New Hampshire v. Maine

Brief Fact Summary.

Plaintiff sued Defendant over the boundary between Maine and New Hampshire. Defendant filed a motion to dismiss on the grounds that the lawsuit was barred by judicial estoppel.

Synopsis of Rule of Law.

When deciding to invoke judicial estoppel, a court may consider whether the party’s position is clearly inconsistent with their earlier position, whether the court was previously persuaded by the earlier position, and whether the party would gain an unfair advantage over the opposing party.

Facts.

In 1977, New Hampshire and Maine entered a consent decree establishing the boundary between the two states to be up the middle of the Pscataqua River. The two states agreed that “up the middle” meant “the middle of the main channel of navigation of the Piscataqua River.” Twenty-five years later, New Hampshire (Plaintiff) sued Maine (Defendant), claiming that the Piscataqua River boundary runs along the Maine shore and that the entire river and all of Portsmouth Harbor belong to New Hampshire. Defendant filed a motion to dismiss on the grounds that the lawsuit was barred by judicial estoppel.

Issue.

Is New Hampshire’s lawsuit against Maine, which argues for a new interpretation of the Piscataqua River boundary, barred by judicial estoppel?

Held.

Yes, judicial estoppel bars New Hampshire from now asserting that the Piscataqua River boundary runs along the Maine shore.

Discussion.

The Court determined that Plaintiff’s new interpretation of “middle of the river” was inconsistent with its previous interpretation in the 1977 consent decree. Plaintiff had access to all the same historical knowledge when agreeing to the consent decree; Plaintiff persuaded the Court of the previous interpretation and benefited from the interpretation in the 1977 consent decree; and accepting the new interpretation would be unfair to the Defendant.