Assessment of the dual functioning of surface drainage and water-table management in Bojili irrigation district

The Bojili Irrigation District faces serious water shortage problems and has thus developed strategies to store excess of surface water and also utilize the ground water. A drainage typology was built at different scales to show that a combined (dual) drainage/irrigation system was designed to remove water at the field level by surface drainage and to store water in the tertiary and upper level ditches. An experiment carried out to determine if this system is sustainable as compared to classical subsurface drainage systems that showed that the existing surface drainage system is well-adapted to BID conditions. However, inequity exists among upstream and downstream users. A simple prospective water balance model has been developed and calibrated to reproduce groundwater fluctuations as a part of the general modeling approach developed for water management in BID.