Storm Overflows in Wales

By 1st July the Better River Quality Taskforce will publish a roadmap that will set out objectives and measurable outcomes for delivering improvements to the management and environmental regulation of overflows in Wales.


The Welsh Government Programme for Government (2021-2026) sets out the vision and ambition to address the climate and nature emergency. It commits to ensuring that nature and the climate are on the agenda of every public service and private sector business. This requires the integrated management of natural resources to maximise economic and social benefits in an equitable way while protecting all ecosystems and the environment.

A thriving water environment is essential for supporting healthy communities, flourishing businesses, and biodiversity. We must act now to ensure that the sustainable management of our water environment benefits the people and communities of Wales today and for future generations.

The need for action

The infrastructure in Wales to deal with our sewage is under pressure from climate change, changes in population density and distribution, and new development. Without action, these pressures will contribute to an increase in the flows at treatment works, risking an increase in the number of spills from storm overflows (referred to as overflows) to have the potential to adversely impact on our water environment.

Coordinated action across organisations is essential if we are to achieve a change and improvement to the management and environmental regulation of overflows in Wales.

The Better River Quality Taskforce

Natural Resources Wales, Welsh Government, Ofwat, Dŵr Cymru and Hafren Dyfrdwy (the partner organisations) recognise this need for action and have established a Better River Quality Taskforce (the taskforce) to evaluate the current approach to the management and regulation of overflows in Wales and to set out detailed plans to drive rapid change and improvement. Afonydd Cymru and Consumer Council for Water are providing independent advice to the taskforce, offering insight and challenge from a stakeholder and customer perspective.

Better River Quality in Wales

The taskforce recognises that acting on overflows is only one of many elements that need to be addressed if we are to improve river quality in Wales. Taking data used for the River Basin Plans in January 2022, overflows have been identified as a reason for not achieving Good Status in 3.7% of waterbodies across Wales. With 4 of the failures confirmed as contributing and 27 assessed as probable reasons for failure and a further 4 waterbodies suspected.

NRW will continue to review the reasons for not achieving good status against the 2021 WFD classification and update and report in July 2022 alongside the publication of the River Basin Plans.

This is why the Taskforce's immediate focus on overflows will be the first important step on the journey to coordinated and focused action in other areas that will ensure improvements in the sustainable management of the water environment in Wales, achieving long term and sustainable improvements to river quality.

This ambition will be similarly supported by co-ordinated action plans to address other areas and sectors that impact water quality in Wales.

Our Goals

In order to drive our action to achieve a rapid change and improvement to the management and environmental regulation of overflows in Wales we want to:

• Deliver seamless support to Welsh Government to achieve their nature and climate change ambitions
• Reduce the adverse impact of any overflow discharges on the environment by targeting investment and taking regulatory action where required to deliver improvements
• Work to develop the existing regulatory framework to ensure water and wastewater companies effectively manage and operate their network of sewers. Regulators will use their existing powers to drive the right outcomes and hold companies to account.
• Gather greater evidence of the impact on our rivers through improved monitoring of both the discharge and the receiving water and, through this, drive towards truly smart networks making best use of technology and real time control.
• Work with water customers to tackle sewer misuse.
• Work with the public and stakeholders to improve the understanding and role of overflows in Wales

Where are we now?

Improving water quality is a key component of the Welsh Government’s Programme for Government and the partner organisations of the Taskforce have a key role to play in contributing towards the achievement of this aim on behalf of the people of Wales.

In Wales, the water companies have been working over a number of years to improve poorly performing assets. This includes improving monitoring to identify where further action is required.

Our roadmap for action, change and improvement

Whilst there is work already in progress to improve overflows in Wales, the Taskforce has identified 5 areas for change and improvement, detailed below, where additional action is required in order to drive rapid change, improvement and investment to meet our goals.

By 1st July 2022 the Taskforce will publish a storm overflows roadmap for Wales in conjunction with our wider River Basin Plans. This roadmap will be informed by 5 detailed action plans that are currently being developed by the relevant Taskforce member(s). These plans set out clear objectives and measurable outcomes for delivering improvements to overflow management from the immediate through to the long term.

