Water rights are not automatically given with an oil/gas lease.
Also in a dry climate with many leases on large ranches, like West and South Texas, those water aquifers are closely guarded. In the old days, some ranchers literally killed people over water rights and access in some of these areas.
It is not unusual for an Eagle Ford well to use 5 million gallons to complete with hydraulic fracturing. Other tight formations like shale in the Permian Basin can take similar amounts.
Last year there were over 15,000 wells drilled in Texas. I believe most of them were shale / tight formation requiring hydraulic fracturing to complete.
Okay, thank you for that info.