Think of downtown’s River Theater as a grand urban gesture. The complex geometry of steps, seating, and ramp overlooking the Chicago River pours down effortlessly from Upper Wacker and sings with energy, serving as a middle finger to the A Sunday on La Grande Jatte–type formality of other riverside parks.

Carol Ross Barney is the architect behind it and the rest of the 15-years-in-the-making Chicago Riverwalk, which has transformed the city’s main waterway into a dynamic public amenity. You need only observe the crowds lounging or walking or biking or sipping wine along the eight-block path, which runs from Lake Michigan to Lake Street, to understand the Riverwalk’s gravitational pull.

But look closer to spot the brilliance of Ross Barney’s design. For example, under each bridge along the walk, a large curved panel of polished steel serves as a buffer from the grated street overhead, maintaining the ambience. “The canopy reflects the adjacent water, immersing the space with light and the water’s movement,” explains Ross Barney.

She also made practicality a priority, pressing the city to eschew railings in certain parts so that kayakers and canoeists could put in easily along the river and adding docking cleats in the marina to allow boaters to tie up. “The big success of the Riverwalk is it has repurposed this really important urban asset and basically returned it to the people,” Ross Barney says. “It was a forgotten space.”

The Riverwalk is a sharp reminder of the power that architects can have as designers of democratic environments, not just trophy buildings. And for Ross Barney, it’s merely one of the latest, though certainly the most ambitious, efforts in her 40-year career of bringing sumptuous yet functional aesthetics to public projects such as CTA stations and federal buildings. This year, through the project Our Great Rivers, she has worked with city and community groups to develop ideas to make the Chicago, Calumet, and Des Plaines waterways more accessible, such as creating swimming holes and jogging paths. “If we are to inhabit this planet for much longer,” she says, “then we must make our cities more livable.”