Modeling efficient water allocation in a conjunctive use regime: The Indus Basin of Pakistan

Efficient resource use where ground‐ and surface waters are used conjunctively may require special policies to rationalize the interaction between water use by farmers and the response of the stream aquifer system. In this paper, we examine alternative policies for achieving more efficient conjunctive use in the Indus Basin of Pakistan. Using a simulation model which links the hydrology of a conjunctive stream aquifer system to an economic model of agricultural production for each of 53 regions of the basin together with a network model of the flows in river reaches, link canals, and irrigation canals, we have studied the joint effect of various canal water allocation and associated private tube well tax or subsidy policies on overall system efficiency. The results suggest that large gains in agricultural production and employment are possible, given more efficient policies.