After moving to the Pacific Northwest, she grabbed the chance to install a new 55-gallon plastic cistern in the home she rented, finding rain harvesting no less appealing in the temperate-forest "drizzle capital" of Bellingham, Wash., than in the tropical forests of Thailand. "We get so much water naturally here in the winter, suffering through droughts in the summer, that it just makes sense to try to save from one season to help the other," Kroll says.
That first barrel multiplied to seven after she and her husband, Sergio Moreno, moved into their own house. Saving money on her city water bills was a bonus; plus, the first rain barrel she acquired for her landlord came free through a special water-conservation subsidy sponsored by the city of Bellingham, while the rest came cheaply, some through a rain-barrel-making workshop. Rather than leaving the blue and black plastic barrels unadorned: "Sergio painted several with mountains and river landscapes," she says, laughing about how he incorporated one spigot emptying whimsically into a river scene.
Even if you don't live in a rainy place—in fact, especially if you live in a sunny or arid place—using harvested rainwater can make a significant dent in your water consumption. Watering lawns, flowers and food gardens can often make up as much as 40 percent of homeowner water use in the summer time.
Like many municipalities, Bellingham encourages rainwater harvesting. "We just don't need to be watering our plants and landscapes with precious supplies of drinking water," says Anitra Accetturo, a water conservation expert at the City of Bellingham's Department of Public Works.
Among other environmental benefits, rain barrels also ease the growing problems of storm water runoff, which carries pollutants that slide off pavement, roofs and gutters, by rechanneling water into the soil.
Today, Kroll's gardens have grown, to 10 beds each of annuals, perennials and native plants as well as a variety of fruits and vegetables including tomatoes, tomatillos, several varieties of chili peppers, lettuce, chard, cabbage, broccoli and herbs. "Now," she says, "I'm a rain-barrel junkie."
The benefits of these age-old devices is well understood, but if homeowners don't properly install and maintain them, they can actually cause more harm than good.
Typically, rain barrels hold anywhere from 20 to 150 gallons of water in big plastic or metal drums. If they are not hooked up properly and tightly, with a mesh screen, they can quickly turn into breeding grounds for mosquitoes, attracting rodents and vermin and becoming hazards for pets and their people.
"Living in Thailand made me especially careful to avoid mosquitoes," Kroll says, "because dengue fever and malaria are realities there." For this reason, she is careful to make sure the top of the barrel is clamped shut and screened to keep insects out and positioned to avoid water overflow so water can't collect beneath.
While most rain-barrel users may not even give it a moment's thought, there's evidence from hydrological studies that rainwater destined for edible plants could be contaminated from with toxic roofing materials and other pollutants. "It's a huge question and people ask it all the time," responds Amy Ockerlander, a hot-line educator with Seattle Tilth, a nonprofit organic gardening organization. However, both Ockerlander, and Bellingham's Accetturo say that not enough research has been done to give people satisfactory answers to the question.
"It comes down to what people are comfortable with" Ockerlander says. "We don't know enough about what toxins come off a shingle roof, and there are a lot of variables, depending on one's location, if urban, suburban or rural. It might be more acid in a city or more polluted." Charlotte Kidd, a Philadelphia-based gardening expert, advises her clients to use rain-barrel water on ornamental plants and have their roof water tested before using it on food gardens.
Since learning about these concerns, Susan Kroll has taken pains to scrub off any moss which might help break down the asphalt or tar in the roofing tiles. She's also had her water tested, and, awaiting results with fingers crossed, is hoping her vegetables and fruits are safe to eat, along with her husband's tomatillo and chili salsas, and all of her preserved jams and pie fillings.