Over 95% of the Earth’s useable fresh water is

stored as groundwater. This key component of

the water cycle maintains soil moisture, stream

flow and wetlands, and is the source of drinking

water and agricultural and industrial supplies in

many parts of the world.

The water flowing out of aquifers to feed springs and rivers is

replenished naturally, at a rate which varies according to local

conditions. Pressures of the modern world to increase water resources

has led to the concept of enhancing these natural rates of recharge so

that groundwater can be used more widely. This brochure describes the

principles of managing aquifer recharge and lists the activities and

achievements of the major international players in this important area

of sustainable development.

Many international, national and localorganisations see great potential for recharge

enhancement to increase the security and quality ofwater supplies in water-scarce areas. But if suchprojects are to succeed, they need to be wellplanned, designed and operated, and should be anintegral part of catchment/basin-wide watermanagement strategies.

A meeting of representative organisations in Paris on25-26 April 2002, agreed to produce coherent plansand activities and to speak with one voice. As astarting point for this communication, this brochuresets out the goals of the members of thisconsortium. We hope that this will spark otherindividuals and organisations to contribute to futurejoint initiatives to make all new rechargeenhancement projects sustainable.

Foreword Peter Dillon Chair, IAH-MAR Commission

Natural recharge to aquifers is vital in order tomaintain the groundwater and to replenish the

discharges from the aquifer, either natural orresulting from Man’s activities. When more water isremoved from an aquifer than is replenished byrecharge then the groundwater level falls and storageis depleted. Recharge occurs periodically, usuallyseasonally even in temperate climates, but lessfrequently in arid and semi-arid regions. Recharge iseither natural (mainly via direct infiltration ofrainfall into permeable soils but also from surfaceflow), or can be managed (by contour ploughing,building bunds/dams, ponds, diversion channels andwells to enhance recharge), or may be incidental(irrigation, waste water disposal, leaky pipes incities or clearance of deep rooted vegetation).

In developing countries aquifers provide a store ofgroundwater, which, if utilised and managedeffectively, 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 (to drought, variations in

precipitation)

Further actions include:● Developing material on wise strategies for

recharge enhancement in Arid and Semi-aridareas – UNESCO/IAH.

● Running a workshop on evaluation of rechargeenhancement in Arid and Semi-arid Areas –Adelaide, 21-22 September 2002.UNESCO/IAEA/FAO/IAH.

● Holding a further planning meeting at the IAH-MAR plenary during ISAR4, Adelaide, 22-26September 2002.

● Publishing a report on enhancing recharge withreclaimed water – WHO.

● Producing a report on recharge enhancementwith respect to climate change and waterstorage needs for water security –WHO/GW.MATE.

● Running a symposium on managing risksassociated with recharge of reclaimed water –IAHS/IAH/UNESCO, Sapporo 7-8 July 2003.

● Producing further publications; runningregional training programmes.

● Facilitating data collection; monitoring andevaluation of projects.

● Encouraging research and development onManaging Aquifer Recharge: MAR.

● Facilitating networking and dissemination ofinformation via a web page and email list(www.iah.org/recharge).

Rainwater harvesting and managed aquiferrecharge (often known as artificial recharge)contribute to the maintenance of the abovebenefits, particularly if practised as part of awider approach to water resourcemanagement that addresses demand andquality dimensions as well as supplyaspects.

For sustainable management of agroundwater resource, demand needs tobe managed to balance the recharge tothe aquifer, be it natural, managed orincidental. This balance should preferablybe made on an annual basis. However, inarid and semi-arid climates a longerperiod of balance may occur to utilisethe groundwater storage capacity toaccommodate climate variability. Demandmanagement can take many formsincluding more efficient use, education,moves to a lower water use economy (i.e.away from irrigated agriculture) as well asfiscal controls.

This brochure has been sponsored by UNESCO-IHP and hasbeen compiled by IAH-MAR with the support of the BritishDepartment for International Development (DFID).

September 2002

There are many methods for enhancing recharge toaquifers (see Figure), the main ones being;

● Pond or basin infiltration is used when watercan be stored in an unconfined aquifer, andleakage from the pond through the unsaturatedzone recharges an aquifer, which issubsequently pumped to provide a watersupply. Percolation through the unsaturatedzone provides relatively rapid attenuation ofsome contaminants in comparison with passagethrough the aquifer. Soil aquifer treatment(SAT) is a form of intermittent pond filtration,in which recycled water undergoes alternatenitrification and denitrification beneath a leakypond.

