Time and Tide Wait for No Man - Oldcorn v Southern Water Services Ltd [2017]

The recent case of Oldcorn v Southern Water Services Ltd [2017] EWHC 62 (TCC) serves as a reminder of the hurdles claimants must surmount in order to recover their losses and of the need to critically assess one’s own expert evidence before trial.

This case served as a test case for claims following the 2012 floods. The claimants’ West Sussex home was damaged as a result of surface water flooding. They alleged that the defendants had been negligent by inserting a tideflex valve into one of their pipes. They averred that this resulted in a significantly reduced flow through the pipe leading to water backing up behind the valve and causing flooding to their property.

The claimants’ home was situated very close to the sea and only just above sea level making it prone to flooding from both sea and rain water. Surface water drained from their land into the defendants’ pipe. The majority of the water would then drain out into the sea. As the pipe was submerged at high tide, there was a valve to prevent sea water from travelling back up the pipe and flooding the land. As surface water could not drain out of the pipe at high tide, the pipe was made of such a size that it could store the drained water for these short periods of time.

The property was flooded in 2009 during high tides and heavy rain. The majority of the flooding was caused by the sea water backing up along the pipe. As a result, the defendant fitted a tideflex valve intended as a further preventative measure to stop sea water from entering the pipe.

The claimants alleged that the defendant had been negligent in failing to undertake a proper assessment before fitting the valve. McKenna HHJ agreed.

However, to succeed in their claim, the claimants had to prove that the negligence had resulted in the flooding of their property. They relied upon a highly experienced and well regarded expert who had created a hydraulic model of the incident. The defendant relied upon an expert who in turn relied upon a model created, not by him, but by the defendants themselves.
The Judge disregarded the defendants’ evidence as a result of this and criticisms levied at it by the claimant’s expert.
However, the Judge also felt that the claimants’ expert evidence on causation fell short of discharging the burden of proof. There were a number of concessions made in his evidence such as the fact that his calculation of the impermeable areas of the property was incorrect.

There were also criticisms of his modelling such as his figure for rainfall uplift was subjective and considerably lower than nearby gauge results and his model produced flooding at a different time to when the flooding occurred in reality.

As a result of the numerous concessions and criticisms of the evidence, the Judge held he could not be satisfied on the balance of probabilities that but for the installation of the tideflex valve, the property would not have flooded.
The claim was therefore dismissed despite the finding of negligence on behalf of the defendants.


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