The rain keeps coming; flood waters keep rising. Insurance claims for this winter’s floods are already put at over £426m, with insurers receiving more than 174,000 claims between 23 December 2013 and 8 January 2014 alone.

All of this adds up to a major headache for local authorities – not just in coping with the day-to-day problems but also in facing the spectre of claims against them for failure of duty.

Local authorities will be aware that section 41(1) of the Highways Act 1980 imposes on highway authorities a duty to maintain adopted roads. ‘Maintain’ is defined to include ‘repair’.

Readers will also be familiar with the defence afforded by section 58(1) of the Act which provides that: 'In an action against a highway authority in respect of damage resulting from their failure to maintain a highway maintainable at the public expense it is a defence …. to prove that the authority had taken such care as in all the circumstances was reasonably required to secure that the part of the highway to which the action relates was not dangerous for traffic.'

Most claims alleging a breach of the duty to maintain or repair are relatively low value personal injury cases. But a failure to maintain and repair can lead to a much more serious claim for damages from, topically, flooding, as the Court of Appeal explained in Vernon Knights v Cornwall Council [2013] EWCA Civ 950.

Cornwall Council is the highway authority responsible for the maintenance of Honicombe Road, a minor road running along the boundary of a holiday village, Honicombe Manor. In one section of Honicombe Road there is a dip where surface water collects. If not drained away after heavy rainfall it will surge into the neighbouring property. In about 2000 the council installed drains, gullies and a catchpit into the dip. The council’s contractors CORMAC were aware of the particular problem with the dip. They visited the site regularly to clear leaves and debris from the dip. That, one might have thought, would have been enough to satisfy a judge that they had done all that was reasonably required of them.

By 7pm on 24th November 2006, six weeks after CORMAC’s last visit, 25mm of rain had fallen in the area. Knowing the dip was a problem, CORMAC did attend, but not until 9.45pm. By then the holiday village had flooded causing £123,000 worth of damage. Another less serious flood occurred in similar circumstances two years later in September 2008 causing £18,000 worth of damage.

The owners of Honicombe Manor sued the council in nuisance and negligence, relying on the council’s failure to clear the drains and gullies in the catchpit. They lost at trial but won in the Court of Appeal. They won because the court concluded that the maintenance system had two flaws, namely that rural maintenance teams were not required to identify hotspots to their line managers and there was no standard procedure requiring rural maintenance teams to check hotspots during bad weather. There were informal arrangements but these did not work. Thus the necessary measures to reduce flooding had not been implemented on dates of the heavy rainfall.

The reasoning is explained at paragraph [49] in the judgment of Lord Justice Jackson:

(i) A landowner owes a measured duty in both negligence and nuisance to take reasonable steps to prevent natural occurrences on his land from causing damage to neighbouring properties.

(ii) In determining the content of the measured duty, the court must consider what is fair, just and reasonable as between the two neighbouring landowners. It must have regard to all the circumstances, including the extent of the foreseeable risk, the available preventive measures, the costs of such measures and the resources of both parties.

(iii) Where the defendant is a public authority with substantial resources, the court must take into account the competing demands on those resources and the public purposes for which they are held. It may not be fair, just or reasonable to require a public authority to expend those resources on infrastructure works in order to protect a few individuals against a modest risk of property damage.

To defend themselves against future claims for flood damage, local authorities will need to be able to show three things: first, that they have considered what preventative measures are available to them to guard against a known risk of flooding; second, that they have allocated their resources sensibly balancing the potential damage to property against the cost of prevention, and third, as Cornwall failed to do, making sure there is a workable emergency plan to deal with known ‘hotspots’.

John de Waal QC is from Hardwicke chambers