When officials decide who gets to use water from a river, it's important to take note of how much water the river normally holds. That number lets governments make their allocations: Twenty billion gallons a year for you; 40 billion gallons a year for you.
Sounds like a good system, right? But there's one problem. Governments usually base these calculations on fairly recent data. A longer-term scientific study, however, might show that the river has had even lower or higher flow rates in the past and may again, in the future. In other words, those numbers from which they're basing their calculations might soon be outdated. That famously happened with the Colorado River in the 1920s, when American states in the West hammered out an agreement about how much water each would draw—based on data from years in which the Colorado was unusually abundant. That historical mistake set the stage for water fights among states as the the river returned to it usual size.
Alberta's tar sands have boosted the province's economy, but environmental groups worry about how much water the industry uses and dirties.
Now, a team of scientists is arguing something like that has happened again with the river that provides water to Canada's Alberta tar sands. The research team, from Canada's University of Regina and University of Western Ontario, re-constructed the flow of the Athabasca River over the last 900 years. The Athabasca has had low-flow years that exceed anything from the Alberta government's records, which are about 60 years old, the team finds.
That means Athabasca River's water allocations—which go to entities such as factories, power plants, and city folks' showers and toilets—could become unsustainable, if those low conditions return, the researchers argue in a paper published in the Proceedings of the National Academy of Sciences. The majority of allocated Athabasca water, however, is set aside for the oil and gas industry, which has faced opposition from environmental groups for years over how much water it takes from the Athabasca River. Alberta's tar sands have boosted the province's economy, but environmental groups worry, among other things, about how much water the industry uses and dirties. (The processes of mining and separating usable oil from tar sands require water.)
Alberta does have a way of responding to fluctuations in the Athabasca River's water levels. Officials measure the river's flow, then label it as "green," "yellow," or "red." If the river is at a green level, oil-sands companies are allowed to draw their entire allocation, if they want. If the river is at yellow or red, the government may require them to draw less than their licensed allocation. But environmental groups say the government policy is not enough, because, no matter what, oil-sands companies are allowed to draw a base amount.
The new study provides more ammunition to such groups. However, it might take another study to predict whether it will be enough to alter Alberta's Athabasca policy.
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