Todd Russell, president of NunatuKavut, as well as seven others were arrested Friday morning while taking part in a demonstration against the Muskrat Falls project.
The demonstrators were arrested by the RCMP on the Trans-Labrador Hghway, about 10 kilometres from the site where a generating station will built on the Churchill River.
Police said the demonstration, although peaceful, resulted in a line of vehicles approximately a kilometre in length, impeding traffic travelling along the roadway.
Russell warned just days ago that his group would be ramping up protests against the hydroelectric project.
Gilbert Bennett, vice-president of Nalcor's Lower Churchill Project, said the demonstration "took place on a public road" and affected crews.
"This activity did impact the ability of workers to get to the Muskrat Falls construction site this morning during the demonstration," Bennett said in a statement emailed to CBC News. "Operations have resumed to normal at the Muskrat Falls construction site."
Russell and the others are being charged with obstructing a peace officer and will appear in court at a later date.
Sources say there are about 30 people still protesting. Although they are not permitted to stop any vehicles, they're slowing them down. It's taking Muskrat Falls project vehicles up to an hour to make it through.
Other vehicular traffic is being allowed through, such as those trying to make the ferry.
The RCMP said they will continue to monitor the situation.