Wednesday, February 17, 2010

Environmental flows in Alberta (Canada) and tar sands exploitation


In the last 10 years, Alberta has experienced an economic boom based on tar sand exploitation. The main tar sand deposits currently exploited are situated in Northern Alberta, in the Athabaska river basin, which is tributary to the Mackenzie river, one of the last great North American rivers left in a relatively pristine state (here is a map of the North American watersheds).

Tar sand exploitation consumes large volumes of water. To extract 1 oil barrel from the sands, a water input of 2 to 4.5 barrels is required depending on the method. The used water is loaded with toxic contaminants and almost all of it ends up in tailing ponds.

Alberta has defined a framework that indicates how much water tar sand companies can remove from the Athabasca River in order to foster economic development while ensuring healthy aquatic ecosystems in conformity with the provincial water strategy (see p.10-11).

Recently, the Cumulative Environmental Management Association (CEMA) has released a report developing recommendations for a Phase 2 Water Management Framework that will prescribe when and how much water can be withdrawn from the lower Athabasca river for cumulative tar sand exploitation. According to the report summary:

«Key lessons and principles that emerged from this exploration, and are strongly recommended to form the basis of the final water management framework, include:

• Water withdrawal rules should generally be more restrictive as flows decrease.

• Although there is a need to provide instream flow protection throughout the entire year, there should be a hierarchy of protection across seasonal time periods: 1)midwinter, 2) late winter/early spring, 3) fall/early winter, and 4) summer.

• A specified EBF threshold is a means of providing increased protection during low flow events and refinements to its application on the Lower Athabasca River should continue to be explored.

• Mitigation using off-stream storage (or other equivalent approach to mitigation) is a necessary means of facilitating an effective water management framework.»

This report has been received with some reservations. The Prairie Chapter of the Sierra Club of Canada has set up the Got Thirst? Campaign that warns of the perils of water resources over-exploitation.

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