Most of the underground storage tanks I've seen tend to require a minimum amount of water to be kept in the tank at all times - which means a person would need to buy and install a tank that holds more water than is need.
Just me (and where I live),but for amounts where above ground tanks start to become too bulky I'd rather turn to digging ponds than install an underground tank/cistern.
Granted digging a pond may not be viable in all areas as it leaves the water more open to the atmosphere and losses due to evaporation ..... so I guess the "best" answer would be switch to an underground storage system makes sense for the location and operation. From what I've seen in my current region, it'd seem ponds tend to be the primary go-to solution for bulk water storage for livestock given rain tends to come frequently enough to keep them at reasonable levels (and winter rains can drop more than enough to offset the driest of summer months).