Oversight for the delivery of the roadmap will lie with the Taskforce, with accountability for delivering individual/specific actions lying with the appropriate Taskforce member(s). All relevant stakeholders will be brought in to assist where appropriate.

5 areas for change and improvement

Reducing visual impact (Installation of Screens)

To combat the visual impacts seen in our rivers, a programme of overflow assessment is required where screening is not currently in place or, where it is in place, may not be sufficient for modern amenity use.

water companies in Wales will work with the environmental regulator to determine assessment criteria and then carry out assessments within the current AMP7 period. These assessments will identify where further screen installation is required and inform companies case for investment in AMP8 and subsequent investment programmes. Working with regulators and Welsh Government, water companies will be expected to identify and prioritise action at those assets that are deemed to require urgent and immediate attention, re-prioritising expenditure already agreed for the AMP7 Business Plans.

Improving effluent quality and river quality

To drive the delivery of evidence-based catchment solutions, better information is required about discharge quality from overflows and the impact on the receiving water quality. Improved effluent monitoring at targeted sites, together with event duration monitoring already in place, will enhance evidence available and enable effective targeting and prioritisation of action. Current and future overflow monitoring must also work in parallel with monitoring programmes for pollution sources from agriculture, diffuse and other sectors.

An investigative monitoring programme will be established between the NRW and the water companies to determine long-term requirements for monitoring overflows throughout Wales. The need to monitor for a wider range of pollutants including micro plastics, pharmaceuticals, and public health parameters will also be assessed.

Water companies will also investigate and promote the use of monitoring and evidence from other sources including innovative solutions and technology. Citizens and local groups can play a key role in helping tackle water quality pollution through providing monitoring intelligence and public awareness. We will actively work with citizen scientists to understand how their work forms part of our final work programme.

Environmental regulation of overflows

To ensure water companies effectively manage and operate their network of sewers, changes to current regulatory approaches and strengthening of environmental regulation if required.

The environmental regulator will review and implement changes where appropriate to the current regulatory framework to ensure clear guidance, processes, and regulatory tools for improving poorly performing assets. Environmental permitting and reporting measures should be tested and refined as required.

The environmental regulator and water companies will ensure that overflow data is easily accessible and understandable to a wide range of stakeholders and the public, building on the current methods of reporting data. The ambition is to achieve real time monitoring of overflows, allowing interested parties to access data as and when required.

We will collaborate with Consumer Council for Water in the delivery of its People and the Environment programme, to improve public awareness of the connection between our water and sewerage services and the health of our rivers and water environment.

Capacity of the network – planning for the long term

To ensure a network that is fit for purpose, now and in the future, we need to strengthen the long-term planning requirements for sewerage infrastructure.
Drainage and Wastewater Management Plans (DWMP) provide the opportunity for water companies and all stakeholders, including local authorities, to play an active part in the development or a 25-year strategic planning process designed to look at sewerage catchments. All Taskforce members must therefore work together to develop the regulatory framework to support DWMPs in Wales.

To support the development of DWMPs, we need to consider how source control and customer behaviour can be tackled through education, pollution prevention campaigns or improved legislation. Stopping rainwater and plastic entering the sewerage system is vital for the longer term if we are to tackle issues.

Public understanding and engagement

We need to develop and improve public understanding of overflows and their interaction with other water quality issues. Customer and stakeholder engagement should also be used to inform understanding of how people relate to their rivers and environment and how they can be motivated to take action to reduce their own impacts on water quality.

Co-ordinated, and prominent communication is required from regulators, Government, water companies and stakeholders to improve understanding of the function overflows play in preventing flooding to properties in a combined sewerage system. This communication must also highlight how customer and stakeholder behaviour directly impacts the effectiveness of the network - that sewer misuse can lead to environmental harm.

We will look to develop the package of advice and tools available regarding sewer misuse, sewer misconnection and blockage reduction. We'll also explore developing an integrated campaign across partner organisations on wider ‘Improving Water Quality’ with particular reference to overflows.

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