Abstract

The multi-purpose use of reservoir systems for irrigations and hydroelectric generation is desirable for the surrounding communities, but it may also be a stressing factor for water resources, especially in regions where climate change is significantly reducing actual and future rain levels. To recover the water level at Laja Lake, the largest natural reservoir in the country, a new water use policy was recently enacted as the "New Laja Irrigation Agreement", ensuring and limiting the reservoir water use assigning irrigation and generation rights yearly. In this work, we present a novel methodology to implement the new policy with, embedded in the Chilean ISO hydrothermal coordination tool PLP, based in the SDDP framework and Benders decomposition including both optimality and feasibility cuts. Our results show feasible and economical solutions for the simultaneous use of irrigation and generation rights, and that the new irrigation agreement positively favors the sustainable recovery of the reservoir water level in the near future.