Groundwater Budget of the ZaratÍ River Sub-Catchment

A groundwater balance is calculated considering inputs, outputs, and changes in storage, which occur in a specific volume of the aquifer in a given period of time. Therefore, as a general objective, it is proposed to study the behavior of groundwater in the middle and lower part of the sub-basin of the Zarati river to know its potential use as a possible source of water supply for the area of Penonome. Measurements of flows in the Zarati river and piezometric levels in monitoring wells were made. Information was obtained from the National Institute of Aqueducts and Sewers (IDAAN for its Spanish acronym) on the extraction flow of the active wells and the production flow of the Penonome potable water treatment plant. The results indicate that, the piezometric level in the monitoring wells decrease during the dry season, affecting the water supply. Also, that the groundwater flow descends from the middle part until reaching the lower sub-catchment, where most look towards the flow areas of the Zarati river. A volume of river-aquifer interaction of ΔV= -1.73 x m3 was obtained and it was determined that the aquifer feeds the river. It is recommended to design and implement a monitoring program in active wells that are within the Zarati river sub-catchment, which allows planning and managing efficiently in the long term, the quantity and quality of water for supply of the population.