● Surface and sub-surface impoundments anddams in stream beds and wadis designed tocapture or slow down, often sporadic, runoff.These are often low-technology structures,designed to meet local conditions and can be

later from the same well. This can beperformed even where the native groundwateris not fit for the intended use, such as whereaquifers are saline or suffering from relicpollution, so long as the injected water after aperiod of storage is of suitable quality for itsintended use.

● Injection and recovery from different wells hasthe advantage of filtration provided by passagethrough the aquifer. This is usually only usedwhen the native groundwater is of potablequality, and injection helps to maintain thesupply. Where unconfined aquifers have a verydeep water table, surficial media arepermeable, and injectant water quality hasextremely low suspended solids, infiltrationfrom dry wells may also be successful.

● All forms of irrigation and leakage from watermains and sewers are unintentional rechargeenhancement, however these are rarelybeneficial and are generally not managed fromthe perspective of enhancing recharge.

filled annually or perennially. Many smallstructures can help to reduce soil erosion. Siltthat accumulates needs to be removed tomaintain infiltration rates and can be returnedto the land. Larger dams may be used torelease water, in a controlled manner, toinfiltrate along the streambed.

● Rainwater harvesting from roof drainage whichis used to recharge aquifers via collectiontanks or through sand filters.

● Induced infiltration or bank infiltrationdescribes pumping of groundwater fromaquifers that are hydraulically connected tolakes or rivers. Pumping induces seepage fromthe surface water into the aquifer and providesfiltration of the water en-route to the watersupply well. This is commonly used in alluvialaquifers in Europe for purifying water supplies.

● Aquifer Storage and Recovery (ASR) involvesinjecting water into a well and recovering it

Factors to consider in all schemes include thequantity, quality and timing of available waterfor recharge, the depth and storage capacity ofaquifers (confined or phreatic), localhydrogeological conditions, quality of nativegroundwater, availability of land andavailability of technical expertise toconstruct, operate, monitor and maintainthe structure. Beyond these technicalissues the institutional and financialconsiderations may determine the successor failure of a scheme. For example, low-technology schemes are usually moresuccessful where there is involvement andcommitment of the communities thatbenefit.

Water harvesting and spreading basins in semi-arid conditions

Some of these techniques have been used for centuries: simple check bunds in gullies tocomplex diversion and infiltration structures, as well as injection wells. Recently, there hasbeen considerable investment in restoring and maintaining such traditional facilities as well asbuilding new structures. Much current effort is, however, empirical in choice of sites, structuresand aquifers. There have been many reported successes with locally raised water tables andwells and streams becoming perennial. Nevertheless, the management of the demand side of thewater balance (groundwater abstraction) alsoneeds to be addressed to ensure that thebenefits of recharge augmentation aresignificant.

Percolation pond near Coimbatore,Tamil Nadu.

International Hydrological Decade (IHD, 1965-1974). Currently, IHP-VI (2002-2007) is in theinitial stages of implementation andcomprises five Themes sub-divided into 21Focal Areas. Many the issues addressed inthese Areas are of common interest to otherprojects and programmes related to AquiferRecharge, some of which are described inthis brochure.

The IHP is fully committed to workingtogether with IAH and other organisationsto promote and develop Managed AquiferRecharge.

UNESCO - IHP

The International Hydrological Programme (IHP),UNESCO’s intergovernmental scientific co-operativeprogramme in water resources, is a vehicle throughwhich Member States can upgrade their knowledge ofthe water cycle and thereby increase their capacityto manage and develop their water resources better.

It also aims to improve the scientific andtechnological basis for the development of methodsfor the rational management of water resources,including the protection of the environment. Furtherinformation can be found athttp://www.unesco.org/water/ihp/

The UNESCO-IHP has a long history starting with the

GW.MATE is a core group of experienced specialists inthe multidisciplinary and multifaceted subject ofgroundwater managemant. They will act globally overa period of 3-5 years to develop operational capacityand capability in groundwater resource managementand quality protection.

GW.MATE are currently providing advice andassistance to World Bank-funded projects in NorthChina Plain, Sanaa Basin-Yemen and QuiborValley-Venezuela. the aim is to promote bothtechnically and institutionally cost-effectivesupply-side management of groundwater resourcesthrough various types of relatively low-cost aquiferrecharge enhancement methods, whilstsimultaneously assisting the appropriate national orlocal government agency and water-users to

Groundwater Management Advisory Team

constrain water demand through a widerange of demand-side managementmeasures.

