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The effectiveness of artificial recharge of groundwater : a review

Gale, I.; Neumann, I.; Calow, R.; Moench, M.. 2002 The effectiveness of artificial recharge of groundwater : a review. Nottingham, UK, British Geological Survey, 60pp. (CR/02/108N) (Unpublished)

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Abstract/Summary

This report is the principal technical output of a project commissioned by the Department for International Development to review the current state of knowledge regarding the effectiveness of Augmenting Groundwater Resources by Artificial Recharge (AGRAR). The focus of this study is on applications to rural environments and communities in semi-arid developing countries but does also refer to applicable users in urban situations. Water harvesting and, to a lesser extent, artificial recharge are currently being promoted as solutions to water scarcity in many nations, especially India. Artificial recharge is one of many techniques used to manage water resources and its efficacy may be limited by a combination of technical and socio-economic factors. The benefits of utilising groundwater in developing countries have been clearly demonstrated; aquifers providing a store of groundwater, which, if utilised and managed effectively, can play a vital role in: • Poverty reduction/ livelihood stability • Risk reduction • Increased yields resulting from reliable irrigation • Increased economic returns • Distributive equity (higher water levels mean more access for everyone) • Reduced vulnerability (drought, variations in precipitation) Rainwater harvesting and artificial recharge contribute to the maintenance of the above benefits, particularly if practised as part of a wider approach to water resource management that addresses demand and quality dimensions as well as supply aspects. Numerous schemes exist to artificially recharge groundwater and they are as varied as the ingenuity of those involved in their construction and operation. Broadly, they can be grouped into the following categories: • Spreading methods • Open wells and shafts • Drilled wells and boreholes • Bank infiltration • Sand storage dams • Roof-top rainwater harvesting, The effectiveness of artificial recharge schemes is governed by climate, geology and hydrogeology, topography, source water availability and quality, operational and management issues, regulatory controls and environmental and socio-economic considerations. The complex interaction of some or all of these factors will determine the degree of success, which itself can be viewed from a variety of perspectives. Broadly, however, the factors can be categorised into physical/technical and socio-economic issues. • Physical technical conditions determine the to effectiveness of artificial recharge schemes: oSoil type (infiltration capacity and distribution) oSource of water (rivers, rainfall distribution/intensity, wastewater etc.) oSub-surface storage capacity (geology, degree of confinement, permeability, groundwater flow and quality etc.) oArtificial recharge method applied (spreading, well, boreholes etc) oManagement and maintance scheme (government, NGO, community). • Socio-economic conditions, including: oThe demand for additional groundwater from either man or the environment oThe economics of artificial recharge oThe incentives communities may have for implementing and maintaining artificial recharge activities; oWhether or not artificial recharge is likely to be implemented as part of a wider package of management interventions In the context of sustainable groundwater management, it is essential to assess the effectiveness of artificial recharge schemes in terms of their ability to recharge the aquifer. However, effectiveness can be difficult to measure directly. A detailed water balance study provides a quantitative estimate of the contribution of a scheme to groundwater recharge. However, these are very expensive and require technical expertise. Existing methods should be developed into indicative measures of the effectiveness of artificial recharge and these methods need to be applied widely to promote improved management of schemes. The uncertainties associated with artificial recharge need to be addressed through systematic assessments of the water balances of artificial recharge schemes in a variety of environments in order to provide guidelines on their effectiveness and sustainability. The importance of different management strategies also needs to be assessed in relation to their impact on livelihoods. Bringing these aspects together will provide sound data and guidelines for future investment and sustainable implementation. The sets of criteria devised for the effective implementation and management of individual schemes, as well as at watershed and regional scales, need to be developed collaboratively with implementers, founders and policy makers. Guidance materials produced will need to be tailored to the needs of end users and their full involvement is needed to ensure knowledge is effectively and appropriately disseminated and internalised. Artificial recharge should be used in conjunction with other sources of water (rivers, lakes, groundwater etc.), and a range of other water management methods including, demand management, conjunctive use, storm water and waste water reuse etc. Only through an improved understanding of the technical effectiveness of recharge structures, combined with a clear assessment of the social and economic benefits and constraints, as well as the impacts on livelihoods, will management of artificial recharge improve.

Item Type: Publication - Report
Programmes: BGS Programmes > Groundwater Management
Funders/Sponsors: British Geological Survey, Department for International Development (DfID)
Additional Information. Not used in RCUK Gateway to Research.: This item has been internally reviewed, but not externally peer-reviewed.
Additional Keywords: GroundwaterBGS, Groundwater, Groundwater resources, Groundwater management
Date made live: 15 Apr 2020 14:30 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/527471

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