A patch of vacant land in the heart of St. Paul will transform next year into a city park, complete with trees, walking paths and a pool of water stretching into a playground, according to a city plan revealed this week.

Construction on Pedro Park at the corner of E. 10th and Robert streets is expected to happen in tandem with an overhaul of the former Public Safety Annex building on the same block. Pending approval from the Housing and Redevelopment Authority (HRA) and City Council this month, Minneapolis-based Ackerberg Group will develop the annex into office and retail space, and the Parks and Recreation Department will revamp the park.

If all goes according to plan, city officials said, the park and the office building will be complete around the same time.

“We need jobs. We need parks,” said Planning and Economic Development Director Bruce Corrie. “Is there a way in which we can get both?”

The city’s design for Pedro Park, which grew out of advisory committee meetings in May and June, includes green space, seating areas, public art and places for children and dogs to play. It’s expected to cost about $3.8 million, with money coming from Ackerberg and the city.

The park could eventually expand into spaces now occupied by a parking lot and another building, said Parks and Recreation Director Mike Hahm.

The fate of Pedro Park has been a point of local controversy. The Pedro family donated 0.45 acres along E. 10th Street to the city in 2009 for use as a park. The city planned to demolish the Public Safety Annex and combine that lot with the donated land to create a larger park.

But last year, city officials started exploring turning the annex into an office building. In November, the HRA voted to give Ackerberg Group tentative developer status.

Park advocates and downtown residents, organized under the name Friends of Pedro Park Expansion, have pushed back. They sued St. Paul in August, arguing that the city is violating its comprehensive plan and multiple ordinances — as well as promises to the Pedro family and residents — by selling the land.

Kati Berg, one of the plaintiffs in the suit, said she’s not convinced the city will expand Pedro Park — especially if the alley through the middle of the block remains.

“What are you going to do to get rid of the alley?” she said in an interview. “Or are we going to have cars driving through our park?”

Ackerberg will pay $1.4 million for the Public Safety Annex, plus $40,000 annually for park maintenance over the next 20 years. The city will create the park using proceeds from the sale of the building, existing parkland dedication funds totaling $200,000 and $2.23 million from the capital improvement budget.

The public will have a chance to comment on the plans Oct. 24. The HRA and City Council are expected to vote that day on whether to move forward with the projects.

“It’s a great opportunity to advance something here that’s been stalled for a long time,” Hahm said. “I would see this as a next step of whatever else is possible to happen on this block.”