High Court confirms Environment Agency can evict houseboats moored above its riverbed land, even where navigation rights exist on the Thames.
In a significant ruling for waterway management, the High Court has upheld the Environment Agency's right to evict houseboat owners from a stretch of the River Thames near Sunbury-on-Thames, clarifying the relationship between riverbed ownership, navigation rights, and residential mooring.
Background
Jaqueline Casey & Ors v Environment Agency [2026] EWHC 178 (KB) concerned houseboats moored above riverbed land owned by the Environment Agency (the Agency). The defendants held licences or registrations under the Environment Agency (Inland Waterways) Order 2010. The Agency, as freehold owner, sought possession, arguing the defendants were trespassers on the riverbed or in the airspace above it.
The Agency maintained that moorings on this stretch were for short-stay purposes only and wished to maintain the stretch as a "natural rural section of the Thames in an otherwise urbanised area." From 2014, the Agency increased patrols, identifying permanently moored vessels. Elmbridge Borough Council served enforcement notices on several defendants, and in September 2022, the Agency required all defendants to move their vessels within seven days. The possession claim was issued on 2 May 2023.
Ownership of the adjoining riverbank was disputed, with some defendants claiming adverse possession (the occupation of land to which another person has title, with the intention of possessing themselves) of adjacent plots. The key issues were whether the Agency could bring a possession claim as riverbed owner without owning the bank itself, whether doing so breached the defendants' right to respect for home and private life and the extent of any possession order.
The first instance judge ruled in favour of the Agency on all points. On appeal, the defendants raised numerous grounds to the High Court including whether the possession order would interfere with the boaters' navigation rights along the river and their rights to respect for home and private life, and whether the judge conducted an impermissible "mini-trial" in the possession hearing.
Decision and Legal Principles
Bourne J dismissed the appeal, finding no error in HHJ Simpkiss' reasoning. The order was intended to prevent the absurdity of defendants simply moving their boats a few metres and followed caselaw including Wiltshire CC v Frazer [1984] 47 P&CR 69 and Hackney LBC v Powlesland [2020] EWHC 2102 (Ch) which established that possession orders can be made notwithstanding that lawful users are permitted.
The judgment establishes several significant principles for waterway management:
Riverbed ownership and trespass
A riverbed owner can claim possession based on trespass by a vessel in the water above, extending property rights vertically: the Agency was entitled to bring possession proceedings even without owning the bank. The boaters' rights were limited to the public right of navigation under section 79 of the Thames Conservancy Act 1932.
Riparian ownership
Relying on Moore v British Waterways Board [2013] Ch 488, the court confirmed that riparian owners — those owning land adjacent to a watercourse — have no positive right to moor permanently against the wishes of the riverbed owner. Even if the defendants had acquired the riverbank by adverse possession, this would not confer a right to moor permanently.
Right to respect for home and private life
Applying Bank Mellat v HM Treasury (No. 2) [2014] AC 700, the Court found the possession proceedings proportionate. Substantial weight was given to the Agency's sustained efforts to improve the amenity of this stretch and to protect its proprietary interests.
Despite a wide range of grounds of appeal, the Court found that the defendants failed to advance a properly evidenced case beyond mere assertion. HHJ Simpkiss' decision was not an impermissible "mini-trial" but rather reflected the weakness of the defendants' evidence when subjected to proper scrutiny. This underscores the importance of supporting legal arguments with substantive evidence, particularly when challenging possession claims.
This judgment provides clarity to houseboat owners holding a navigation licence that this does not confer a right to moor permanently, and riparian ownership of the bank is no answer to a possession claim brought by the riverbed owner.
