WFD21c Development and review of a TraC Hydromorphology Decision Support Tool

Development and review of a TraC Hydromorphology Decision Support Tool for (a) screening proposed new or altered activities / structures for compliance with WFD water body status and (b) classifying TraC waters under the WFD

The TraC-MImAS tool is a simple risk based regulatory decision-support tool in Excel.  Specifically, the tool is intended to help regulators identify those proposals that could threaten the aim of achieving ‘good ecological status or result in a deterioration in ecological status resulting from changes in hydromorphology.  It was developed as part of a wider UKTAG programme in 2007. 

The underpinning principles behind the TraC-MImAS tool is to ensure that there is appropriate ‘space’ for habitats to continue to thrive, and to ensure that there is no potential for deterioration. The use of the TraC-MImAS tool will be used to protect these key WFD and other habitats by application of the tool as a regulatory aid. By emphasising these elements of the tool to flag those important habitats, the user of the tool is forced to consider the impact of the historic and new pressures on the water body.

The tool is not intended to be applied in isolation, and would be used to complement existing regulatory procedures as part of a pre-screening exercise. Similarly, the tool is not intended to replace expert judgment or existing impact assessments, or to provide a detailed assessment of hydromorphological or ecological processes.  The tool will complement these areas and provide risk-based guidance to provide a regulatory decision matrix of the cumulative impacts acting upon water bodies.

As many elements of TraC-MImAS tool are underpinned by professional judgment, it operates within an ‘adaptive management’ framework.  TraC-MImAS will be reviewed as new evidence on the relationships between ecology and hydromorphology become available.  Where necessary, the tool will be updated.  The ultimate aim will be to test / validate the assumptions underpinning the tools and, where necessary, replace professional judgment with empirically tested data.

Minor revisions to documents 06/11/2013


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