John Briscoe, a leading authority on water resources who championed dams as an essential anti-poverty tool, helping reverse a prevailing view at the World Bank that such projects were mostly environmental and social menaces to the developing world, died Nov. 12 at his home in Poolesville, Md. He was 66.

The cause was colon cancer, said his wife, Conceicao Andrade.

Since 2009, Dr. Briscoe had been professor of the practice of environmental engineering and environmental health at Harvard and director of the university’s Water Security Initiative.

In a four-decade career spanning as many continents, he had been a water engineer in Mozambique, an epidemiologist focusing on cholera research in Bangladesh, and World Bank country director for Brazil.

He was associated with the World Bank from 1986 to 2008, many of those years as senior water adviser shaping a $40 billion portfolio of water resource, irrigation, hydropower and sanitation projects.

In September, King Carl XVI Gustaf of Sweden presented Dr. Briscoe with the $150,000 Stockholm Water Prize, the most prestigious award in global water management. The honor cited “his fusion of science, policy and practice, giving him unrivalled insights into how water should be managed to improve the lives of people worldwide.”

Dr. Briscoe spent his early childhood in a South African mining town “at the edge of the desert,” an experience that shaped his work on alleviating water scarcity. After studying environmental engineering at Harvard in the early 1970s, he spent several formative years working in Bangladesh and Mozambique.

He said residents appreciated new schools and lending practices brought from the outside, but their livelihoods improved dramatically only with the coming of roads and bridges and the building of embankments to stanch flooding. Many interviews with villagers only confirmed this view, he said.

By the time Dr. Briscoe arrived at the World Bank, lending for infrastructure projects was under attack and “social-sector lending” on health and education had become a priority. Many dam projects were scuttled as the bank became a target for environmental nongovernmental organizations and protesters with general grievances against what they saw as a corporate model of development.

The complaints, Dr. Briscoe said, often came from places where the lights and water flowed with regularity because of hydrodams.

“Time and time again I have seen NGOs and politicians in rich countries advocate that the poor follow a path that they, the rich, never have followed, nor are willing to follow,” he once wrote.

In his book “The World’s Banker,” about the World Bank, journalist Sebastian Mallaby wrote that Dr. Briscoe continued to fight what he regarded as “excessive safeguards” and an “inflexible set of standards” that activists put on dam and other infrastructure projects.

It took years for Dr. Briscoe to find a receptive audience among bank leaders, slowly finding converts among people in the Indian, Chinese and Brazilian governments who held significant sway because of their combined populations. He also knew the World Bank had to take into account the concerns of activists.

After 2000, when the World Commission on Dams raised safeguards on hydrodams to the point at which it would be hard for them to go forward, Dr. Briscoe steered the bank away from what he regarded as excessive hostility to hydropower.

One of the bank’s first returns to major hydroelectric dam-building was the Nam Theun 2 dam in Laos, which began operating in 2010.

“Largely thanks to him, the Bank emerged from an extended period of politically correct refusal to build infrastructure,” Mallaby, now a Council of Foreign Relations fellow, wrote in an e-mail.

“Before,” he continued, “western NGOs had vilified dams so successfully that the Bank and the broader development community had cut back its support for water projects, despite good evidence that hydropower and protection from flooding could sometimes matter more for poverty reduction than schools or health clinics.”

John Briscoe was born on July 30, 1948, in Brakpan, South Africa, and grew up in Johannesburg. His father worked for the stock exchange, and his mother ran an orphanage and day-care center in Soweto at the height of apartheid.

“As a child I was inculcated with a sense of tremendous inequality and a quest for the rights of people to develop,” he told the Harvard Crimson this year.

He was a 1969 civil engineering graduate of the University of Cape Town. He studied environmental engineering at Harvard, receiving a master’s degree in 1972 and a doctorate in 1976.

Besides his wife of 35 years, survivors include a daughter from the marriage, Alexa Briscoe, both of Poolesville; three stepchildren, Bela Gary of Potomac, Md.; Marla Benton of Chapel Hill, N.C., and Charles Briscoe of Gaithersburg, Md.; and four grandchildren.

For Dr. Briscoe, the continuing challenge was finding a practical way to address poverty reduction through dams, which by their nature were bound to arouse protest.

He told the New York Times, “You’re never ever going to do one of these in which every single person is going to say, ‘This is good for me.’ ”