In this case, Sir George Hugh Pigot v Environment Agency [2020] EWHC 930 (Ch), Sir Hugh Pigot owned a water powered turbine, and the Environment Agency operated a fish pass close by that had been installed using powers under the Salmon & Freshwater Fisheries Act 1975.The relevant powers in the 1975 Act allowed the Environment Agency to install a fish pass provided that “no injury is done to the milling power, or to the supply of water of or to any navigable river”, and the case came to turn on whether that limitation on the Environment Agency’s powers actually meant what it said, and whether it applied to the new statutory circumstances under which Sir Hugh Pigot had to apply to the Environment Agency for an impoundment licence, and in due course he replaced and upgraded his mill turbine to a more powerful model.

The problem was that in low water conditions, the Environment Agency required Sir Hugh Pigot to close or restrict the flow of water to his new turbine so that water remained available to flow down the fish pass although some might suggest that in low water conditions few if any fish use a fish pass anyway.

Stephen Jourdan QC found for Sir Hugh Pigot, to the effect that the Environment Agency was not entitled to divert water away from the turbine to the fish pass in low water, and it could not reply upon the defence of statutory authority whether the statute giving it certain powers was expressly limited to require “no injury” to the milling power. It is not yet clear whether the Agency will appeal the judgement, but the case is an interesting reminder of the limits to the vires or powers of a statutory authority contained in some specific legislation.