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.

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Recharge calculations based on daily soil moisture balance models define the resource available for most regional-scale groundwater models used by the environmental regulator in England and Wales. A switch in recent years from the Penman–Grindley methodology to the Food and Agricultural Organization approach has improved the representation of soil properties in these calculations. A new Meteorological Office algorithm for calculating potential evapotranspiration inputs has also been adopted and rain-gauge data processing on individual models are currently being streamlined towards the use of nationally derived grids. A range of infiltration, bypass and runoff–recharge mechanisms have been conceptualized and modelled incorporating simple representation of unsaturated zone storage and flow processes. This paper reviews the recent changes adopted and considers future challenges.

The usage of modelling results by their intended audience is an important aspect of undertaking any project. However, providing the appropriate results in the correct way to key stakeholders is not a straightforward task. Fortunately, there is a growing body of work about approaching the engagement of stakeholders in a way to maximize the impact of modelling results. Using the lessons learnt from a number of recent workshops, including those conducted for the benefits realization process undertaken for the Environment Agency of England and Wales, suggestions for best practice are presented and their relative merits discussed. Best practice for getting groundwater modelling results used by their intended audience is proposed.

The described methodology for the assessment of the reliable outputs of groundwater sources was developed during a recent contract for UK Water Industry Research. It is relatively simple and flexible so that it can be applied to the wide range of groundwater source types and aquifers encountered in the UK. It can be used for all water level conditions, including that of drought, and for various demand conditions. There are two approaches, one based upon operational data and the second upon the analysis and extrapolation of pumping test data. The operational approach has several options of increasing refinement – the choice of option depending on data availability and user requirements. The application of the methodology to real groundwater sources is described using three examples.