If there has been no rain for some time, as is often in the Australian Climate. Then the base of the tank will contract. If water is gently sprayed onto the outside of the tank at the bottom, then this will maintain the moisture at the base.
However, depending on how long the tank has been left leaking, most tanks can be repaired.
There are many products on the market which can be used to repair tanks. Sometimes a product called “Xypex”, or the like is used.
These products are mixed with water into a paste. This powder is sugar based, and the crystals expand and fill the holes in the tank.
Sometimes, bands are placed around the tank whilst the tank is healing, this keeps the tank in its shape.
So if your concrete water tank needs repairing why not give Terry a call and ask his advice?