Watercourse – Flooding — Damage to property — Culvert adjacent to respondent’s property causing flooding – Respondent bringing proceedings in nuisance — Whether appellants liable – Preliminary issue whether relevant section of culvert was sewer – Whether second appellant as sewerage undertaker having statutory duty to maintain –Appeal allowed by majority
The watercourse at the centre of the dispute constituted a channel through which flowed a former natural spring; the channel was covered for much of its length and the bed of the stream had been lined with concrete. Part of one of the uncovered stretches ran along the southern boundary of the respondent’s property, upon which buildings had been constructed in 1998. A section of the culvert at the western end of the respondent’s land was covered.
The Environment Agency had given permission for a foul sewer overflow into controlled waters at times of flash floods. During high rainfall, therefore, foul sewage flowed through the culvert. The respondent argued that the flow bordering its property was a sewer, whether public or not, and not a watercourse, so as to impose liability for its flooding on either the first appellant local authority or the second appellant sewerage undertaker. The appellants sought to shift liability onto each other or onto the respondent, as riparian owner.
The judge at first instance decided, as a preliminary issue, that the relevant section of the culvert was a private surface-water sewer but not a public sewer. The test was whether the character of the natural stream had changed to such an extent that the channel had become a sewer in the ordinary non-statutory sense of the word. Relying upon British Railways Board v Tonbridge and Malling District Council (1981) 79 LGR 565 and George Legge & Son Ltd v Wenlock Corporation [1938] AC 204, the judge said that that was a question of fact and degree in every case and was not an easy test to satisfy.
It was common ground that parts of what had once been a natural watercourse had become a surface-water sewer, but not the part adjacent to the claimant’s property. The second appellant appealed on the ground, inter alia, that the change in the nature of the flow along the culvert was not sufficiently substantial to satisfy the requisite test.
Held: The appeal was allowed (by a majority).
The judge’s decision had been wrong. The culvert remained a watercourse and had not become a sewer. The judge had approached the question wrongly by considering the status of the channel as a whole, rather than that of the culvert, albeit in the context of the rest of the channel so far as was relevant.
The nature of the flow through the culvert was certainly relevant. The stream started as a watercourse, carrying natural groundwater as well as some surface water. It started in the same place and remained partly open there. Accordingly, the natural assumption was that it still carried natural groundwater and the burden of proof was on the appellants to contend otherwise. There was no relevant discharge of foul sewage. Although the discharge of surface water had increased, something more fundamental than that was required.
On a true analysis of the facts regarding the culverts, the statutory undertaker had done nothing to that stretch of the channel to affect its status. There was nothing more than an increased discharge to rely upon, so that the status of the stream as it flowed through the culvert as a watercourse had not changed, however much its appearance might have changed, and notwithstanding any changes to the status of the watercourse elsewhere in the channel, both upstream and downstream: British Railways Board applied.
Jeremy Burns (instructed by the legal department of Southampton City Council) appeared for the first appellants; Clifford Darton (instructed by the legal department of Southern Water Services Ltd) appeared for the second appellant; Graham Chapman (instructed by Jacobs & Reeves, of Poole) appeared for the respondent.
Eileen O’Grady, barrister
