A massive dirt field in St. Paul's Highland Park neighborhood could one day house up to 7,200 people and be the workplace of a thousand or more.

That vision for the former Ford Assembly Plant, which excites some and alarms others, got a key stamp of approval Friday from the city's Planning Commission.

"The Ford Site represents a once-in-a-lifetime development opportunity," Mayor Chris Coleman said in a statement after the commission unanimously recommended the plan. "This well thought-out plan lays the foundation for a vibrant livable community on the banks of the Mississippi River."

The City Council will likely consider the plan in the fall. The document, which will frame zoning and development at the 122-acre Ford property, continues to face opposition from residents who argue the city has downplayed community concerns.

Neighbors for a Livable St. Paul, a group of residents against the plan, said St. Paul staff left some comments out of the material presented to planning commissioners. They called for the Planning Commission to delay its vote and have a third party review the community input.

"The public and decisionmakers should have accurate information. … This is something that is going to affect the Highland neighborhood and the city for decades to come," said Charles Hathaway, who lives in the area and is a member of the group.

Site of the former Ford Assembly Plant in St. Paul.

A "technical glitch" caused city staff who were compiling feedback to miss some e-mails, both for and against the plan, said Mollie Scozzari, with the Planning and Economic Development Department. A resident alerted the city of the missed messages and Scozzari said a staff member found them in a separate inbox.

Planning commissioners voted 9-7 not to delay their decision. Several commissioners said city staff shared the missing comments with them a couple weeks ago and they had plenty of time to review feedback.

St. Paul staff have been gathering resident input on the site over the past decade. The plan they arrived at has a mix of building uses and heights, two stories high closest to the Mississippi River and increasing to eight or 10 stories near Cleveland Avenue. It includes a street grid that would connect to surrounding roads and pockets of green space that would dot the site, including a stormwater feature that resembles a creek.

Ford, which still owns the property, is expected to put the site on the market this year or in early 2018 and the city expects development would occur over 15 to 20 years.

Some Highland Park residents are concerned with the housing density and traffic congestion the plan could create. Other neighbors — who created their own group, Sustain Ward 3 — agree with the vision in the plan, which they said is an environmentally friendly design that will encourage transit use.

Two city committees recommended the plan and said in a memo that Highland Park already has plenty of single-family homes and needs more multifamily housing as the city's population grows. And the site developer would make more money if it is able to add more housing units on the site, Principal Planner Merritt Clapp-Smith said, which could decrease the potential need for public subsidy.

The Planning Commission agreed to a few changes to the plan Friday, including limiting building widths to 500 feet in an effort to encourage developers to add courtyards or space for public amenities. They also agreed to increase the number of housing units allowed on the five blocks along Mississippi River Boulevard, which could reduce density elsewhere on the site.

"You have the most prime piece of property on the entire site," said Commissioner Kris Fredson, who didn't want stringent limits on the number of people who can live along the boulevard.

Jessie Van Berkel • 612-673-4649