Drought in a country can kill crops, contribute to numerous natural disasters, and cause wildfires to spread at a catastrophic pace that can devastate communities. In India, agriculture is heavily dependent on the southwest summer monsoon season for irrigation. A deficit of this monsoon can cause severe water shortages and below-average crop yields. According to the Drought Early Warning System (DEWS), more than 44% of India is now under varying degrees of drought. As per a report by NitiAayog, 21 cities in India will run out of groundwater, the main source of drinking water, by 2020. This fact is troubling as low rainfall during other seasons will not be able to make up for the delay and reduction of the southwest monsoons.
With the threat of acute water shortage looming, the conservation and management of water has become a nationwide concern. This means that there is now an urgent need for improved measures to manage water resources and that is where rainwater harvesting can play a crucial role. Urban environments like sidewalks and roads lose water every time it rains with only 15% of rainwater reentering the ground. On the other hand, in rural areas, 50% of rainwater reenters the ground. Here, rainwater harvesting can help people collect rain for later use like watering plants, washing cars, flushing toilets, etc.
People can collect rainwater using large barrels or cisterns with the addition of a gutter to the roof of their house. Once collected, the rainwater can be used as either potable or non-potable water depending on the process you put the water through. Potable water requires better purification processes, whereas non-potable water requires only basic filtration processes. You can also use rainwater harvesting methods to replenish groundwater systems by decreasing the demand for water from wells for irrigation and drinking, which in turn, enables groundwater levels to be sustained.
With the rapid growth of population and agriculture, rainwater harvesting can be used as a sustainable resource to meet various growing demands. Research shows that for every 1000 square feet of roof space, approximately 620 gallons of water can be saved every time it rains. This can fulfill at least 70% of the water demand for a household of three people during a drought year. This water can also be used for irrigation and can fulfill the water requirement of crops in a drought-like situation. The rainwater once collected, can be redirected into landscapes from downspouts, via channels and mulch basins, to slow, spread, and sink into the ground. Basins and depressions in the soil that are filled or partially filled with mulch, create a focal point for water to percolate into the soil, creating a biologically rich sponge that is a perfect medium for nurturing drought-stricken areas.
Run-on storm water can be captured in the soil, in the yard or parkways, and hydrate the soil. Surprisingly, solar panels can also be utilized for harvesting most of the rainwater that falls on them. All these uses make rainwater harvesting an extremely viable resource to combat droughts. Not only this, but it can also help mitigate the flooding of low-lying areas by reducing the demand on wells. In drought-prone areas, rainwater harvested in past months can be used in a cheap and reliable way. If the rain is scarce and unpredictable, a rainwater harvesting system can be critical to capturing the rain when it does fall.
India has the potential to drought-proof the entire country using rainwater harvesting. Previously, community-based small-scale rainwater harvesting was more prevalent in the worst drought-hit areas. Today, the potential of rainwater harvesting has been noticed by various state governments with Tamil Nadu, becoming the first state to make rainwater harvesting compulsory for every building to avoid groundwater depletion. Karnataka, Rajasthan, and Maharasthra soon followed with their rainwater harvesting policies. If these policies are properly implemented, we will be able to completely eradicate rural poverty, generate massive rural employment, and reduce distress migration from rural areas to urban areas due to droughts in the country.