Implementation of sustainable urban drainage systems as an alternative for regulation and control of floods in Metropolitan Region of Santiago (Chile)

Abstract

Climate change has led to an increase in the frequency of extreme storms and the uncertainties associated with flood risk in urban areas, posing greater challenges for flood prevention. As temperatures rise there is greater evaporation of water, which consequently causes flooding and extreme rainfall, leading to more destructive storms. The Metropolitan Region of Santiago has registered the amount of 201 mm of annual precipitation until September 2023, with August having a precipitation of 89,8 mm/month, the highest in the last thirteen years, surpassed only in the same month with 111,4 mm/monthly, year 2015.

Sustainable Urban Drainage Systems (SUDS) are surface, permeable, preferably vegetated elements, members of the urban-hydrological-landscape structure and prior to the rainwater sewer system, intended to filter, retain, transport, accumulate, reuse and infiltrate rainwater into the ground, so that they do not degrade the quality of the water they manage. This would generate greater permeable spaces, reducing urban stormwater runoff. In the Metropolitan Region of Santiago, there are some pilot SUDS, however, their implementation has been difficult due to little experience; it has been carried out in different environments: roofs and gardens of homes, parking lots, squares and urban parks. Regarding the progress and implementation of the SUDS, it has been possible to establish the connection between different organizational levels of the country, developing norms and laws, which guide the financing and correct management with the intention of promoting them in the urban context.