Thames Water Utilities Ltd v London Regional Transport and another

Negligence — Statutory duty — Nuisance — Causation — Damage caused by claimants’ burst water main — Whether additional load on water main resulting from defendants’ tunnelling works causing failure — Whether defendants liable in damages — Claim allowed A water main owned by the claimant burst during the course of the defendant’s tunnelling works, causing substantial damage. The cost of remedial works and compensation ran into many millions of pounds. The claimant contended that the defendants had caused the main to burst and were therefore liable for the consequent loss and damage. The claimants brought claims for: (i) a breach of statutory duty under section 42 of the London Transport Act 1963; (ii) at common law in negligence for a failure to use reasonable skill and care in the carrying out and completion of the works; and (iii) in nuisance for removing and/or undermining ground support from the main. The defendants contended, inter alia, that the claimant had not proved that the works were a material cause of the pipe failure. The history of the area indicated that the main had been highly stressed and vulnerable prior to the burst such that any additional loading caused by the works would not be a material cause of the failure of the main. Both parties called expert witnesses. Held: The claim was allowed. A single test of causation applied to the same set of facts, irrespective of whether the case was pleaded in negligence, nuisance or for a statutory breach. The question of causation was a matter for factual inquiry by the court. This was traditionally undertaken by the application of the “but for” test, that is, whether the damage of which the claimant complained would have occurred “but for” the negligence (or other wrongdoing) of the defendants. The “but for” test was a necessary but not determinative test of causation. It might serve as an exclusionary filter or to identify viable causes. Even where the claimant satisfied the “but for” test, the court had an obligation to evaluate the cause in terms of its materiality. The court took a common-sense approach to the task of evaluation, being informed and guided by reference to the scope of the duty owed. No exceptional or policy grounds warranted the relaxation of the normal rules as to causation: Banque Bruxelles Lambert SA v Eagle Star Insurance Co Ltd [1997] AC 191 and Fairchild v Glenhaven Funeral Services Ltd and others [2003] UKHL 22; [2003] 1 AC 32 applied. On the evidence, the court was satisfied that the defendants’ works carried out had been the prime and effective cause of the differential settlement that had loaded the joints of the main such as to cause shearing or prising and thus bursting. Had that settlement not occurred, the pipe would have continued in use for many years to come. The ground movement caused by the defendants’ works could not be said to have been so slight that they could be characterised as de minimis, by adding a nominal loading to a pipe grossly loaded as a result of historic locked-in strains and stresses. Marcus Taverner QC and Simon Hughes (instructed by Lane & Partners) appeared for the claimant; Robert Moxon Browne QC and Tim Lord (instructed by Watmores) appeared for the defendants. Eileen O’Grady, barrister