TR(BR)-11/96-97 : Assessment of irrigation return flow

Abstract

Irrigation return flow is one of the most significant components in the water balance of irrigation command areas. A part of the water applied to irrigated fields percolates deep to recharge the ground water which is known as irrigation return flow. In absence of any studies, it is usually taken as 35% of the water applied for irrigation in case of canal irrigation and 30% in case of irrigation from ground water. But this is only an approximate estimate. The irrigation return flow will depend upon soil moisture characteristics, meteorological parameters, crop types, method of irrigation, and depth to water table.

This report presents the various methodologies for correct assessment of irrigation return flow.