Planning your future water supply
We’re planning ahead to make sure we have enough water in the future.
Water is essential for everything we do - from having a drink, to washing our clothes, and flushing the loo. It’s also essential for a healthy environment and a prosperous economy.
Many people think there is plenty of water in the UK, but the South East of England is one of its driest regions and London gets less rain than Rome, Dallas and even Sydney. Our water supplies are being stretched further and further as the number of people living in our area increases. We have to plan ahead because the choices we make today will shape the water supply we can provide in the future.

Our current plan - Water Resources Management Plan 2019
Developing a plan for the South East
Looking at new strategic resource solutions
Water Resources Market Information
Our current plan - Water Resources Management Plan 2019
Every five years we prepare a Water Resources Management Plan (WRMP) which sets out how we will provide a secure and sustainable water supply for our customers, whilst protecting the environment.
In March 2020 the Secretary of State for the Environment, Food and Rural Affairs approved our plan which covers the 80-year period from 2020 to 2100 and sets out how we plan to manage our water resources efficiently alongside developing new supplies of water. Our plan is available to read and download.
You can also download the feedback received from the public consultations and the further information requested by the Secretary of State for the Environment, Food and Rural Affairs in December 2019.
WRMP19 - An overview
Technical report
Technical appendices
Environmental report
Feedback to the consultations on the draft and revised draft WRMP19
Further information requested by the Secretary of State for the Environment, Food and Rural Affairs
An update on our performance
We monitor and report on performance against the commitments we made in WRMP19. The annual report for the period from 1 April 2020 to 31 March 2021, and the mid-year update from April to September 2021, are available to download. These reports present information on our performance against the commitments set out in WRMP19, including leakage reduction and development of new water sources, as well as information on the work to develop a multi-sector resilience plan for the south east region.
Developing a plan for the South East
Population growth, climate change and the need to protect the environment are all putting increased pressure on our water resources. And the South East region, already designated as seriously water stressed, is facing potentially greater pressures and challenges than most other regions.
To meet these challenges requires a joined up response. We are working closely with the other water companies in the South East region through the Water Resources South East (WRSE) Group to ensure we take a coordinated and collaborative approach to planning our future water supply.
WRSE is producing a regional plan which will provide an affordable, resilient and sustainable water supply so that customers, businesses, industry and the natural environment have the water they need. The plan will look ahead to 2100 and will include measures to make the most efficient use of resources through better connectivity, catchment solutions to improve the environment, and new infrastructure.
The draft regional plan will be published in 2022. We are currently working on the technical assessments and tools that are needed to develop the plan. We are sharing this work with stakeholders and customers to ensure their views and preferences are considered. To read more about this work, and to get involved, please visit their website.
The regional plan will be the foundation of our next WRMP – Water Resources Management Plan 2024.
Looking at new strategic resource solutions
To ensure we have a secure and sustainable water supply for future generations and protect the environment, we need to invest in new sources of water. In this section we provide information on the strategic resource solutions that we're exploring with other water companies.
Background
Ofwat provided funding to investigate and develop strategic water resource solutions that will benefit customers and wider society, and help to protect and enhance the environment. The aim of the funding was to encourage collaboration and accelerate the development of solutions.
The Regulators’ Alliance for Progressing Infrastructure Development (RAPID), a joint team made up of the three water regulators: Ofwat, the Environment Agency and the Drinking Water Inspectorate, was set up to support and oversee this work. RAPID is overseeing more than a dozen projects across several water companies including recycling, desalination, transfers between regions and reservoirs to identify optimal regional solutions that could be started in 2025-2030. We are working with partners to examine 5 potential solutions.

RAPID has introduced a new regulatory process which sets out the activities that need to be completed, allows comparison of the solutions at regular intervals, and has clear checkpoints, or gates, to assess progress and determine which solutions should be taken forward for further work. Learn more about RAPID and the gated process.
Here's a summary of RAPID’s Gate 1 process and the timetable. Please note this has been updated.
| 5 July 2021 Gate 1 submission to RAPID |
Early conceptual design and assessment of solution feasibility. |
| July - Sept 2021 Gate 1 review |
RAPID review, formal query process and recommendation to Ofwat. |
| 14 September 2021 Draft decision |
Ofwat publish the draft decision for each solution. |
| September 2021 Start of Gate 2 activity |
More detailed solution design and assessment. Gate 2 submission October 2022. |
| October 2021 RAPID representation period |
Opportunity for stakeholders to make representations to RAPID on draft decision. Closing date 29 October 2021. (SESRO only - 19 November 2021) |
| 8 December 2021 (SESRO only - 5 January 2022) Final decision |
Ofwat publish the final decision. |
For Gate 2 we will undertake more detailed work including regulatory, technical, and environmental assessments. There will also be opportunities for stakeholders to comment as the work progresses.
