Collecting of rainwater during the rainy season is important in providing water for agricultural use, domestic and household uses and also for commercial and industrial uses. There are various ways of harvesting rainwater with rooftop water harvesting being the most common way. Enhancement of self-sufficiency as well as provision for water in the future when the common source of water is unavailable is done by harvesting rainwater. Rainwater harvesting helps reduce the cost of purchasing water for various uses as well as promoting environmental conservation. Harvesting of rainwater from a rooftop is made possible by use of gutters which collects the water as discharges it in a collection point.
Collecting rainwater is mostly done into rainwater tanks which can be made of different materials. Plastic, concrete, fiberglass, aluminium metal, and stainless steel which should be resistant to rust and other chemical reaction are some of the main materials used in the making of rainwater tanks. Factors affecting the choice of a rainwater tank includes affordabilitily as well as the durability. Concrete rainwater tanks are usually more durable than the other tanks although rainwater tanks more preferred are those made of plastic materials. The rainwater tanks can be placed on the ground surface to collect the rainwater, or they can be placed underground. It is a little hard to fit underground rainwater tanks with taps or valve, so water has to be pumped from the tanks so as to use it.
Rainwater tanks should be covered at all times leaving just a small hole where the pipe discharging water can pass through so as to avoid unwanted materials from dropping into the water. Plastic rainwater tanks are used in many places since they come in different sizes, and volume and also one can find them almost everywhere. Algae growth is common when plastic tanks are placed on the ground hence should be placed on a surface that keeps away algae such as concrete. Solar radiation exposure reduces the lifetime of plastic tanks hence should be placed in places where there is little or no direct sunlight. Other materials using in making rainwater tanks have their shortcoming mostly in releasing contaminants to the harvested water hence safety precaution measures should be put in place to minimize contamination.
Rainwater collected from rooftops for human consumption should always be sterilized through various means. This is because there are so many contaminants that settle on the rooftop and ones it rains they usually find themselves into the water. Some techniques for removing contaminants from the rainwater to make it safe for drinking is by chlorination as well as filtration. Chlorination is usually preferred since it is not a costly method and it is also effective in sterilization. When harvesting rainwater from rooftops, it is important to ensure that the water is not collected immediately during the first rain to prevent a lot of contaminants from getting into the water with had settled on the rooftop.