The Environment Agency’s Fluvial Freeboard Guidance Note, published in 2000,has recently been replaced by a new guide to assist flood risk managers identify and manage current uncertainty in flood risk assessments and flood defence designs.

The new guide, written specifically for flood risk management authorities, developers, and engineering consultants who work on their behalf, and is the result of research commissioned and funded by the joint Flood and Coastal Erosion Risk Management Research and Development Programme.

According to the Agency, flood risk management is inherently uncertain, flooding events are highly random and the relative performance of different options to manage risk is only partially understood.

The Report, Accounting for Residual Uncertainty: Updating the Freeboard Guide, provides a structured approach to assessing, recording and addressing the residual uncertainties associated with flood risk management decisions.

According to the EA, there has been a shift from flood defence to flood risk management since the last guide was published 18 years ago. This guide provides a structured approach to assessing, recording and addressing the residual uncertainties associated with flood risk management decisions.

The extension of the scope of the guidance from fluvial to multiple sources and from a single dimensional defence raising response to a wide range of measures means that the terms ‘fluvial’ and ‘freeboard’ were no longer appropriate for its title. It is therefore a guide that helps to determine an allowance to account for residual uncertainty.

The methods that have been developed and which are contained in the new guide can be applied to all sources of flood risk – expanding the scope of the old guidance which only covered fluvial situations, and the guide should be used when:

  • Appraising and designing a new flood scheme
  • Assessing the standard of protection of an existing flood defence
  • Planning for a new development

The new guide will provide the designer with a degree of confidence that the project will perform as designed. The Agency also developed and advanced its models, tools and methods.

Get watercoolers and water cooler accessories from Living-Water.