M. Gordon "Reds" Wolman, a longtime Johns Hopkins University geography professor and internationally respected expert on river science, died at his home on Feb. 24. He was 85.

Wolman-known as "Reds" to everyone from his students to the highest-ranking Hopkins officials-was both a fixture at the university and in Chesapeake Bay circles. In the 1960s, he developed some of the earliest research on how construction projects were choking streams with sediment and runoff. That work led to major changes in the law and helped Maryland develop some of the strongest water protection laws in the nation.

In the 1990s, Wolman chaired the influential Oyster Roundtable, which was tasked with devising a plan to restore the Bay's signature shellfish after years of disease and overharvesting. Some of its ideas are still in practice today.

Most recently, Wolman chaired the Advisory Committee on the Management and Protection of the State's Water Resources at the Maryland Department of the Environment. He was one of the first to sound the alarm that, despite the vast Bay, the state's many rivers and the Baltimore area's reservoirs, Maryland could face a serious water shortage if it didn't keep development in check.

News of his death spread quickly through government and university circles.

"The State of Maryland has lost a great citizen, friend and conservationist," said Gov. Martin O'Malley, who was the third governor to endorse Wolman as chairman of the water resources committee.

Ronald J. Daniels, president of Johns Hopkins, told the student body that the university had lost "one of the most distinguished and beloved men ever to grace this university."

Wolman's colleagues were quick to send out e-mail tributes. In one, Peter R. Wilcock, associate chair of the department of Geography and Environmental Engineering, noted both Wolman's great personality and his career achievements.

"We have lost a giant, marking the end of an era. But even more, we have lost an extraordinary human being who inspired and delighted so many of us," he wrote.

Wolman got his nickname for his shock of red hair, which turned gray long ago. But he was also known for his dapper dressing-always a bow tie, often suspenders-and his infectious joy. Spry and droll, he never stopped advocating for a clean Bay, and he infused the same sort of enthusiasm in his students.

Until his death, Wolman still taught two classes a term at Hopkins, often wading into the streams around Baltimore to study sediment and runoff.

He came to his love of water naturally. His father, Abel Wolman, designed water and sewage systems for Baltimore and cities around the world. Abel Wolman's research helped to lead to the chlorination of drinking water.

The younger Wolman grew up in Baltimore and studied geography at Hopkins. He earned a master's and a Ph.D. at Harvard University, finishing in 1953. His first job was with the U.S. Geological Survey, where he became interested in fluvial geomorphology-how land forms, how rivers flow, and how to forecast changes in that movement. In 1958, he became chair of the Hopkins geography department. An early proponent of inter-disciplinary studies, he would later work to combine that department with the department of sanitary and water resources to create the department of geography and environmental engineering.

In 1964, Wolman wrote "Fluvial Processes in Geomorphology" with John Miller and Luna Leopold, son of the renowned conservationist Aldo Leopold.

It became a seminal book on understanding how rivers form and the way human activities change the landscape over time. It is still used in classrooms today. In 2006, Wolman won the prestigious Benjamin Franklin Medal in earth science for his work on the book. He was also a member of the National Academy of Sciences and the National Academy of Engineering.

"He wrote the book on sediment problems," said Robert Summers, deputy secretary of the Maryland Department of the Environment. "All of the stuff we're doing today that's in the news related to stormwater and erosion control, Reds was the pioneer of that."

Summers first met Wolman in 1975, when he was a Hopkins junior. Wolman, he said, persuaded him to make a career in environmental engineering and advised Summers on his Ph.D. The two have worked together consistently since then, and Summers has long admired his mentor's stamina. Four years ago, when the two went to Japan to speak at a water conference, Wolman led colleagues all over the country using his cane.

After the drought of 2002, when it became clear the department needed to further study Maryland's water resources, Summers immediately thought of Wolman as the chairperson. The committee's reports led to a state law requiring a water management plan before any building. The Wolman committee's work continues, despite tight budgetary times. The state is conducting several studies on water resources.

Wolman's legacy lives on in the committee's work as well as in the six generations of students he trained. And, of course, in the memories of those who knew him.

"When you saw that carrot top and bow tie headed your way, you couldn't help but smile," Daniels wrote in his tribute. "You couldn't help but know your day was about to take a turn for the better."