Sustainable Drainage in Challenging Environments

Abstract

The 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.

Hybrid infrastructures, hybrid governance: New evidence from Nairobi (Kenya) on green-blue-grey infrastructure in informal settlements

“…The public health implications of poor storm and wastewater management require that upgrading drainage systems is fundamental to any serious effort to improve wellbeing in informal settlements (Armitage, 2011;Charlesworth et al, 2017). However, the high density of structures, lack of open space, ambiguous legal status, complex social and political dynamics, and limited available resources present major challenges to the development of sustainable drainage systems (Pegram et al, 1999) whether they are green, blue, or grey.…”

“…However, the high density of structures, lack of open space, ambiguous legal status, complex social and political dynamics, and limited available resources present major challenges to the development of sustainable drainage systems (Pegram et al, 1999) whether they are green, blue, or grey. Charlesworth et al (2017) make an explicit connection between stormwater and wastewater drainage in "challenged environments" (informal settlements and refugee camps) and argue for considering drainage alongside the traditional Water, Sanitation, and Hygiene (WASH) programs to create "WASH'D". Many papers and practitioners point towards the potential of SUDS in the specific context of informal settlements (see for e.g.…”

“…Many papers and practitioners point towards the potential of SUDS in the specific context of informal settlements (see for e.g. Parkinson, 2002;Reed, 2004, Charlesworth, 2010Armitage, 2011;Mguni et al, 2016;Charlesworth et al, 2017;Reed, 2017). Parikh et al (2012) demonstrate the value of naturesensitive solutions following natural drainage paths to provide water management for slums in India.…”

“…Parikh et al (2012) demonstrate the value of naturesensitive solutions following natural drainage paths to provide water management for slums in India. The residents of informal settlements are encouraged to be proactive and install measures themselves in the absence of government action (Charlesworth et al, 2017), though the financial and technical means for them to do this are not always clear (Mulligan and Bukachi, 2017). Jiusto and Kenney (2016) argue that drainage strategies designed explicitly for informal settlements need to take various upgrading contexts, including community-led, ad-hoc, and systematic upgrading, into particular consideration.…”

“…In urban informal areas, managing storm and wastewater drainage is especially important because of high flood exposure and public health impacts, but inadequate governance in these areas presents a significant barrier (Reed, 2004;Armitage, 2011;Mguni et al, 2015;Douglas, 2016;Du Toit et al, 2018). While many have attempted to implement GI in informal contexts, few have successfully navigated the inherent constraints of space, contested land tenure, and the need for local maintenance (Haase et al, 2014;Mguni et al, 2015;Charlesworth et al, 2017). Mguni et al (2015 and make the case for starting with "niche experiments" at the "local community scale" by non-governmental actors to demonstrate how GI can work in the informal context.…”