Systems methodologies are employed to investigate water quantity and quality problems in Canada’s oil sands from a multiple-objective-decision-making viewpoint. Because water is one of the most important elements for human survival, many countries consider water issues to be of vital concern with respect to national security. Likewise, Canada is not an exception in terms of addressing its water resources problems as being of great import. In particular, water issues, such as large-scale water usage and troublesome polluted water disposal concerns connected to Canada’s oil sands industries, must be resolved. In this paper, Canada’s oil sands are described with respect to their characteristics, scale, and location. Then, technologies for recovering bitumen from oil sands and processes for upgrading the bitumen are discussed in terms of water consumption and water disposal. In addition, the environmental impacts and challenges with regards to water quantity and quality in Canada’s oil sands are examined in order to understand conflicts that have arisen in recent years. Multiple-criteria decision analyses based on the ProGrid methodology are carried out in order to grasp the structure of the conflict over alternatives for using and treating the water resources in oil sands development in Canada. An evaluation matrix, comparing the multiple criteria, is built, and the Language Ladders with different weights are established to allow the various groups of experts to evaluate the alternatives. Based on their evaluations, alternative solutions for the utilization of the water resources in Canada’s oil sands are prioritized with respect to the critical criteria using the ProGrid methodology. In conclusion, the strategic issues in water resources are addressed and priorities are determined to enhance decision-making.