Our 2 x 23650 litre tanks were delivered and “installed” right at the start of June. That is, they were maneuvered into place and taps drilled in. The plumbing in part came the following weekend.
The plumbing was a little tricky. We want to collect from all of the downpipes on our big shed, plus one that comes down right next to it from the veranda. That last one is particularly important as the veranda covers a large area and some of the house roof dumps onto it. We’re not exactly sure what area is collects, but it’s potentially more than the shed.
The real tricky part comes from the fact that it’s a “wet system”. That is, it runs along the ground to the tanks and then up to the inlets, which means that the pipes are always full of water. We also need to use in-line leaf catchers as the area is surrounded by huge gumtrees. This means the leaf catchers have to be above the level of the inlets, or water will come pouring out of the wrong end. We can work that out pretty easily from the side of the shed near the tanks, but the other side took some doing as the veranda is low and the tanks are tall. We thought we were okay, but only just.
As it turns out, our plan changed a couple of times, and then our implementation changed once after-the-fact. The veranda collection point was just a little low for the amount of flow. The level of water in the pipe was below the leaf catcher, but the flow from the veranda was so high that it still overflowed. We ended up having to T the veranda pipe in below the leaf catcher, which is completely counter-intuitive. To make sure we didn’t collect trash from that pipe we put some mesh in and along that gutter, and we’ll have to get up there and clean it every month or so over the wet times.
I’ve worked out that we have just under 500 square metres under roof area, and maybe 70 of that we’re not collecting yet (one downpipe). That means we can collect around 275k litres a year, but we’re collecting about 240k litres. That’s heaps more than we thought, and probably means we need more tanks. In fact, I think we could do with two more at the size we just got, which would be one more on either side of the house in the collection areas.