Rights of riparian owners in the face of foul water discharge

Background to the case

The case of Manchester Ship Canal Co Ltd v United Utilities Water Ltd [2024] UKSC 22 concerns the discharge of untreated or inadequately treated foul water into private watercourses. The Manchester Ship Canal is owned and managed by the Manchester Ship Canal Company (MSCC). The canal serves as a critical waterway, stretching from Manchester to the Mersey Estuary. United Utilities Water Plc (UU), the sewerage undertaker for the Northwest of England, had historically discharged water and treated effluent into the canal from outfalls, predating the WIA 1991.

Prior to reaching the Supreme Court, the Court of Appeal found in favour of UU, finding that under the Water Industry Act 1991 (WIA 1991), MSCC were barred from bringing an action in nuisance against UU for the discharge of foul water into the canal without deliberate misconduct or negligence by UU.

MSCC appealed to the Supreme Court.

Key legal issue

The Supreme Court was tasked with determining whether common law claims for nuisance arising from pollution of watercourses by effluent discharges were excluded by the WIA 1991. Specifically, the Court examined whether UU could rely on statutory authority under the WIA to avoid liability for such discharges without obtaining MSCC’s consent.

Decision

The Court ruled decisively in favour of MSCC, finding that:

• Common Law Rights Survive: MSCC has a common law right to the maintenance of water quality. Section 186 of the WIA 1991 acknowledges the survival of common law rights and remedies.
• No Blanket Immunity for Sewerage Undertakers: The WIA 1991 did not authorise sewerage undertakers to discharge untreated effluent into private watercourses in a manner that constitutes a nuisance or trespass. Such discharges are actionable under common law if they interfere with the use or enjoyment of the property.
• Statutory Obligations do not Justify Pollution: The Court rejected UU’s argument that discharges of untreated effluent were an inevitable consequence of its statutory duties under the WIA. Instead, it held that such outcomes could be mitigated through investment in improved infrastructure and treatment processes.

Implications for riparian owners

The decision underscores that riparian owners retain legal protections against pollution of their watercourses by sewerage undertakers. While the ruling does not establish a general prohibition against the discharge of untreated effluent, it affirms that such discharges must not interfere with property rights.

Moving forward, this judgment could inspire litigation by riparian owners, especially in cases involving widespread pollution of rivers and watercourses. However, claimants must still prove causation and demonstrate substantial interference with their property rights - a potentially challenging task.

This case serves as a reminder of the balance between statutory duties and common law property rights, ensuring accountability for environmental harm caused by foul water discharge.

For more information or advice, please contact Zac Martin-Taylor in our Real Estate team on 07340 630 934, or complete the form below.