This project was undertaken to review the current practice for the evaluation of groundwater abstractions on river and stream flows when assessing groundwater abstraction licence applications. This research contract formed Phase I of the National Groundwater and Contaminated Land Centre’s IGARF programme. The primary objectives of the project were to present a reasoned, robust and technically supportable rationale for the evaluation of the effects of groundwater abstraction on river/groundwater inteaction, and to develop a ‘User Manual’ for use by Agency staff in the determination of abstraction licence applications and reviews.
The scope of work included a thorough literature search and review documenting the available methodologies and quantitative approaches to the evaluation of river/groundwater interaction and the impact of abstractions. A survey of the methodologies in use by the Agency Regions was undertaken through questionnaires and consultations.
From the literature review and Agency consultations the preferred methodologies were identified and trialled in selected areas using a simple spreadsheet modelling tool developed as part of the project.
A suitable tiered approach to the evaluation of the impact of groundwater abstraction on river flows was recommended following a review of the pilot trials. A User Manual was developed with detailed guidance notes to aid Agency staff in the selection and application of the most appropriate method of determination of the impact on river flow from groundwater abstraction.
The IGARF 1 project was rolled out to the Agency’s operational staff at one-day seminars and workshops and proved a very successful approach to disseminating the results of the R&D project attracting favourable feedback from operational staff across the Agency.