What Is Rain Water Harvesting?
So what is rainwater harvesting? It is a technique or strategy for the collection of rainwater and storing it in the right way for future use. The water can be collected from various surfaces and platforms and stored for later use. In most cases, the water is usually collected from rooftops and other hard surfaces. Rainwater harvesting is considered as a very reliable way to conserve water.
There are three main types of rainwater harvesting system: direct pumped, indirect pumped, and indirect gravity. In certain situations it may be possible to have a purely gravity system; though such occasions are rare.
The most basic form of harvesting is the humble garden water butt. Water collects in the container from drain pipes and/or natural rainfall, and is mainly used for the watering of garden plants. Users with gardens of a decent size will see a reduction in the amount of mains water used. Pairing the water tank with a rainwater filter can further improve the quality of the harvested rainwater.
This is the most common type of more professional rainwater harvesting system, particularly for domestic properties, and is generally the easiest to install. The pump is located within the underground tank and harvested water is simply pumped directly to the WCs or other appliances. If the tank should be in danger of running dry, a small amount of mains water is fed to it in order to maintain supply. For commercial projects, such systems tend to be dual pump arrangements .
This system differs in that the pump is not inside the tank, but instead is located within a control unit within the house (e.g. utility room). The unit also deals with the backup from mains water supply, so there is no need to send mains water down to the tank.
This type of system differs in that the harvested water is first pumped to a high level tank (header tank), then allowed to supply the outlets by gravity alone. With this arrangement, the pump only has to work when the header tank needs filling. Also the mains water is fed directly to the header tank, not into the main harvesting tank.
Techniques of Rainwater Harvesting
The collection of rainwater can be done in various methods depending on a few factors. A few common methods include the following:
1. Rain barrels
It is the easiest and affordable method of rainwater harvesting, especially at home. It is where barrels or water tanks installed below the downspouts of the rooftops guttering system. The water is then funnelled/directed into the tanks. The tank can be connected to provide backup water to your current plumbing system, or it can be attached to a pipe for drip irrigation. The use of barrels or tanks is ideal since it can store significant amounts of water.
2. Dry System
It is similar to the barrel’s system, but with the dry system, a larger storage container is used. The container is usually a few meters away from the property. The gutter is redesigned so that water is diverted to the large storage tank. It is a quick and cheap method to implement but has significant rewards.