no longer likely to accept wiping out species that rely on the habitats created by the rivers."

With these three peaks essentially giving an indication of 'peak water' and the limit of sustainable water use, the study has stated that US water use paralleled GDP growth for most of the 20th century, until 1970. After that, water use tailed off, peaking around 1975. After a short period of decline, water use has remained stable even as both GDP and population have continued to climb.

According to the authors Dr. Peter Gleick, president of the Pacific Institute, and Meena Palaniappan, director of the Institute's International Water and Communities Initiative, the report does not say that we are 'running out of water on Earth', but that we are very close to using much of the renewable supply and in some regions we are well past the point of peak ecological water. Not just that, but the environmental damage of human use of water exceeds the benefits of that water use.

Perhaps it's time to invest heavily in desalination plants?

Read the article abstract at Proceedings of the National Academy of Sciences.

Download a pdf of the early edition of the journal article.

Relevant articles:

America's rate of water consumption |The importance of US waterways | The Californian water crisis | Philadelphia to harness storm water

Timon Singh

Timon Singh is a graduate of Liverpool University where he received a degree in Social and Economic History. He has previously worked for BBC Magazines on BBC Who Do You Think You Are? Magazine, the publication for the popular genealogy show.

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