A cylinder of 30cm diameter and 10km deep would hold around 700k litres.
700k litres = 0.184920437 million US gallons
"How much water does the typical hydraulically fractured well require?" https://www.usgs.gov/faqs/how-much-water-does-typical-hydrau... :
> Water use per well can be anywhere from about 1.5 million gallons to about 16 million gallons
https://www.epa.gov/watersense/statistics-and-facts :
> Each American uses an average of 82 gallons of water a day at home (USGS, Estimated Use of Water in the United States in 2015).
So, 1m gal / 82 gal/person/day = 12,195 person/days of water.
Camping guidelines suggests 1-2 gallons of water per person per day.
1m gal / 2 gal/person/day = 500,000 person/days of water
The 2016 Mars NatGeo series predicts dynamics of water scarcity on Mars.
Water on Mars: https://en.wikipedia.org/wiki/Water_on_Mars
700k litres = 0.184920437 million US gallons
"How much water does the typical hydraulically fractured well require?" https://www.usgs.gov/faqs/how-much-water-does-typical-hydrau... :
> Water use per well can be anywhere from about 1.5 million gallons to about 16 million gallons
https://www.epa.gov/watersense/statistics-and-facts :
> Each American uses an average of 82 gallons of water a day at home (USGS, Estimated Use of Water in the United States in 2015).
So, 1m gal / 82 gal/person/day = 12,195 person/days of water.
Camping guidelines suggests 1-2 gallons of water per person per day.
1m gal / 2 gal/person/day = 500,000 person/days of water
The 2016 Mars NatGeo series predicts dynamics of water scarcity on Mars.
Water on Mars: https://en.wikipedia.org/wiki/Water_on_Mars