GRAND RAPIDS, MI - A grand plan to remove dams and restore rapids in the Grand River through downtown is growing in cost as planning stages drag into their fifth year.

New cost estimates for the Grand Rapids Whitewater project now sit at $44.67 million, up from the $35 million that the nonprofit shepherding the project anticipated last year and from $20 million when the idea was first proposed in 2012.

Ongoing scientific studies and engineering work are pushing the costs up as planning continues, said Matt Chapman, project coordinator for Grand Rapids Whitewater. The nonprofit group is overseeing the permits, grant applications and overall coordination of the project.

Part of the slow progress is due to the discovery of the snuffbox mussel, an endangered species, in the river.

The projected costs are divided between construction -- $32.89 million - and development -- $11.77 million.

Work is targeted to start in 2019, Grand Rapids Whitewater CEO Richard Bishop told Grand Rapids city officials at a commission meeting this week.

The project will remove five dams between Sixth and Pearl streets to restore an 18-foot drop in the river's elevation across a 2.2-mile stretch.

Below the Sixth Street dam, boulder-strewn rapids would be recreated.

A sea lamprey barrier would also be installed.

View the Grand Rapids Whitewater plan

Construction would likely stretch through 2024.

The project still needs two major permits from the Michigan Department of Environmental Quality and the U.S. Fish and Wildlife Service before it can move forward.

The first step to obtaining the federal incidental take permit - a habitat conservation measure - was submitted Nov. 1, Bishop said.

The federal permit process may take 12 to 18 months, Chapman said.

To date, about 31 percent of the project has funding pledged, including $6 million in private donations, $6.3 million in federal money and $1.5 million in state funding, Chapman said.

Most of the federal money pledged so far is from an $8 million grant from the U.S. Dept. of Agriculture's Regional Conservation Partnership Program to the Grand Valley Metro Council -- of which the river project will receive half.

Grand Rapids Whitewater will continue to seek grant funding from state and federal sources - and plans to launch a capital campaign in 2018. Eventually the campaign will open to the public for contributions, Chapman said.