The attractions of riverside locations should not blind developers to the risk of third party rights. Paul Tonkin explains.

For obvious reasons, developers (particularly residential developers) are attracted to riverside  sites. Riverside apartments remain ever popular and the views continue to command substantial  premiums. However, whilst  the attractions are obvious, developers should bear in mind the special status of riparian land and the often increased risk of third parties  scuppering their development plans.

Ownership of the river bed

The presumption of ad medium filum applies to most riverside land. This means that, where there is  no evidence of third party ownership, the respective owners of the land abutting the river bank on  either side will be presumed to own the river bed up to the halfway point, together with the  airspace above it. This can be particularly useful where, as is often the case, title to the  riverbed is unregistered. A developer can rely upon the presumption to register title to the river  (up to the half-way point) in its own name. This could be important where, for example, it wishes to incorporate the river into its development – for example, by constructing marinas, moorings or  even just balconies directly overhanging the river.

Importantly, however, the presumption does not apply to tidal rivers, including large parts of the  River Thames. In most cases, it is presumed that ownership is vested in The Crown. In the case of  major waterways, statute often intervenes and ownership of the river is vested in a designated regulatory authority. For example, ownership of the Thames is vested in the Port of  London Authority. Where any development involves land adjoining a tidal river, the statutory river  authority will invariably have to be consulted and licence may be required, for example, to  overhang the river.

Third party rights

Tidal rivers are subject to a public right of navigation, meaning that there is a general right for  the public to navigate vessels along the river. It is generally accepted that there is no such  right in the case of a non-tidal river, where any right to navigate and/or moor up will require the  permission of the owner of the riverbed. Where mooring or access to the riverbank is sought, the  permission of the bank owner (if different) will also be needed. Nonetheless, it is all too common for developers to discover that the river and the riverbank are being used by third parties, often without any  written entitlement to do so. These could range from local people using the river for fishing or  recreational purposes, to pleasure boats or even the permanent homes of barge owners moored along  the river. Any third party use of the river has the potential to interfere with the developer’s  plans, particularly where the third party claims a legal right to continue with their use  notwithstanding the developer’s objections. The status of any third party use, therefore, needs to  be investigated fully.


Third parties may claim to have acquired easements over the river, such as a right to moor or a  right of access, by way of long user (also referred to as prescription). As a general rule, they  will need to establish a period of at least 20 years’ use of the river “as of right” (that is,  without the owner’s permission). However, an easement can only be created for the benefit of land  (the so-called “dominant tenement”) and, therefore, to successfully argue for an easement, the  third party will need to identify some land in their ownership which they say benefits from the  rights claimed over the river. Where the riverside is owned by the developer, it may be difficult  for third parties to satisfy this requirement (in which case they may try to bring an adverse possession claim in  parallel – see below).

Town and village greens

Alternatively, it might be claimed that the river and  its bank are vulnerable to being registered  as a town and village green under the Commons Act 2006. To establish this, it would need to be  shown that the river has been enjoyed “as of right” for the purposes of lawful sports and pastimes  for at least 20 years by a significant number of the inhabitants of the locality. There is no need  to identify any dominant tenement. The requirement for use by a significant number of local people  and the limitation to use for sports and pastimes means that uses such as the mooring of private barges for residential use would be unlikely to form the sound basis for a claim. Where it  is apparent that the river is being used for community enjoyment without permission then early  advice should be taken on what can be done to protect it from potential town and village green registration.

Profit a prendre

A right to extract something from the river (for example, fish) can arise legally as a profit à  prendre. Again, these rights can be acquired by long use for at least 20 years and, unlike an  easement, they can exist on their own without having to benefit any dominant land. Where it appears that the river is being used for fishing or some other form of  extraction then the basis and history of this use should be carefully considered to establish  whether there is a risk of rights being claimed.

Adverse possession

In addition to claiming rights to use the river, the developer should also be aware of third  parties claiming ownership of the riverbank and/or the riverbed. This risk is perhaps most likely  to arise where third parties have vessels such as barges moored permanently along the river. The question then arises as to whether the presence of those vessels over a long period  without objection can be relied upon to assert ownership by adverse possession.

These issues have been considered by the courts in the recent cases of Port of London Authority v  Ashmore [2010] EWCA Civ 30 and Couper and others v Albion Properties Limited and others [2013] EWHC  2993 (Ch). Those cases both concerned claims of adverse possession by barge owners moored on the River  Thames in Chelsea. In the Ashmore case, the court considered that it was possible, at least in  principle, for a barge floating on the river at high tide and resting on the riverbed at low tide  to establish a claim for adverse possession of the riverbed. The Court did not however decide  whether a claim had been established on the particular facts of the case.

The Couper case concerned claims of adverse possession of both the riverbed, owned by the Port of  London Authority, and the river wall, owned by a developer. In the case of the riverbed, the court  held that where there is a public right of navigation over a river, as is the case with the Thames,  the river should be regarded as analogous to the public highway. In R (on the application of Smith) v Land Registry (Peterborough Office) & another [2010] EWCA Civ  200 the Court of Appeal had decided that it was not possible to claim adverse possession of the  highway. The Court in Couper applied this decision and held that it is not possible to acquire title by adverse possession to any part of the bed of a navigable river. In relation to the river wall, the court found that  merely mooring against the wall was not sufficient to found a claim for adverse possession, on the  basis that this could be explained by something short of possession, such as an easement right to  moor. Whilst the claimants claimed to have used the wall for other purposes, such as storage, those claims were rejected and  the claim for adverse possession failed.

The decision in Couper gives some comfort to developers looking to defeat claims of adverse  possession over riparian land. However, it is  important to bear in mind that the bar on claiming  adverse possession will not apply where the river is non-tidal (and, therefore, not subject to a  public right of navigation). In those cases the vessel owner’s case will need to be examined on its  individual facts.

In conclusion, the existence of unexpected third party rights can potentially scupper any riverside  development. The risks can be particularly acute where third parties have a long history of use of  the river which has not been adequately regulated. Enquiries should be made at an early stage to  ascertain the extent and legal basis of any third party use. Developers should be aware of the possibility that rights may be in the process of being acquired by long user; it may still be  possible to prevent  them being acquired by bringing the use to an end or ensuring that it is carried out with permission. If in doubt, take early advice.

An earlier version of this article was published in Estates Gazette on 21 March 2015