New-build drainage is a hot topic these days. With an increase of flooding in parts of the UK over recent years, there’s been more scrutiny of developers’ building activity in certain areas, especially on floodplains.

New-build drainage: the critical foundations of your project

It goes without saying that drainage should be one of the very first considerations tackled when planning a new-build project of any size, whether you’re a self-builder tackling the creation of your dream home, or you represent a company undertaking the construction of a large-scale housing or mixed-use development. 

Good new-build drainage systems underpin the site itself (literally), as well as the wellbeing of the eventual dwelling occupants. Drainage is also responsible for the continued good repair of the buildings themselves by ensuring that all waste water (whether surface water run-off from roofs and hardstandings, or foul water from WCs and sinks) can be carried away from the properties in the proper manner, without overwhelming either the new pipework or existing public sewers. 

With the drainage system literally underneath the buildings, gardens and roadways, it’s imperative to get it right first time. Having to invite your drainage contractor back to undertake remedial works could prove disruptive and would incur an unexpected cost – especially as the true test (under real-life conditions) will only happen once the houses are occupied. 

Save money with best practice drainage design

It’s not just about finding a contractor who has the required accreditations for compliance. Choosing the best drainage contractor is the surest way to ensure best value and cost control. This means you can avoid common mistakes, such as the wrong pipe gradients or pipe sizes, accidental cross-connections, poor back-filling, or even damage to existing pipes and sewers. If drainage system errors are made, then problems such as flooding, foul water discharge into watercourses, or pipe blockages can make residents’ lives a misery and prove costly to put right.

With the support of a drainage specialist, it’s possible to create a drainage system design that is compliant, will operate effectively, and will ensure best value for money. A simple asset search is the way to start. This will tell you:

• Where the nearest existing sewer is – if there’s none in the vicinity, then the design would need to incorporate a treatment plant, with a discharge into a water course or drainage field.
• If the depth of the existing sewer is correct, then a gravity connection can be achieved.
• If the public sewer is not deep enough for the required falls, you might need to design in a pumping station. If it is too deep then you will need to add an external back drop to an existing manhole – or if there isn’t one in place already, a new manhole will need to be installed over the existing public sewer, incorporating an external backdrop.
• Whether the existing sewer can bear the extra capacity – in the majority of cases this isn’t a problem, but there are some situations that might make it a key consideration. For example, if a developer intends to build a new estate in, or near, a small village – or they plan to convert an office building into residential units – then there’s a chance the sewer might need upgrading to accommodate the larger amount of waste.

Use your drainage contractor’s expertise

It’s a good idea to get your chosen drainage contractor involved in the process as early as possible, so that they can advise on the best sewer connection methods and the optimal scheduling of the drainage works on site. They’ll also be able to carry out the required Section 106 applications (the permission required from the sewer provider, to connect to the public sewer) and Section 50 applications (permission to place new apparatus in the highway). You’ll also find the process for having sewers adopted by the local water company – via a Section 104 application – much easier if you have expert advice from the off.

Bringing your drainage contractor onto site early can also reap specific rewards relating to the build itself, as well as its costs. We find that many customers are planning to leave public sewer connections until fairly late on in their build, but in fact, drainage should be one of the first services to be connected, for a number of reasons:

• It’s possible to save money and improve site welfare by having a temporary connection, avoiding the need to have tankers collecting wastewater from a Portaloo or welfare cabins.
• Where the water table is high, or there has been heavy rain, dewatering can help construction to progress safely and smoothly, without unnecessary delays (you will need a permit from the sewer provider). Provided the sewer has been connected with the right permissions and permits, this water can be discharged into the sewer as long as it has been through a suitable treatment process first.
• Costs can be controlled simply by completing sewer connections before construction work has started – in some cases even just having the space to do this work, without having to work around other trades and the beginnings of the build, can reduce the price of the works dramatically.

At Premier Drainage Solutions we don’t just carry out the high-quality, specialist works you need to complete your build. We also help you to control costs, and avoid the possibility of expensive and disruptive remedials further down the line. We can also take care of your compliance paperwork, including Section 106 applications, to streamline the process as much as possible.

To find out more about how we work, and benefit from our free professional advice on your drainage works, call us on 01268 950050 or send us an email to [email protected].