1 October 2011 saw the automatic public adoption of private drains and sewers in England and Wales which connect with the public sewerage system. This will have implications for property owners and developers both in relation to their existing drainage arrangements and where proposed developments involve the installation or alteration of drains and sewers.


Defra and the Welsh Assembly Government issued a joint consultation in August 2010 on regulations for the public adoption of privately owned sewers and drains, being (a) sewers serving more than one property and (b) lateral drains serving one property but which lie outside the boundary of that property, and in each case which connect to the public sewerage system.

This was the culmination of several years of review and consultation by successive governments, which identified several problems with private ownership:

  • Householders were often unaware that they were responsible for a private sewer or drain serving their property, particularly where this lay outside the boundary of their property, and could be hit by an unexpected bill in the event of a problem
  • Problems with sewers or drains could be very expensive to fix, with the financial burden falling on just a few property owners, who were already paying for sewerage services and so effectively paying twice for the upkeep of sewers 
  • There could be disputes between property owners as to access to drains and sewers for repair and maintenance, and liability for the costs
  • A system of disparate private ownership did not allow for planned maintenance and management of the sewerage network

The consultation concluded that the best way to address these problems was an overnight transfer of ownership of most private sewers and lateral drains connected to the public sewerage system to the regulated water and sewerage companies.

The Water Industry (Schemes for Adoption of Private Sewers) Regulations 2011

The Regulations came into force on 1 July 2011 and the transfer scheme made under them took effect on 1 October 2011. Sewerage undertakers were obliged to give notice of adoption to property owners not less than two months before the date of transfer. Owners were allowed to appeal against adoption but if they did nothing, then adoption took place automatically.

From 1 October 2011, only the private drain serving a property and within its boundary remains the responsibility of the property owner.

Adoption took place regardless of the state of repair of the drains and sewers. The 2010 consultation envisaged that a new mandatory build standard for sewers would be imposed prior to the date of transfer, so that the sewerage companies could be confident that the sewers they were obliged to adopt were of a requisite standard. However, no such standard has yet been established.

Some pipes are not classed as drains and sewers and so are not affected by the Regulations. These include pipes within sites which, although in multiple occupation, can still be viewed as a single property, such as some industrial parks, caravan parks, airports and railway stations. There is no precise definition of what will constitute a single property and so there is potential for uncertainty as to whether drainage assets within, for example, a multi-let business park, have transferred. The result will depend on the pre-existing circumstances and arrangements for drainage. If drainage within the site is being internally managed as a single system it is likely to be viewed as a single property.

Sewers and drains not connected to a public sewer (for example, those connecting to a septic tank) also remain in private ownership.

Section 104 agreements

The Regulations have obvious implications for agreements under section 104 of the Water Industry Act 1991, whereby a developer agrees terms with the sewerage undertaker for the adoption of sewers serving a development.

Where a section 104 agreement exists and the sewers were already connected to the public system by 1 July 2011, then due to the automatic adoption on 1 October 2011, the agreement has no ongoing purpose and so will cease to have effect. However, any provision providing financial security to the sewerage undertaker for the sewers to be built to the required standard by the developer will remain enforceable.

Existing section 104 agreements in respect of sewers which are not yet constructed or connected to the public system will remain live, until section 42 of the Flood and Water Management Act 2010 comes into force (see below). Under the Regulations, the drains and sewers will automatically be adopted six months after section 42 comes into force, if they have not already been adopted under the section 104 agreement.

It is not clear what will happen to any drains and sewers which are not the subject of a section 104 agreement and which are not connected to the public system when section 42 comes into force, as these will not be automatically adopted.

Further changes in the pipeline

Section 42 of the Flood and Water Management Act 2010 will amend the Water Industry Act 1991 to provide that all new sewers intended to connect to the public system must be the subject of a section 104 agreement. Once it comes into force, developers will be obliged to enter into a section 104 agreement with the sewerage undertaker which includes:

  • provision for the drains and sewers to be built to published standards; and
  • provision for adoption to occur automatically on the occurrence of specified events.

However, the sewerage undertaker will not be entitled to refuse adoption, even if the conditions set out in the section 104 agreement have not been fulfilled. Therefore, there may be little incentive for developers to comply with the mandatory standards. To minimise their potential liability for sub-standard construction, the sewerage undertakers are likely to insist on rigorous bond or security provisions in the section 104 agreement.

Implications for purchasers and developers

The scale of the transfer effected by the 2011 Regulations should not be underestimated: the 2010 consultation estimated that an additional 184,000 km of sewers and 36,000km of private lateral drains would be transferred to the sewerage undertakers.

This is likely to lead to informational difficulties for purchasers and developers. Mapping will remain incomplete for some time: Defra's guidance suggests that property owners should pass on information they hold to the sewerage companies, but there is no obligation on them to do so. The 2010 consultation estimated that a full mapping exercise would cost in the region of £1 billion and felt that this would not be a proportionate exercise. Instead, sewerage undertakers will be expected to update their records in the course of working on the previously private drains and sewers. So although no specific exemption from the requirement to keep records has been granted to the sewerage undertakers, their liability for any failure to do so will be considered in this context. There is no requirement for the sewerage undertakers to register their rights at the Land Registry.

As a result, purchasers and developers may be unaware of the presence of drains and sewers even after carrying out the usual searches. Title documents may still be of important assistance. The significance of this is that where actions affecting a drain or sewer (such as building over) would previously have given rise to a claim for damages by the private owner, interference with a public sewer without the consent of the statutory undertaker is a criminal offence. Careful investigations should therefore be carried out where there is a possibility that a sewer or drain passes through land proposed for development.

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