If you've done this already, hurray for you!
Rain barrels, little do many people seem to know, are ridiculously easy and inexpensive to make.
Considering the vast market for rain barrels of varying types and fancy "designer" ones out there, rain barrels are nearly an accessory for the garden now and sadly, taking all the fun and learning away from people who have the actual moola to purchase them.
Never fear, I will provide the resources (uh, web-links and some info, not actual physical ones, sorry) to put the work and learning back into garden water retention!
The easy part is a definite for making your rain barrel as long as you have the tools.
The inexpensive part is a little more difficult, because step one, is to find a barrel big enough and suitable for water collection. You can be easy on yourself and go out and purchase a large plastic trashcan, though there are some schools of thought that insist you look around for an actual distributor of sorts, like a soda/pop or pickling company that uses food grade plastic barrels, if you worry about plastic chemicals leaching into the water you will be using to water your plants.
Personally, I was able to track down a local soda company with a couple weeks of effort and phone tag and once I managed to get to the site where the barrels were held, the kind personnel there informed me that I could take as many barrels as my mini-van could hold.
"REALLY?!?!" I sort of eeped, and went to work taking advantage of this opportunity.
Soon, I found a way to fit SIX, 55 gallon barrels into my mini-van and away I went, not very safely able to see out my rear view mirror.
Please learn this lesson though: Never, ever, EVER leave your barrels in your car for longer than the time you've parked the car when you get home.
The stuff that they had in the barrels, soda syrup concentrate, or pickles... is concentrated, and VERY smelly.... I was so nauseous for weeks afterwards when I drove because the car reeked of sugar-sweet cola smell and there was no real good way of getting it out even though I drove with the windows down. The scent just PERMEATES into the car's pores or something.
As a matter of fact, if you can let the barrels air out outside for a good while, like weeks in a shady, windy spot, GOOD IDEA.
Though I won't give directions here (links will be provided below), essentially the concept of the rain barrel is simple: cut a hole at the top for rain to fall/be directed in, cut a hole for a spout at the bottom. (Elevate as needed)
Ta da! You has a rain barrel!
The problem then becomes, every time it rains, you get excited... and then you think, "My ONE rain barrel ought to have an attachment..." and so you do it.
And then the next ferocious downpour occurs and you think this same thought again or that your other gutter/downspout is rain barrel-less and soon you want rain barrels everywhere to the consternation of your spouse (unless he/she is into conservation as much as you are).
The only other problem after that is how to hide your ugly pickle-barrel. (My plant is to try tall grasses or vines next year)
Anyways, it's easy, saves you water, provides your plants with non-chlorinated stuff that they like (unless you live in a severely polluted location with serious acid rain) and your can feel good about having learned how to do something new.
N.B. Though this might have been a better project to complete prior to the spring rains, it's nice to get some rain barrels going during these wet autumn ones and prior to having to drain them when winter hits so you can avoid a barrel bust. Think of it as a great winter project in preparation for spring.
LINKS to rain barrel instructions:
http://www.gardengatemagazine.com/extras/52droughttolerant_build.php
http://www.lid-stormwater.net/raincist_construct.htm
http://www.dnr.state.md.us/ed/rainbarrel.html
http://www.wikihow.com/Build-a-Rainwater-Collection-System
