U.S. Sen. John Cornyn (R-TX) added his voice to the growing number of people who are suggesting Fort Worth’s “Panther Island” project needs a more detailed analysis to determine its benefits to taxpayers if the project is to receive more federal funds.

Cornyn told NBC 5 Investigates, the project, which has already received millions of dollars from the federal government, needs what is known as a “benefit-cost ratio” study, in order to compete with other projects seeking federal flood control funds.

Such a study is used by the U.S. Army Corp of Engineers to determine whether the expense of a flood control project – which Panther Island is supposed to be – is worth it for the taxpayers.

“It’s required essentially before we can get the Corp to make that move” to spend more money on the Fort Worth project, Cornyn said.

“So that’s something we are going to have to work on. Maybe that would be the next logical step for us to take,” Cornyn said.

He added that the Office of Management and Budget, which is an arm of the White House, “has some concerns” that the cost-benefit ratio findings would not justify the estimated $400 million additional federal dollars that is needed to complete the project.

At issue is whether Panther Island is primarily a flood control project, as the Tarrant Regional Water District maintains, or is, instead more of an economic development endeavor to create an entertainment district for Fort Worth.

The project, when complete, is expected to cost more than $1 billion, with the money coming from federal, state and local coffers.

Earlier this year, voters in Fort Worth approved a bond package that would kick another $250 million into the project.

However, Mayor Betsy Price and city council members have voted to delay any of those funds until an outside cost analysis is performed on the project.

Panther Island, also known as the Trinity River Vision, is more than a decade in the making, with U.S. Rep. Kay Granger credited with bringing federal dollars to the table.

Critics – both in Fort Worth and in Washington – have questioned the fact that the project is led by Granger’s son, J.D. Granger, executive director of the Trinity River Vision Authority.

They have also suggested the TRWD has avoided a study of the Panther Island project because it would likely raise more questions.

But the water district gave a different reason, saying such a study was never done because it wasn’t required when Congress first authorized the work more than a decade ago.

This week, J.D. Granger praised the endeavor, telling NBC 5 Investigates “we have managed this project well over the last 12 years and actually received funds in that time period. So I think we are doing well.”