The setting sun illuminated the St. Paul skyline, with city hall on the left, as seen from Harriet Island Park in 2018. (ANTHONY SOUFFLÉ • anthony.souffle@startribune.com/The Minnesota Star Tribune)

The landscape and urban design firm that transformed an elevated railroad into New York's popular High Line park will draft plans for a proposed 1.5-mile promenade on the river bluffs of downtown St. Paul.

The city and the Great River Passage Conservancy, a nonprofit that is fundraising and advocating for a trio of capital projects along the Mississippi River in St. Paul, on Thursday announced that they selected New York-based James Corner Field Operations to design the ambitious river balcony project that local leaders have for years envisioned as a means of reconnecting residents with the downtown waterfront.

The company will team up with a group of local partners to devise schematic designs, cost estimates and long-term maintenance operations, a construction plan, public art opportunities, community engagement efforts and a funding strategy.

"To have the money to be able to go into the design phase is such a big deal because you're moving from just an idea to a vision that people can rally around and bring to fruition," said Mary deLaittre, executive director of the Great River Passage Conservancy.

James Corner Field Operations will begin its work in mid-September and expects to wrap up design work by June 2022. The city will pay $475,000 for the design process, according to Clare Cloyd, Parks and Recreation Department spokeswoman.

The concept of a river balcony, which would stretch from Union Depot to the Science Museum of Minnesota, was included in the Great River Passage master plan the City Council approved in 2013. The 300-page document laid out grand plans for projects along the city's 17-mile river corridor, which staff at the time said could cost $300 million to $500 million over the next 50 years.

"Realizing transformative projects like the river balcony will further spark economic development, attract new residents, workers and businesses, and improve community health and well-being," Mayor Melvin Carter said in a statement Thursday. "I look forward to seeing this incredible vision come to life for St. Paul and our entire region."

In addition to the High Line, James Corner Field Operations' portfolio includes dozens of major developments in cities around the world, including projects in Seattle and Newark, N.J., that focused on connecting urban areas to their waterfronts. The firm also led the recent $50 million redesign of Nicollet Mall in Minneapolis.

A 12-person committee picked James Corner Field Operations from a field of 12 firms that submitted design proposals. Lisa Switkin, a senior principal at the company, said the firm was drawn to the St. Paul project for the chance to work around "one of the most iconic natural and cultural landscapes in the country" and because of the "incredible collective effort" to reconnect the city to the Mississippi.

The river balcony designers will work closely with developers and Ramsey County officials proposing an $800 million development that would bring housing, commercial space and a park to St. Paul's downtown riverfront.

"This is hopefully something that is a spark," Switkin said of the river balcony design contract. "I hope that our reputation and our ability to have successfully done these projects will help people feel more confident that this is moving forward."