Drainage and Wastewater Management Plans are the new way for organisations to work together to improve drainage and environmental water quality.
To find out more, and how to get involved in and benefit from Drainage and Wastewater Management Plans, have a look at this overview.
The full details of the technical framework for Drainage and Wastewater Management Plans can be found in this main report and six appendices:
- Appendix A Collaborative drainage and wastewater planning
- Appendix B Risk-based catchment screening
- Appendix C Baseline risk and vulnerability assessment; and problem characterisation
- Appendix D Options development and appraisal
- Appendix E Case studies
- Appendix F Example contents of a drainage and wastewater management plan
These reports were originally published in September 2018 and were updated in May 2019.
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.
It provides the basis for more collaborative and integrated long-term planning by water 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 to enable investment to be targeted more effectively and provide customers and stakeholders with better information about the UK’s drainage and wastewater services.
Water and sewerage companies in England and Wales will publish draft Drainage and Wastewater Management Plans using this framework in the summer 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 implementation, and where appropriate refinement, of the DWMP framework is being overseen by a cross-sector steering group, including representatives from water and sewerage companies from across the UK, Defra, the Welsh Government, Ofwat, the Environment Agency, Natural Resources Wales, the Consumer Council for Water, ADEPT and Blueprint for Water.
The minutes of meetings of the steering group are published below:
Capacity Assessment Framework
Working with the Environment Agency and other stakeholders, we commissioned 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.
Companies throughout the UK have been putting the new framework into practice, supported by HR Wallingford, to produce an assessment of the available capacity in companies’ 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. We commissioned Atkins to develop a standard basis for assessing the resilience of wastewater services, This measure has now been adopted by Ofwat as a common performance commitment measure for companies in England and Wales