Relaxing the Principle of Prior Appropriation: Stored Water and Sharing the Shortage in Alberta, Canada

Abstract

Prior appropriation (allocation), 'first-in-time is first-in-right', provides a dominant water policy in western North America and some other regions worldwide. Concerns with this chronological prioritization arose during the Canadian Oldman River Dam project, since anticipated water for environmental flows and an indigenous group would have been unreliable with junior licenses. It was considered that in Alberta prior allocation applies only to the natural flow and water captured in a reservoir during surplus is not later bound by license seniority. Consequently, the Oldman Dam operation ensures minimal environmental flows and thereafter, 'sharing the shortage' is applied, with licensees receiving partial allotments during shortages. A related test-case for adjacent rivers with publicly-funded reservoirs accompanied a water shortage in 2001. It was considered unacceptable to cut-off water to a food-processing plant, a town, and water co-operatives with recent licenses, and consequently irrigation districts and others agreed to share the shortage, with all receiving 60% allotments. Following success, water sharing was also approved for 2002 and 2007. The discretionary use of stored water and sharing the shortage represent 'equitable allocation', an alternative to prior appropriation, which may benefit other jurisdictions facing water shortages.

The Influence of the Pacific Decadal Oscillation on Annual Floods in the Rivers of Western Canada

“…We explored creating a similar regional index for the equally economically important South Saskatchewan River Basin (SSRB), a premier agricultural region of Canada, which is heavily dependent on SSRB surface flows for irrigation (Figure A). This region is under such severe demand for surface water supplies that large portions of the SSRB have been closed to further allocation (Rood and Vandersteen, ; Sauchyn et al ., ). It was also severely impacted by the June 2013 southern Alberta floods, heightening interest in more accurate flood frequency curves.…”

Hydrologic linkages between a climate oscillation, river flows, growth, and wood Δ13C of male and female cottonwood trees

“…). The middle interval (1999–2001) represented an extremely low‐flow period due to low snowpacks and rainfall, and substantial water withdrawal for irrigation (Rood & Vandersteen ). The annual hydrographs for the low‐flow years 2000 and 2001 (Fig.…”

“…The first interval (1994)(1995)(1996) included 1995, with the highest peak flow of the century-long record ). The middle interval (1999)(2000)(2001) represented an extremely low-flow period due to low snowpacks and rainfall, and substantial water withdrawal for irrigation (Rood & Vandersteen 2010). The annual hydrographs for the low-flow years 2000 and 2001 (Fig.…”

Adaptive Water Resource Planning in the South Saskatchewan River Basin: Use of Scenarios of Hydroclimatic Variability and Extremes

“…Over the entire projected period of 2025-2054 and for the 2-year Min hydroclimatic scenario, results demonstrate that the use of forecast-based rationing dramatically reduces shortage days (Figure 8). Importantly, this approach suspends the First in Time First in Right allocation system, demonstrating that collaboration (as actually occurred in 2001 with the sharing of the water deficit among users; Rood and Vandersteen, 2010) can add significant value to strategies that incorporate more storage to help meet the needs of junior water licence holders. The breakdown of these results over the seven irrigation districts in the OSSK shows that the C3 scenario reduces the number of days with shortages for all irrigation districts over the 30-year period (Figure 8c).…”