Thanks to Col Major of Major Sheds and Tanks in Ipswich we have our new 5,000 gallon water tank installed. Their website is Here.
Added to the existing inground Concrete tank we now have 10,000 gallon clean drinkable water holding capacity. They say an adult drinks about 200 gallons a year so I think we have plenty to get by on.
The main house roof of over 200 sqm pours into the old tank. Its overflow plus the water harvested from the Carport (approx 30 sqm) pours into the new tank. The new tank's overflow joins the pipe carrying the water from the BBQ area (approx 30 sqm) and the double shed (approx 30 sqm) down to the dam. With all the rainfall we have had lately they (tanks and dam) are all pretty much full.
We are on trickle town water here but we have not had to use much of that all over the last 12 months. With the new tank we are banking on not having to use it all again.