Landscape - Capturing Rainwater

With water conservation a continuing concern, one potential way to reduce water usage from municipal sources or wells is collecting rain water for later use. The following is an article on the subject.

Capturing rainwater during the wetter times of the year and storing it could be an ideal source for a supplemental supply. This is often referred to as rainwater harvesting and has been used for thousands of years to provide people with water for drinking, cooking, sanitation, agriculture, and many other uses. Its use all but disappeared in developing nations during the twentieth century because of centralized water supplies, deeper wells, and other technologies. However, with consistent droughts in many parts of the U.S., people are looking to the skies once again for its free water.

A rainwater harvesting system can work in two ways depending on someone’s needs and location. The first method is ground catchment systems. This involves collecting water in open air areas, such as a pond, or storing the water underground in the aquifer. It is done by slowing down the runoff of water and directing it to the desired location. This method is good to store large amounts of water for uses such as irrigation, livestock watering, fire protection, or even recreation.

The second method of rainwater harvesting is to collect rooftop runoff into tanks or cisterns for later use. This is the more practical form of collection if the intended use is domestic supply. The main components include a catchment area (usually an established roof), a conveyance system (gutters and downspouts), and storage (tank). Because most people already have the roof and gutters in place, installing a rainwater harvesting system may be as simple as putting in a storage tank.

Tanks can be homemade, ranging in variety from reused barrels to large steel-reinforced cement cisterns. They can also be installed by professionals who specialize in rainwater harvesting. Either way, it is essential that every tank includes certain components to be low-maintenance and long-lasting. These include a filter, inlet, vent, overflow, access opening, and tap or inside pump.

With this in mind, it is important to mention just how much water can be collected from the rain. With one inch of rain, a roof with 1000 square feet can collect up to 620 gallons of water. With the average rainfall in Delaware around 45 inches per year, this amounts to nearly 28,000 gallons! Certainly, this amount could supplement well or municipal water for watering important landscape plants in dry conditions.

Adapted from the August 2008 Agricultural Newsletter, Prince Edward County, Virginia, Virginia Tech Extension.