The Manchester Ship Canal Company Ld United Utilities Water Ltd

A claim in trespass cannot be re-packaged as a new cause of action merely by identifying the origin of material discharged through an outfall. Where earlier proceedings concerned the same alleged interference and the new facts are relied on only to defeat a defence of statutory authority, the causes of action are the same. Cause of action estoppel therefore bars points which could and should have been raised earlier. The Henderson v Henderson principle separately requires a broad, merits-based assessment of whether later proceedings would misuse the court’s process or oppress the opponent.

Under the Water Industry Act 1991, the statutory right to discharge through an existing outfall extends to material entering the sewerage system through post-1991 connections or adoptions, subject to statutory safeguards. A proposed claim based on section 186 was also barred by issue estoppel and constituted an abuse of process.

The claimant, owner of the Manchester Ship Canal, brought a Part 8 claim against the defendant sewerage undertaker. It sought a declaration that discharge through an existing outfall was trespass to the extent that the discharged material originated in a sewer adopted after 1 December 1991.

The claim followed earlier litigation between the same parties concerning statutory authority to discharge through the outfall. The Supreme Court had held that a sewerage undertaker could continue to discharge through outfalls in use before the Water Industry Act 1991 came into force, subject to statutory safeguards. The claimant also sought permission to amend its claim to rely on section 186 of that Act.

The issues were whether the present claim was defeated by the earlier decision, cause of action estoppel, issue estoppel or abuse of process, and whether the proposed section 186 case should be permitted.

1. Present claim struck out. The claim was based on the same cause of action as the earlier trespass claim. At the highest level of abstraction, trespass required possession or a right to possession and direct physical interference with the land. The origin of the discharged material was not an element of the cause of action. It was relied on only to answer the defendant’s defence of statutory authorisation. The claim was therefore barred by cause of action estoppel.
2. The Supreme Court’s decision was binding, or in any event strongly determinative, on the Origin Point. Its reasoning treated sections 106 and 116 of the Water Industry Act 1991 as part of the statutory context requiring a continuing right to discharge through existing outfalls. That reasoning could not coherently distinguish material from post-1991 connections or adoptions. The right was expressed by reference to the outfall and was not qualified by the source of the material. The discharge through Outfall 61, including material originating in the Marshbrook Sewer, therefore did not ipso facto constitute trespass.
3. The Origin Point could with reasonable diligence have been raised in the earlier proceedings and should have been raised there. Applying the broad, merits-based approach required for Henderson v Henderson abuse, the court weighed finality, judicial resources, the substantial costs of repeated investigations and the oppressive burden on the defendant. The present claim was an abuse of process, and no exceptional feature justified declining to strike it out.
4. Proposed section 186 amendment dismissed. The section 186 case involved a different cause of action from the earlier private-land trespass claim, so cause of action estoppel did not apply. Issue estoppel did apply because statutory authorisation to discharge through Outfall 61 was a common issue and the section 186 point could and should have been raised earlier. The proposed amendment was also abusive under Henderson v Henderson.
5. The court did not finally determine the substantive construction of section 186. The proposed pleading lacked particularity and supporting evidence and was unsuitable for Part 8 procedure, but those matters did not need to be decided because the amendment was barred by estoppel and abuse of process.

This was a first-instance decision in the Present Claim. The judgment describes earlier proceedings between the same parties, culminating in the Supreme Court’s decision in [2014] UKSC 40, followed by consequential proceedings before Newey J. Those decisions concerned the parties’ earlier 2010 claim and were not appeals from the Present Claim.