Forecast: The Impact of USAID WASH Cuts
by Erin Braid
In 1945, George C. Dunham, a major general in the US Army Medical Corps, wrote, “Like the war against the Axis, the war against disease has required international cooperation on a larger scale than ever before. [...] In the Americas, the war on disease has taken new shape in a great inter-American cooperative health and sanitation program.” Dunham worked at the Institute of Inter-American Affairs, one of the predecessors of USAID, providing development aid in Central and South America. In his article, Dunham explained that improving international public health contributes directly to the “mobilization of hemisphere resources,” and thus to the strategic interests of the United States during and after World War II. Along with direct medical care, medical research, and mosquito control, the IAA prioritized improving water and sewage infrastructure to prevent disease.
Unsafe drinking water spreads deadly infections like cholera, typhoid fever, dysentery, and other diarrheal diseases. A lack of water and sanitation services also contributes to the spread of respiratory infections (like pneumonia or the flu) and neglected tropical diseases (like intestinal worms or trachoma). In addition to disease, there are huge economic and quality-of-life costs when safe water is not available on tap, and people — usually women and girls — have to travel to distant water sources and haul water back to their households. For all these reasons, US foreign aid has supported water and sanitation systems since before the creation of USAID.
In recent years, USAID’s water, sanitation, and hygiene (WASH) work has been funded through the Water for the Poor Act of 2005 and the Water for the World Act of 2014, bipartisan bills passed during the Bush and Obama administrations that direct USAID to enable access to clean water and sanitation throughout the world. In 2023, Congress directed $475 million to WASH development aid. This category includes constructing and maintaining infrastructure, improving governance of the water and sanitation sectors, providing technical assistance to local service providers, and increasing demand for water and sanitation services.1
USAID reports that in 2023, its WASH development aid projects brought drinking water services, like piped water or protected wells, to 3.2 million people who had never had them before. They provided sanitation services, like sewers or septic tanks, to 3.6 million people. These estimates come from USAID, and whenever an organization reports on the benefits of its own activities, there are incentives to overestimate. However, in this case I am not too worried, because this particular statistic is pretty strictly defined: It counts only the people who gained access to water and sanitation services for the first time as a result of a USAID partner working directly with the service provider.
I’ll be forecasting the impact of defunding USAID WASH programs for one year and for five years.2 For this, I’ll need to estimate how many people these programs would have reached in 2025 through 2029 in a “business as usual” scenario — that is, with no Trump-era budget cuts. The latest complete reports on USAID activities are from 2023, but in 2024, before the current round of cuts, there was already a 5% budget reduction for WASH programming. I assume that in the “business as usual” scenario, USAID WASH programming in 2025-2029 has the same annual budget as in 2024, and that the budget is spent as effectively as it was spent in 2023. This means that from 2025 through to 2029, USAID would have spent $451 million annually on WASH development aid, which would have given approximately 3.0 million people access to clean drinking water each year, and 3.4 million access to safe sanitation each year. With USAID programs halted, these people will instead use systems that expose them to higher risks of disease.
The most common kind of illness resulting from unsafe water and sanitation is diarrheal disease. For people living in the United States today, diarrhea is usually an inconvenience rather than a fatal threat, but this wasn’t always the case, and it still isn’t in poorer regions of the world. Without proper treatment, the severe dehydration caused by diarrhea can kill children and other vulnerable people. Frequent diarrhea also contributes to chronic malnutrition, which in turn makes people more vulnerable to diarrhea.
As of 2021, diarrheal diseases were the sixth leading cause of under-5 mortality globally, responsible for about 340,000 deaths of children younger than 5 years old — nearly 1,000 a day. Across all ages, diarrheal diseases were the 14th leading cause of death. For comparison, diarrheal diseases caused more deaths than road injuries, tuberculosis, or malaria; diarrheal diseases caused fewer deaths than lung cancer, diabetes, or hypertensive heart disease.
To estimate the increased risk of death from diarrheal disease for the people who would be reached by USAID’s WASH activities, I assume that the regional breakdown of USAID’s work would remain approximately the same as in 2023 (but reaching 5% less people in each region). USAID itself doesn’t provide estimates of death rates by region and cause, so I adjusted the regional groupings of 2023 beneficiaries to match the regional groupings used by the Global Burden of Disease study, which does. These rates vary widely, even among the regions where USAID works — for example, in Latin America approximately four out of every 100,000 people die due to diarrheal diseases each year, while in sub-Saharan Africa the death rate is nine times higher, at 38 out of every 100,000.
These death rates are averages across huge regions and don’t specifically reflect the risks faced by the people that USAID programs would have reached in the absence of budget cuts. On one hand, USAID would probably prioritize the communities that need water and sanitation infrastructure the most. On the other hand, communities with higher death rates tend to be harder to reach with new infrastructure, because, for example, they live in conflict zones, because they don’t have institutions that could manage and maintain infrastructure if it was put in place, or because they are very remote. For this reason, and for simplicity, I assume that USAID’s work would reach people who are at a typical level of risk in their region. With this assumption, I estimate that among 3.0 million people who could be reached with clean drinking water and 3.4 million who could be reached with safe sanitation, 1,640 people will die of diarrheal diseases in 2025 without those services. This is an estimate of the pool of diarrheal deaths that one year’s worth of WASH projects could potentially prevent: If the projects were 100% effective at preventing diarrhea, they would save 1,640 lives from this cause alone.
