The U.S. Army Corps of Engineers on Monday released a tentative plan to restore parts of Long Beach’s coastline but proposed no changes to the city’s 2.2-mile breakwater.

The city for more than a decade has anticipated the results of an Army Corps’ study to determine whether parts of the breakwater could be torn down to restore waves to the coastline.

But ultimately, the study on Monday concluded that any breakwater changes were too costly and could result in significant impacts to the U.S. Naval operations, the ports of Long Beach and Los Angeles, the oil islands, the city’s Carnival Cruise terminal, Shoreline Marina, the Peninsula and other maritime stakeholders. The study found that notching the breakwater to restore waves could cost nearly $1 billion.

The Army Corps instead has proposed an open-ocean ecosystem restoration project for East San Pedro Bay that would be the first of its kind for the agency, according to a city news release. The plan, referred to as the Reef Restoration Plan, would include rocky reefs, kelp reefs and eelgrass beds to improve water quality and support for habitat biodiversity.

Acting City Manger Tom Modica on Monday said the results put to rest the city’s long-time question of whether tearing down the breakwater, which was built by the U.S. Navy in the 1940s, was feasible.

“I feel that we have done everything we can to answer that question, and the answer came back that it is not feasible,” he said.

The draft study is available for public comment starting Friday through Jan. 27. The draft proposal will go before the City Council for approval next year after the public comment period.

The Army Corps’ reef restoration plan is estimated to cost $141 million. The city would be responsible for $49 million, while the federal government would pay the rest, Modica said.

Modica said the city does not have the identified funding for the project at this time, but it could find funding in the coming years. Any funding for the project would require City Council approval and would come from Tidelands funds.

Last year, the city in partnership with the Army Corps unveiled six possible options to improve the ecosystem along the coast, of which two included notching parts of the breakwater. The study found that the two breakwater notching projects would cost $993 million or $670 million, respectively.

The Army Corps had originally identified three draft alternative plans that did not include any changes to the breakwater, but the breakwater options were later added at the city’s urging, Modica said, adding that the city’s main goal was to get a final answer on the breakwater.

The total study cost $4.3 million, of which the city paid $2.9 million from Tidelands funds, he said.

“Obviously we’re disappointed there was not a feasible alternative for the breakwater, but we’re looking forward to hearing public feedback on the (Army Corps’) alternative,” he said.

The Army Corps study noted that any changes to the breakwater could have an impact on national security because the Navy operates an explosives anchorage used for transfer of ammunition inside the breakwater near Seal Beach.

“Any modifications to the breakwater resulting in an increase to wave energy will impact the Navy’s ability to safely perform ordnance and fuel transfer operations,” the study found.

Long Beach Mayor Robert Garcia in a statement said he was disappointed with the results and was hopeful that breakwater modification was possible while also protecting coastal homes and the port complex.

“However, I have always said that we would be guided by the science and data,” the mayor said. “The Army Corps’ conclusions that any modification to the breakwater poses a national security risk is substantial and must be taken seriously.”

The news also comes as a disappointment for surf advocates like Assemblyman Patrick O’Donnell, D-Long Beach, who has long proposed tearing down the breakwater.

“I thought there was potential for something to happen but I’ve always said that science should dictate the outcome of the study,” said O’Donnell, a former Long Beach city councilman. “I just hope the outcome of the study is based on science and not political science.”

The public is invited to attend one of two public meetings for a presentation of the report on Dec. 9 at the Aquarium of the Pacific (100 Aquarium Way): one meeting takes place from 3 to 5 p.m. and the second from 6 to 8 p.m. A presentation led by Col. Aaron Barta, commander of the Corps’ Los Angeles District, will take place after opening remarks from city officials.

“The Corps’ Los Angeles District is excited about the release of the tentatively selected plan,” Barta said in a statement. “We look forward to public input on our plan to help restore the unique underwater ecosystem environment of East San Pedro Bay.”

Bound copies of the report will be available at Long Beach libraries; the report is also available online.