In the Sana’a Basin, Yemen, for example, theadvantages of constructing cascade check damsin the steeper minor wadis are beinginvestigated. In addition to storing flashy runoffthat would be lost from the catchment, or throughevaporation, these structures reduce soil erosion,flood damage and the flushing of pollutants into theaquifers in the major wadis. Spring flows have alsobeen observed downstream of several check dams,where the gradient is suitable.

Contact: Dr Stephen Foster. GW_mate@bgs.ac.ukor Kkemper@worldbank.org

The EWRI of the American Society of Civil Engineers(ASCE) has a number of standards developmentCommittees, including the ‘Standards Committee onArtificial Recharge of Ground Water.’ Outputs fromthis committee, organised by Dr A Ivan Johnson,include:

● The ‘Standard Guideline for Artificial Rechargeof Ground Water, 2001’ is available for sale bycontacting the ASCE web page.

● The results of a widely circulated questionnairepublished as ‘International Survey on Existing

Water Recharge Facilities, 1970’. Publication No.87 of the International Association ofHydrological Sciences.

● Dr Ivan Johnson has continued to distributethe ASCE questionnaires worldwide to scientistsand scientific organisations. The ASCE/ EWRIStandards Committee is working at making allof the data available through an EWRI webpage.http://www.asce.org/instfound/ewri.cfm

The Environmental and Water Resources Institute (EWRI)

The American Water Works Association ResearchFoundation (AwwaRF) has supported, or is currentlysupporting, the following projects:

● Aquifer Storage Recovery of Treated DrinkingWater [#713]. Published in 1996. (Out ofprint.)

● Aquifer Storage Recovery of Drinking WaterFrom the Cambrian-Ordovician Aquifer inWisconsin [#2539]. Completed in 2001.

● Water Quality Improvements During AquiferStorage and Recovery [#2618]. To be completedin 2003.

● Comparing Basins, Galleries, and Shallow Wellsfor the Recharge of a Deep Aquifer [#2529].Completed in 2001.

● Predicting Water Quality Changes From ArtificialRecharge Sources to Nearby Wellfields [#486].Completed in 2001.

● Augmenting Potable Water Supplies WithReclaimed Water [#371]. NRC published thiswork in 1998 as Issues in Potable Reuse: TheViability of Augmenting Drinking Water SuppliesWith Reclaimed Water (ISBN 0-309-06416-3).Available from the National Academy Press;website: http://www.nap.edu

● Soil Treatability Pilot Studies to Design andModel Soil Aquifer Treatment Systems [#901].Published in 1998. (Order 90731)

● Investigation of Soil-Aquifer Treatment forSustainable Water Reuse [#487]. Phase Icompleted in 2000; Phase II to be completed in2003.

The # numbers refer to the individual projects; moreinformation can be found on AwwaRF’s web site,www.awwarf.com.

The American Water Works AssociationResearch Foundation (AwwaRF)

Freshwater scarcity and saline intrusion of coastalaquifers are currently problems for many regions andare predicted to get worse as human populationsincrease in affected areas. Artificial recharge ofaquifers with treated wastewater (both intentionallyand unintentionally) is being used more frequently inmany areas to restore groundwater levels and preventsaline intrusion. This practice, if not properlymanaged, can result in significant risks to publichealth, especially when the groundwater is a sourceof drinking water.

There is a need to evaluate best practices anddevelop multi-barrier approaches for safeguardinghuman health. Additionally, environmental andsocio-cultural concerns associated with the rechargeof groundwater with treated wastewater need to beaddressed. With these goals in mind, WHO organizedan expert consultation on health risks in aquiferrecharge with reclaimed water in Budapest, Hungary

in November, 2001. A report from this meeting isavailable athttp://www.euro.who.int/watsan/MainActs/20020416_3

The main conclusions of this meeting were:● The health implications of groundwater

recharge with wastewater need to be furtherevaluated.

● A technical report is needed to provideguidance on the best practices for protectinghuman health during groundwater rechargewith wastewater.

WHO is currently developing a technical guidancedocument on groundwater recharge with treatedwastewater. The draft document will be available in2003 for public review and comment. The proposedtable of contents of this report is contained inAnnex 1 of the meeting report (see above).

