Criteria for WFD Groundwater Good ‘Quantitative Status’ and a Framework for the Assessment of Groundwater Abstractions
WFD53

September 2005

The aim of this project was to determine a framework to evaluate the criteria for Water Framework Directive (WFD) ‘good quantitative status’ within each groundwater body and a further framework to assess applications groundwater abstractions to maintain good status.

The WFD explicitly states that member states should ensure a balance between the abstraction and recharge of groundwater and implicitly establishes the need for member states to regulate groundwater abstractions through an assessment and control regime.

It is intended that outcomes from the project concerning the criteria for good status have application throughout the UK and Ireland. Subsequent recommendations regarding an appropriate assessment framework and tools are intended for application in Scotland, Northern Ireland and Ireland and are tailored as appropriate for the hydrogeological environments and legislative regimes in these countries.

The objectives of the research were to set the criteria for good groundwater quantitative status and to develop a regulatory assessment framework. These objectives were subdivided into the following phases:

• An assessment of the criteria for good quantitative status based on the Directive and associated guidance;
• A review and critical evaluation of existing methodologies internationally and within the UK;
• Proposals for the criteria to determine good groundwater status; and the
• Development of a comprehensive framework for the assessment of applications for groundwater abstraction.

Key Findings and Recommendations

Criteria for Good Quantitative Status
An international review concluded that many countries use a regional or aquifer specific ‘groundwater management plan’ rather than applying a ‘one system fits all’ approach. This avoids the over-regulation of ‘minor’ aquifers and focuses management on aquifers with hydraulic properties which can allow over exploitation in areas where abstraction pressures are greatest.

Based on the WFD and UKTAG Guidance five tests were proposed as the criteria for groundwater good quantitative status:

Test 1:     That the total abstraction from the groundwater body should not exceed the recharge to the groundwater body, after an allowance for dependent ecosystems if no assessment of these has been possible.

Test 2:     That groundwater abstraction should not cause a reversal in groundwater flow direction which results in the significant intrusion of saline or other poor quality water into the groundwater body.

Test 3:     That groundwater flows to dependent surface water bodies should not be diminished by groundwater body related pressures to the extent that they do not achieve good status, or that their status is reduced from high to good.

Test 4:     That groundwater body related pressures should not diminish groundwater flows or levels supporting groundwater dependent terrestrial ecosystems (GWDTEs) such that these ecosystems suffer “significant damage” in relation to conservation objectives.

Test 5:     That a review of available groundwater level monitoring data is conducted.  Groundwater levels, on their own, rarely provide a reliable indication of quantitative status in relation to the groundwater body scale balance between abstraction and recharge but may be helpful in investigating potential abstraction impacts on GWDTE receptors.

Indicators of the confidence in the status assessment are presented in Table 6 of the report, based on consideration of all the available evidence.

Framework for the Assessment of Groundwater Abstractions
Assessment of applications for groundwater abstraction must aim to avoid a deterioration in quantitative status and to permit good status to be maintained or achieved. A Good Status classification of a groundwater body does not automatically permit abstractions where these would result in unacceptable stress to surface water bodies or groundwater dependent terrestrial ecosystems, or cause saline intrusion. Equally, Poor Status does not preclude groundwater abstractions where it can be demonstrated that the proposed abstraction does not increase the stress which resulted in the Poor Status classification.

The assessment of groundwater abstraction should be based on the criteria for determining quantitative status (summarised above). Additional criteria also include practical considerations (e.g. borehole yield), impacts on other abstractors or receptors, socio-economic considerations, consultation and sustainability assessments.

The level of assessment of an application (i.e. detail, site investigation and time required) should be linked to the risks it poses and the consequent confidence required in the predicted impacts. A GIS based desk-study is recommended as a first screening tool for all abstraction applications. Further site specific assessment, including water features surveys, pumping tests and, in some cases, numerical groundwater modelling may be required which must be scoped according to the local risks and hydrogeology.

Simple examples of application of the groundwater abstraction assessment framework to contrasting groundwater bodies in Scotland and England are presented.

Keywords:GROUNDWATER, ABSTRACTIONS, WATER FRAMEWORK DIRECTIVE