Nature based solutions: an example from San Salvador city

Abstract

San Salvador, capital of El Salvador, is an intermediate city located in a mountain area. It has a limited drainage system in unplanned settlements on slopes and streams, which results in floods and landslides, due to intense rains in short periods, which are increasingly frequent. One of the areas with the highest incidence of urban floods in this city is the Arenal Monserrat micro-watershed; For this reason, it was selected for the implementation of pilot interventions of Nature-based Solutions (NbS), under the City Adapt project, executed by the United Nations Environment Program. The implementation began with the elaboration of a mapping of actors, the development of a vulnerability assessment of the micro-watershed, consultations with focus groups to know the perception of risk, valuation of the ecosystems present and their link with the livelihoods used by the population, the selection of the NbS measures to be implemented at the basin, landscape and local community levels and the identification with the ecosystem services that it enhances; until its start-up and monitoring and follow-up.

The main results presented are: i) an intervened surface of 451 hectares, between different ecosystems such as coffee plantations, riparian forest and urban area used for planting fruit trees; b) an infiltrated volume of surface water of 284,984 m³ in one year, coming from the water collected in the infiltration ditches and in the absorption wells, built in the upper part of the micro-watershed; iii) a total number of trees planted of 54,529, among coffee, fruit trees and native species.

With these results, the next step is the incorporation of NbS measures in urban planning processes in the medium and long term.