Project: CBA of WVC’s Water, Sanitation, and Hygiene (WASH) Investments

In a world where access to safe water, sanitation, and hygiene services is still a challenge for millions, World Vision Canada’s WASH core program model stands on a mission of expanding access to these essential services. In doing so, WVC aims to improve the health and nutrition of children by reducing the incidence of diarrhea and other infections, increasing the productive time of women and girls, and reducing barriers to education for girls. Limestone Analytics was contracted to conduct an economic analysis of World Vision Canada’s investments in the WASH program model, specifically a cost-benefit analysis (CBA).

Limestone prepared a desk review of the WASH program model, as well as a complementary literature review focused on WASH-related interventions and their impacts. From this research, Limestone identified the main expected impacts of WASH interventions:

  • reductions in disease burdens (diarrhea, acute respiratory infections, stunting, wasting, and trachoma),
  • time savings from water collection, and
  • improvements in education outcomes from reductions in school absenteeism.

Limestone constructed a spreadsheet-based analytical model to estimate the costs and benefits of World Vision Canada’s investments in 111 implementations of WASH across 29 countries between 2019 and 2021.

One of the key innovations of Limestone’s analysis was the aggregation of health benefits across WASH interventions. Limestone estimated an effective range of benefits by applying both a conservative aggregation approach (when multiple WASH interventions are implemented for a population, the combined effect is equal to that of the single most effective intervention) and a moderate aggregation approach (when multiple WASH interventions are implemented for a population, the combined effect is equal to the sum of their individual effects).

Limestone delivered a final report to synthesize its analysis, highlighting the scope of the investments in WASH, the estimated gains in human health, and the cumulative and net social benefits of these investments. Limestone’s analysis estimated that WVC-funded investments in WASH reached an estimated 1.2 million participants and will avert approximately 58,000 disability-adjusted life years (DALYs) and 4,900 deaths. The net social gain on WVC’s WASH programming was estimated at more than $313 million (USD), yielding more than $14 in social benefits for every $1 invested.

Clients / Partners




Desk and Literature Review




Economic Analysis Model (CBA)


Final Report