Rain Barrel located away from downspout

Old 05-30-11, 08:14 AM
Thread Starter
Join Date: Jul 2008
Location: USA
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Rain Barrel located away from downspout

I purchased and installed two 55 gallon rain barrels. They are located in the back of the house near a downspout that I assumed would get 1/4 of the rain. Unfortunately, in heavy, driving rains like we have had recently, this gutter is getting nothing, and the one at the front of the house is flowing like a firehose. I think that it is the way the rain is driving. That said, I would like to capture some of the rain from the front, but the wife has forbid me from putting barrels up there. I am thinking that if I put in a Rain Reserve diverter (already have one unused) or an Aqua Saver, I could run it into 1" or 1 1/2" PVC down the side of the downspout, into the ground, 40 feet over to the barrels and then up to the barrels. If the diverter is higher than the barrels, the water should flow freely into the barrels and any overflow would go into the diverters. Are there any flaws to this plan that I am not thinking of?
Old 05-30-11, 10:11 AM
tldoug's Avatar
Join Date: Jan 2009
Location: USA
Posts: 284
Upvotes: 0
Received 0 Upvotes on 0 Posts
One inch of rain falling on 1,000 SF of roof yields 83 cubic feet or 620 gallons of runoff. Your system seems a bit undersized.

The relationship is linear, so 1/4 inch yields 155 gallons, etc.
Old 06-01-11, 05:26 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 26,804
Received 1,951 Upvotes on 1,747 Posts
You will get some flow through a 1" or 1 1/2" pipe but you will not get much but the larger the pipe the better. You will only be working with the head pressure of having the infeed higher than the discharge end of the pipe subtract from that the friction loss to the pipe walls and and fittings (like 90 elbows) and you get very little flow. This is basically why gutters are so large. Since the only power is gravity a large pipe must be used to get a decent flow rate. Even a minor increase in pipe diameter will greatly increase it's capacity. For example a 1" diameter pipe has a cross section of about .75 inch to carry water but if you go up to a 1 1/2", which is only 50% bigger diameter, the cross section area to carry water is 1.77 inches. An increase of 230%.

If you have electricity available near your front downspout I would bury a barrel in the ground and install a submersible pump with a float switch and pump the water to your other rain barrels. My plan B would be to run the largest diameter pipe possible like you mentioned. The Romans did it 2'000+ years ago so it should still work.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: