Harvesting Rainwater—Part Three
>> Monday, August 29, 2011
(If you missed parts one and two you can read part one here and part two here.)
It was hard to see in the photo in my last post but in the middle of the piping connecting the two tanks together I ran a 1/2” pipe up into the crawl space under the house. This will be connected to the water pump. But, before any water can be pumped out it has to be “harvested” and put into the tanks.
I had put rain gutters on both the front and back of the house a few years ago and was capturing some of the rainwater in a couple of poly tanks that I had placed under the back deck. The only problem with these gutters were that they drained the water in the opposite direction from what I needed now. So, I took down the gutters and reinstalled them, swapping them front to back and back to front. This was due to the solid end and the end for attaching the drainpipe being opposite to what I now needed.
This photo shows the front of the house with the gutter reattached. While I had the gutters down I put a coat of brown paint on the fascia. The brown blends in with the brown of the gutters which were prepainted.
The water from off of the roof goes into the drainpipe which you can see in this picture goes into a vertical pipe. This is made from 4” PVC sewer pipe. It is hard to discern in the photo but at the bottom there is an elbow which has a screw-in plug. Near the top you see another pipe that tees off to the right. What is this all about? That my friends is my roof washer! The idea is that when it starts to rain the first few gallons of water that comes off of the roof will normally have dust, bird droppings, etc. in it. The tall pipe will catch this first runoff with this material. Once the pipe fills to the tee the much cleaner water will run on over into this second pipe. You can see that this pipe runs into a black box.
Here is a close shot of the box. It is a “drop box” normally used with drainage and septic installations. I ran the pipe in near the top on the left side and have another pipe running out from near the bottom on the right side. Inside, between the “in” and the “out” I have screening to catch what debris that isn’t caught by the guards I have on the gutters.
The water then is directed down along side of the house to the cistern tank. This pipe is 3” PVC and it goes into a 4” pipe along the end of the tank, which goes into the tank. The water from the backside of the house goes through a similar setup and is piped to this same point—all of the water entering the cistern tanks at this end.
This picture is of the roof washer and screening box at the back side of the house. I have 3” PVC pipe running along side the house to the other end of the tanks, going into the same 4” pipe that enters into the tanks. In the photo below you can see the 3” pipe attached to the side of the house.
With this all in place we have yet to take care of the overflow when the tanks are filled and the installation of the pump to get the water into the house. That will be in the next installment.