Environment – Nuisance – River – Dispute arising between respondent turbine owner and appellant Environment Agency concerning operation of fish pass in river – Respondent complaining that fish pass interfered with operation of turbine at times of river low flow – Respondent obtaining declaratory relief – Appellant appealing – Whether appellant prima facie liable in nuisance by keeping fish pass open at low flow – Appeal allowed
The respondent was the freehold owner of The Mill House, Mill Lane, Padworth, Berkshire, on the River Kennet. He owned a turbine which generated electricity using the power of river water. In 1999, the appellant Environment Agency constructed a fish pass in the river to enable fish to swim through and restore a self-sustaining population of salmon. The pass diverted water away from the respondent’s turbine.
From 2015, the respondent alleged that, in lower flow conditions, his turbine generated less electricity. When the fish pass was open, water flowed through it rather than through the channel where the turbine was located. When it was closed, the water flowed through the turbine channel. If the fish pass was open in lower flow conditions, the electricity generating potential of the turbine could be affected.
The respondent commenced proceedings for damages for nuisance and breach of statutory duty and sought declarations that, contrary to section 10 of the Salmon and Freshwater Fisheries Act 1975, the fish pass, as constructed and maintained, injured the milling power enjoyed by the respondent by diverting a significant flow of water from the intake to the respondent’s turbine so that he was unable to operate the turbine to its maximum operational capacity at times of low flow, causing loss and damage. The High Court rejected the contention that any claim lay for breach of statutory duty, but otherwise granted the declarations sought: [2020] EWHC 930 (Ch); [2020] PLSCS 72.
The appellant appealed contending that: (i) it operated the fish pass in discharge of its statutory duties and had a defence of statutory authority to any claim in nuisance; and (ii) when initially constructed, the fish pass caused no appreciable injury to the operation of the turbine, and its subsequent replacement with a more powerful turbine did not entitle the respondent to require closure of the fish pass.
Held: The appeal was allowed.
(1) In the absence of negligence, a body was not liable for a nuisance attributable to the exercise by it of a duty imposed on it by statute, even if by statute it was expressly made liable, or not exempted from liability, for nuisance. In the absence of negligence, a body was not liable for a nuisance which was attributable to the exercise of a power conferred by statute if, by statute, it was not expressly either made liable, or not exempted from liability, for nuisance. A body was liable for a nuisance by it attributable to the exercise of a power conferred by statute, even without negligence, if by statute it was expressly either made liable, or not exempted from liability, for nuisance: Department of Transport v North West Water Authority [1984] AC 336 followed. “Negligence” was used in the sense explained in Allen v Gulf Oil Refining Ltd [1981] AC 1001 of requiring the undertaker, as a condition of obtaining immunity from action “to carry out the work and conduct the operation with all reasonable regard and care for the interests of other persons”.
A neat distinction could not be drawn between the construction of the fish pass and its operation. It was not the building of the pass by itself that injured the milling power of the river but the opening of the pass and allowing water to run down it. Therefore, when section 10 provided that the appellant might construct and maintain a fish pass “so long as no injury is done by such a fish pass to the milling power”, that had to mean “so long as no injury is done by [the construction and operation of] such a fish pass to the milling power”. It was the construction, opening and operation of the fish pass which together would injure the milling power and prevent the power in section 10(1) from being available.
The owner of a mill or turbine, who established that as initially constructed a fish pass injured the then milling power, was entitled to complain that the person constructing the fish pass had no power under section 10(1) of the 1975 Act to construct it or operate it thereafter. The appellant could not rely on its statutory duties under section 6 of the Environment Act 1995 to provide it with a defence of statutory authority to a nuisance caused by operating the fish pass; the appellant had no duty to keep a fish pass open if it had no power to do so.
(2) The effect of section 10(1) of the 1975 Act was that the appellant could lawfully construct a fish pass provided that it did not materially or substantially injure the milling power of the river that was then being exploited (or capable of being exploited) by an existing mill or turbine, and having done so, could thereafter keep it in place and operational even if the turbine was subsequently replaced by a turbine which was adversely affected by keeping the fish pass open. If there was an existing mill, the appellant could not install a fish pass if the milling power was adversely affected: section 10(1). Nor could it alter an existing fish pass if that would injure the milling power: section 10(2). Nor could they do so if it would adversely affect the supply of water to navigable waters. Conversely, a riparian owner who did not have an existing dam could not build one so as to obstruct the existing migration of salmon or migratory trout, and had to make a fish pass if required to do so: section 9(1); and that did not permit any interference with the supply of water to navigable waters: section 9(4).
The words “milling power” in section 10 referred to the power actually being exploited (or capable of being exploited) by an existing mill or turbine at the relevant time. That meant that if the construction of the fish pass in 1999 did not cause any tangible injury to the milling power required for the operation of the turbine, as the judge found, then the initial construction was permitted by section 10(1) and was not unlawful.
Richard Turney and Rupert Cohen (instructed by the Environment Agency legal services) appeared for the appellant; Nigel Thomas (instructed by Aaron and Partners LLP) appeared for the respondent.
Eileen O’Grady, barrister
Click here to read a transcript of Pigot v Environment Agency
