Builders and architects are giving a first look at a huge development that would link downtown Dallas with the planned Trinity River park.

The 40-acre, 505 Riverfront project would include one of the largest new shopping centers planned in Dallas, along with towers for apartments, hotels and office space.

Developers Forest City Realty and Trademark Property are teaming up on the mixed-use development proposed on Riverfront Boulevard at the Margaret Hunt Hill Bridge.

"This site is the connection between downtown Dallas and the Trinity," Forest City senior vice president Jim Truitt told city planners and urban designers in a Friday morning meeting. "This is going to bring a lot of retail sales back to Dallas."

Preliminary plans call for a high-density development with 400,000 square feet of shopping and restaurant space plus 3.5 million to 4 million square feet of commercial and residential building.

The developers plan to work with the Army Corps of Engineers and the city to come up with a way to access the river levee for public and private use.

"This is a Trinity-centric project," Truitt said. "This is a long-term project — it's a 10-year project."

The developers plan to ask the city for financial incentives to help pay for expensive infrastructure necessary to develop the site which was previously a rail yard and warehouses.

In return for public sector help with the funding, Truitt said Forest City will commit to providing housing in the project for people with a mix of incomes.

The proposed development site is about half the size of Victory Park, which is just across Stemmons Freeway from the 505 Riverfront location.

The planned mixed-use development will include a large shopping district plus high-rise residential, hotel and office buildings on the Trinity River. The pink buildings are storefronts and restaurant space with towers above.

Truitt said the developers want a different feel for the project.

"Our vision for this is to be different from Uptown and downtown," he said. "We want it to be more gritty and industrial."

Forest City and Trademark have hired architects Callison RTKL, GFF, S9 Architecture and Perkins Eastman to plan the development.

A new street is planned to run through the middle of the project from Stemmons Freeway to the river.

"We would create a focal retail spine street — that would be the focus of the retail development," GFF's Larry Good said. "We will place open space strategically in the heart of the development."

Between Riverfront Boulevard and the highway, the project would include a big-box retail center built on several levels.

Forest City and the architects are working on several proposals to raise high-rise buildings planned along the riverbank up to the level of the levee. The buildings and the new neighborhood would be linked to the river park by either bridges or infill on the backside of the levee.

"The way we tie this development to the Trinity comes down to what the corps allows us to do," Callison RTKL's Erich Dohrer said.

The Corps of Engineers has final approval for any construction that impacts the river flood way protection.

Development of the riverfront has long been a goal of Dallas planners who want to bring residents and businesses to the Trinity.

The 505 Riverfront site is one of the largest building sites along the downtown side of the river.

Pruitt said his firm and partner Trademark Property have "monitored this site for a long time.

"Now is the time to develop it," he said.

Dallas senior planner Evan Sheets said at the meeting of the Urban Design Peer Review Panel that the 505 Riverfront project can draw together growing areas in West Dallas, the Design District and Victory Park.

"This is an opportunity to make a new neighborhood where one doesn't exist," Sheets said. "We have an opportunity to enliven the riverfront district and make connections between neighborhoods that currently aren't connected."

The vacant land that Forest City and Trademark have contracted to purchase includes land on both sides of the Margaret Hunt Hill Bridge. The developers would link the properties with new roadways under the arched bridge.

Before the recession, the development site was owned by an apartment builder that hoped to build high-rise housing. But that deal fell apart during the economic downturn.

Forest City and Trademark's plans for 505 Riverfront are much more ambitious that previous designs.

"There is no question almost anything you do here from a development standpoint is going to be successful," Dallas architect Kevin Sloan and a chairman of the design review panel said. "How does it become a great place?

"This is a project that has the aspiration to historically change Dallas," Sloan said. "If there was ever potential for a project in Dallas it's at this location."

Forest City and Trademark are two of North Texas' most experienced commercial developers.

Based in Cleveland, Forest City has redeveloped a few Dallas landmarks including Mercantile National Bank tower and Mercantile Continental building in downtown. And Forest City is building its second high-rise with apartments, retail and hotel rooms in Uptown's Cityplace project.

Trademark Property has developed 11.8 million square feet of retail and mixed-use projects valued at $2.5 billion.

Trademark built the Watters Creek retail and apartment complex on U.S. Highway 75 in Allen. And the firm is part of the team redeveloping the Victory Park project on the northwest edge of downtown Dallas.