Applied geology to the design of handcrafted dikes (tapes) and its impact in the recharge of the manglaralto coastal aquifer, Santa Elena, Ecuador

Abstract

North of the Santa Elena province, the Manglaralto parish is located. Its population is primarily supplied by the groundwater extraction by wells, located on the alluvial terrace of the Manglaralto River. The lack of rainfall, the increase of inhabitants and tourism in the last decade, has caused a decrease in levels of the aquifer, leading to seek alternatives for recharging. Rescuing ancestral knowledge is emerging as an option for innovation with “tapes” (artisanal dikes) that allow taking advantage of the seasonal passage of surface water through the Manglaralto River, and at the same time creating conditions for the artificial recharge of the aquifer. The aim of this study was to optimize the location of “tapes” by analyzing geological, geotechnical and hydrological information to obtain the greatest surface accumulation of water and improvement in artificial recharge in the context of aquifer sustainability. The methodology used in the study was: i) Information analysis of the Manglaralto basin and aquifer, ii) Field and laboratory work in relation to the topography and geology of the area and interpretation of the information obtained in field and laboratory, and, iii) Proposal for the location of the axis of a “tape” for optimum water recharge and storage. The results show that the lower part of the sub-basin of the Manglaralto River has greater thicknesses of the aquifer unit so that there will be greater accumulation of water, so 5 favorable places for artisanal tapes have been proposed, from these an optimal place was chosen with a height of 3 meters the dike would lead a volume of 4.641,88 m3.