Over the last 10 years there has been a unique regulator-led programme involving extensive development of regional groundwater models across England and Wales for water resources purposes by the Environment Agency for England and Wales. Eight regionally managed programmes are underpinned by a framework, which has allowed a coordinated national approach. The main uses of the models are for catchment abstraction management and licensing. Models have also assisted in monitoring network design, investigating groundwater quality and implementing groundwater source protection zones. A five-yearly review of the programmes recognized the importance of benefit realization and stakeholder involvement as well as technical good practice. The programme already delivered provides a solid foundation for supporting the management decisions required in areas such as climate change mitigation and integrated catchment management using appropriate tools at a time of rapid organization change and financial uncertainty.

Under the Water Framework Directive (WFD) the requirement for 'good groundwater status' is dependent upon there being no 'significant damage' to groundwater-dependent terrestrial ecosystems, i.e. groundwater-dependent wetlands. An ecohydrogeological framework was developed to assess the risk of significant damage for groundwater-dependent terrestrial ecosystems in the UK and the Republic of Ireland. The framework will be used by the competent authorities implementing the WFD as a decision support system to apply the WFD guidelines on a local to regional basis. The framework considers the variety of groundwater controls and pathways of different wetland types and allows a specific assessment to be made of the vulnerability of different wetland types to groundwater related risks. Seven distinct wetland types were identified and the potential pressures were evaluated. A GIS framework was developed in order to analyse the spatial coincidence of potential risks to each wetland type. The framework was tested for a trial dataset of 10 groundwater controlled wetland ecosystems in England and Wales in order to evaluate their current risk of damage.

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Numerical groundwater models have been used by the Environment Agency and its predecessors for over 30 years to help understand the behaviour of aquifer systems and as one of the tools to help manage groundwater resources effectively. The Agency has recently reviewed the past use of distributed numerical models with a view to improving their utilization for groundwater resource management. This is particularly important due to the changes in groundwater management strategies that will occur as a consequence of the new European Union Water Framework Directive. The review has highlighted a number of areas where changes are desirable. Three in particular are the role and importance of the conceptual model, the requirement for a nationally coordinated programme of modelling and the need to develop further the Agency’s in-house modelling expertise. The Agency is currently developing proposals in these and other areas as part of a Research and Development project.

The Environment Agency of England and Wales uses its calibrated regional models to estimate the reduction in river flows resulting from proposed groundwater abstractions. Where there is no regional model, analytical equations can produce quick initial estimates of river flow depletion. However, users often want more confidence in their estimates by representing more faithfully their understanding of the real river–aquifer system. This paper shows that, when using a numerical model designed to predict river flow depletion, it is important to include adjacent catchments and intermittent streams and less important to include river elevations and variations in transmissivity with groundwater head. Recharge does not usually need to be included unless part of the river becomes disconnected or dry. Therefore, for rivers where stream length is constant and transmissivity variations are small, it is valid to use a ‘no-recharge’ depletion model, which can be built quickly (within a month). A case study on the River Leith in NW England illustrates the use of such a model to assess the ecological impact of two groundwater abstraction licences under the European Union Habitats Directive.