India is home to 18 percent of the total world’s population, but it has access to only 4 percent of the world’s freshwater resources. Reports by the think-tank of the Indian government i.e. NITI Aayog states – India is facing the vilest water crisis in its history. This 2018 report predicts, 21 Indian cities, including major metros like Delhi, Chennai, Hyderabad, and Bangalore will run out of groundwater by 2020. This situation is extremely alarming, as 2020 is just a few months away.
The drought situation in few parts of the county, in times when good monsoon showers are expected mirrors clearly that waning climate change is all set to cause mayhem. By now, most of the parts of the country should have been experiencing good amounts of rainfall but the reality is far more disturbing. Severe drought threatens the country, and poor infrastructure is making it worse. But there are potential solutions one of which is ‘Catching the Rains’ with different types of rainwater harvesting systems.
Rainwater Harvesting – What Is It?
Rainwater harvesting is a technology used to collect, convey, and store rainwater from relatively clean surfaces like the roof, rock catchment, or land surface – essentially for later use. This collected rainwater is either directed to recharge groundwater or stored in a rainwater tank.
Rainwater harvesting isn’t some modern technology, it has been practiced for over 4,000 years throughout the world. Traditionally in arid and semi-arid areas, rainwater harvesting systems have provided water for domestic use, drinking, livestock, and small irrigation purposes. Today, rainwater harvesting is gathering a lot of significance as a modern, water-saving and simple technology.
Why Rainwater Harvesting?
In many regions across the globe, clean drinking water is not easily and readily available. For potable water, huge investment costs and expenditure is needed. Rainwater is one free water source and comparatively clean; with proper treatment, it can be used for several non-potable uses. Rainwater harvesting relieves the pressure on sewers and the environment by mitigating floods, soil erosions and replenishing groundwater levels; also it helps in saving the high-quality drinking water sources by reducing the consumption of potable water.
There are so many reasons why we should start collecting rainwater. From doing our part for the environment and saving money on water bills to having constant access to water – collecting rainwater can be beneficial in so many ways.
7 Different Types Of Rainwater Harvesting Systems
Below mentioned are the different types of rainwater harvesting systems:
1. Water Butt
One of the most basic types of rainwater harvesting systems; water Butt collects rainwater in a container from natural rainfall and/or drain pipes. The collected water is used mainly for watering the garden.
Another very common and professional type of rainwater harvesting.
- Submersible – Used particularly in domestic settings and is the easiest systems to install. The pump is placed within the underground tank and the harvested water is pumped directly to WCs or other appliances used daily for domestic purposes.
- Suction – In this system, the pump is located within the control unit of the house (e.g. utility room). This unit also deals with backup from the mains water supply, hence there is no need to direct mains water down to the underground tank.
Most rainwater harvesting systems need pumps to transfer the collected rainwater from storage tanks to the point of use. Submersible pumps are generally more efficient than suction pumps and do not suffer from the same limitations.
3. Indirect Pumped
This type of rainwater harvesting system doesn’t rely on gravity to supply water to the outlets. Instead, it pumps the harvested water to a tank which can be at any level in the building. Furthermore, a booster pump is used to provide a pressurized water supply. One of the most significant benefits of this system is that it offers great flexibility to tailor the booster pumps to adjust the flow and pressure requirements of a building.
4. Indirect Gravity
This system ensures water is supplied to the outlets by gravity alone. For this, the harvested water is first pumped to the header tank, i.e. high-level tank and then allowed to free-flow. In Indirect gravity systems, the pump works only to fill the header tank.
5. Gravity Only
In few conditions, a system which functions purely through gravity may be needed. Such systems do not demand pumps hence involves no energy use. With such an arrangement, water can be collected only when collection tanks are located below the level of gutters, yet higher than the outlets which it will supply. Here the only power of gravity is needed to feed collected and harvested water to various parts of the household. Gravity only is one of the most energy-efficient rainwater harvesting systems.
6. Retention Ponds
Retention ponds are used to collect surface runoff water and improve the quality of water by natural processes like sedimentation, decomposition, solar disinfection, and soil filtration. This type of pond normally has a mud bottom, but in some cases, it may be lined with concrete. The most common use of water collected and harvested by pond harvesting is watering livestock, however, it can also be used for groundwater recharge, irrigation or any other purpose other than potable uses.
7. In-Ground Storage
Underground storage tanks are very popular in areas where the majority of rainfall occurs in one single season. These underground tanks are insulated and have a very low rate of evaporation. In addition, the water stored in these doesn’t freeze if it is buried below the frost line, this is a huge advantage that surface storage tanks do not offer. Underground tanks need to be connected to an electric pump to ensure supply of the stored water to the outlets.
Rainwater Harvesting Is Crucial For The Future
It is the human’s unfriendly attitude towards nature which has poisoned our water-bodies and turned them unfit for any use. We are stretching our local water resources to provide for the exponential population growth and economic development. Turning to new water supply strategies and paradigms are indispensable to meet this demand.
Today most of the parts of the world are facing scarcity of water, taking up rainwater harvesting is necessary for survival. Natural resources come in abundance but they cannot be produced – attempts need to be made to collect and harvest it at an individual level.