The effect of reservoirs on water availability

The difficulty in satisfying water demands is a critical issue in our society. Storing water in reservoirs is a widely employed alternative to guarantee water supply. The objective of this study was to assess the effect of constructing streamflow regularization reservoirs on water availability throughout the hydrography in a case study for the Entre Ribeiros River Basin. The effects assessed the substitution of superimposed streamflows by streamflows distributed over time and the possibility of considering the stored water criterion for issuing water withdrawal permits instead of that used for natural conditions. Distributing streamflows over time increased the potential for using water resources by up to 60%; when the stored water criterion for issuing water withdrawal permits was considered, there was an increase of up to 1,610% in water availability.