I am building a large development

As a property developer building a new site with multiple domestic or commercial properties, you’ll need to use our water and wastewater services from your pre-development enquiry through to the final connections.

Non-household customers can choose who provides their water retail services, such as billing. As a non-household customer, you’ll need to choose a retailer before requesting a connection from them. A retailer will be allocated if you don’t choose one yourself. Temporary connections, in site welfare facilities, show homes or for temporary building supplies, all need a retailer. Find out more on the changes and choosing a retailer.


New water and wastewater infrastructure for your development

When you’re building a large development, you’ll probably need a new water main and a new sewerage main that will connect into our network.

You can offer newly constructed sewers to be adopted by us or you can request us to build the sewer for you. The sewers submitted for adoption by Southern Water will need to meet our requirements. More details can be found on our Sewer adoption page.

You can have a water main and sewer main designed and built by a contractor (Self-Lay Provider), New Appointee or Variation (NAV) or through us as a water main application. 

Please check the contestability document to explore all your delivery options.

We can help you make an informed decision for your specific project. Please send us a pre-development enquiry and we’ll advise the best options for your site (i.e. water company requisition, self-lay, new appointment or variation (NAV)). The pre-development enquiry is also helpful when your site has not reached the planning approval stage, or you’ve chosen Self Lay Provider (SLP) route and if you just wanted to know if the proposed development site can be supplied with water, sewerage, or both.


Before working near our assets

It’s important to identify where our water and sewer pipes are located on site to ensure they’re not damaged and that distances are maintained. If any of our assets (water mains/sewer mains) conflict with your development plans, you can submit a diversion application and we can assess their potential relocation.

If you’re not sure, you’ll need to carry out a ground penetrating radar survey, or hand dug trial hole in line with PAS128 guidance for either Type A or Type B surveys to check the depth and position of our pipe. We don’t hold this information on file.


GetConnected portal

We have made it easier to connect with us. You can apply, make payments, track your project and talk to us using our GetConnected portal.



List of services for development projects

Water connection

Guidance on connecting to a public water main.

Find out more

New water main

Guidance on requesting a new water main.

Find out more

Sewer connection

Guidance on connecting to a public sewer main.

Find out more

Sewer requisition

Guidance on requisitioning a new sewer main.

Find out more

Sewer adoption

Guidance on the adoption of a new sewer main.

Find out more

Sewer diversion

Guidance to divert an exisiting sewer main yourself or through us.

Find out more

Water main diversion

Guidance to divert an existing water main.

Find out more

Build over a sewer

Guidance on building over or close to a public sewer.

Find out more
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