Relative to existing methods of appraisal for new flood defence schemes, current approaches to justifying maintenance needs are more crude, as identified by the recently completed report on Operations and Maintenance Concerted Action. The PAMS project will provide an asset management system that enables flood and coastal defence managers to assess the performance of and maintenance requirements for flood defence assets. Furthermore, the project will provide a means of identifying the optimum management intervention to achieve a particular outcome.

Background

Flood defence managers need an asset management system that allows the assessment of risks associated with a flood defence system and provides a means of identifying the optimum programme of management interventions to achieve a particular outcome (i.e. some desirable reduction in flood risk).  ‘Assets’ in this case is defined as ‘flood defence assets’ (i.e. flood and coastal defences, channels, beaches, and components such as gates, pumps, and sluices).  However, a system of this nature is difficult to construct because:

• The flood defence system is complex, with multiple components contributing to performance (or reliability) during a flood event;
  
  
• Inspecting and monitoring regimes that produce meaningful indicators of asset condition are difficult to develop; and
  
• Assessing the improvement in performance resulting from management interventions (ranging from routine maintenance to major renovations) is difficult.

Recently, significant advances have been achieved in understanding the concepts underpinning a risk-based approach to flood management, for example the DEFRA / EA R&D Report, SR587, entitled Risk, Performance and uncertainty in Flood and Coastal Defence – A Review (2002). http://sciencesearch.defra.gov.uk/Document.aspx?Document=FD2302_3433_TRP.pdf. 

This has built on the Government’s standard “Source / Pathways or Barrier / Receptor” approach to risk management (see figure below).  SR587 established the concept of a tiered approach to risk-based decision-making with an interactive suite of tool, models and data addressing the national, catchment / coastal cell, and local (i. e. asset management and river reach) levels.

Source / Pathway / Receptor / Consequence model for flood risk

PAMS will capitalise on ongoing research and development work (see Links), with a view to integrating these developments and providing a complete framework for decision-making.  While additional research will be required in PAMS (e.g. for determining type and frequency of inspections and assessing need for management interventions), research into these areas will focus on adopting best practice from other fields (or other countries) (e.g. Dutch practice in applying flood defence reliability analysis).
 

Issues

The following list summarises the outstanding issues to be addressed by the PAMS project:

• Current data is not wholly appropriate for performance / risk-based asset management, and the demonstration project will highlight weaknesses and identify future needs / benefits;
  
  
• Whole life asset management will need closer integration of maintenance and capital decision-making, as well as good representation of asset life and performance;
  
  
• Risk assessment will need to include social / environmental as well as economic risks;
  
  
• Value management will need to assess the implications of improved cost / performance data so as to enable identification of best asset management options;
  
  
• Maintenance options will need to consider the links between maintenance and performance; and
  
  
• Management approaches will need to recognise a range of different maintenance interventions.