In countries and areas where water is scarce, rainwater harvesting systems have become as common as ordinary plumbing. These systems collect rainwater in bins, basins or large containers so that the water can be used during hot days or when there is a shortage in the supply of water.
There are several types of rainwater harvesting systems, the most popular of which are discussed below.
Ground catchment Rainwater Harvesting systems
Ground catchment systems. These systems collect rainwater in a prepared cement or treated catchment area on the ground. These systems can even collect runoff or flood water from streams, rivers or other bodies of water. The area should be sloped, which allows water to flow down into a filtering mechanism (usually made of stone and sand), and into a tank for storage.
Roof catchment Rainwater Harvesting systems
Roof catchment systems. Using gravity flow pressure and a network of pipes, roof catchment systems let rain fall from the roof, into gutters and into filters such as leaf screens, diverters and roof washers to remove debris and particles. The cleansed water then goes into a cistern or into a standpipe. It is then treated or released for use by pumps or through a gravity-driven mechanism.
Subsurface Dike rainwater harvesting system
Subsurface Dike. This rainwater harvesting system is affordable to build and easy to maintain. It is constructed in an aquifer (a collection of saturated rocks where water can pass through), so that it raises and conserves groundwater levels and consequently increases the water stored in the aforementioned aquifers or in catchment areas. Ideally, a subsurface dike should be built in a sloping valley, with loose soil or permeable rocks on top and impervious rocks below.
Why Use Rainwater Harvesting Systems?
Besides giving dry areas or cities the water needed to sustain a population, rainwater harvesting systems also have other advantages, including those listed below.
- A proper rainwater harvesting system can reduce costs because it effectively reduces water usage.
- Collecting rainwater in a huge catchment system prevents erosion and minimizes the downstream impact of bodies of water, which in turn, can help prevent floods.
- These systems help reduce water consumption from cities’ main sources, thereby also reducing the use of pumps, electricity and energy. Another result of this is lower carbon emissions and pollution levels.
- Using rainwater also reduces the demand and the pollution on rivers and groundwater. Studies show that 86% of a regular household’s water needs can be supplied solely by rainwater, even without purification or treatment.
- Rainwater has been proven to be great for washing clothes since it is soft water and doesn’t leave residue or lime scale. It is also better for plants since it is all natural and does not contain chemicals.