Lance Blackley: This project encapsulates a number of different surface areas where we’re collecting water from. The first, and the main one, is the roof of the REB [Royal Exhibition Building] which is some 10,000 square metres and that’s a considerable amount. The paving and driveway paving on the southern side, that is around about 7,000 square metres. And then we also have sections of the museum blade roofs – they’re the roofs that are out the front of the museum that form the walkway before you actually enter the museum – and I think they are around about 7,000 square metres in total. So it’s a lot of surface area and during a major rain event we would expect something in the order of about 250 litres a second of water to be coming off those roofs.
Now, the water that falls into the tank, that will sit in there and be stored until it’s needed in the various areas. What we will have is a pressurised pump system that will draw the water from the tank. We’re going to have some filtration in there to remove any suspended solids that are in there - and that will be filtered down to a 50 micron level - and then we’ll be having an ultraviolet disinfection system in there, which will kill any bacteria, E. coli and anything that may want to grow in the tank. Then it will be distributed out through a pipe network system to irrigation areas at the western forecourt, lawns, gardens, throughout the whole system.
We have to keep in mind at all times the historical value of a site such as this, so one of the main challenges we have is hiding our services, because we’re trying to create a historical garden and we don’t want to see brand new pumps and things sitting above the ground. We’ve got to hide everything away so that it’s just not visible to create the authenticity of what this site would have looked like when it was first constructed.