Hey,
I’m looking for materials and information on catching rain-water in an urban environment, storing it and using it as grey-water for watering plants mostly. Has anyone done this? I need resources that tell me simple ways to complex, cheap to expensive, small vs. large, etc etc. I’d like the whole gamut pleeez.
The Permaculture Design Manual by Mollison has some pretty good water capture/storage stuff. expensive book, but worth it. RUns the gamut of small individual collection to 50,000 gal dams.
Find a natural spring near you
roof catchment works well, but it helps to have metal roofing, for plant watering it may not matter as much as it does for us with the drinking water.
you don’t have to have the gutter go all the way to the barrel either, it’s just more efficient that way. you also don’t have to have special barrels, especially if you’re saving it for plants. Those rubbermaid roughneck trash barrels work fine. Just try to position them so they will be mostly out of the sun, and be sure to cover them so nothing drowns in them.
the link is pretty cool, but damn, nice and pricey.
Yes, any old barrel will do under the rainspout if you’re just watering plants. You’ll get some amount of toxins (tar, glues, etc) in the water from the roof, but the amount should be relatively minor. The barrel should be thick-walled, if it’s plastic I suggest it be at least a year or two old to minimize the amount of phthalates leeching into the water.
To get the water out, an old pot works well. Just scoop it into a watering can.
You may also want to create some sort of cover, or else you’ll be host to a mosquito larvae convention ;p
So do you just open them up when the rain falls and keep them covered the rest of the time? Most of the commercial ones I see have crazy contraptions for letting the water in and keeping everything else out. I never thought about making it as simple as opening a trashcan lid when it starts raining. Funny how the obvious often eludes us. 
We just use a fine grate to keep leaves, sticks and other big stuff out.
well, we’re set up simple here so yeah, we just run around like rain soaked madwomen removing trash can lids when the water comes. It’s really a very fun little rain ritual, especially considering the torrential downpours we get in the summer in the sw.
we have a storage system too, so we have certain barrels under the gutter and then other barrels we transfer water into for storage.
We’ve tried various grates and screens and most still let itty bitty insects in and bacteria. Sometimes we have to skim the juniper berries and pine needles out though.
If you keep it simple and cheap, you’re more likely to actually do it.
As far as the original question goes, the other scale of things is a big underground catchment system like this one described on the Dancing Rabbit website:
You may want to consider swales. Granted, it may not be the best for every situation, but if you can do it, then “storing the water in the soil” is quite probably the best way to go.
I foraged a giant 60 cubic foot plastic bin and put it under a roof cornice intersection then added a comet goldfish , a few mosquito fish(gambusia) and some duckweed. Add an overflow bucket to catch the duckweed and mosquito fish run off and we only ran out during severe drought . If you make it worth my while I will catch some for you and try to live ship them. I’ve also tried to raise nonhemophagic predatory tree hole mosqitoes with limited success.
We just yesterday caught about 200 gallons using almost exclusivly just large trash bins (cought from 2 sections of a suburban roof). We need rain gutters and bigger and more buckets to get more, but ai think thats pretty good considering the method and materials. My back hurts like hell from carting them arround though, so you might want to get the rain gutters and a permanently-placed, large bucket.
We used rain water and snow melt for all our wash water for about 20 years. We carried water in jugs from the creek for drinking. Though we now have a well and a pump, I still use mostly rain water and snow melt in my work shop because it’s easy.
We have rain gutters and 55 gal. barrels.
For snow melt we have a barrel that sits next to the wood stove. In the winter we shovel it full of snow. Once it’s full of water it’s not that hard to top it off with snow each day and keep it full. Still what I do in my shop. We keep one in the house too in case the power goes out and our pump won’t work.
My grandparents had a wooden barrel underneath the downspout of their house, with nothing special. If you are using it to water plants, then having leaves and other things get in is actually benificial. It decomposes in there and makes “compost tea”, adding delicious nutirents for the plant to the watering mix.
My mother just has some metal trashcans by the front door positioned under where the gutter leaks. She leaves them open except in summer, but then she doesn’t really care if it dehydrates away too much. It never has, because after the water level does down about halfway the sun doesn’t penatrate any farther into the can. My mother wuld love to install a better system to collect drinking water.
Which is really what all the more complex systems are about. If you aren’t going to drink it yourself, then you don’t need complicated systems meant to insure the purity of the water.
Me, I just put my plants where the rain will fall directly on them. I barely watered my garden at all this year and got decent returns. When it rains I put the potted plants outside.