CLEVELAND, Ohio – Cleveland will soon have a completed set of construction drawings for a radical, $30 million makeover of Public Square, the city’s historic but gray and tired-looking downtown center.

What it needs now is the civic will – and the cash – to get the project done quickly, with construction starting this fall.

So says the city's Group Plan Commission, the civic body appointed by Mayor Frank Jackson in 2010 to enhance public spaces around the city's new casino, convention center and Global Center for Health Innovation.

Leaders of the commission, which released the newest and most refined version of their plans exclusively to The Plain Dealer, are trying to create a sense of urgency so the project doesn’t languish the way other recent efforts to improve the city’s public spaces have.

Urgency is needed because, although leaders of the commission say negotiations with potential funders are going well, they haven’t yet identified specific donations or pledges.

"We believe in the coming months we're going to be able to announce, on a scheduled basis, more details on our financing to achieve the goal" of a fall groundbreaking, said lawyer Anthony Coyne, chairman of the Group Plan Commission and the city's Planning Commission.

The pitch from Coyne and other supporters is that work needs to start on the square this fall to boost the city’s burgeoning downtown revival – and also to help attract a national political convention in 2016.

Because the project will take 18 months to build, it can’t be finished by the presidential election year unless construction starts within months.

"We think there's a sense of urgency that comes with a deadline," said Jeremy Paris, the newly appointed executive director of the commission. "We've looked at the potential of holding conventions in 2016, and that's our deadline."

The project, designed by the leading American landscape architect James Corner, calls for routing automobile traffic counterclockwise around the square, and removing the two blocks of Ontario Street that run north-south through it.

Superior Avenue, which runs east-west, would be narrowed in the square from 77 to 44 feet and would remain open to buses, but it could be closed on a regular basis to unify the square for concerts, performances, farmers markets and other events.

Features of the plan include a cafe, a “splash zone” and a speaker’s terrace south of Superior Avenue, along with a broad lawn for movies and concerts to the north.

A meandering, ribbon-like path would trace the park’s perimeter, unifying the big central spaces with more intimate garden and seating areas in the corners.

Amenities would include streamlined and gracefully curved concrete benches and seating walls, granite cobblestones arrayed in a scalloped pattern, and sleek, contemporary-style lighting.

In the winter, a temporary skating rink could be installed.

Beloved bronze statues of city founder Moses Cleaveland and progressive Mayor Tom Johnson will be positioned on the centers of the north and south edges of the park.

The towering 1894 Soldiers and Sailors Monument dedicated to veterans of the Civil War would be surrounded with new paving and lighting aimed at making it look more accessible and integrated in the square.

The idea, overall, is to unify a public space now carved into quadrants of greenery and monuments that are marooned by the flow of traffic and surrounded by hard surfaces.

The project would remove 50,000 square feet of pavement, and increase green space inside the 5.5-acre heart of the square by 40 percent. The new landscaping would feature 300 trees, 50 more than the square currently has.

“The big picture is that we’re trying make a place that is recognized and loved as the new heart and the new civic center for Cleveland,” Corner said Wednesday in a telephone interview, speaking from his office in New York.

The proposed revision of the square, initiated originally by the Downtown Cleveland Alliance in 2009, would be the first revamp since new gardens and landscaping were installed in the 1980s.

The project is also part of a global movement among cities that view parks and public spaces as essential tools to attract new residents and to boost their economies.

Corner, who co-designed New York's wildly popular High Line park, a greenway set atop a disused elevated rail line on Manhattan's lower West Side, is a major contributor to the trend.

“We’ve been seeing this in Seattle; Chicago; Santa Monica, [Calif.]; Memphis, [Tenn.]; and New York,” he said. “All these cities are making big investments in the public realm, and they’re doing it in an effort to try to make their cities distinctive from other cities. They’re competing for residents, businesses, conventioneers, tourists.”

Corner's design for Public Square will be ready for additional public review by May or June, said Ann Zoller, executive director of LAND Studio, the nonprofit Cleveland organization carrying out much of the Group Plan Commission's work.

The drawings would then be presented to the city’s Planning Commission and the downtown-area Design Review Committee this summer, and would be ready for bids soon thereafter.

What happens next depends on whether Coyne, Paris and members of the commission can raise $30 million over the next five or six months.

The commission estimates that it will need $60 million in all for three major projects, including the Public Square makeover, enhancements to the downtown Mall and construction of a pedestrian bridge from the north end of the Mall across railroad tracks and the Shoreway to North Coast Harbor and the Rock and Roll Hall of Fame and Museum.

As part of the total, the commission wants to set aside $7 million to $10 million to create a reserve fund for long-term maintenance of Public Square, the Mall and the pedestrian bridge.

Annual withdrawals from the fund would be added to existing funds dedicated to maintenance of Public Square and the Mall, Zoller said.

So far, the city and Cuyahoga County have pledged $10 million each toward the pedestrian bridge, with another $5 million recently contributed from the state’s capital budget.

Paris said that the $25 million in public money should help persuade corporations, foundations and other private donors to come forward with money for Public Square.

Coyne also said the city is considering helping the project with a TIF, or tax increment financing, based on value added to the Higbee Building by the recent addition of the Horseshoe Casino.

The school portion of the tax increase would not be diverted to Public Square, he said.

The Public Square project is first in line among the commission’s projects in part because the design has advanced beyond those of the other components.

Planning for the pedestrian walkway will await completion of a parking study intended to determine whether an additional garage is needed near North Coast Harbor, Coyne said.

Enhancements to the Mall can't be designed until plans are completed for the county's new convention center hotel.

Above all, backers of the Public Square effort want to avoid the fate of other plans for parks, trails and civic improvements that have moved slowly in recent years, creating a sense that the city can’t follow through on big ideas for public spaces.

“This is absolutely going to get done,” Coyne said. “I’ve seen too many things in this town not get done.”