Rainwater management in high rainfall rainfed areas

Abstract

The basic objective of water harvesting in high rainfall areas is to allow maximum possible rainwater to be stored in soil profile in-situ, and the excess runoff to be collected, stored and used in the same area or other areas. So, rainwater management in high rainfall areas involves creating a saturated soil profile, and storing water in ponds, ditches, streams and river beds. This helps in mitigating the water needs during dry spells in kharif season. Harvesting potential can be enhanced by integrating the check dams with ponds, and multi stage harvest with ponds. In high rainfall areas, the water storage structures are usually refilled in the same season with the subsequent rainfall, stream flow, spring water, or seepage water. The stored water in the soil profile and also in storage structures
should be used judiciously by early sowing and promoting early growth, using crops with low water demand and deep rooting system, zero tillage or reduced tillage, residue recycling, and mulching. Rainwater productivity of the harvested water can be further enhanced by multiple use of water, and integration of water harvesting with seepage and evaporation management practices. Enhanced rainwater productivity due to water harvesting has associated benefits of groundwater recharge and biodiversity promotion.