Executive Summary: Key Legal and Evidentiary Issues

• Whether PBCN’s proposed amendment to reintroduce a treaty infringement claim was barred by res judicata (cause of action and issue estoppel).

• Interpretation of the 2016 Court of Appeal order limiting PBCN’s surviving claims to continuing trespass alone.

• Application of the doctrine of abuse of process to prevent relitigation of previously adjudicated matters.

• Whether the new pleading represented a distinct legal claim or merely reframed previously dismissed treaty arguments.

• Impact of PBCN’s 2019 amended reply, which had disclaimed any ongoing treaty rights claims in the action.

• Whether the Chambers judge erred in exercising discretion to deny the amendment based on legal standards.

Facts of the case

This case stems from historical flooding of the Southend Reserve (IR 200), a reserve of the Peter Ballantyne Cree Nation (PBCN), caused by hydroelectric dam projects along the Reindeer River in northern Saskatchewan. Dams built in the 1930s and 1940s—particularly the Whitesand Dam—altered water levels and led to flooding of PBCN’s lands. Ownership and operation of the dams eventually passed to SaskPower.

In 2004, PBCN sued the Governments of Canada and Saskatchewan and SaskPower, alleging multiple causes of action including trespass, breach of fiduciary duty, infringement of treaty rights under Treaty 6, and failure to consult. In a 2014 decision, the Court of King’s Bench dismissed all but one claim, finding most were statute-barred. The only claim permitted to proceed was for the continuing tort of trespass.

In 2016, the Saskatchewan Court of Appeal upheld the dismissal of all claims except for continuing trespass, making clear that all treaty-based claims were extinguished by the limitation period. PBCN’s attempts to further appeal to the Supreme Court of Canada were refused.

Outcome of the appeal

In 2023, PBCN sought to amend its claim again—this time seeking to plead that the continuing trespass was also an infringement of its treaty rights to exclusive possession under Treaty 6, protected by section 35(1) of the Constitution Act, 1982. The King’s Bench Chambers judge allowed some amendments, but rejected this particular paragraph on the basis that it attempted to revive a barred treaty claim. PBCN appealed.

In its 2025 decision, the Saskatchewan Court of Appeal dismissed the appeal, finding no error in the Chambers judge’s ruling. The Court held that the proposed amendment was barred by:

• Cause of action estoppel: The claim for treaty infringement had already been litigated and dismissed in the 2016 appellate decision.

• Issue estoppel: The issue of whether PBCN’s treaty rights were infringed due to the flooding had already been resolved.

• Abuse of process: Allowing the amendment would relitigate a matter conclusively determined and would undermine the finality of court decisions.

The Court reviewed the 2013 statement of claim and determined it had already advanced broad claims regarding treaty rights—including rights to land possession—and those were struck and not permitted to proceed. The new amendment, which characterized the trespass as a treaty infringement, was merely a reframing of the previously dismissed cause of action.

Additionally, the Court noted that PBCN had in 2019 filed an amended reply stating that no infringement of treaty rights was at issue. While the Court declined to rely on that inconsistency alone, it further supported the finding that PBCN was attempting to reopen closed issues.

The Court found no basis for exercising discretion to allow the amendment. It affirmed that PBCN’s sole surviving claim remains one of continuing trespass, and no treaty-based relief or constitutional claims are allowed to be reintroduced in this litigation.

PBCN was ordered to pay costs to both Saskatchewan and SaskPower.