Imagine a time in the not-too-distant future when a couple from Paris can disembark from a Viking River Cruise ship onto a platform at the St. Paul riverfront, walk up a gently rising ramp and stroll a beautiful summer’s evening along a promenade connecting dozens of buildings overlooking the Mississippi to the Science Museum of Minnesota, or maybe to a ballgame at CHS Field.

Such is the vision of those tasked with making a reality of St. Paul’s River Balcony, an elevated pedestrian path that will better connect downtown St. Paul with its long-ignored riverfront.

On Thursday evening in the concourse of Union Depot, planners unveiled their concept of what the River Balcony might look like and how it would weave together the downtown that rests atop the river bluffs and the flowing waters below.

At an open house that attracted about 100 visitors, planners laid out conceptual drawings, guiding principles and even a large 3-D model of what the River Balcony might look like. While Mayor Chris Coleman and project planners say it is much too early to affix cost estimates or a construction timeline to the project, the work done so far on a master plan will help developers and city officials better meld upcoming riverfront projects into an overall theme, Coleman said.

Besides, he said, it’s just fun to dream a little bit about what St. Paul can be. “If this doesn’t capture your imagination, then you don’t have an imagination,” Coleman said.

The River Balcony idea was first envisioned as part of the city’s Great River Passage Plan, St. Paul’s vision to better connect the river town with its 26 miles of Mississippi River shoreline through use of parks, green space and walkways. Developed jointly by the city and the University of Minnesota’s Metropolitan Design Center, the River Balcony seeks to overcome long-standing obstacles in the way of a greater embrace of Old Man River — mainly, steep river bluffs, railroad tracks and the zipping traffic of Shepard Road. The City Council put $100,000 into the planning phase back in April.

In concepts revealed Thursday, the River Balcony would integrate 50 to 60 different pieces into a continuous meander alongside riverfront buildings and parkland downtown.

In much the same way that the city’s skyways are a combination of public facilities and private property, the River Balcony would be open to the public all year long, said Lucy Thompson, project manager for the city — “but better,” she said, because the River Balcony would be outside and give people several points to safely wander down to the river’s edge. Along the way, they would pass restaurants, entertainers, and places to sit and relax. Today, pedestrians can get to the river only at the Science Museum or Jackson Street.

“It won’t be cheap,” Thompson acknowledged. “And it’s going to take a while too.”

Proponents envision a public-private partnership in which developers work and pay for portions of the balcony in concert with the city, which will bolster Kellogg Park by transforming it into a multilevel park that features a grass-covered land bridge and an amphitheater right down to the waterline.

Parts of the project may not be so far away. Custom House, the new luxury apartment, hotel and retail development going into the old downtown post office, is certain to incorporate part of the River Balcony into its riverfront exterior. Herb Tousley, of Exeter Group, developer of Custom House, foresees a connection to Union Depot to the east and Kellogg Park to the west.

“The river is a great asset,” he said. “When we bought the building, we knew this was part of the Great River Passage. It’s a very appealing idea.”

Ken Avidor, a sketch artist who lives in a condominium at Union Depot, sees a River Balcony as another magnet to bring people downtown.

“There is just a synergy here, with all the modes of transportation coming together,” he said. “If it better connects people with the river, you’ll have more likelihood of it being successful.”

Coleman said the project would be a culmination to decades of planning and dreaming of ways to turn back to the river that gave St. Paul its start and its early momentum.

“The fact of the matter is, we are reclaiming the Mississippi River, and this becomes an important next step in that process,” he said.

One of the biggest steps will be the river cruise ships of Viking River Cruises, on schedule to bring the world’s well-heeled travelers north from New Orleans beginning in 2017. Coleman sees the River Balcony becoming a world-class point of entry into St. Paul.

“This is just a beautiful vision,” he said to people gathered around the 3-D model. “Let’s keep on dreaming — and let’s get this project done.”