Health implications of groundwater rechargewith treated wastewater

Assessing the effectiveness of artificial rechargeschemes is essential. So is devising criteria todetermine the cost-effectiveness of schemes at arange of scales, from individual structures tocatchments and at a regional level. However,effectiveness can be difficult to measure directly. Adetailed water balance study is the most common butthere are other methods that will indicate theeffectiveness of artificial recharge schemes, bothrelatively and temporally. The societal impacts alsoneed to be checked in relation to differingmanagement practices and the equity of benefits forexisting and planned uses, and users. The keyuncertainties are:

● The hydrauliceffectiveness of rechargestructures

● The impacts of differentstructural designs andmanagement techniques

● Impacts on livelihoods

These issues are being addressed in a three-year,DFID-funded study. Starting in July 2002, the studyis based in India and Nepal and is led by the BritishGeological Survey (BGS), in collaboration withGovernment agencies, NGOs, universities andUNESCO. Guidance materials will be tailored to theneeds of end users with their full involvement toensure knowledge is disseminated effectively andappropriately.

Further details can be found onwww.iah.org/recharge/proj.html#AGRAR

Augmenting Groundwater Resourcesby Artificial Recharge (AGRAR)

The Omaruru River Delta Aquifer (OMDEL) on the aridcoast of Namibia is one of two major aquiferssupplying water to the central Namib settlements. Recharge to the aquifer is from ephemeral river flow.However, on rare occasions, large quantities offloodwater pass over the riverbed and into the seabecause a layer of fine silt on the surface of theriverbed impedes recharge.

Artificial recharge involves the temporary storage ofephemeral floodwaters in a large reservoir (OMDELDam) to allow the fine sediment to settle, with therelease of clean water in a controlled manner toinfiltrate over designated sites on the Main Channel.The aim is to transfer the water in the reservoir to

Artificial Recharge, Namibia

Pre-sedimentation basin in front of the flowdivider with infiltration basin in the background.(S. Zeelie, 1997)

Aerial view of the OMDEL dam (R. Albrechts, 1994)

the aquifer during a dry period. In the event ofconsecutive good rainy seasons, enoughstorage space will then be available in theOMDEL Dam, ensuring that the storagepotential of the reservoir would bemaximised.

The very good rainy seasons of 1997 and2000 tested the OMDEL artificial rechargefacility, with 53% of the 1997 flood event(18 Mm3) infiltrated artificially, more thanseven times the expected natural recharge.It was calculated that 29% of the waterwas lost to evaporation and 11% remainedin the OMDEL Dam.

The International Association ofHydrological Sciences (IAHS)

The aims of IAHS include:● The study of all aspects of hydrology.● Comparison and publication of research results.● The initiation and coordination of research that

requires international cooperation.

IAHS organizes conferences, symposia and workshopsin various parts of the world, including a symposiumon ‘Methodologies for risks assessment of wastewater re-use on groundwater quality’ –IAHS/IAH/UNESCO, Sapporo, Japan 7-8 July 2003.Proceedings of these meetings are published in theso-called Red Books. Some deal with general themesrelated to groundwater management, like calibrationand reliability in groundwater modelling (Publ. No.

237, No 265), tracers and modelling in hydrogeology(Publ. No. 262) and integrated water resourcesmanagement (Publ. No. 272). Others describeprocesses in specific hydrological systems, like hardrock systems (Publ. No. 241) and karst hydrology(Publ. No. 247).

IAHS also publishes a scientific journal, theHydrological Sciences Journal (HSJ) containingarticles on groundwater and aquifers that describenatural and man induced flow and water qualityprocesses. More information about IAHS, symposia,Red Books and HSJ can be found on the IAHSwebsite: http://www.cig.ensmp.fr/~iahs.

Recharge enhancement for agriculture

The UN Food and Agriculture Organisation is activelyengaged in promoting three methods of recharge toshallow aquifers:

● water harvesting techniques (‘run-off farming’)by which water is stored in the root-zone andexcess water percolates to the aquifers.

● water management in wetlands to provideover-season storage and enhanced recessionflows to contribute to recharge and provideresidual soil moisture for a dry season cropping,

● construction of small reservoirs, even onpermeable soils, to store water but at the sametime also to recharge the local shallow aquifer.