Feasible solutions will be considered as options in regional and water company Water Resource Management Plans. The draft regional plans will be published for consultation in January 2022, and these will set out which solutions will be promoted and when the solutions are expected to be required. Our draft WRMP24 will be published for statutory public consultation in autumn 2022.
What are our strategic resource solutions?
We, working in partnership with other water companies, are involved in 5 potential solutions – transfers within the south east and into the south east, water reuse and a reservoir.
We're examining the feasibility of these solutions to understand how much water they could supply, how much they'll cost to build and operate, their carbon footprint, and the wider benefits they could bring to the environment and society.
Information on the 5 solutions including the Gate 1 report submitted to RAPID, additional information requested by RAPID to help them to complete their assessment and Ofwat’s draft decision is published below.
At this stage of development the content of the information is considered draft and relates to material or data which is still in the course of completion in travel to Gate 2, and should not be relied upon at this early stage of development. We continue to develop our approach for each SRO in preparation for Gate 2.
Water transfer from the River Severn to the River Thames
South East strategic reservoir
Water recycling (reuse) schemes in London
Water transfer from Thames Water to Affinity Water
Water transfer from Thames Water to Southern Water
Information which is geographically specific, or commercially sensitive, has been redacted from published documents.
If you'd like to discuss the strategic resource solutions email us.
Proposing new options
If you'd like to suggest a new solution to provide water or a way to manage our current water more effectively, please read the market information and the bid assessment process.
Water Resources Market Information
In line with Ofwat’s Water Resources Market Information guidance, the information below has been provided to enable third parties to begin to identify opportunities and put forward proposals to us to supply water resources, or provide demand management or leakage services.
Our Water Resource Zones
For each of the six water resource zones (WRZ) within Thames Water’s area, we have provided information on key market factors plus our water resources position as set out in our Water Resources Management Plan. This information is in industry-standardised spreadsheets, for the dry year annual average (DYAA) and dry year critical period scenario (DYCP), and is based on templates provided by Ofwat.
The information provided should help third parties to identify where to look for opportunities. However, it is really important that you come and talk to us about your proposal, as our network and the way we provide services to our customers is subject to a range of factors that can change how beneficial opportunities may be or how, when and where we might be able to use them. If you are interested in pursuing any commercial opportunities arising from this information, please view our Bid Assessment Framework for further information.
London
Guildford
Henley
Kennet Valley
Swindon and Oxfordshire
Slough, Wycombe and Aylesbury
Thames Water WRZ boundaries
Our Trading and Procurement Code
The Trading and Procurement Code sets out how we approach water trading, setting out the policies, principles and requirements that will apply when we trade with appointed water companies and other service providers.
Bid Assessment Framework
Encouraging third parties to submit bids for solutions covering water resources, demand management and leakage services that create value for customers is very important to us. These solutions will help us meet our future water needs, as identified in our Water Resources Management Plan, and benefit our current and future customers. Our Bid Assessment Framework (BAF) will provide clarity to third parties on the process that we will apply and how bids will be assessed in line with our key principles of transparency, equal treatment, non-discrimination and proportionality.
We already publish information for third parties, and it is important that the BAF is read in conjunction with our Network Access Code, Water Resources Market Information, Trading and Procurement Code and Water Resources Management Plan. Details of how to access these can be found within the BAF.
To accompany this statement, we have released a Periodic Indicative Notice (or PIN) via OJEU and the UK Find a Tender service which outlines the process for third parties to engage with us to offer solutions as part of the WRMP24 process.
Third parties looking to offer solutions to Thames Water as part of the WRMP24 process should contact us to register their interest by email.
Suppliers will need to provide the following in their email:
- Project applying for (Title and Reference Number as stated in section II.1.1 of the PIN – for WRMP24, this is 1484 WRMP24 – BAF).
- Company name.
- 2 x Contact names.
- 2 x Contact phone numbers.
- 2 x Email addresses.
- Whether you are proposing a water supply or demand management/leakage services solution.
Third parties may contact Thames Water at the above address at any time to register their interest, however the proposal may at Thames Water’s discretion be considered for inclusion within the WRMP29 process rather than the WRMP24 process, depending on the point in the process at which the proposal is received. Proposals which are clearly beneficial, robust and which are smaller in terms of volume of water delivered (Ml/d) are more likely to be considered for inclusion in our programme sooner in the planning process.
On registering their interest, third parties will be registered on Thames Water’s IASTA SmartSource portal within two weeks and provided access to complete an initial pre-qualification (PQQ1) survey.
Should third parties feel that Thames Water has not followed the BAF during a bid assessment process, they may at any time submit a complaint by emailing a copy of the bid assessment framework complaint form with the subject line “BAF Complaint”. Complaints will be considered in accordance with the complaints process detailed in Section F of the BAF.
Third parties are welcome to share any feedback they have on our BAF process by email using our bid assessment framework feedback form.
