This question is pondered by many people. I remember when we lived on tank water and it was always a game whether to buy the water or wait for rain.
Following is a few things to consider.
First up you need to know how much water you are using. Hop up on the tank every day for a few days and measure the depth of water. Calculate how much you are using. Remember from school, volume of water in a tank is Pi (3.1416) x radius of the tank squared x the depth of the water. Work it out in meters and multiply by 1,000 and this will give you litres. After you have worked out how much you are using each day on average you can work out how many days water you have left.
Next, is it going to rain? No sense spending money on water if there’s a flood coming. Remember that it will take about 100mm of rain to fill a 20,000 litre tank on the average 4/2/2 home. So if BOM says there’s a 60% chance of 1-6mm coming, that’s next to nothing.
How much should you buy? Most of the water cartage operators in Bundaberg carry between 12,000 and 13,500 litres. Most of the poly and corrugated tanks in Bundy are 20,000 litres. So if your tank is about 30% or less, it’ll fit. There are also a lot of multiple tanks connected together.
A really important one I’ve noticed lately is people accidentally letting their tanks run dry. Filling a dry tank will result in a LOT of turbidity in the water caused by the disturbance of the sediment in the bottom.
So, when’s the best time to put water in the tank? About 10% remaining in the tank. This will still leave enough water in the tank to stop heavy turbidity. (One of the requirements of our licences is we must have a dissipator on the end of our delivery hose to spray the water out at 90 degrees, not straight into the bottom of the tank stirring everything up). And if we get 25mm of rain the tank won’t overflow and waste money. It’s also probably a good idea to call one of the water delivery suppliers and ask what the current waiting time is. No good when having only 4 days supply if the waiting time is 7 days.
Learn more about Bundaberg Water’s bulk water delivery service…..