Ecosystem services from rainwater harvesting in India

Abstract

Availability of a safe and reliable water supply is an issue in developing nations, including India. Rainwater harvesting (RWH) is a site-specific source control used to satisfy human, agricultural, and safety demands for water. This study analyzed the effects of capturing rainwater for a 12.5 year period (Jan 1999–Jun 2011) to provide three ecosystem services: water supplementation for indoor use, water supplementation for food production and groundwater recharge (GWR). A hydrologic analysis was completed using satellite rainfall data and a water balance approach. Two demand scenarios, indoor and outdoor, were considered, with water in excess of demand and storage directed to recharge groundwater. An economic analysis quantified RWH system net present value. The results indicated significant ecosystem services benefits were possible from RWH in India. RWH for the purpose of providing irrigation to a small garden and allowing overflow to a drywell for GWR was concluded to be an approach to maximize benefits. This scenario provided the greatest net present value (21,764–38,851 INR), fastest payback period (0.30–0.98 years), and recharge to groundwater of more than 40% of onsite rainfall. The benefit of the outdoor vegetable irrigation was determined and the results showed that the caloric demands of the typical Indian household (2.75 kg of tomatoes and 1.05 kg of lettuce) could be met with a 20 m² garden, and excess food could be sold to offset the capital cost of the system and later for economic gain.

Keywords::

• rainwater harvesting
• ecosystem services
• India

Acknowledgement

This research was partially supported by the NASA Precipitation Measurement Mission (PMM) Program.

Disclosure statement

No potential conflict of interest was reported by the authors.