FORT ELLIS, N.S. -- On the muddy banks of Nova Scotia's Shubenacadie River, Dorene Bernard is listening for sounds that will let her know the historic waterway is about to change direction.

"The wind will pick up, and you'll start hearing the water and waves coming," the Mi'kmaq activist says as she walks through the tall grass, carrying a large fan made from an eagle's wing.

The Shubenacadie is a 72-kilometre tidal river that cuts through the middle of Nova Scotia and flows into the Bay of Fundy. But when the world's highest tides rise in the bay, salt water flows up the river for almost half its length, creating a wave -- or tidal bore -- that pushes against the river's current.

It's an unusual natural phenomenon that draws tourists from around the world. It has also helped support the Mi'kmaq for more than 13,000 years.

"This is a major highway, a major artery for our people," says Bernard, a social worker, academic and member of the Sipekne'katik First Nation in nearby Indian Brook, N.S.

"Our ancestors are buried along here ... It has a very significant historical, spiritual and cultural relevance to who we are."

Before the bore arrives, the river is like glass on this humid, windless day.

However, Bernard is mindful that another change is coming for the river and her people.

For the past 12 years, a Calgary-based company has been planning to pump water from the river to an underground site 12 kilometres away, where it will be used to flush out salt deposits, creating huge caverns that will eventually store natural gas.

AltaGas says the leftover brine solution will be pumped into the river, twice a day at high tide, over a two- to three-year period.

The initial plan is to create two caverns about a kilometre underground. But the company has said it may need as many as 15 caverns, which would be linked to the nearby Maritimes and Northeast natural gas pipeline, about 60 kilometres north of Halifax.

The storage is needed by an AltaGas subsidiary, Heritage Gas, which sells natural gas in the Halifax area and a few other Nova Scotia communities. It says it wants to stockpile its product during the colder months to protect its customers from price shocks when demand spikes.

Drilling for the first two caverns has been completed.

After years of consultations, legal wrangling and scientific monitoring, the company's Nova Scotia-based subsidiary, Alton Natural Gas Storage LP, has said it plans to start the brining process some time later this year.

Bernard says her people are not going to let that happen.

The $130-million project has been largely on hold since 2014 when Mi'kmaq activists started a series of protests that culminated two years later in the creation of a year-round protest camp at the work site northwest of Stewiacke.

"We're not going to let anyone destroy our water," Bernard said in a recent interview, declining to elaborate on what will happen if police or security guards try to reclaim the site.

"The impacts will be huge. You can't just put something in your vein and think it's not going to affect your whole body."

She says the company has consulted with Indigenous leaders, but she insists it has done a poor job of reaching out to the Mi'kmaq people, particularly those who are members of her First Nation.

"There was never a public hearing with Alton Gas in our community. Never."

For its part, the company has insisted it has consulted with local Indigenous people, and the provincial government has agreed.

More importantly, the company says it has already secured the permits it needs to start pumping water from the river.

At the entrance to the protest camp off Riverside Road, a steel gate is covered in placards and a canvas lean-to. A sign that warns against trespassing -- installed by the company with the help of the RCMP -- has been covered with a blanket.

In May of last year, protesters built a tiny, two-storey house out of straw bales and lime plaster. It has a dirt floor, wood stove, bunks and plenty of provisions inside.

There's also a garden. Chickens and geese roam the makeshift squatters camp.

On this day, there are only three protesters -- they call themselves water protectors -- at the site. But some supporters from Halifax later drop by for a visit.

"We have a lot of allies, settlers who are supporting this camp -- it's not just the Mi'kmaq," says Ducie Howe, Bernard's cousin and a resident of what she calls Shubenacadie Reserve No. 14, the original name for the nearby First Nation.

"There's people from all over who will come. And they'll keep coming."

Howe says Nova Scotians need to be reminded that the company is operating on unceded Mi'kmaq territory.

"We signed peace and friendship treaties," she says. "We never signed treaties that gave up any part of our lands ... Giving out permits? Those are illegal. They didn't have the right to do that."

Closer to the river, there's a smaller, flat-topped wooden building that Bernard describes as a truckhouse. The reference is to the 1752 Peace and Friendship Treaty, which states that the Mi'kmaq are free to build "truckhouses" along the river to facilitate trade.

In the distance, a small hut for security guards sits empty.

Company spokeswoman Lori Maclean says some protesters have been served with trespassing notices.

"The company is aware of the activity of protesters at the site and continues to engage with law enforcement and the community," she said in a recent email. "Alton sites are work areas that are open only to Alton staff or approved contractors."

Alton has received the environmental and industrial approvals it needs to proceed, including two environmental assessments and an independent third-party science review. However, provincial Environment Minister Margaret Miller has yet to make a decision about an appeal of the industrial approval filed by the Sipekne'katik First Nation.

As for the brine that will be pumped into the river, the company says the peak release on each tidal cycle will be approximately 5,000 cubic metres, which will be mixed in with four million cubic metres of brackish tidal flow.

The company says the brine flowing into the Minas Basin "would not be detectable and would be insignificant in terms of the natural fluctuation of salinity the ecosystem is subject to during each tidal cycle."

Alton Gas also says the intake pipe will not suck in fish or small organisms because the water will be filtered through a rock wall, and the intake flow will be low enough to allow all fish to swim away.

"The requirements of our monitoring program with provincial and federal regulators will ensure that the brine will not impact the ecosystem," the company's website says.

Before Bernard and Howe leave the river, the pair stand at the edge of the bank to make an offering through song.

The lyrics are sung in the original Ojibwa and then in Mi'kmaq: "Water, I love you. I thank you. I respect you. Water is life."