Maintenance of a river embankment

The High Court has dismissed a claim for judicial review brought by two local farmers challenging Natural Resources Wales’s decision to cease maintaining the 3km-long Tan Lan Embankment on the Afon (River) Conwy in north Wales: R (Williams and Owen) v Natural Resources Wales [2026] EWHC 9 (Admin).

In October 2024, NRW decided no longer to use its flood risk management powers under the Water Resources Act 1991 (“the WRA 1991”) to maintain the embankment. NRW had concluded in an ‘Outline Business Case’ analysis that continued maintenance of the embankment would not be a cost-effective use of resources, having regard to the Welsh Government’s national flood risk management strategy, in view of the low level of flood protection it offered.

The claimants contended that NRW had acted unlawfully by only considering the use of its powers as flood risk management authority under the WRA 1991. In Wales, NRW is also the internal drainage board (“IDB”) for each of Wales’s 13 internal drainage districts (“IDDs”), including the Afon Conwy IDD. NRW as IDB has powers under the Land Drainage Act 1991 (“the LDA 1991”) to carry out drainage and flood risk management works in the Afon Conwy IDD. The claimants contended that NRW, as flood risk management authority, could not have lawfully decided to cease maintenance of the embankment without at the same time considering whether to exercise its alternative powers as IDB in relation to the embankment.

HHJ Keyser KC, sitting as a judge of the High Court, rejected that argument. The court held that, although NRW is both the flood risk management authority under the WRA 1991 and the IDB under the LDA 1991, “the two roles are distinct and discrete and operate under different statutory regimes”: [48]. A decision under the WRA 1991 neither required a simultaneous decision under the LDA 1991 nor, as the claimants submitted, “prejudged” it. In any event, the court agreed with NRW that, as IDB, it has no power to maintain the embankment as it is a “bank” of a “main river”. Maintenance of main river banks lies within section 165 of the WRA 1991, not sections 14 and 14A of the LDA 1991: [51].

The Claimants’ alternative argument relying on Article 1 of the First Protocol to the ECHR (“A1P1”) was also rejected. The court held that the decision no longer to fund the maintenance of the embankment did not involve the deprivation or control of property. Insofar as A1P1 was engaged, the court was satisfied that NRW’s decision struck the required fair balance between private and public interests, with the court being in no position to “second guess [NRW’s] expert judgment and cost/benefit analyses” in the Outline Business Case: [80]. In reaching that conclusion, the judge relied on Sir Ross Cranston’s observations in King v Environment Agency [2018] EWHC 65 (QB), [2018] Env. L.R. 10 on the proper approach to the “fair balance” when the court is reviewing decisions made by national expert agencies charged by Parliament with supervising the management of flood risk in the public interest.

Gwion Lewis KC is a barrister at Landmark Chambers. He acted for the successful defendant, Natural Resources Wales. Gwion also acted for the Environment Agency in King.