Priority? Licence transfers? Here's how Alberta's water system works

Alberta's relationship with water has changed over the past century and a half — not only how we use it, and how much of it we use, but also how it gets allocated.

As this year seems certain to bring worsening drought conditions, the laws, regulations and history of water in Alberta are increasingly relevant — and worth unpacking.

The Water Act of 2000 states that all water in the province, as well as the right to its diversion and use, is vested in the Crown. This means that water can only be used with the permission of the provincial government. For municipalities and businesses, including most agriculture, this permission is tied to a licence.

The Water Act certainly isn't the first time that the Crown had asserted its ownership and control over water. In fact, that idea pre-dates Alberta as a province.

According to David Percy, an expert in water law at the University of Alberta, the province's current system traces its origin to the arrival of significant numbers of members of the Church of Jesus Christ of Latter-day Saints in the 1880s.

When the Mormons arrived in what is now Cardston, in southern Alberta, "they started doing what they did in Utah, which was to irrigate," says Percy. "And that was not permitted under the prevailing English common law of riparian rights, which said you can only take a certain amount of water from the river and you can only apply to lands adjoining the river, basically."

The passage of the North West Irrigation Act in 1894 laid the foundation for much of today's water licence system, borrowing from the prior appropriation doctrine that was prevalent in the western United States.

"Water law is not shaped by legal tradition. It's shaped by geography," says Percy.

"So if you take a line from Lake of the Woods on the Manitoba, Ontario boundary, to the Gulf of Mexico, everywhere west of that is a priority state or province, including British Columbia. Everywhere east of that, at least initially, was based on riparian rights, because east of that there's plenty of water, basically."

There are tens of thousands of licences for surface and groundwater in Alberta. From municipalities to agricultural operations, golf courses and oil companies — with few exceptions, anyone taking or diverting water in meaningful quantities needs a licence to do so.

Each licence comes with a priority number. These numbers are sequential, meaning that the oldest licences are the highest ranked.

The priority principle is known as first in time, first in right. In essence, the users with the earliest water licences are entitled to their water first. More specifically, they have the right to take the full amount of water allocated under their licence before more junior licensees receive any water at all.

In times of plentiful water, or in under-allocated parts of Alberta, this isn't much of an issue. However, in times of drought, some water licensees could be stuck.

Percy says the principle has "never been applied to cut off a major user." However, it also provides needed clarity.