In reality, of course, no project is 100% effective. For an estimate of the actual effectiveness of WASH projects, I use a recent meta-analysis of the effect of improved water and sanitation on diarrhea in children. This study estimates the impact of moving between various levels of water and sanitation quality. The authors found that moving from an unimproved water source (like a river or an unprotected well) to a basic improved source (like a protected well) prevents 19% of diarrhea cases. Based on this, I start by assuming that USAID beneficiaries who get access to basic water services for the first time will see 19% less deaths from diarrheal disease.
Some USAID projects deliver not just basic but “safely managed” water services. “Safely managed” drinking water means that water from an improved source is available at each person’s home, water is available at least at least 12 hours a day and four days a week, and the water is free from fecal bacteria like E. coli. The meta-analysis estimates that moving from a basic improved communal source to an improved source that’s available at home and has higher water quality prevents 41% of diarrhea cases, so I’ll assume that moving to safely managed water services would prevent 41% of diarrheal deaths.
Combining these estimates and similar estimates for sanitation services, I calculate that about 410 of the 1,640 expected diarrheal deaths in one year would be prevented by USAID projects continuing as usual.
For this estimate, we’re assuming that preventing some proportion of cases of diarrhea also prevents that proportion of deaths from diarrhea. But this assumption is not necessarily accurate — WASH interventions might be good at preventing mild cases of diarrhea without having much effect on the more severe cases, or, indeed, the reverse might be true. Also, I haven’t accounted for WASH projects preventing deaths from causes other than diarrhea, like respiratory infections. To address both of these issues, I’ve used a finding from a recent working paper from Michael Kremer and his colleagues at the University of Chicago’s Development Innovation Lab. The study is a meta-analysis of the effect of water quality interventions — but unlike earlier studies, the authors looked at the effect on all-cause child mortality. Most studies of WASH programs don’t try to estimate their effect on child mortality because they’re not powerful enough to identify real changes; child death is, fortunately, rare. By combining data from many different studies, Kremer and his colleagues were able to generate a more reliable estimate. They found that estimating lives saved by WASH programs based on diarrhea cases substantially undercounts total lives saved: The true impact on all-cause mortality is six times higher.
This study measured mortality only for children under 5. The same methodology likely also undercounts the deaths of older children and adults, but perhaps not by as large a factor. Balancing these concerns, I’ve applied this factor of six to the share of the 410 lives saved that represent children under 15, which I estimate is about half (the proportion of diarrhea deaths in low-income countries that occur in children under 15). I therefore estimate that about 1,560 deaths would be prevented in one year if USAID projects continued as usual.
With this baseline number established, I want to account for the fact that infrastructure projects can continue to save lives for multiple years. Specifically, I’ve decided to credit each project with four years’ worth of lives saved based on my guesses about how long projects continue to function before needing additional investment and when water and sanitation infrastructure would have been improved without USAID. I also want to create a forecast for the scenario in which USAID is defunded for five years. When estimating how many lives will be saved or lost several years into the future, I want to incorporate the general trends in water and sanitation. The number of deaths due to unsafe water and sanitation in low-income countries has decreased every year since 1994; I don’t expect this general trend to halt or reverse without USAID’s WASH programs. In recent years, there have been about 4% less deaths from unsafe water and sanitation each year, so I apply this trend to my estimates.
In total, I expect that about 5,850 people will die due to a one-year pause in USAID WASH programs, and about 26,930 people will die due to a five-year pause.
Finally, I want to emphasize that the diarrheal diseases causing many of these deaths are not only preventable with clean water and good sanitation but also very treatable with a mixture of salt, sugar, and clean water known as oral rehydration solution.3 ORS for childhood diarrhea is one of USAID’s priority practices for preventing child deaths, and in 2023 about 6,750,000 cases of childhood diarrhea were treated with ORS in USAID programs. Sadly, we cannot expect that these children will receive ORS in some other way if the USAID programs are halted: In 2023, only about half of all children who needed ORS received it, suggesting a lack of other organizations and systems that are willing and able to fill the gap. Based on published estimates of the risk of death posed by each case of diarrhea, and the effectiveness of ORS, I estimate that during a year-long pause of USAID’s child health work, about 2,510 children will die (and during a five-year pause, about 11,120 children will die) due to a lack of this simple treatment, in addition to the people whose deaths could have been prevented by improved water and sanitation infrastructure.
Some other kinds of water-related work, like providing water in humanitarian emergencies, are funded and managed separately. For this forecast, I’ll focus on development aid.
We still don’t know what the full extent of these cuts will be. The current best estimate is that 86% of funding for WASH programs has been eliminated so far, but it’s not clear if USAID still has the staff and resources to administer the remaining programs. For simplicity, this forecast is based on the scenario in which all funding is functionally eliminated.
See also “Salt, Sugar, Water, Zinc” by Matt Reynolds.