CHICAGO (CBS/AP) — Gov. JB Pritzker is moving forward with the first steps on a project to fortify a dam and lock system near Joliet, in an effort to confront the state’s Asian carp problem, and keep the voracious fish out of the Great Lakes.

The governor has authorized initial engineering and design work on an enhanced electric barrier at the Brandon Road Lock and Dam, but cautioned the U.S. Army Corps of Engineers that he won’t sign off on a final agreement unless other Great Lakes states help share the costs of the project.

The Corps of Engineers has proposed installing a new electric barrier, noisemakers, and an air bubble curtain at the dam to try and stop Asian carp from swimming upstream near Joliet, and making their way to Lake Michigan. The project also would include a lock system to flush away unwanted species floating in the water.

The project would cost $778 million, much higher than an earlier $275 million estimate.

Pritzker said he wants to look at options for reducing costs, and more funding from other states.

“I would like to discuss how we can lower the cost of this plan and still effectively address the threat of Asian carp,” Pritzker said. “I will not sign a Project Partnership Agreement without a cost control strategy and additional cost sharing among the states.”

Corps spokeswoman Samantha Heilig said Monday that Pritzker’s letter was forwarded to the agency’s headquarters in Washington, D.C., where a final report on the project awaits approval from the chief of engineers.

The Brandon Road complex is on the Des Plaines River, which is part of a waterway network that links Lake Michigan with the Illinois River. The Illinois River is infested with several varieties of Asian carp, which were imported decades ago to cleanse Southern sewage lagoons and fish farms but escaped into the Mississippi River and invaded many of its tributaries.

Scientists said if the Asian carp becomes established in the Great Lakes, it could unravel food chains and out-compete native species.

Environmentalists and some states, including Michigan, have called for walling off Lake Michigan from the Chicago waterway system, which Illinois opposes as disruptive to commercial navigation. The Brandon Road project is considered a compromise.

Former Michigan Gov. Rick Snyder proposed a partnership last year to help cover costs of operating and maintaining the Brandon Road structures, drawing support from Ohio, Wisconsin, the Canadian province of Ontario and Chicago.

But former Illinois Gov. Bruce Rauner rejected fellow Republican Snyder’s offer of $8 million in support of the arrangement, saying he didn’t want to commit to the deal in the final days of his term.

Snyder’s successor, Democratic Gov. Gretchen Whitmer, is willing to make good on his proposal and appreciates Pritzker’s decision to move forward, spokesman Ed Golder of the Michigan Department of Natural Resources said Monday.

Illinois Sens. Dick Durbin and Tammy Duckworth, both Democrats, supported Pritzker’s position in a statement and agreed other Great Lakes states should share the costs.

“Invasive Asian carp are a serious threat to the Great Lakes ecosystem and the region’s economy,” they said.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)