Flooding FAQs - Thames Water responsibilities

The information provided below was given to us by Thames Water in response to questions received from Westminster residents. If you have any queries regarding the information Thames Water have given, please contact their Customer Service team on 0800 980 8800 or through the Thames Water website.

Responsibilities

Responsibility for flooding is held jointly among several bodies. There is no single body responsible for managing flood risk in the UK because of the role of the devolved administrations in Scotland, Northern Ireland, and Wales. The Flood and Water Management Act defines who is responsible for different types of flooding.

Responsibilities are broken down as follows:

• Thames Water is responsible for managing the risks of flooding from water and foul or combined sewer systems.
• Highway Authorities are responsible for providing and managing highway drainage and roadside ditches.
• Lead Local Flood Authorities (LLFAs) are responsible for developing, maintaining, and applying a strategy for local flood risk management in their areas and for maintaining a register of flood risk assets. They also have lead responsibility for managing the risk of flooding from surface water, groundwater, and ordinary watercourses.
• The Environment Agency is responsible for taking a strategic overview of the management of all sources of flooding and coastal erosion. It also has operational responsibility for managing the risk of flooding from main rivers.
• Thames Water, Highway Authorities, LLFAs and the Environment Agency are all contactable in instances of flood waters rising.

Flood response

Immediate response

Immediately following the flooding on 12 July, Thames Water worked alongside emergency responders, local authorities, Lead Local Flood Authorities (LLFAs) and deployed additional teams to ensure communities were supported.

This support included:

• putting extra staff in place overnight to respond to customer calls and ensuring Thames Water engineers were ready to respond to calls as quickly as they could
• deploying teams directly to the worst affected areas, to offer hands on support to those who needed it
• increasing Thames Water clean-up resources ten-fold to support customers to help clear the debris left behind, and providing support to help nearly 150 properties deal with the aftermath of the flooding
• working in partnership with local authorities to ensure residents were kept up to date with Thames Water’s response
• meeting with residents to ensure they continue to have access to the information they needed

Call centre

On 12 and 25 July Thames Water’s customer centre received an unanticipated number of calls relating to flooding. This meant that many customers were waiting longer than usual to reach customer service.

To help prevent this in the future, Thames Water is now in the process of installing a new telephony system that will help call handlers to log calls more easily, reducing waiting time significantly.

Cause of flooding

Thames Water’s initial investigations show there is no evidence of any failure or significant blockages that caused the flooding. July 2021 saw record levels of extreme heavy rainfall across the capital. At its peak on Monday 12 July, Thames Water recorded a month’s rainfall in just one hour, whilst parts of London on 25 July saw up to two months of rainfall across three to four hours.  In some parts of London, the speed, severity, timing, and sheer scale of rainfall tested Thames Water’s and other Risk Management Authorities’ (RMAs) drainage assets beyond the limit of what they were designed to cope with.

With ‘convective’ thunderstorms, such as those that caused the flooding on 12 and 25 July, it is very difficult to forecast where the rain will fall and the intensity/duration of the rainfall. For the 12 July event, the Met Office issued a ‘yellow’ weather warning, with a forecast rainfall of only 20mm. The 25 July warning was initially yellow and then upgraded to Amber in the afternoon, giving services no time to do anything about it. The forecast was 24mm of rain and no one, including the Met Office, expected the storms to be as intense as they were. The key challenge is most rainfall warnings do not result in adverse weather that affects Thames Water’s customers. Thames Water cannot proactively stand up a full emergency response ahead of rainfall warnings covering all areas.

In the short term, Thames Water is commissioning an independent review of its sewer network to see if any issues with its operation contributed to the flooding. This investigation will seek to scrutinise and understand the underlying reasons for July’s flooding, and allow Thames Water to understand where adaptations and improvements can be made to help mitigate the risk of future flooding. This study will play a key role in ensuring that Thames Water can plays its part in building a wastewater system that is fit for all future needs. The results of this review will be published by Thames Water once complete.

In the meantime, Thames Water is working to continually improve its network. Thames Water is installing thousands of Sewer Depth Monitors in its network to measure actual flows in the sewers and combine this with improved data analysis to help identify potential problems separate from day to day and seasonal fluctuations. This ‘smart’ capability improvement is being rolled out over the next few years.

