Process for self-laying new mains and services

The sooner we know about your development, the better. Once you’ve submitted your point of connection application, we’ll issue you with a point of connection (POC) report within 28 days. The report is valid for 12 months. You can use this to help with your planning permission and project planning.

Find out more about pre-planning enquiries.

Find out how and when to apply for your mains and service connection.

Once we’ve received your full application, we’ll send you a quote within 28 to 42 days. You can choose whether you'd like us or your SLP to complete the technical design of your new main system. Our quote will include both options.

Your quote is valid for six months. Please sign and return it by email to developer.services@thameswater.co.uk. Please make the payment before your quote expires. We update charging arrangements on 1 April each year.

If your SLP is designing your mains, we’ll need to check these. You’ll then liaise with the SLP to discuss next steps.

If we're designing your mains, we’ll contact you once you’ve accepted the quote to arrange a commencement meeting. At this meeting, we’ll confirm:

• The scope of works
• Lead times
• On-site facilities
• Any traffic management requirements

The WMAA is a legal agreement between us, the SLP and the developer/land owner for the completion of works. This need to be signed by all parties before works commence on-site.

The agreement includes:

• Terms and conditions
• Technical and job specification
• Water company works to be undertaken, and associated charges
• Indicative self-laid main phasing programme

Your SLP will construct the new main system, according to the technical designs and Design and Construction guide.

A 10 day notification will need to be submitted before any construction of mains can start. 

Commissioning

Before connecting the new main, it must be pressure tested and chlorinated. Water samples must also be taken for bacteriological testing. It's not necessary for one of our engineers to be on site for this, but we may conduct audits to ensure compliance.

When you receive the results, you must send them to us for review within one day.

The total time taken to commission the new main is seven days. It must be completed within 14 days of the sample being taken.

Connecting

A Thames Water engineer must be on site to witness the connection. This is to ensure EUSR accredited professionals are completing the works.

You'll need to submit a safe control routine mains connection form seven days before the connection takes place.

Once the new mains have been commissioned, we will adopt (vest) the assets. When the connection is complete, the SLP must tell us within one day. We’ll then issue a vesting certificate within five days. The SLP will also need to submit an updated as-laid drawing showing that the main is live.

You and the SLP will be responsible for rectifying any defects in the mains for 12 months following the commissioning.

• Once we’ve vested the new water mains, the SLP has 14 days to connect the plots
• A service notification form will need to be submitted seven days before the connection takes place
• Most SLPs use WaterSafe approved contractors to complete the water regulations. This means we don't need to inspect the pipework. Instead, they must send us the approved plumber certificate three days before connection
• If not using a WaterSafe accredited contractor, the SLP will need to book a water regulations inspection
• Once completed, you’ll need to send us the meter information for each plot. The deadline is 24 hours for non-household properties, and 72 hours for household properties
• Our billing team will contact you within 60 days with account information
• If applicable, we’ll be in touch with information on infrastructure charges. Our connection charging arrangements are updated on 1 April each year