Cambrian: Opinion

Rainwater capture, routing, storage and purification in 5 steps

Bill Seavey of Cambria with one of his homemade rainwater catchment systems. The pipe he's holding is connected to the house's rain gutter and swivels so it can fill up any of these 32-gallon garbage cans.
Bill Seavey of Cambria with one of his homemade rainwater catchment systems. The pipe he's holding is connected to the house's rain gutter and swivels so it can fill up any of these 32-gallon garbage cans.

Rainwater harvesting is a subject I’ve dealt with firsthand by offering four free demos/tours of my home system in Lodge Hill the past three years.

I don’t plan to offer any more, but it’s not too late for you to take action one way or the other. (And I haven’t really written about specific strategies in these pages.)

Anticipating a very wet, El Niño-type winter, Cambrian editor Stephen H. Provost made it very clear last week what needs to be done. We’re all keeping our fingers crossed that we get significant rainfall. But not too much — flooding could be possibly worse than a partial “cure” to the drought!

In any event, it’s an opportunity to get prepared for any eventuality.

The article below is partially excerpted from my new monthly blog at Go to it for further details on this and other subjects (and please let friends or relatives know about the site if they don’t get the Cambrian, and/or live out of the area).

It really is amazing how much water can be collected from your roof. A formula exists that reveals that even a half inch of rain falling on a 2,000-square-foot roof (40 by 50 feet) can generate about 625 gallons of relatively fresh, nearly potable water.

This water — direct from the sky and pure until it hits a hard surface — can be the cheapest, most viable way to get water for gardens, various cleaning needs — and, yes, even for drinking and bathing in a pinch — next to having it piped and delivered by the Community Services District.

And with water delivery (and sewage treatment) prices going up (and restrictions already being imposed on how much potable water can be used before fines and surcharges kick in), rain harvesting is certainly worth a look.

Here’s what you can do in five steps to capture, route, store and purify rainwater for around $1 a gallon initial set-up (after that it’s free!):

▪ Clear your rain gutters of any debris hampering water flow. You can do this yourself by getting up on your roof with a blower, broom or special trowel for gutters — or you can hire a gardening professional to do it for you.

▪ Once cleaned, go to Home Depot or Lowe’s and get 3-foot-long sections of gutter screens that snap into place and prevent leaves and fine particles from entering gutters. (If you live where there are no overhanging branches, this may be an unnecessary step and expense). Your house may already have leaf-proof enclosed gutters installed — if so, that’s one less chore.

▪ There are several installable devices that insert into downspouts. One manufactured in Canada called Catch-A-Raindrop costs only about $5 and connects to a hose that you can then route into a barrel or other rain-collecting vessel. A simple hacksaw and two cuts is all that is necessary. I also inserted a 1-inch PVC pipe right into a gutter, dammed it off where the downspout starts, and was amazed at how much rainwater that gravity and pressure fed to my trash barrels right below. (The Tribune ran a picture of me and that approach on the front cover a few months ago).

▪ The author’s water-storage vessels are “eclectic.” I have a 1,100-gallon poly tank, which cost about $900 (with delivery). It’s connected to a garage roof by a slowly descending 2-inch PVC pipe and is the “heart” of my system. I also have a 275-gallon square “tote” recycled from food-grade use (locally it cost me $140), a 300-gallon stock watering tank, 50-gallon upright sealed storage barrels and cheap 32-gallon plastic trash barrels with lids (about $15 each). I can store about 2,000 gallons, and the initial cost has worked out to about $1 a gallon, as mentioned above. (If you hire a contractor to do all this, figure $2 to $3 a gallon). Once paid for, however, your costs are basically nada, zilch and zero!

▪ If you are using your water for anything other than gardening/landscaping, (and even then, if you want to prevent some sediment getting into your tanks), you may want to install a “first flush” mechanism (about $40 from Any water you use for drinking or bathing needs to be carbon-filtered or, using the simple method, adding a few drops of household bleach per gallon. Obviously, this is necessary because the water could be contaminated from roof-originating animal waste — although after a big storm, your roof is likely to be scrubbed pretty clean.

Setting up your rainwater harvesting system is not that complicated. It will necessitate you being a little handy and not being afraid to get up on ladders occasionally. (I clear my gutters manually because I do not use gutter screens uniformly).

Local plumbing and contracting companies can help you. Some have asked me to advise them, but I am not really doing this commercially. (For a list of local contacts, send a SASE to P.O. Box 1681, Cambria 93428)

William L. Seavey writes on green saving subjects at monthly and special to The Cambrian quarterly. His green DIY projects have included a portable solar electric system for outages, a geodesic dome to cover a hot tub, and a strawbale house.