The best example is the Ogallala Aquifer. &quot;At places, the water table was measured to drop more than five feet (1.5 m) per year at the time of maximum extraction.&quot; <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Ogallala_Aquifer" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Ogallala_Aquifer</a>  So it&#x27;s a huge resource of fresh water that&#x27;s being drained much faster than it&#x27;s replacement rate.  But, building deeper wells is cheap and there is little value in untapped water so it&#x27;s reasonable for now.<p>However, long term it&#x27;s a finite resource.  At the same time a lot of fresh water ends up in the ocean so desalination needs to compete with simply moving water around.<p>Locally when transport is more expensive than desalination it may be useful, but long term it&#x27;s a balancing act between moving water a thousand miles+, desalinating locally, or increasing efficiency.<p>PS: In theory these Aquifers could be used as a cheap form of transport, but when any well get&#x27;s to tap the water for &#x27;free&#x27; who pays for it becomes a major issue.