Like the similar phrase, peak oil, the term refers to the characteristic  of finiteness.  Oil is not inexhaustible and can eventually run out.  In contrast , water is considered a renewable resource, like wind and sun.  It is closer to being infinite since it will continue to exist as long as we get precipitation, whereas oil does not regenerate itself.

Yet given the increasing pressure on water resources, including from population growth, expanding agriculture, pollution, and droughts from climate breakdown, water is running out in some places, at some times.  And rainfall is insufficient to renew the resource.  This is often referred to as “overexploitation.’

Below 2C

Of course, if fewer people (or cows) were allowed to tap into the water resource, it would last longer.  But that is a challenging socio-politico proposition.   Just look at struggles to allocate the water from major interstate/international water resources, e.g., the Colorado River.

Some further ideas to explore on Peak Water:

What is the source of your own water supply?  If public water, where does it come from?

What is the estimated volume of water available for use?

Who else shares that water resource?

What percentage of your water resource is used by which groups or sectors (residences, businesses, industries, agriculture, etc)?

Sources:

“Peal Oil.”  iePEDIA section of www.irishenvironment.com (1 March 2022).

Peter Gleick, Pacific Institute, “Peak Water.”  video.search.yahoo.com/yhs/search?fr=yhs-tro-freshy&ei=UTF-8&hsimp=yhs-freshy&hspart=tro&p=Peak+Water&type=Y219_F163_204671_102220#id=1&vid=55573f227e37ffc5762d391b4e46ed5f&action=click

Ugho Bardi, “Peak Water: Are we Running out of a Critical Resource?” Resilience (28 April 2021). bit.ly/3r30Baq

Peter Gleick and Meena Palaniappan, “Peak water limits to freshwater withdrawal and use,”  PNAS (24 May 2010).  bit.ly/3XtY8BU