Water availability management in the Sucio river basin, Nicaragua

Abstract

With the problems of water in terms of: scarcity, irrational use, pollution, among others; governments and organizations are seeking ways to reduce this situation, requiring policies and laws for better management of water resources, however, a policy or law will not be enough if there is no willingness to act in situ in each river basin . Water resources need efficient management, based on the knowledge of their availability based on the analysis of supply and demand. In the present article, water availability was evaluated in the Sucio river basin unit, located in basin 64, in the Pacific zone of Nicaragua, as a starting point for water resources planning in the basin. The estimation of the water supply was done by applying the surface water balance, applying the Thornthwaite (1948) and soil water balance methodology, based on the methodology of Schosinsky and Losilla (2000); the water demand was determined by identifying the different uses in the basin. In the supply and demand analysis, it was determined that the basin generates flows of 165 Mm³ per year of surface water and 131 Mm³ of groundwater recharge, the demand was estimated at 153 Mm³ per year; estimating that of the water uses in the basin there is a return flow of 22 Mm³ annually and a discharge of groundwater to other basins of 19 Mm³ annually, it was determined that the net water availability is 151 Mm³ annually, however, it is considered that availability is not constant during a hydrological year, since it is affected in the dry season with a deficit of 4 to 9 Mm³ per year in surface water and 8 to 9 Mm³ in groundwater. It should be noted that, in consultation with the records of water use concessions granted by the National Water Authority in the basin, water withdrawals occur in dry season (November to April); In this period, the supply is lower than the demand, sustains the production of water, is the contribution of the aquifer to the rivers and underground reserves, which puts at risk the sustainability of water resources, which will be depleted over time and the result could be catastrophic