Pumping water long distances consumes power, using fossil fuels and contributing to environmental problems. People who wish to reduce their carbon footprint, or simply want to cut water bills, can utilize rainwater for their gardens and washing cars.
Reduces Water Shortages
In dry areas, the strain on municipal water supply can become intense, even in developed countries. Home-collected rainwater reduces the risk of water shortages. Using rainwater for non-essential activities such as watering the lawn means less strain on the supply of safe drinking water. You can also purify rainwater for drinking and washing in emergency situations.
As populations grow, they use more water, to the point that groundwater may be utilized faster than it is replenished. Extended rainwater harvesting schemes (with the water diverted into storage tanks or reservoirs) are necessary to ensure a sustainable groundwater level.
If rain falls on an impermeable surface, such as concrete, or falls faster than the ground can absorb it, flooding will result. Effective catching and storing of rainwater reduces the risk of flooding. In areas where long dry periods are interspersed with very heavy rainfall, such as the monsoons in Asia, rainwater harvesting significantly reduces both the impact of short-term floods, and water shortages experienced during the rest of the year.
Reduces Soil Erosion
Heavy rainfall causes erosion because some of the soil is carried along with the movement of water. Soil erosion depletes agricultural land of topsoil and nutrients, contributes to sediment build up in rivers and, in extreme cases, can render land unsuitable for agriculture. Soil erosion has a serious impact on agricultural communities worldwide. Harvesting rain stops a great deal of soil erosion before it can start.