Proposal of an alluvial dike as a nature-based solution for sustainable water management in coastal areas

Abstract

Climate change affects several environments, and one of the main problems is the availability and pollution of water resources. As a sustainable strategy, nature-based solutions and rescue of ancestral knowledge are economical and environmentally friendly measures. This study aimed to analyse the design of an alluvial dike by integrating ancestral and engineering knowledge to obtain a surface water reservoir that improves the recharge of the coastal aquifer in the Manglaralto community. This study considers a geological-geotechnical analysis of the study area and presents an environmental analysis of civil work to determine its impact on the surrounding ecosystem systems. The alluvial material dike, green structure, 8 m high, allows the reservoir of approximately 0.06 hm3 of water, which allows the recharge of the coastal aquifer with a field capacity (volumetric content) of 0.1 and conserves its ecosystem. From an environmental perspective, reforestation of the riverbank would reduce annual evapotranspiration, and from an economic perspective, the budget would be reduced considerably (60 % owing to ancestral knowledge and community work). The proposed construction of this second dike relates to the context of Sowing and Harvesting Water (SHW) and nature-based solutions, with community participation leading the processes, with technical accompaniment, to contribute to SDG 2030. This study provides the criterion that the integrality of the green structure offers more significant benefits for the ecosystem and its inhabitants.