“MUSIC FOR THE EYES”: The building designed by Farewell Architects for the Stony Brook-Millstone Watershed Association has brought in more visitors and expanded programs while promoting sustainability.

When administrators and trustees of the Stony Brook Millstone Watershed Association started thinking about the need for a new facility back in 2007, space was the primary motivation. But by the time the Watershed Center for Environmental Advocacy, Science, and Education opened eight years later, the project had become as much about sustainability and being “green” as it was about making more room for the classes, exhibits, and laboratories that are at the heart of this 67-year-old sanctuary in Hopewell Township.

Designed by Farewell Architects, the building has made a dramatic difference in how the 930-acre expanse educates the public about becoming better environmental stewards. “There has been a quantitative and qualitative impact on our world here,” said Jim Waltman, the organization’s executive director. “A lot more people are coming, and we’re interacting with them. We have more space, and more beautiful space. But more importantly, the building has allowed us to expand and broaden the content of our programs.”

It was during the creation of a campus master plan that the focus was broadened to prioritize environmentally friendly practices as well as creating more space. “The idea was to be as ‘green’ as we could, and really set an example,” Mr. Waltman said. “We did a lot of thinking about what kinds of programs we wanted to host in the future. There was a nice coming together of thinking about the building and the programs, with the idea that we’d design and construct a really green building and have educational programs about what we did. It all kind of evolved.”

Construction finally began in 2013 and the opening was May 2, 2015. The project took longer than usual to move from the idea stage to construction because of the economic downturn. “We had raised a couple million dollars after we started in 2008,” said Mr. Waltman. “And then, the economy tanked. But actually, it gave us a little more time to think and make refinements.”

The Watershed Association was founded in 1949 by a group of community leaders who were concerned about agricultural runoff, soil erosion, and stream sedimentation. The focus has evolved since then to the idea of protecting clean water and the environment through conservation, advocacy, science, and education. As more programs have been added over the years, space has become an issue.

“We had an old nature center that was much beloved — maybe loved to death,” said Mr. Waltman. “But we didn’t have formal classrooms. There was a room that could hold about 30 people, and there were no restrooms associated with that classroom.”

The new space includes two large classrooms that can expand into one, a new laboratory with new tools, and sophisticated technologies. Designed to reduce energy usage, the building includes such features as cool sensors that detect how bright a room is and send a signal to automatic dimmers, highly efficient lighting and hot water systems, and an increased reliance on natural daylight.

“We’ve been able to have a greater emphasis on STEM [Science, Technology, Engineering and Mathematics],” Mr. Waltman added. “Last year, we had all of the kids in the sixth grade at John Witherspoon Middle School for two days. Part of what we taught them about was the technologies that allow us to lighten the impact on our environment.” The Watershed also hosts the Watershed STEM Academy, geared to teens entering 10th to 12th grade who are interested in science careers. “We have a small computer learning center with workstations,” Mr. Waltman said. “They’ll be learning how to use GIF to do mapping of environmental features, and how to use computer-based architectural drawing. We couldn’t touch something like that before.”

Improved programs have also included an adult education series that has been successful, bringing in college level professors and weekend field trips. “We’ve sold out every one,” Mr. Waltman said. A list of community groups that have made use of the Watershed Center during the past year includes various departments from Princeton University, the Princeton Area Community Foundation, the Princeton Food Salon, the Arts Council of Princeton, the Princeton Garden Club, Morven Museum and Garden, and HomeFront, among others.

Since water is the main focus of the organization, it makes sense that the building was designed to be a model of how to conserve water and reduce the polluted runoff from the site. Two rain gardens, a green roof, and a water “capture” at the roof line were all part of an effort to improve the site’s water quality and provide an example to others of how it can be done.

“The essence of this building is that it give focus to human occupation and the natural world,” architect Michael Farewell wrote in an email. “It tries to make evident the interconnectedness of people and environment, a sort of ecological lens. Its signature feature is the overflow scupper at the entry, a rain harvesting cascade that splashes on diabase boulders and irrigates a rain garden — the cycle of water, geology, landscape, and people placed in the foreground. And great music for the eyes!”

The project took a long time, but it was worth the wait. “We gave Michael this crazy challenge to design a spectacular green building, one that would tempt people in but also make them want to go back outside,” Mr. Waltman said. “It is a beautiful, spectacular building that does things I think are rare — the phenomenal sightlines, the wonderful use of natural light. We couldn’t be happier.”