Watery rights and wrongs – and causation too

TA-ArcticCharr-002R (o.t.a Seiont, Gwyfrai and Llyfni Anglers Society) v. Natural Resources Wales [2015] EWHC 3578, Hickinbottom J, 17 December 2015, read judgment and

Chetwynd v. Tunmore [2016] EWHC 156 (QB), HHJ Reddihough, sitting as a judge of the High Court, 4 February 2016, read judgment

This is a wintry double-bill on two recently decided cases about water quality, quantity, fish – and causation.

In the first, Seiont, Snowdonian anglers complained that the Welsh water regulator (Natural Resources Wales or NRW)  had misunderstood what was required by the Environmental Liability Directive in respect of Llyn Padarn, a freshwater lake the home of the Arctic charr, Salvelinus alpinus.  So they sought judicial review of NRW’s decision.

The main legal question was – did environmental damage within the Directive include slowing down recovery from previous damage, as the anglers argued, or was it confined to deterioration from an existing state (as the regulator had decided)?

Hickinbottom J held the latter, and the claim was dismissed.

In the second case, the claimant owners of fishing lakes in Norfolk said that their neighbours, in constructing rival lakes (without planning permission) had caused water levels to fall, and hence loss of fish and consequent income. Had that been established, the claimants would have had a claim for breach of statutory duty under section 48A Water Resources Act 1991. Such a claim, the judge held, would have been a strict liability one, in which foreseeability of damage played no part.

But the claimants lost on the facts, not before the judge had given an interesting analysis of the law of causation in this field.


The particular interest of the Arctic charr in Llyn Padarn is that the population is genetically distinct, unsurprisingly given that the lake is landlocked. Charr like deep cold lakes, high in dissolved oxygen. They do not like nutrients, especially phosphorous, which may affect those dissolved oxygen levels.

At which point, enter the Interested Party in this judicial review, Dwr Cymru (Welsh Water), which discharges sewage into the lake via an outfall consented to by Natural Resources Wales. Most of the sewage is treated, though as is very common in sewage systems, there are untreated flows as a result of storms.  Phosphorous in lakes is largely derived from sewage.

The anglers said that the sewage flows were causing “environmental damage” within the meaning of the Environmental Liability Directive (ELD), in two different ways, because there was a worsening in (i) the conditions within a Site of Special Scientific Interest (SSSI) and (ii) in the water which formed “a surface water body” as defined by  the Water Framework Directive. And this was what the NRW had got wrong. Forgive the shorthand, but I have compressed about 6 pages of the very clear judgment into the last two sentences.

The argument underlying (i) and (ii) was the same, summarised by the judge in [93] as

-“environmental damage” includes not only deterioration of the environmental condition, but preventing, limiting decelerating or otherwise impairing the progression of any relevant element to the environmentally acceptable

“Damage” was defined by Art. 2(2) ELD as “a measurable adverse change in a natural resource or measurable impairment of a natural resource service which may occur directly or indirectly.” “Adverse” is self-explanatory, and the judge rejected a submission that “measurable impairment” when read in context could involve a slowing down in improvement of the water in question: [139].

On the evidence, the judge rejected the contention that there had been any deterioration of the water such that the charr were affected since April 2007 – the date from which member states had to bring the ELD into force. This turned on detailed findings by the NRW in its decision letter that the reduced dissolved oxygen levels in fact had not impaired the charr population.

At first blush, it is odd that a failure to improve caused by a certain agent is not caught by the ELD, whereas a deterioration caused by the same agent is. But, as the judge pointed out, the ELD is all about imposing liabilities on polluters for their conduct since its coming into force, in circumstances where a causal link between the damage and those polluters’ activities can be established. Contrast other directives such as the Water Framework Directive where, and again I over-simplify, member are under broader obligations to secure the improvement of water bodies so that they attain “good” status as defined by the WFD.


From the cold deep waters of Snowdonia, to some shallow ponds and lakes in South Norfolk.

The claimants sustained a substantial fish kill over one winter due to reduced levels in their ponds, and further loss of profits over the next years. They sought damage for these losses from the neighbours who had unlawfully abstracted water in the course of constructing their fishing lakes.

The first legal point of interest in this decision is that a neighbour can be strictly liable under the Water Resources Act for causing damage by water abstraction even though he may not have been negligent or indeed have foreseen the damage caused to his neighbour. This point has not arisen for decision before.

But the facts are interesting too, and tell a cautionary tale for those thinking about litigating about water resources. They also gave rise to the second legal question, as we shall see. The hearing lasted 10 days, and you can tell from the judgment that experts gave some very detailed evidence about the groundwater and surface waters in the locality. Nowhere near enough to say – you abstracted water next door, and the levels in my ponds went down – ergo I have proved my case. This was because there were a number of other potential causes which might have led to the reduction in water levels, including variation in climate, the levels in the local river, and indeed the growing of willow trees nearby.

Hence the remaining issue of law. The defendants said that the claimants must prove that, but for their abstraction, they would not have sustained their damage. The claimants said, no, all they need show that abstraction was a significant cause or made a material contribution to the reduced water levels – as long as it was more than de minimis (as we lawyers say, thinking it is better and more mysterious in Latin). The cases which supported the claimants’ argument were principally industrial disease cases, and a dictum in Bailey v. Ministry of Defence that where medical science cannot establish “but for” but can establish a more than negligible contribution from the act of negligence, then the “but for” test is modified.

As the judge pointed out at [31]

a common feature of these cases was that there was more than one agent or condition brought about by cumulative or consecutive causes, one of which involved fault by the defendant..”

He thought that the current situation was very different. The “but for” test applied:

If, therefore, for example, other causes would have resulted in the lowering of the water levels such that the loss and damage occurred in any event, then the Lakes would have made no difference to the outcome and causation is not proved. On the other hand, if other potential causes would only have lowered the water levels to a limited or insignificant degree at most and the claimants prove on the balance of probabilities that the Lakes caused additional lowering of levels such that the loss and damage resulted, they will succeed on causation. In short, I hold that the claimants must prove that it is more likely than not that, but for the excavation of the Lakes, the crucial lowering in the water levels of the Ponds and any consequent loss and damage would not have occurred.

I am not sure that the line is quite as clearcut as the judge would seek to make it, between the two categories of case, at least in principle. However, on the facts found by the judge, the claimants could not establish this. After hearing the conflicting  evidence of the hydrologists, the judge thought that climatic variation was the main cause of the lowering of levels – acting via a chalk aquifer which fed one of the key ponds in issue.


Causation is key in environmental cases, sometimes rightly, sometimes wrongly. If you are holding someone responsible for something, then in general, it is not asking too much to expect you to prove that the other party actually caused your loss or some environmental impairment which lies behind your claim. But sometimes, when the science is cutting edge, it may be thought that there are strong policy reasons to take a different view as to what needs to be proved. That might be more akin to that applicable to industrial disease, particularly where there are strong reasons to take a precautionary view about the effect of some pollutant. If you increase the risk of something which medical or environmental science cannot say one way or another was the definitive cause, then perhaps you should be responsible for that risk.

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