The Imagine Boston 2030 plan is almost done — here are some highlights

The Boston 2030 plan projects continued population growth in coming years and decades. David L. Ryan/The Boston Globe/Globe Staff

Boston’s first citywide plan since the 1960s is just about done.

Mayor Martin J. Walsh on Thursday is set to unveil the nearly-final version of the Imagine Boston 2030 plan, a pile of goals and maps and pictures that lays out how his administration – and thousands of Bostonians who weighed in with their ideas – wants the city to grow over the coming years.

It builds on a preview laid out last year that envisioned dense new neighborhoods in tucked-away corners of Boston, better transit connections between poorer pockets and jobs downtown, and a greener city, oriented around its waterfront, but also built to withstand whatever climate change may throw at it.

At nearly 400 pages, there’s too much in the plan to explain here. Best to read it yourself. We got a sneak preview Wednesday, and here are a few highlights.

The current building boom is really just beginning. Much of this is predicated on the belief that Boston will keep growing. The plan projects a population of more than 800,000 people by 2050 — up from 656,000 in 2014 — and more than 900,000 jobs.

To keep pace with all that growth, the city will need to hit its current goal of 53,000 new housing units by 2030, and add 42,000 more in the two decades after that. Office developers had better keep building, too.

Boston isn’t growing any more acres. At 49 miles of land area, it’s one of the geographically smallest big cities in the U.S. Much of the plan is about how to find room for another 150,000 or so people.

The answer lies in building big in odd corners of town. The plan identifies six “expanded neighborhoods,” from Suffolk Downs to Readville to Beacon Yards in Allston, where the city sees opportunities for large-scale growth. Help will come by building more housing downtown. There are calls for a new generation of high-rise housing on the dense, walkable streets of job hubs from Longwood Medical Area to the Financial District.

Do all that, said Rebekah Emanuel, who’s spearheading the project and “there’s enough space to meet our growth through at least 2050.”

The Fairmount corridor is the future. This plan isn’t just about growth; it’s also about improving economic opportunity. For that, it leans heavily on the Fairmount line.

The commuter rail line connects some of Boston’s poorest neighborhoods to downtown and other job centers, and Imagine Boston envisions major investments along it from Roxbury down to Hyde Park. There would be new industrial growth targeted for Readville and Newmarket, upgrades to Franklin Park and Columbia Road, big improvements in Upham’s Corner, and spending on early childhood education, schools, and a new library.

Some things are out of the city’s control, like frequency of trains on a line where cancellations have been a source of controversy. But eventually, Imagine Boston says, the city wants to work with the state to provide “subway-level service” through the corridor. And no matter how often the trains run, it is well past time to pump more resources into neighborhoods that have lacked them for too long, Emanuel said.

“It’s an area where we need to invest in order to be the city we want to be,” she said.

Climate change is coming. The plan continues to flesh out ideas to help Boston adapt to rising sea levels. All those new neighborhoods would be designed with higher flood risk in mind. New “flood management areas” are envisioned along Boston Harbor, the Mystic River and Dorchester Bay. And more waterfront open space could help both connect neighborhoods to the harbor and buffer against the impacts of flooding.

Perhaps even more ambitious: Imagine Boston calls for Boston to be “carbon-neutral” by 2050, which would mean a dramatic reduction in greenhouse gas emissions that have fallen 17 percent since 2005. How that will happen remains to be figured out, but city officials said they’ll focus on reducing emissions from cars and trucks, buildings, power usage and waste.

The plan goes on forever. Imagine Boston has been nearly two years in the works, but it’s really just a start. After 30 days of taking more public comment, the city team working on the project will make any tweaks and issue a final version. Then the real work begins.

There will be street plans and waterfront plans, neighborhood plans by the Boston Planning & Development Authority, and parks plans by the Parks Department, all guided by the ideas in this document. Some of the specific ideas are funded in the city’s five-year budget. Many aren’t, so money will need to be found, either through the city or through various public and private-sector partners.

And the plan itself calls for more big plans, including a new vision for the Shawmut Peninsula – the original spit of land that today is downtown Boston – through 2100. That will be a monumental effort in itself.