For decades, abandoned concrete silos cresting the horizon like post-apocalyptic chess pieces presented an eerie curiosity for drivers crawling along one of the busiest arteries in and out of Washington, D.C.
The McMillan Sand Filtration Site was once an engineering marvel that supplied clean drinking water to District residents—including the president and first lady—for close to a century. Now, an inventive adaptive reuse project led in part by University of Maryland architecture faculty and alums highlights McMillan’s history in D.C.’s largest new park since 1903, creating a vibrant destination for surrounding communities.
The master plan and recreation center at Reservoir District received the 2025 Regional & Urban Design Award from the American Institute of Architects (AIA) in June for its sustainable, inclusive and resilient design. The project was conceived and developed over eight years by UMD Professor Matthew Bell, FAIA, FCNU, Senior Urban Designer Christian Calleri M.Arch ’01 and a design team from Perkins Eastman, in collaboration with Nelson Byrd Woltz Landscape Architects. The baton was then passed to Tom Jester M.Arch ’99 of Quinn Evans in 2018, whose team served as the architect of record.
“This was an opportunity to bring something special to this part of D.C.,” said Bell, who served as the project’s principal in charge. “It’s a unique site and a wonderful opportunity to reactivate a site for the community in a way that also celebrates a forgotten part of its history.”
Opened in 1902, the McMillan project helped to conquer waterborne illnesses plaguing D.C. through a nontoxic, slow sand filtration system. Water drawn from the Potomac River flowed through aqueducts to the McMillan Reservoir, where it was pumped into catacomb-like cells below grade; sand stored in cylindrical silos was distributed through dozens of manholes nestled on the grassy field above. Landscaping, a public promenade and an adjoining park were later designed by Frederick Law Olmsted Jr. to serve the many residents who flocked to McMillan, and to strategically keep them off the field.
The 25-acre site between North Capitol Street and First Street NE was sold by the federal government to the city in 1987. It remained unused until city officials tapped a development team, including Perkins Eastman as architects and planners, to design a vision for its future in 2007. Extensive research and community outreach, said Bell, revealed the need to balance development, public open space and preservation.
“The people who wanted this project most were the longtime residents,” he said. “They sought the same great new public spaces and amenities popping up all over D.C. Our challenge was to address those needs while also demonstrating that we understood the characteristics of the historic landmark, an important key to creating compatibility.”
Working with city agencies, community members, preservationists and engineers, Bell and his team developed a master plan and design for the new Reservoir District Recreation Center that restored the site’s history, and advanced connectivity, opportunity and health for the surrounding neighborhoods.
Quinn Evans, which was named Architecture Firm of the Year by AIA in 2024, ensured the site’s original architecture was preserved and stabilized for its new public use, and that new interventions —from materials selection to building and landscape details —were done with the master plan in mind.
“It’s a labor of love, really, to be involved in something so unique that created this community asset,” said Jester. “It’s why we get up in the morning to go to work. And it was a privilege to get to complete this project and make sure that everyone who worked on it was proud of it.”
Beginning with the park’s main entrance off North Capitol Street, the site’s history is intentionally front and center. The new design carves into the landscape to create a tiered, sunlit plaza that gently blends into exposed underground filtration cells. Above grade, a magnificent green lawn extends to the west, flanked by the preserved Olmsted Walk and relocated historic fountain. The shining jewel is the light-filled recreation center, nestled on the edge of the plaza, which offers an indoor pool and indoor/outdoor community spaces. A row of restored silos and former regulator houses remains on the south side of the site, preserving the iconic view for drivers and pedestrians along North Capitol Street.
Phase One, which included the recreation center and green space, opened last summer. The second phase, which will bring a grocery store, retail, housing and medical offices to the remaining 17 acres, will be constructed over the next 10 years.
Depending on the time of day or year, said Jester, visitors encounter different experiences, from quiet, early morning walks to the cacophony of midday squeals at the splash park in August. While architecture is often associated with buildings, it’s as much about the people, he said.
“It’s so nice to see it come to life,” he said. “I can name five projects that I’ve worked on over the past 25 years that really stuck out, and this is one of them. You never forget them because of the impact that they have.”