Moncton city councillors are ignoring reports from their own staff and two outside engineering firms by refusing to allow the provincial government to cover about 300 metres of riverbank with protective rocks to prevent erosion.

Since the gates of the Petitcodiac River were opened three years ago, the river has eroded much faster than predicted.

In an effort to safeguard the area from future erosion, the provincial government wants to spend $430,000 to place large rocks, also known as rip-rap, along the banks at Bore Park.

However, Moncton city councillors — urged by the Petitcodiac Riverkeeper, a local environmental group — say they want the Petitcodiac River to run free, despite the potential of future erosion.

"I am prepared to take the risk," Coun. Pierre Boudreau said.

'Two wrongs do not make a right. Mankind has ruined nature too many times that it is not for us to ruin it some more.'— Coun. Daniel Bourgeois

Coun. Dawn Arnold also acknowledged the decision could leave the area open to erosion, but said that is a chance she is willing to take.

"I think we've done enough injustice to our river and it's time to let our river flow free," she said.

Coun. Daniel Bourgeois said it would be wrong to try to stop the river from moving freely now, just as it was wrong to build the causeway decades ago.

"Two wrongs do not make a right. Mankind has ruined nature too many times that it is not for us to ruin it some more," Bourgeois said.

"Let the river run free is my position."

Two engineering reports and city staff warn of unknown costs and risks in the future as the river continues to wear away at the banks.

An engineering firm, hired by Riverkeepers, says the erosion will stop once it reaches the natural banks of the river.

City staff say the provincial government will only drop its plans to protect the banks of the river from more erosion if Moncton agrees to accept all the future costs associated with letting the river take its natural course.

The New Brunswick government started reinforcing the riverbank with the large rocks in 2011.

The decision to open the causeway gates was extremely controversial. The causeway was built in 1968 between Moncton and Riverview and the gates were opened in April 2010.

Concerns over potential future erosion also prompted the Department of Transportation and Infrastructure to purchase four residential properties west of the Petitcodiac River causeway.

The four properties cost taxpayers more than $1 million.

The provincial government assessed more than 700 properties upstream from the causeway before deciding to buy the four properties.