A scene of rapid change unfolds in front of David Campbell's deck that overlooks Fort Chipewyan's Lake Athabasca.

His house used to be lake front property — not any more. Over the last 50 years, water levels have transformed a once sandy beach into an arid field of willows and weeds.

"It's slowly receding. Slowly drying out," Campbell said.

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David Campbell is a hunter, fisher, trapper and Mikisew Cree First Nation member. (David Thurton/ CBC News)

Today two UNESCO monitors toured the lakes and channels around Fort Chipewyan, a hamlet 223 kilometres north of Fort McMurray. They are there to review the threats that low water levels and stressors like climate change and the oilsands pose to Wood Buffalo National Park — a World Heritage site.

Fort Chipewyan sits on the edge of the park and its water systems are connected.

The monitors are expected see the dry land that was once wet, water marks that indicate levels have dropped and hunting areas that are no longer accessible by boat.

"This past spring we couldn't get out on to our major lakes to go geese hunting," Campbell said.

"You couldn't pull a boat. You couldn't paddle out there. You couldn't hunt out there. You couldn't access your traditional lifestyle out there because there is no water."

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Year by year, people in Fort Chipewyan say the water levels in Lake Athabasca keep falling. (David Thurton/ CBC News)

Campbell, a Mikisew Cree First Nation member, grew up on the land and has a cabin where he spends his summers.

"I am still a traditional land user. I get out there as much as I can [on] weekends, holidays to go and have barbecue and hunt."

"You go to have water to move around and to hunt and sustain your way of life."

Dam impacts

Campbell blames the construction of dams, such as the BC's Bennett Dam, that he's observed over time on the reduce the flow of the Peace River.

The Mikisew Cree First Nation say the Bennett Dam's construction in 1967 has reduced the flow rates during certain times of the year and the ability of the inland delta's thousands of lakes to recharge itself.

He fears the future construction of BC's Site C Dam will make the problem worse .

He also thinks upstream oilsands industry is responsible for low water levels saying that it's using too much water.

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Alice Rigney, a member of the Athabasca Chipewyan Nation, is a hunter and owns a cabin on the land. (David Thurton/ CBC News)

Alice Rigney, from the Athabascan Chipewyan First Nation, agrees. Rigney says low water levels have made it impossible for her and others to hunt.

'They say the delta is a place that always changes. Okay. I believe that part but at the rate that it's happening?' - Alice Rigney

"We can't get to the lakes where the birds are," Rigney said. "We can't get to the lakes where the moose are."

Rigney describes the land as her medicine, source of food and church. She has a cabin on the lake with a garden.

In addition to site visits, the UNESCO mission will review research that has been done on the river delta. However, Rigney, who regularly attends research presentations, said scientists can't provide clear answers why the water levels have fallen.

Rigney said she is impatient with the lack of clarity and the rapid changes in the water she's witnessing.

"They say the delta is a place that always changes. Okay. I believe that part but at the rate that it's happening?"

Next steps

UNESCO declared Wood Buffalo National Park a world heritage site in 1983.

If the United Nation places the park on an in-danger list, it will join 55 others and it will be eligible for immediate assistance from the World Heritage Fund. At the end of the mission, the United Nations will also issue recommendations to the Canadian government that it can accept or reject.

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Fort Chipewyan sits on the outskirts of Wood Buffalo National Park. The park is home to the "largest self-regulating bison herd in the world," according to Parks Canada (Mikisew Cree First Nation/ Submitted)

However, if Canada fails to react to the suggestions, the Wood Buffalo National Park could lose its World Heritage Site status.

On Sunday, monitors will leave for Fort McMurray and then travel to Edmonton where they will meet with industry officials, the province and B.C. government officials.

Follow David Thurton, CBC's Fort McMurray correspondent, on Facebook, Twitter and via email.