In summary, the principles followed when applyingaquifer recharge include:

● Ideally, recharge activities, includingmechanised water harvesting techniques, shouldfocus on the most favourable soil/aquifersituations and be combined with the overallresource management of the linked aquifersystems, at the watershed scale

● Full participation from the farmer’s community,paying particular attention to the role of

women, through involvement during planning,design, implementation, operation andevaluation of the system.

● The investment should result in income in theshort term. Water harvesting results in surplusproduction of grain or fodder. Artificial rechargeshould result in more water for irrigation andincreased production.

Many field projects and, in particular, the activitiesundertaken in the water control component of theSpecial Programme for Food Security contribute tothe recharge of groundwater. These projects dealwith irrigation, soil and water conservation, wetlanddevelopment and management including small-scalewater harvesting; irrigation and drainage systemsusing rainfall, water runoff, small streams, shallowgroundwater and simple lifting devices, such as thetreadle pump; and land development and tillagesystems that offer greater resilience to climaticvariation. Details can be found at the websites:http://www.fao.org/spfs andhttp://www.fao.org/ag/agl

Components of the water cycle at reservoirand watershed scales.

expected to quadruple in the next 4 years. Thecombined group was honoured in October 2001with the UNESCO Great Man-Made River Prizefor Innovative Water Resources Managementin Arid and Semi-Arid Zones.

In addition, work is also advancing onunderstanding and predicting the waterquality improvements that occur in aquifersduring aquifer storage and recovery ofwater intended for potable use. TheAWWARF supports this work. Furtherinformation: www.clw.csiro.au/issues/water_reclamation.

Artificial Recharge of Groundwater, II: 1994. Proceedings of the Second International Symposium onArtificial Recharge of Ground Water, Orlando, FL, United States, ASCE, New York, NY, United States.

Artificial Recharge of Groundwater 1996. Proceedings of an International Symposium, Helsinki, Finalnd,Nordic Hydrologic Programme Report #38.

Management of Aquifer Recharge for Sustainability: 2002. Proceedings of the Fourth InternationalSymposium on Artificial Recharge of Groundwater (ISAR-4), Adelaide, Australia. Ed. P.J. Dillon,A.A. Balkema.

Artificial Recharge of Groundwater, III: 1998. Proceedings of the Third International Symposium onArtificial Recharge of Ground Water, Amsterdam, Ed Jos H Peters, Balkema.

Artificial recharge of groundwater: hydrogeology and engineering. 2002. Bouwer, H., in HydrogeologyJournal 10: 121-142.

Atelier Sous-Regional sur la Collecte des Eaux de Surface en Afrique de L’ Ouest et du Centre, tenu à Niameyau Niger du 26-29 Octobre 1999 – FAO RAF, Case studies: Nigeria, Cameroon, Burkina Faso, Niger,Mauritanie, Gambie and Tchad.

Groundwater and Society: Resources, Tensions and Opportunities. 2000. Burke, J.J. & Moench, M.H.Themes in groundwater management for the 21st century. United Nations Publications.

Groundwater recharge and wells – A guide to Aquifer Storage and Recovery. Pyne R. D. G. 1995. LewisPublishing, Florida, USA.

Guide on Artificial Recharge to Ground Water. 2000. Central Ground Water Board, Govt. of India, NewDelhi.

Rainwater harvesting and Artificial Recharge to Groundwater: a guide to follow. 2000. UNESCO-IHP andCentral Ground Water Board, Govt. of India.

Standard Guidelines for Artificial Recharge of Groundwater. 2001. Environmental and Water ResourcesInstitute, American Society of Civil Engineers, 2001EWRI/ASCE 34-01.

Water Harvesting, A Manual for the Design and Construction of Water Harvesting Schemes for PlantProduction. Critchley, W., Siegert, K., Chapman, C. and Finkel, M. FAO publication AGL/MSC/17/91.Available on line at: http://www.fao.org/docrep/U3160E/U3160E00.htm. Also, training workshop onwater harvesting available in 2002 on CDROM in English, French, Spanish, Arabic and Chinese:http://www.fao.org/af/AGL/ag|w/wharv.htm

For eight years CSIRO and the South AustralianDepartment for Water Resources have workedtogether to develop aquifer storage and recoverywith urban stormwater runoff and reclaimed water.They store this in brackish or saline aquifers tocreate irrigation water supplies. Techniques havebeen developed to measure fate of injectant in theaquifer, anisotropy of the aquifer material at in-situstresses, fate of colloidal material and organiccarbon, the clogging potential of low-grade waters,and survival of pathogenic organisms. Together withgroundwater flow, solute transport and geochemicalmodelling, this information has been used todevelop operating practices at these sites andimprove the design of new sites. Almost 1 millioncubic metres/year of installed capacity is nowoperating from more than 6 sites and this is

Aquifer storage and recovery research in Australia

A review of the potential for ASR in the UK (1998),identified several aquifers with good potential andalso drafted guidance on regulatory aspects. Severalfield trials were undertaken by water companies.Among the issues constraining development were:

● Impacts of the dual-porosity behaviour of theChalk and other aquifers on recovery efficiency.

