The province has told Alberta’s oilsands giants to hold off on the amount of water it uses from the Athabasca River.

Alberta Environment says water flow levels in the river have dropped into the “yellow warning zone” under the province’s Water Management Framework that was introduced in 2007.

Further water withdrawals by the oilsands industry from the river “may increase stress to aquatic ecosystems,” said Alberta Environment.

The government says the low levels seen in the river are naturally occurring, but it’s the first time the province has made such an order to reduce the amount of water is used since the framework was introduced.

Companies affected by the order include Shell’s Albian Sands, Suncor Energy Inc., Syncrude Canada Ltd. and Canadian Natural Resources Ltd.

All of the companies’ projects are located downstream from Fort McMurray in northeastern Alberta.