Sustainable Drainage in Challenging Environments

Abstract

AbstractThe provision of Water, Sanitation and Health (WASH) is recognised by the UN as a human right. However, drainage is not. The lack of drainage leads to flooding and can impact on quality of life and human health. This is particularly true in the most vulnerable of populations who live in informal settlements, favelas and refugee camps. This paper shows the potential of sustainable drainage systems or SuDS to address issues of excess surface water and lack of greywater management in these challenging of environments. SuDS mimic nature by encouraging infiltration, storage and slow conveyance of water to attenuate the storm peak, reduce flooding, improve water quality and provide opportunities for amenity and biodiversity. A layer of complexity is added when considering disease vectors such as mosquitoes which may be prevalent in these environments. By encouraging water underground and reducing puddling of water between dwellings and on the street, their breeding sites are reduced, providing a means of reducing their impacts on health due to zika, dengue or chikungunya. Due to the lack of governance, land tenure and any form of planning, residents of informal settlements and favelas need to be actively engaged in improving the quality of their surroundings. Refugee camps, on the other hand, are formally set up by the UNHCR with WASH installed, thus there is potential to influence policy, to encourage installation of drainage at the same time as WASH so that WASH becomes WASH'D, possibly a first step in recognising drainage as a human right.