The CON29DW questions explained – sewers within property boundaries

Our series examining the CON29DW takes a look at one of the most common issues raised by the search: sewers within property boundaries.

Question 2.4 of the CON29DW asks “Does the public sewer map indicate any public sewer, disposal main or lateral drain within the boundaries of the property?” This seemingly innocuous question is in fact one of the main areas of concern in the search, and results in more queries to ourselves from customers than any other question.

Although public sewers within property boundaries are extremely common, there are a couple of good reasons why a prospective homeowner might be concerned about their presence.

The first of these, and the one usually of most concern is around development. Water companies have a number of legal rights in place that they can use to protect their assets. Included in these is the right to either veto or demand changes to any proposed development in the immediate vicinity of their sewers.

If sewers are under or close to a building, then access to them becomes difficult. Additionally, water companies need to protect both sewers and the buildings themselves. Should a sewer be built over without adequate protection, or excavation carried out under a sewer, it can burst or collapse, which would cause problems with any buildings overhead, as well as presenting a difficult repair job.

Because of this, water companies are regularly consulted as part of the planning process for development work. Planning officers at local authorities will refer applications to Severn Trent for their opinion on any proposed development that runs within three metres of any of their assets.

For developments that don’t need planning permission, such as conservatories or porches, permission is still needed should there be a sewer within three metres. In these cases, the homeowner should seek permission  from Severn Trent directly.

As a statutory undertaker, the company has the right to request changes to any development, or in extreme cases, to veto it entirely. Fortunately, the majority of sewers within property boundaries tend to have a fairly small capacity, and only serve a few properties. In these cases, it’s fairly common for Severn Trent to request specific measures are taken to protect their sewers.

With larger sewers serving a high number of properties, there’s a higher risk of problems, and greater consequences if something goes wrong. In these cases, it’s possible that Severn Trent will require the pipe to be diverted around the development, at the property owner’s expense.

Some larger sewers are also protected by easements. These are a legal document imposing restrictions on what landowners can do within the vicinity of a sewer, and can extend to a distance beyond the standard three metres. Generally, these only occur with large capacity sewers, where a problem could have serious implications for a number of properties.

The second area of concern for homeowners is related to the first. Water companies have statutory rights of access to private land, to allow them to maintain their assets. This means they can legally enter private land (usually with advance notice unless the work is urgent) to repair or replace sewers and other assets such a pumping stations.

For inspecting sewers, this can generally be achieved via a manhole, meaning it’s important that any of these on the property are not permanently covered. For maintenance or repair work however, this can often include excavation, which can cause damage to properties. However, providing the correct procedures were followed during any construction work near sewers, Severn Trent will repair any damage to a reasonable standard.

Whilst this may sound alarming, sewers through boundaries are very common, especially since the private sewer transfer in 2011, which transferred most private sewers in England and Wales into public ownership. This means that the majority of properties now have a public sewer within their boundary.

A public sewer within your boundary may seem like cause for concern. In actuality, it is relativity common, and more often than not, causes minimal issues for the property owner.

You can read more about Severn Trent’s procedures surrounding development here