The Knowledge Base for Achieving the Sustainable Development Goal Targets on Water Supply, Sanitation and Hygiene

Abstract

Safe drinking water, sanitation, and hygiene (WASH) are fundamental to an improved standard of living. Globally, 91% of households used improved drinking water sources in 2015, while for improved sanitation it is 68%. Wealth disparities are stark, with rural populations, slum dwellers and marginalized groups lagging significantly behind. Service coverage is significantly lower when considering the new water and sanitation targets under the sustainable development goals (SDGs) which aspire to a higher standard of 'safely managed' water and sanitation. Lack of access to WASH can have an economic impact as much as 7% of Gross Domestic Product, not including the social and environmental consequences. Research points to significant health and socio-economic consequences of poor nutritional status, child growth and school performance caused by inadequate WASH. Groundwater over-extraction and pollution of surface water bodies have serious impacts on water resource availability and biodiversity, while climate change exacerbates the health risks of water insecurity. A significant literature documents the beneficial impacts of WASH interventions, and a growing number of impact evaluation studies assess how interventions are optimally financed, implemented and sustained. Many innovations in behavior change and service delivery offer potential for scaling up services to meet the SDGs.

Keywords: cost-benefit; cost-effectiveness; economic analysis; environment; health; hygiene; nutrition; sanitation; water; water security.

Figure 1

Drinking-water coverage trends by developing regions and the world, using the JMP improved water definition, 1990–2015. Reproduced with permission from World Health Organization and UNICEF [11].

Figure 2

Sanitation coverage trends by developing regions and the world, using the JMP improved sanitation definition, 1990–2015. Reproduced with permission from World Health Organization and UNICEF [11].

Figure 3

Example from Mozambique on how average access values mask massive disparities in household coverage. Reproduced with permission from World Health Organization and UNICEF [18].

Figure 4

Economic costs of poor water and sanitation in selected countries, as a percent of gross domestic product, disaggregated by health and non-health damages. Source: Compiled by authors (see Table S1 for fuller data sets and references).

Figure 5

Costs of basic and safely managed services as percentage of gross regional product (GRP) by MDG region, with uncertainty range. Reproduced with permission from the World Bank [126]. Note: WASH = water, sanitation, and hygiene; SDG = Sustainable Development Goal; SSA = Sub-Saharan Africa; LAC = Latin America and the Caribbean; CCA = Caucasus and Central Asia. Gross regional product is based on the aggregated GDP of countries in each region. An economic growth rate of 5 percent is assumed all regions. Lower and upper bounds were based on three significant sources of uncertainty: (1) 100 percent of population using low-cost technology to 100 percent using high cost technology (baseline 50% each); (2) discount rate varied from 3 percent to 8 percent (baseline 5%); and (3) alternative method of transferring cost data to countries with limited unit cost data, using absolute U.S. dollar values instead of adjusting taking into account differences in purchasing power.

Figure 6

Cost per disability-adjusted life-year (DALY) averted from treatment at source and four household (HH) water supply and water quality interventions in two WHO sub-regions. Africa Epidemiological Stratum D and South and SE Asia Epidemiological Stratum D (US$, 2005). Source: [89].