Installing A Rain Catchment System

rain_catchment_system_3pack_in_winter

Photo by: DIY Alternative Energy

I have a series of rain catchment systems around the house and thought I’d share how I installed them.  We live in the “high desert” which just means a desert at high altitude. There’s not much rainfall and when rain does happen it’s usually one of two scenarios – a torrential downpour that lasts a couple of days, or just enough rain to wash the dirt out of the air and not much more than that. With the torrential type of rains, it’s a great opportunity to catch some water with a rain catchment system for watering the plants – so it isn’t necessary to water from the well. Some of the neighbors up here have had problems with their wells going dry, so we have been conserving water much longer than the rest of California.


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When we first moved in up here I placed a 55 gallon “pickle” barrel at each of the (then) only two existing down-spouts.  After the first few rains, the first improvement made to the house was to put up guttering all around.  That actually should have been my second improvement, as I didn’t notice there was no drip edge around the roof line.  (It directs water away from the edge of the roof.)  It would have been much easier to install it before the gutters went up, or even at the same time as when the gutters went up, as some of the roof line is more than 15 feet off the ground – and I am not a huge fan of heights..  Ahhh – 20-20 hindsight.

rain_catchment_system_3pack_drain_system

Photo by: DIY Alternative Energy

All the down-spout configurations include a clean-out in case the down-spout ever gets clogged up with anything, a first-flush system to get rid of the first few gallons of each rain that are pretty filthy, an air intake to allow the water to be able to flow quickly through the system, and an overflow so once the totes are full the overflow is directed toward the back of the property – away from the house and toward the planted area of the property.

Most of the need for watering of plants is way at the back of the property, in the hoop house, so the first corner installed was at the location to make the water handiest for watering the plants at the back.  The property has a gentle slope from the front to the rear of the slightly more than one acre.  That is great, as no pumps are needed to get the water from where we capture it to where we need it. 

The first bank of totes built for the first part of the rain catchment system had three totes side-by-side.  Right off the bat I decided to use a concrete block and gravel foundation. This type of foundation allowed me to use what I had on hand and proved to be easy for one person to work on effectively.  I could do as much or as little work as I wanted at any given time. If I wanted to work for an hour after work, cleanup was fast and easy – unlike pouring concrete.  The ground was “scalped” with a shovel as flat as possible, then the concrete blocks were placed on top and leveled with as little movement of dirt as possible.  They were tilted slightly away from the house (toward their drain spout) so the water would drain out of them easily in the direction the water was needed.

rain_catchment_system_2pack_concrete_block_pad

Photo by: DIY Alternative Energy

The totes really only contact the concrete block pad at the very outer edge so, although there was no load bearing need to make the foundation “solid,” there was another reason.  The property is riddled with ground squirrel burrows, so the blocks were filled with sharp edged gravel to help deter the little buggers from digging up in the middle from underneath. I would later add a small border around the edges of the blocks that was also filled with the same sharp edged gravel. Ground squirrels are very industrious little diggers.

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Photo by: DIY Alternative Energy

The Next Step

At the corner of what should have been the shortest run of gutters (only about 10 feet) there is a single 275 gallon tote.  There wasn’t really enough space to put more than a single tote at one of the front corners at the house, so we managed to stack a couple of them for maximum capture – and that seems to be working out for now.  There is one corner that hasn’t been completed yet and the plan is to put a wall of 10-12 totes (5 or 6 stacks of 2) there.  The wall of totes will be about 12 feet away from the house, creating a “carport” of sorts (once shade cloth is added) that will add some privacy to a more open part of the house – and provide an extra space with shade to park a car.

The Last Step

I’m planning to cover most of the totes with a frame and horizontal wood strips that will match the fence that is currently under construction at the front of the property.  The photo above is not of our fence, but is what ours is intended to look like. This fence will surround a patio area. This privacy fence is located about 10 feet away from the house.

After all the totes are installed, we will have a total capacity to save almost 5,000 gallons of rain water.  That seems like a lot, but it’s amazing how fast the totes fill with a heavy rain. There are plenty of websites with formulas out there that will tell you exactly how much rain can be captured per square foot of roof.  I didn’t use them – I just guessed and my “method” has turned out to be sufficient for us.

What I Wish I Had Done Differently

Well, first I wish I had done the drip edge around the roof-line at the same time as the guttering to save me MANY additional trips up and down the ladder.

Secondly, I wish I had done better at planning the gutter runs so there was actually more gutter directed toward the corners where it would have been easier to use more totes, rather than just dividing it up evenly.  I have not redone all the gutters, but I plan to while replacing the drip edge.

Third is the fact that I found out (the hard way, of course) that you should NOT use duct tape to seal the edges of the black plastic around the totes. I used a decent grade of duct tape on the first three totes and it didn’t last a year out in the hot sun. For the next totes, I used a black tape with UV protectant called Christy’s pipe wrap.  You can find it at Home Depot or Lowe’s in the pipe insulation area.  It’s not cheap (roughly $7 a roll) and it takes about a roll per tote. Don’t worry – you’ll be glad you used it if you live in a sunny or hot area.  Here’s a link to a thorough YouTube that will (besides the duct tape) provide great explanation and detail about how and why to wrap the totes with the black plastic.

Fourth, I wish I knew that the stuff they sell at Lowe’s / Home Depot that is sewage pipe is NOT the same size as PVC pipe sold at a piping store.  I purchased the fittings, like the elbows and caps at Home Depot.  Neither Home Depot nor Lowe’s had any 4″ pipe in stock except for stuff meant for sewage – which seemed questionable to me to use for water that is meant for plants.  (I don’t know what the black junk is on the inside of them and whether or not it’s got all kinds of noxious chemicals in it.)  Turns out there is about an 1/8″ difference – just enough so the fittings didn’t fit onto the PVC – which I had already cut up and couldn’t return.  It was expensive – $75 bucks for a 20 foot piece – and I have to look at it laying in my garage every day and that torques me off.  I know I will eventually find something useful for it to be doing, but until that time, grrrr.

Last, this was a fairly easy project and I probably could have made better use of my time by hiring out the making of the foundation/pads to a neighborhood teenager.  I did have a friend (thanks again Robert!) helping me for the first large foundation/pad, so that one went a lot easier.  Actually, as I remember, he did most of the work and I sat in a chair and ordered him around – so I guess that did turn out to be a pretty good use of my time after all…

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