Recent efforts by the United States to support global health, food security and environmental stewardship are to be commended. But looking ahead at the next four years, we can do more to support a cause that undergirds international development and ensure the effectiveness of U.S. assistance abroad.

That cause is clean water, sanitation and hygiene (WASH). It is a basic crucial ingredient for effective development work across all sectors. We can provide medicine to people, but without clean water, they are at risk of contracting bacterial infections or diarrhea that prevents their bodies from absorbing it. We may spend millions providing food aid to children in the Horn of Africa, but if their bodies are ravaged by water-borne diseases, the food will not provide enough nutrients to nurse them back to health. Without adequate sanitation facilities in schools that allow girls to deal with their menstrual needs, the money we spend on basic education may not help them stay enrolled.

I can think of no better way to improve U.S. investments in international development than to prioritize water and sanitation programming and identify it as key to the success of many other development sectors. More must be done to support the integration of this work across all sectors, and President Barack Obama has the opportunity to lead on it.

Former U.S. Sen. Paul Simon (D-IL) brought this issue to the forefront in the late 1990s in his book ”Tapped Out,” and the Senator Paul Simon Water for the Poor Act became law in 2005. Unfortunately, although mandated by this law, it has taken more than six years for the U.S. Agency for International Development to put together a comprehensive water strategy for its global development programs.

However, Senators Dick Durbin (D-IL) and Bob Corker (R-TN) and Representatives Ted Poe (R-TX) and Earl Blumenauer (D-OR) have led the effort to pass “Water for the World” legislation in the last two Congresses. This legislation seeks to improve coordination and oversight of WASH programs within the U.S. government, increase the sustainability of WASH projects, enhance WASH expertise within USAID and integrate WASH programming throughout other development sectors. The proposal’s emphasis on integrating WASH programming across other development sectors will require USAID, other donors and nonprofits to prioritize this type of program-wide integration.

The U.S. administration should prioritize the completion of USAID’s water strategy and support “Water for the World” legislation. It should also continually increase its partnerships with multilateral, religious and nonprofit organizations already working hard to increase access to clean water and sanitation. Focusing on WASH within these valuable partnerships will increase accountability for improved sustainability and the level of integration among other development sectors. It will also help foreign aid go farther: The World Health Organization reports that for every $1 spent on water and sanitation, an estimated $4.30 is returned in increased productivity and decreased health care costs.

On a recent trip to Zambia, I was reminded again just how important the integration of WASH into all development sectors is and the life-altering impacts clean water, sanitation and hygiene can have on people. One family shared how a spigot of clean water in their front yard – piped via a solar-powered, mechanized bore hole next to the community school – allows them to grow food for themselves and bring in around $600 in income annually. This family has suffered less from water-borne diseases and diarrhea after learning proper hygiene practices. Their fourth-grade daughter isn’t late to school each day because now she doesn’t have to collect bath water before school. Clearly, the integration of water, sanitation and hygiene into other development sectors multiplies the benefits across all sectors and, ultimately, improves people’s lives.

But this is just one family’s story. About 783 million people in developing countries don’t have access to clean water and 2.5 billion lack access to a latrine. Prioritizing WASH in the next four years will help ensure that millions more have a better chance at accessing clean water and proper sanitation – that millions more have the opportunity to thrive.

By Erin Jeffery, Advocacy and International Development Coordinator at InterAction. This article was originally published January 16 by Devex. It is part of InterAction's series of guest opinions by NGO leaders on ways to make U.S. foreign assistance more effective.