We have to collect our own water from roofs or by pumping from a permanent spring/ water hole in first rain forest, eg no water rates.
Total tank capacity is 65,000 litres
However pumps are needed to feed water to the houses.
To minimise the use of a pump to feed water to the new house, we use gravity feed from the top tank. if faster flow of water is required, a switch in the new bathroom, activates the pump.
All systems are linked together so any tank can provide water.
The new house has a holding tank of 8,000 litres. Water for this tank is fed from the roof or pumped up from the permanent spring.
Water from the holding tank can be pumped up to the top tank and then by gravity to replenish water levels in other tanks, also to top up the swimming pool.