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Networks

21st Century drainage

Over 40 organisations have come together through the programme to identify the major risks for drainage in the future and provide options for how these risks could be addressed.

21st Century Drainage Programme: the context

Rhaglen Ddraenio’r 21ain Ganriff: y cyd-destun

Understanding what causes sewer blockages

Wipes and other so-called disposable products are the main cause of sewer blockages and emergency call outs to sewage pumping stations. A 2011 study showed that baby wipes and other items not suitable for flushing down toilets made up a substantial proportion of blockages. With Defra and EDANA, we have commissioned WRc to carry out a more detailed study to see if this is still the case.

Raising consumer awareness

We have commissioned City to Sea to run a 12-month campaign to raise awareness of the consequences for the environment and for households of flushing wipes and sanitary waste down toilets.

City to Sea website

Monitoring product labelling

Consumers can only act if they have clear information on what can and cannot be safely flushed down the toilet. With Defra, we have commissioned The Water Bureau to monitor changes in the labelling of products that might be flushed, and to examine the use of plastics in these products.

Developing a UK standard for ‘flushability’

Consumer demand to be able to flush products like wipes has risen in recent years, but there is no formally recognised standard to identify which products can be safely flushed without risking sewer blockages, causing sewer flooding and harm to the environment.

We have commissioned WRc to develop a new Water Industry Specification (WIS) to provide a UK water industry recognised standard for ‘flushability’. This standard is designed to be used by retailers and manufacturers to modify product labelling, such that only products which do not block the sewer are labelled as ‘flushable’.

The Water UK Standards Board has consulted on a draft standard and the final standard will be published shortly.

Drainage and wastewater management plans

The 21st Century Drainage Programme has worked with Atkins to develop a new framework for the long term planning of drainage and wastewater services: Drainage and Wastewater Management Plans.

The framework was commissioned by Water UK in collaboration with Defra, Welsh Government, Ofwat, Environment Agency, Natural Resources Wales, Consumer Council for Water, ADEPT and Blueprint for Water.

The Drainage and Wastewater Management Plan framework provides the basis for more collaborative and integrated long term planning by companies, working with other organisations that have responsibilities relating to drainage, flooding and protection of the environment. It makes use of the tools and approaches below, developed by the 21st Century Drainage Programme to enable companies to target investments more effectively and provide customers and stakeholders with better information about the UK’s drainage and wastewater services.

Water and wastewater companies in England and Wales will produce Drainage and Wastewater Management Plans using this framework by the end of 2022, to support their business plans for the 2024 Price Review. The framework is also expected to be of relevance to other parts of the UK.

The main report is supported by six technical appendices:

Capacity Assessment Framework

The 21st Century Drainage Programme has worked with HR Wallingford to develop a new capacity assessment framework – a standard way to assess how much capacity is available in drainage systems now, and what capacity might be available in the future, to enable investment to be targeted more effectively.

The initial framework focuses on capacity in the foul and combined sewer network; the framework could be extended to surface water sewers in the future.

To provide information for different audiences, there is an executive summary, the full report, a supplementary appendix on climate change, and a guidance document for practitioners.

Companies throughout the UK have been putting the new framework into practice, supported by HR Wallingford, to produceĀ an assessment of the available capacity in companiesā€™ foul and combined sewer networks.

This assessment gives an indication of sewer capacity and overflow performance, showing an index of risk, providing an extra tool to help companies prioritise investment.

Where there are higher risks, companies investigate further, including detailed computer modelling and monitoring, to understand the risks better and identify what action is needed.

To investigate the potential for the capacity assessment framework also being used to assess the capacity of surface water drainage assets, Water UK and Defra commissioned HR Wallingford to trial using the framework to assess the capacity of surface water sewers.

Storm overflow assessment framework

Storm overflows are an important part of our drainage system. They are designed to provide protection to properties from flooding by acting as a ‘safety valve’ when there is too much rain water for the drainage system to cope with.

Significant investment by the water industry over recent decades has reduced the impact of storm overflows on the environment, and a major programme to improve the monitoring of storm overflows is underway, for completion in 2020.

The UK Water industry has worked in partnership with our regulators and with MWH, CH2M, PJM Economics and EcoFutures to develop a framework for valuing the benefits of further improvements to storm overflows. There is a full report, and a practitioners’ guide.

This forms part of the new Storm Overflow Assessment Framework for use as companies consider their investment programmes beyond 2020.

Wastewater resilience metrics

Ensuring that services are resilient is a key part of long term planning for drainage and wastewater services. The 21st Century Drainage Programme, led by Water UK and Ofwat, has developed a standard basis for assessing the resilience of wastewater services, which has been developed and tested by Atkins with a view towards their potential use as common performance commitments at price reviews in England and Wales.