The Army Corps of Engineers will submit a report on concerns about the design of the EAA reservoir by its Jan. 18 deadline; but it probably won't have answers for those concerns, a Corps spokesman said Friday.

Getting the answers won't delay the project, said John Campbell, public information officer for the Corps' Florida command.

Two members of the state's congressional delegation aren't so sure.

U.S. Sen. Marco Rubio, R-Florida, and U.S. Rep. Brian Mast, R-Palm City, Thursday asked R.D. James, who leads the Corps as assistant secretary of the Army for Civil Works, to prevent the Corps from unnecessarily delaying the design and construction of the project.

"Delays will not be tolerated," Mast said in a prepared statement.

"No, this won't delay the project," Lt. Col. Jennifer Reynolds, the Corps' deputy commander for Florida, told TCPalm Thursday.

Read:The letter Sen. Rubio and Rep. Mast sent to the Corps

The reservoir is meant to store excess Lake Okeechobee water to help reduce the need to discharge the polluted water to the St. Lucie and Caloosahatchee rivers, where it often causes algae blooms harmful to people, animals and the economy.

The project also will clean water and send it south to Everglades National Park and Florida Bay, which need a consistent flow of freshwater during dry periods.

James gave the thumbs-up to the South Florida Water Management District's project design last summer, but said he had a few concerns that could be worked out in the detailed design phase.

More: Corps approves reservoir plan, sends it to Congress

When Congress authorized the project as part of the Water Resources and Development Act in October, the law included an order that the Corps issue a report within 90 days resolving James' concerns.

More:President signs bill authorizing EAA reservoir

The 90-day deadline is Jan. 18.

“The Corps cannot simply ignore the parts of federal law that they find inconvenient or don’t want to comply with,” Mast said in a news release. “If they fail to submit their report to Congress by January 18th, they will have violated the law, and that’s absolutely unacceptable.”

The Florida command will submit a report by the 90-day deadline, Campbell said, "but we're going to need more time to fully address the concerns raised by Secretary James. We don't want to delay this important project, and we fully believe his questions can be answered concurrent with the design of the project."

Reynolds said technical work is being done at the reservoir site "in order to answer the secretary's questions."

Two of the outstanding issues:

How seepage through the reservoir walls will be managed

The need for an analysis of how safe the reservoir walls will be

The water management district began preliminary work on the reservoir project Nov. 14 by clearing land for a staging area for rock and other material needed to build the reservoir walls.

More: Preliminary work begins at EAA Reservoir site

The district this week announced crews had begun taking soil samples up to 80 feet deep where the reservoir walls will be built to determine the exact composition of the soil and rock.

That work is instrumental in determining how the reservoir walls will have to be built to eliminate seepage and make sure they'll be safe, Reynolds said.

For the 10,100-acre reservoir to hold up to 78.2 billion gallons of water, it will have to be 23 feet deep; and the walls could be taller than the Herbert Hoover Dike around Lake Okeechobee.

Known as the Everglades Agricultural Area Storage Reservoir, the project also will include a 6,500-acre man-made marsh to clean the water before it's sent south to Everglades National Park and Florida Bay.

More:EAA Reservoir project design submitted to Army Corps

"This is a really big project," Reynolds said, "and resolving these issues will take some significant effort."

In their letter, Rubio and Mast say the Corps and the district should immediately "begin the preconstruction engineering and design phase" of the project, "subject to the availability of appropriations."

"We have engineers ready to start the detailed design," Campbell said.

As for money, the Corps is "re-allocating" funds from other South Florida projects "to do this preliminary work now and to do design work," Reynolds said.

The state and the federal government are to each pay about $800 million on the estimated $1.6 billion project.

Rubio warned the Corps not to delay the project by "duplicating feasibility study efforts for projects that Congress has already authorized."

Rubio and Mast "clearly have some concerns," Campbell said. "We'd all like to have the project in place tomorrow. But we have to design it in a prudent manner to make sure it's safe and make sure it works."