If the summer of 2013 is true to form, many of us will be turning on the hose spigot over the next few weeks. When you consider that what appears at the end of the hose is drinkable - overkill for landscape purposes - and that it will make a second appearance on your household bills at a later date, it's a good moment to ponder the value of rainwater collection. It was built into the design of many ancient homes, as archaeological digs have shown around the world.

Now, it makes so much sense that even water companies offer discounted rain barrels.

"We're lucky to have abundant water resources in the area," said Peter Fazekas, a spokesman for Aquarion, a large regional provider that serves both Groton and Stonington. "But that doesn't mean we don't have to save. We often get severe droughts during the same season when water demand almost doubles."

Aquarion sold rain barrels to its customers this spring.

Fazekas points out that delivery of drinkable tap water involves many stages of purification, filtering, chlorination, fluoridation, storage, and finally, delivery through an extensive system of tanks, pumps and pipes.

"It's a very resource-intensive process," he said.

Wood, metal, tile, slate, or asphalt shingles add little to the water that is of concern to the home gardener, even vegetable gardeners. Unless your roof has tar or asbestos shingles or the gutter system has lead pipes, now's the time to consider rainwater collection.

How much can a rain barrel really supply? Let's say you have a 10 x 10 garden, or 100 square feet. During the growing season, assume it will require the oft-quoted inch of water per week. For one inch of water to infiltrate 100 square feet of garden requires about 62 gallons. (See links at bottom for more about calculations.) A full 60-gallon barrel would just about meet the need of that 10 x 10 garden for one week.

One inch of continuous rainfall on a 1,000-square-foot roof produces about 600 gallons of water. If you're prepared, you can collect a lot of rain in a short period of time. The best barrels are equipped to be connected in a series.

Collecting the water is sometimes a bit tricky. Most users either shorten the downspout to the top of the barrel or use a downspout diverter. These may be purchased when new gutters are installed or from barrel providers (see below).

If you outfit your own barrel, be sure to use a food-grade container. Avoid PVC plastics (recycling # 3) and polystyrene (# 6). For a variety of reasons, avoid black plastic. Food-grade white plastic buckets are fine for short-term water collection, but don't expect the water to stay algae-free for long.

The lid is arguably the most important safety feature, because children, pets and backyard wildlife can fall in. For this reason, some rain barrels have sealed tops with only a screened, louvered 3- to 6-inch intake. Some have a solid screw-on lid, yet others have lids made entirely of high-strength screen.

Furthermore, no one wants to create a mosquito nursery and the lid is the first line of defense. A few drops of dish soap or olive oil will keep the water surface unfriendly to mosquitoes, as will mosquito dunks containing Bt. None of these will harm vegetables.

To distribute the water, most barrels come equipped with an outlet near the bottom and a short hose. You can certainly add hose length, but the farther your garden from the barrel, the higher you'll want to station it.

According to Sharon England of Sky Juice New England, the company that supplied Aquarion's rain barrels, at 24 inches above ground a barrel can create enough pressure to operate a low-flow hose.

"A full rain barrel can weigh around 400 pounds," she said. Concrete blocks or other stone platforms are good ways to elevate and stabilize the barrel.

What's the payback? Aquarion's Peter Fazekas said that tap water costs most of us a bit less than 1 cent per gallon. Simple math shows that a 75-gallon rain barrel holds about 70 cents worth of water. If you fill and drain a $75 barrel a few more than 100 times, the barrel will have paid for itself. I purchased my first rain barrel more than a decade ago, so it's probably been providing free water for the past eight years.

But as England said, "Saving rain water isn't totally about your water bill."

For more information visit Sky Juice New England at www.skyjuice.us and Sharon England at (207) 363-1505. Or New England Rain Barrel Company at www.riwaterlady.com and Beverly O'Keefe at (401) 539-0667.

KATHY CONNOLLY IS A LANDSCAPE DESIGNER, GARDEN WRITER AND FREQUENT SPEAKER. LEARN MORE ABOUT RAIN BARRELS IN THE "ARTICLES" SECTION OF HER WEBSITE AT WWW.SPEAKINGOFLANDSCAPES.COM OR EMAIL KATHY@SPEAKINGOFLANDSCAPES.COM