Well, it seems unlikely we will see any more overpowering images in the cinema this year. Within its first 10 minutes, Edward Burtynsky’s combination of visual poem and stealth polemic has offered at least three tableaux that will cause some contemporary viewers to question the truth before their eyes. Were this a work of fiction, the opening shot of water pluming from China’s Xiaolangdi Dam would have little chance of passing for anything other than CGI. It’s a disease of the age.

It's all real. Burtynsky is justifiably famous for his huge, imposing photographs of industrial landscapes. Here, working with Jennifer Baichwal, he turns his attention to man's interactions with water. Somehow or other, form and intent mesh together utterly seamlessly.

That is to say, virtually every shot is beautiful and virtually ever shot addresses ecological concerns. The waterways of a vast delta fan out like capillaries. While travelling along a crashing river, we can’t help but notice the effects of logging on either bank. Oily sludge emerges from a tanning facility in Bangladesh.

Comparisons with vast visual epics such as Godfrey Reggio's Koyaanisqatsi are unavoidable. The ambient music, though effective, is not as overpowering as Philip Glass's score for that film. There is less obvious forward momentum in the montage. But Burtynsky's images are, if anything, even more bewitching than those in Reggio's picture.

Watermark is also a little more explicit in its ecological message. "Because I understand nature, I understand what was there before we came," Burtynsky says. "This is a lament for what is lost."

That point is made most forcefully by the sheer implausibility of what the film-maker puts before us. Can it be right to impose all these circular irrigated fields across so many miles of American prairies? Should there really be dancing fountains in the heart of Nevada?

A terribly beautiful and beautifully terrible piece of work.