● Geochemical interactions; water/water andwater/rock in different aquifers.

● Environmental impacts in relation tooperational cycles.

These issues were addressed by a project entitledASR-UK through physical and geochemical modelling,the results of which are summarised atwww.nwl.ac.uk/gwf/asr/asr_intro.htm

The main conclusions drawn from ASR-UK were:● British aquifers can be considered as part of a

continuum (see figure) ranging from singleporosity unconsolidated aquifers to fractureddual-porosity aquifers.

● The response of these aquifers to ASR varies ina predictable manner that is controlled by theproportion of fracture and matrix porosity, bothfrom the physical mixing and geochemicalinteraction perspectives.

● Simple modelling tools have been developed toassist in decision-making from the early stagesof ASR schemes.

Aquifer Storage Recovery in the UK

The application of isotope techniques to aquiferrecharge studies can contribute greatly to theunderstanding of processes and mechanisms as wellas providing solutions to particular problems. Onechallenge is to find the scope of genericapplications, as many isotope applications aredependent on the particular case study.

Tracing enhanced aquifer recharge using isotopemethods is, in a sense, the reverse of dam leakagestudies in that the intention is to infiltrate as muchsurface water as possible into an aquifer. Thereforemany of the principles that are used in dam leakagestudies could be adapted and applied to aquiferrecharge by surface infiltration.

Numerous areas of possible application of isotopemethods include:

● Infiltration basin studies and variants (e.g. aridzone water harvesting from wadi floods). Thepossible tracers are �2H, �18O, tritium andhydro-geochemistry.

● Injection well applications – tracer tests,efficiency of injection and recovery using aconservative isotopic tracer in a mass balanceapproach. Flow path and travel time between

injection and recovery wells using 3H, 3H/He orCFC.

● Constraining water balance of infiltrationbasins using isotopes and solutes, therebyestimating infiltration efficiency, using thecombined water, isotope and solute massbalance approach.

● Managed aquifer recharge is recognised as akey element of water management strategies inarid regions (Saudi Arabia, Oman, Kuwait,Egypt, Lebanon). Wastewater reuse is asignificant issue – therefore �13C and Nisotopes in NH

4& NO

3are potentially useful to

determine N-depletion processes, egdenitrification.

● Others include pathogen transport and viability(fate and degradation of DOC - �13C, �2H),dissolved oxygen consumption (�18O) andmixing reaction, oxidation and reaction withpyrite and Natural Organic Matter (C isotopesand �34S).

For further information seehttp://www.iaea.org/programmes/ripc/ih/

Applications of environmental isotopes toaquifer recharge studies

International Association ofHydrogeologists Commission onManagement of Aquifer Recharge.IAH-MAR

IAH-MAR aims to expand water resources and improve water quality in waysthat are appropriate, environmentally sustainable, technically viable,

economical, and socially desirable. It will do this by encouragingdevelopment and adoption of improved practices for management of aquiferrecharge. This will be achieved by increasing awareness of MAR among IAH

members, related professions and the community, by facilitatinginternational exchange of information between members (e.g. via a web

page and an email list), by disseminating results of research and practicalexperience (e.g. via conferences and a reference database), and by

undertaking joint projects and activities identified as important by itsmembers.

International Symposia on Artificial Recharge of Groundwater have beenheld at approximately 4-yearly intervals in Anaheim, Ca. (1989), Orlando, Fl.

(1994), Amsterdam, Netherlands (1998) and most recently ISAR-4 inAdelaide, Australia (2002). The proceedings of the first two symposia are

published by the ASCE (www.asce.org) and the latter two by A.A. Balkema.Publishers (http://balkema.nl see under IAH). The next symposium is

planned for about 2006.

Web: http://www.iah.org/recharge/index.htmlChairman: Peter.Dillon@csiro.au Vice-chairman: i.gale@bgs.ac.uk

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