|The problem is the small pipe going into the barrel on the right. This comes out of my cistern as overflow. Water was pouring in so fast last night that the smaller diameter pipe was not letting enough into the overflow to keep up..|
The good news is that 1/2" inch of heavy rain topped off my cistern and would have easily filled my outside barrels. With 70 gallons outside to water the garden I should be able to last 8-10 days with no rain (more like 8). I may tie 1 more rain barrel in, giving me an outside capacity of 100 gallons....that would be nice.
So the Moral of the story is that the overflow pipe needs to be the same diameter as the inlet pipe on your rain system or a very heavy rain will overflow the cistern. That's not a big deal if your cistern is outside but mine is in the shed/bathroom. Not Good.
Hope this helps.....