Rain provides water shortage solution

By for CAES News
By Stephanie Schupska
University of Georgia

Water bans may still be in place for many Georgia residents, but they can keep their gardens growing and lawns watered. All it takes is a roof, a gutter, a tank, a little rain and some ingenuity.

“In rainwater, we can have a really good solution to our irrigation problem,” said Frank Henning, a watershed agent with University of Georgia Cooperative Extension. “When we start to look at how much water can be harvested from an average size rooftop, the quantities are there, even in a drought year like 2007.”

He’s not talking about catching it in a rain barrel, although any water saved is better than sending it all into roads and streams as runoff. Henning is encouraging Georgians to take a lesson from some of their Western neighbors and install a rainwater holding tank.

For Billy Kniffen of Menard, Texas, it takes more than a rain barrel to collect enough water to keep his entire household going. His drinking water doesn’t come from a municipal supply or a well. It comes from rain harvesting.

“Rain is my only source of water,” he said, which he purifies before he drinks it. “If I run out, I run out of water. Every raindrop is very valuable.”

Kniffen is an extension agent for Texas A&M University. He and his wife rely on less than 5 inches of rain per year for their indoor water needs. For comparison, Atlanta got 25.48 inches of rain in 2007, an extremely dry year, according to UGA’s Georgia Automated Environmental Monitoring Network (

In Georgia, 9.5 million people depend on a clean water supply. Half of the state’s population lives in 12 urban counties, with the rest spread out among 147 other counties.

“How can we work to still have the vegetative growth we enjoy?” Henning said. “Rain catchment is one of the better solutions.”

Rain catchment, or harvesting, can be anything from a grouping of 50 gallon barrels connected by tubing to Kniffen’s five 3,000-gallon tanks. Kniffen’s tanks are connected to his roof, where every inch of rainfall produces just over a half gallon of water per square foot of roof. In his case, the 5,900 square feet of roof on his home and barn captures about 2,900 gallons of water per inch of rain.

His system cost $6,500 in 2003, not including gutters or labor. In comparison, a 50-gallon rain barrel costs $100 and up.

Henning isn’t advocating disconnecting from the water main. He does encourage Georgians to use rainwater. After catching it, he says to zone landscapes according to plant water needs, determine which plants really need water and then “work that into your rain harvest scheme.”

“Even in a drought year, we can collect enough water to irrigate ornamental plants in most landscapes,” Henning said.

On San Juan Island in Washington state, Tim Pope can’t connect to a water main, because there isn’t one. Pope has been building rainfall catchment systems in the Pacific Northwest for about 15 years. He can guarantee his clients fresh water, something wells can’t always provide. The island is “rocks next to salt water covered in clay,” he said. And sometimes that salt water breeches a well’s fresh water source.

Pope’s goal is to make rain harvesting systems as easy as possible for homeowners. But he also reminds them “the water we get out of the sky, although it’s probably the best water we can get, still isn’t perfect.”

To that end, most rain harvesting systems have a screen somewhere on the downspout to filter out large debris. Pope then follows the screen with a ceramic carbon block for sediment filtration and an ultraviolet light to kill bacteria and disinfect the water.

Once a rain harvesting system is in place, upkeep is the homeowner’s responsibility.

“Three things in life are certain,” Kniffen said. “Death, taxes and another drought is on its way. Conservation is the No. 1 thing we need to do. Rainwater harvesting is just one piece, but it’s a very important piece.”

(Stephanie Schupska is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)

Stephanie Schupska is a news editor with the University of Georgia Public Affairs Office.