The claimant was the riparian owner of a property adjacent to the river which included a mill and water turbine. The defendant Environment Agency constructed a fish pass purportedly under the power provided in section 10(1) of the Salmon and Freshwater Fisheries Act 1975 to enable salmon to pass up and down the river between the sea and their spawning grounds without obstruction and the claimant did not object to its construction at the time. By section 10(1) of the 1975 Act, the agency was permitted to construct and maintain a fish pass “so long as no injury is done by such a fish pass to the milling power”. The claimant later installed a new turbine that generated electricity both for the property and for sale to the National Grid. It later became apparent that the effect of keeping the fish pass open at certain conditions of low water prevented the turbine from operating at full power. On the claimant’s Part 8 claim for declaratory relief, the judge made declarations that (i) the agency was prima facie liable in nuisance by diverting the river flow through the fish pass and away from the turbine when the amount of water flowing down the river was low enough to adversely effect the electricity generation of the turbine when the fish pass was open but not if it was closed, (ii) section 10 did not entitle the agency keep the pass open in times of low water, and (iii) the agency was unable to rely on the defence of statutory duty unless it had a power other than that derived from section 10 to keep the pass open at low water. The agency appealed on the grounds that it was entitled to a defence of statutory duty to any claim in nuisance arising (i) from the installation and operation of the fish pass, which had been installed pursuant to various legal duties including that in section 6(1) and (6) of the Environment Act 1995 to maintain, improve and develop salmon as well as its duties, and (ii) out of the installation of a turbine after the date of the construction of the fish pass under section 10 of the 1975 Act. The agency asserted that its statutory duties could not reasonably have been performed in a way that would have avoided the nuisance.
On the appeal—
Held, (1) Section 10 of the Salmon and Freshwater Fisheries Act 1975 could not be regarded as analogous to a non-exoneration provision. The requirement that there be no injury to the milling power of the river did not just preserve a right of action to a person injured but created a pre-condition or limitation on the exercise of the power. If the condition that there be no injury to the milling power could not be satisfied then the right to construct a fish pass was not available under section 10(1) of the 1975 Act. Therefore, the power in that subsection enabling the Environment Agency to construct and maintain a fish pass “so long as no injury is done by such a fish pass to the milling power” had to be taken to mean “so long as no injury is done by [the construction and operation of] such a fish pass to the milling power”. The question of the operation of a fish pass could not be divorced from its construction. It was the construction, opening and operation of the fish pass which together injured the milling power and prevented the power in section 10(1) from being available. The subsection did not prevent complaint about the subsequent operation of a fish pass, however substantial its interference might be to the milling power of a turbine, where the injured party did not object to the initial construction of the pass. “Maintain” in subsection (1) did not simply mean “carry out works of maintenance” but “keep in place and operational”. The natural meaning of that was that the agency had no power to keep a fish pass in place and operational if its original construction was not authorised by section 10(1). Therefore, the owner of a mill or turbine who established that a fish pass as initially constructed injured the then milling power was entitled to complain that there was no power under section 10(1) to construct it or operate it thereafter and the agency could not rely on its statutory duties under section 6 of the Environment Act 1995 so as to assert a defence of statutory authority to a nuisance caused by operating the fish pass. Accordingly, the judge had correctly held that the agency did not have a duty under section 6 to keep a fish pass open if it had no power to do so (paras 62–66, 68, 91, 94).
(2) Appeal allowed. “Milling power” in terms of the words “so long as no injury is done by such a fish pass to the milling power” within section 10 of the 1975 Act referred to the power actually being exploited (or capable of being exploited) by an existing mill or turbine at the relevant time. Therefore, the initial construction of the fish pass was permitted under section 10(1) and was not unlawful if it did not cause any tangible injury to the milling power required for the operation of the original turbine. The legislation as a whole represented a balance between the interests of riparian owners and of those concerned with the free migration of fish by seeking to minimise any adverse effect on existing interests rather than giving priority to one or the other. Parliament could not have intended for the possibility of the agency spending large sums of public money on constructing a fish pass, which it could not then lawfully use as intended, with the possibility of turbine owners at other places insisting on the closure of a fish pass with the consequence that an entire chain of fish passes could be rendered useless. Nor was it Parliament’s intention to use the licensing regime that arose under different legislation to meet any such practical consequences. Therefore, the effect of section 10(1) was that the agency could lawfully construct a fish pass provided that it did not materially or substantially injure the milling power of the river that was or was capable of then being exploited by an existing mill or turbine. Having done so, it could thereafter retain it in place and operational even if the turbine was subsequently replaced by a turbine that was adversely affected by keeping the fish pass open Accordingly, the declarations made by the judge below would be replaced by suitable declarations (paras 80, 86–90, 91, 92, 94).
Richard Turney and Rupert Cohen (instructed by Director of Legal Services, Environment Agency Legal Services) for the Environment Agency.
Nigel Thomas (instructed by Aaron & Partners LLP, Chester) for the claimant.