TAMPA — Four months after the Tampa Bay Rays' search for a new home hit a dead end in Ybor City, a development partnership is pitching a new ballpark site to Tampa City Hall, where Mayor Bob Buckhorn has pronounced it dead on arrival.

The site is about three miles west of the Ybor location, on 18 acres that City Hall owns near the Hillsborough River. Tampa Riverfront Sports, headed by architect William Henry and developer Geoff Weber, is one of four groups that submitted proposals for the land on March 20.

But Buckhorn on Wednesday called the proposal a "non-starter" because he said the proposed scale, density and intensity of the development would overwhelm what is an existing neighborhood.

"I don't see that as viable," Buckhorn said of the Tampa Riverfront Sports proposal. "We're not going to waste a lot of time thinking about that one."

BACKGROUND: Tampa City Hall seeks developers for 18 acres near the Hillsborough River

Meanwhile on Wednesday, Henry outlined his proposal to Hillsborough County officials, who took a lead role in studying financing possibilities for the now abandoned Ybor site but have no role in deciding how the city will use the land it owns just south of Columbus Drive in the West River area.

Henry's 6-minute pitch was the 39th of 40 public comments heard by county commissioners during their board meeting. Commissioners were unable or uninterested in responding to the surprise proposal and moved on with their agenda.

Henry told them his only request was their support.

The proposal was developed as an "insurance policy" option should the Tampa Bay Rays seek a new home outside of Pinellas County or Ybor City, he said.

"This is not to be any threat whatsoever to any plans that are going on," he said. "Consider it as a 'Plan C' or 'Plan D', just maybe not a 'Plan F.' "

Tampa Riverfront Sports consists of Henry, principal architect with RGA-Design, Weber, principal at the development firm Bayside/Broadway, and the Ohio-based NRP group, a national residential developer that has done work near Tropicana Field in St. Petersburg.

Together they are thinking big — bigger in some ways than Jeff Vinik and Cascade Investment are thinking about at their $3 billion Water Street Tampa development near Amalie Arena.

Tampa Riverfront's first phase would include two high-rise towers with more than 1,500 residences. By comparison, the two apartment towers now under construction at Water Street Tampa will include a total of 420 apartments. Their second phase calls for a 30-story, 750-room hotel — bigger than the Tampa Marriott Waterside Hotel & Marina. The 28,000-seat stadium — home for any sport from baseball to tennis — could come in phase three.

Buckhorn called Tampa Riverfront's proposal a "non-starter" that would be unacceptably out of scale with the surrounding neighborhood.

"I don't think it's an appropriate location" for a stadium, Buckhorn said. "It's certainly not an appropriate location for two 60-story towers. You don't want that intense of a use right in the middle of an existing neighborhood."

The proposal states the project would be funded through $1 billion of private investment in addition to a share of new property taxes from the city's West Tampa community redevelopment area. The site is also within a designated opportunity zone and could qualify for a brownfield site designation, two federal incentives offered to developers to build in blighted areas.

Henry has not discussed the proposal with the Rays, who declined comment Wednesday. The team is forbidden by its Tropicana Field lease agreement to discuss alternative ballpark sites

The West River site is about nine blocks north of Interstate 275. Henry said traffic from a ballpark could also use Columbus Drive to the north and Rome Avenue. Water ferries could be used to convey fans to and from the game.Henry, who served on the Hillsborough Planning Commission around 1990, said his project would dovetail with the city's plan to extend the Riverwalk to the west side of the Hillsborough River and the West River redevelopment project, which would remake 44 acres that once were home to the now-demolished North Boulevard Homes public housing complex.

He pointed out that it's close to the Armature Works site that Rays owner Stu Sternberg said would have been his first choice but was already under development by the time the team got permission from St. Petersburg to talk to developers.

But Henry's proposal isn't the city's only option. Other groups that submitted proposals:

• Related Urban, a subsidiary of the Related family of real estate development companies. Related, which has a regional office in Miami, is involved in redeveloping the North Boulevard Homes site and has built multi-family residential projects on the former Tampa Tribune property, in the Channel District and on Harbour Island.

• Urban Progress Alliance, a Tampa nonprofit headed by Andre Hill Sr. that proposes to build affordable and workforce housing on the property, along with a hotel and commercial uses that would be aligned with the alliance's efforts to redevelop the Main Street commercial corridor.

• Framework Group, led by Tampa developer Phillip Smith, the Barclay Group and architecture firm Torti Gallas+Partners, a global firm with a Tampa office.

The proposals are exempt from disclosure under Florida's public records law for 30 days after bids are opened or until the city issues a notice of an intended decision. Buckhorn said city officials had not determined whether to recommend any of the proposals or go out again for another set of proposals later.

"The response was not as robust as I had hoped," said Buckhorn, who leaves office May 1 because of term limits. "As much as I want to get this done while I'm here, I'm not going to take a bad deal just to get it done."

Times staff writer Christopher O'Donnell contributed to this report. Contact Anastasia Dawson at adawson@tampabay.com or (813) 226-3377. Follow @adawsonwrites