Sewerage Risk Management (SRM) is the title of this website, developed to hold the information collated during the update of the Sewerage Rehabilitation Manual. The project was undertaken by WRc and funded by eleven of the UK’s sewerage utilities and supported by Defra and Ofwat. 

The main thrust of the work was to set the philosophy of the Sewerage Rehabilitation Manual into a new context - that of an integrated, risk based approach with the costs of planned interventions to sewer systems underpinned by economic justification, e.g. cost benefit analysis.

Sewerage Risk Management

This website provides the UK sewerage utilities with a comprehensive Sewerage Risk Management (SRM) approach which will: 

  1. Satisfy the need by Ofwat (and other UK financial regulators) for a Sustainable Water Industry, in particular regarding MD219.
  2. Suitably ‘dovetail’ with the UKWIR Capital Maintenance Planning Common Framework (CMPCF).
  3. Accommodate other relevant ‘drivers’ for change including:
    • Defra’s Making Space For Water (MSFW) initiative;
    • Water Framework Directive and UK targets that must be met by 2016;
    • The transfer of private drains and sewers;
    • Climate change and associated ‘highly likely’ factors (e.g. rising sea levels, more intense summer storms, etc.),
    • The European Standard on Drain and Sewer Systems outside buildings (EN752:2007) where relevant.
  4. Build on relevant parts of previous best practice, in particular from the WRc Sewerage Rehabilitation Manual.

The methodology for a risk based approach to the management of sewerage assets, presented in this website, will assist the UK sewerage utilities to: 

  1. Satisfy the new requirements being placed on them by regulators, for example to maximise their chances of undertaking successful negotiations with their regulators in the next periodic review (and beyond).
  2. Deliver better value for money in sewerage management services to their customers. 


The Sewerage Risk Management website will provide users with the following benefits: 

  1. Adopting and addressing as many of the regulators’ perceived needs, e.g. regarding sustainability, rolling timescales, involvement of all stakeholders, etc;
  2. Focusing on and adopting risk based logic for decision making relating to all sewerage management financial and service decision making, i.e. balancing the risk of performance failure against the cost of intervention;
  3. Developing and justifying prioritised lists for all key sewerage expenditure plans;
  4. Having a Sewerage Management Plan (SMP) for suitably defined spatial units within an appropriate temporal horizon (typically up to 25 years in line with MD219) which will provide a business planning context for decisions and will involve all stakeholders;
  5. Using procedures that can be readily adjusted/updated to reflect changing priorities (e.g. regarding new development or new regulation) without needing a fundamental change to the underpinning SRM logic;
  6. Adopting electronic (web and CD/DVD) delivery means to enable the latest guidance to be readily available to all who need it (and have paid for access);
  7. Retaining whatever is relevant from the previous WRc Sewerage Rehabilitation Manual but also leaving behind what is no longer thought relevant (e.g. Category A, B & C sewers);
  8. Bringing out the new SRM guidance and associated tools in stages to fit with the PR09 and other planning timescales;
  9. Recognising the significant interactions between different aspects of sewerage performance (including risk transference) and the major potential for optimising costs (value) by using interventions that address multiple aspects of performance need, i.e. the SRM Integrated Approach.
Updated: 20/03/2013