How rainwater can save rupees

A new study, using NASA data, has suggested that rainwater can save people in India a bucket of money.

The University of Utah study found that collecting rainwater for vegetable irrigation could reduce water bills, increase caloric intake and even provide a second source of income for people in India.

India has severe problems getting potable water for all of its residents, said Dan Stout, one of three authors of the study, adding that researchers considered collecting water in a relatively small tank and it was amazing to see the effect of doing something that small and simple can have on the Indians.

The team examined the possibilities if Indians collected precipitation in cheap 200-gallon tanks that they could easily engineer to fit in densely populated urban areas, such as many of India's growing cities.

The team used data sets provided every three hours from 1997 to 2011 to determine how much precipitation, on average, was available for collection and supplementation in each of the six test cities: Bangalore, Delhi, Hyderabad, Kolkata, Mumbai and Srinagar. The team input TRMM data into algorithms that Stout developed to determine the benefit to each of two scenarios: indoor use and outdoor vegetable irrigation.

The team found that rainwater harvesting provided for nearly 20 percent of the average indoor demand overall, though some seasons, such as southern monsoon season, provided more. It also provided a sufficient water source for vegetable irrigation, which demands less water than indoor use.

While rainwater collection for irrigation resulted in fewer water bill savings, it did provide vitamin-rich food, profit from selling excess vegetables and a significantly shorter payback period for infrastructure, operation and maintenance required for the endeavor. This can help boost cost savings and increase quality of life in India.

The study is published in Urban Water Journal.