However, events like this are a harsh reminder of the devastating impact that extreme weather can have, and that these events are now taking place with much greater frequency, and with increased severity. These severe weather events look set to quickly become more frequent across the UK and ensuring Thames Water’s network can operate and prevent flash flooding needs to now become the collective new focus for all organisations involved in the UK’s water network and drainage systems. Looking to the future, Thames Water is committed to working alongside national and local government, and other service providers to make sure Thames Water is playing its part to support the communities worst affected by the recent floods, whilst building better resilience into its systems for the future.

Maida Vale Flood Alleviation Scheme

The Maida Vale flood alleviation scheme is designed to provide protection for a 1-in-30 year rainfall event, which is less than the amount which fell in July. At this stage, Thames Water’s initial investigations have not found any evidence of a failure that would have contributed to the flooding. The independent study Thames Water is commissioning to better understand the performance and capabilities of Thames Water’s existing wastewater system and understand further the underlying reasons for July’s flooding, will include a review of the Maida Vale flooding scheme.

Thames Water Senior Management Team

Responding to the storms has been the top priority of Thames Water’s executive team, including the CEO, who have attended many public and private meetings following the storms. Thames Water’s senior management, who have much of the technical knowledge have also attended, as they are best placed to answer many of the local questions.

With regards to awarding performance bonuses, Thames Water’s executive reward packages are benchmarked with those at other similar-sized organisations. Bonuses remain dependent on achieving specified performance improvements, including leakage and customer service targets.

Support

Compensation

This was an extraordinary and un-forecast weather event where a month’s worth of rain fell within an hour. The cause of the flooding was due to severe weather overwhelming the capital’s network, rather than a failure of Thames Water’s assets. This means that Thames Water will not be providing compensation payments in response to this incident.

Thames Water do offer a range of financial support tariffs for customers who are struggling with their bills, and a dedicated trust fund provides additional support for those facing financial hardship. Thames Water encourage customers to contact the Customer Service team directly, so it can ensure the right support is provided to those who need it. You can contact the team on 0800 980 8800.

Insurance

In extreme weather incidents like this, claims should be made through respective home or business insurance. Thames Water do offer a range of financial support tariffs for customers who are struggling with their bills, and a dedicated trust fund provides additional support for those facing financial hardship. Thames Water encourage customers to contact the Customer Service team directly, so it can ensure the right support is provided to those who need it. You can contact the team on 0800 980 8800.

Maintenance and prevention

Sewer maintenance

Thames Water have a formal programme for maintaining and cleaning its sewers which is carried out across the network. At this stage, Thames Water’s initial investigations have not found any evidence of a failure that would have contributed to the flooding. 

Please report any specific locations where there may be ongoing issues and Thames Water will be glad to investigate. If you would like to discuss further, please contact Thames Water’s Customer Service team on 0800 980 8800 and the customer service team will do their best to help.

The ‘Super Sewer’

The ‘Super Sewer’ is predominantly an environmental scheme which is designed to stop sewage from entering the Thames. It is not a specific flood alleviation project. It is intended to take the excess flow that would have entered the River Thames via Combined Sewer Overflows (CSOs). By default, sewers will become full when it rains and when the tunnel is empty, the interception points will provide capacity to absorb storm water flows. However, it cannot help in situations where the rainfall falls some distance from these sewers and the connecting infrastructure is inundated or overwhelmed. It will have some impact on flood levels in places close to the river, but it would not stop flooding on this scale in London.

Review and investigation

Independent Review

Thames Water is commissioning an independent review of its sewer network to see if any issues with its operation contributed to the flooding.

Stage one of the report is now available to read.

To ensure the full independence of the investigation, Thames Water will be taking advice from its regulators Ofwat and the Consumer Council for Water on the best way to proceed. Once Thames Water have appointed an appropriate organisation to carry this out, timescales will be provided.

Customers will not be part of the independent report as it will focus primarily on the performance of Thames Water’s network. However, customers and the wider public will be involved in the consultation of Thames Water’s forthcoming Drainage and Wastewater Management Plan (DWMP), which will identify the challenges that climate change, population growth and further losses of permeable surfaces will have over the long-term. This consultation will be held in summer 2022.

Thames Water recommend that customers affected by the flooding fill out the relevant questionnaires on its website.

Surveying affected properties

Thames Water is adding as many impacted properties as possible onto its Sewer Flooding History Database to create an official record of who was affected. Thames Water is delivering 800 questionnaires to properties that were flooded across the impacted areas. Customers who fill out these questionnaires will be added to the database.