External water taps

[Russell griffiths]

2 hours ago, ProDave said:

If your land can't absorb it in some form of soakaway, then I can only assume before the house was built, you had standing water sitting as a pond on your plot?

 From all the work that was done on our place I've found out that this is not really how it is looked at. 

 

Without a house all the rain that falls will land spread evenly around the whole plot

by building a house you are collecting all the rain and condensing it into a couple of down pipes so it comes out in a concentrated area, this is the problem that needs addressing. 

100 litres of water falling over an area of 400 square m is not a problem, but send that 100 litres down a pipe over a 4 hour period is when you get dramas. 

[ProDave]

 

The rain water harvesting is interesting in the context of comparing it to Australia.

 

Rural properties there routinely get all their water from rain, and store it in huge above ground tanks.  My In Law's place in Queensland collects water from the roof of the house and the roof of a big barn, stored in 4 large above ground tanks. They can select with valves which tank to draw from to feed the house.  About the only criterea is the tanks are light proof.  They prefer using the water from the two corrugated steel tanks as these have been encases with a concrete skin so deliver much cooler water than the other tanks.

 

All the time I was there I never got ill, the water tasted nice and it was clear.

 

In the dry season if they run short on water, they buy in a tanker of water to refill one of the tanks.

 

I suspect the reason it woks there is the weather pattern. They have a wet season where it rains a lot and I suspect they collect most of their water in a short period. I don't know if they have a system of letting the initial rainfall just run off to clean the roof before collecting it, but it would make sense if they do.

 

Another factor is they have moistly tin roofs, so they probably wash clean and then deliver fresh water a lot quicker than a typical moss covered concrete tiled British roof would.

[Jeremy Harris]

We used to collect rain water at sea to refill the tanks on a friend's yacht.  We had a canvas funnel, with a pipe sewn in the end, so the pipe could be stuck in one of the tank fillers.  In heavy rain, the procedure was to luff up, tie the main sheet both sides to hold the boom steady, partly lower the main, so there was a sort of gutter along the side of the boom, attach the canvas funnel to it and then lower the topping lift just enough to get rain to flow into the funnel.    We'd let the first few minutes worth of water run away, as it was usually salty and mucky, then when it was running clear and tasted OK we'd stick the pipe into one or other of the water tanks.  Back then, before reverse osmosis water makers were invented, it was the only way of topping up with fresh water at sea.

[Russell griffiths]

In oz they fit a system called a first flush it allows the first so many litres to go straight to waste, a floating ball in a pipe then rises to shut off a valve this then diverts the water to a tank. 

 

Before the water even gets to the first flush the downpipes empty into a hopper with a stainless mesh in it this gets rid of the big things like leaves. 

[Russell griffiths]

Like this pic. 

[Vijay]

A lot to take in and put to the various suppliers of RWH systems - especially what nasties are potentially in the water and how their systems remove them. I'll update when I get more information