A River Runs Across It: Solving Trans-border Disputes Over Water.

• Author: Surtees, Jeff

People get very passionate about both water and borders. So how do we avoid or resolve disputes involving rivers and lakes that cross the border between Canada and the United States?

At almost nine thousand kilometers, our border with our closest neighbour is the longest unprotected political border between two sovereign nations on Earth. The southern section of the border roughly follows the forty-ninth parallel while the northern section, between Alaska and the Yukon, mostly follows the one hundred forty-first meridian west. In places, like the St. Lawrence River and the Great Lakes, water forms the border. In hundreds of other places water flows across the border, sometimes from Canada to the United States, sometimes the reverse. Occasionally, as is the case for the Milk and St. Mary's rivers in southern Alberta, streams cross the border in one direction then turn and cross again in the other direction.

With such a long border and with water being so important to human health, to wildlife and to the economies of both countries, disputes are inevitable. Harm could be potentially be caused by direct pollution, inadequate water treatment, poor industrial practices, poor forestry practices, side effects of building infrastructure, such as increased sedimentation from building roads for forestry, mining and oil exploration, stream diversion for irrigation, raising or lowering the natural water levels of streams or damage to upstream fish habitat, especially in spawning areas.

How do we avoid or settle disputes? The answer, as always in environmental law, is complicated. Several international agreements play a role and there is a movement toward more local methods.

The first international document is the draft "UN Convention on the Law of the Non-Navigable Uses of International Watercourses" (here) which calls for 'equitable and reasonable utilization' of transboundary waters. This Convention could play a role in defining the obligations of Canada or the United States if it were held to have become part of customary international law, even though neither country has signed on to it. International environmental law works differently than domestic law. It is a world of norms, customs and "moral suasion". So if most of the world is following something they accept as a rule, there will be pressure put on other countries to follow the same rule, whether or not they have formally signed an agreement.

The second international agreement which might be...