Rain. Without it, nothing can survive.

The Shreeman family would know. Two years after they bought their home, the well went dry. They scrambled to find an alternative.

Looking to the clouds to provide, the couple started catching rainwater.

"We capture water from the roof, store it, clean it, purify it and use it," says Alan Shreeman.

That was 10 years ago. The Shreemans were the first residential customer of Salem's Rainwater Management Solutions. The company installed a basic rainwater collection system in the home.

FAST FACT: A 2,000 square foot roof can collect over 40,000 gallons of water per year. The Roanoke Valley typically sees around 41 inches of rain per year.

That was 10 years ago. Today, the family collects thousands of gallons of water a year from their home's roof.

HOW DOES IT WORK?

Each time it rains, water runs off the roof into an ordinary seamless gutter. Only instead of going into the ground, the water is diverted to a collection system.

Six, 400 gallon tanks are stored in an unfinished part of the basement. Next to the tanks, an elaborate array of pipes leading to various filters which turn the water into a potable source.

When needed, the water is pumped from the tanks, through the filters, and into the existing pipes inside the home.

SUPPLY VS DEMAND

To have water, you have to have rain. A typical year would bring the Roanoke Valley around 41 inches of rainfall. But what if there's an off year?

"It happened several years back," says Shreeman. "It didn't rain for nearly the entire summer."

The nearly full tanks emptied to the point their was only 30 gallons left.

Alan began thumbing through the phonebook to try to purchase water to ship to the home. Luckily, mother nature provided.

"God heard us, and it rained. We have never had a situation where we ran out," says Shreeman.

WHAT'S IN THE WATER?

"I drink the water. It's not an issue. It's not specially treated, we do have a filter system."

The filters take out any of the bacteria, dust, dirt and other microbes collected along the way. However, there are other things that are in rainwater.

Elements such as Hydrogen, Ammonium, Calcium, Magnesium and Carbonic Acid are often found in rainwater.

Rainwater pH is typically acidic with a pH in the range around 5.0 – 5.6. With thunderstorms the pH can drop as low as 2.0, according to water purification specialists at PurePro.com.

The quality of the rainwater is determined by the particles in the atmosphere. Some of those particles can travel in the clouds for hundreds of miles.

HOW IS IT REGULATED?

First off, unless you are stranded with nothing else to drink, you shouldn't drink unfiltered rainwater. Untreated, rainwater just doesn't live up to the standards that our bodies are used to.