RYEA\18655007WinaNssue01 Water Resource Management and Desalination Options for Small Communities in Arid and Semi-Arid Coastal Regions (Gaza) November 1996 Institute of Hydrology COPYRIGHTANDREPRODUCTION 0 AEA Technology plc, ETSU, 1996 Enquiries about copyright and reproduction shouldbe addressed to: Dr K J Brown, General Manager, ETSU, B156 Harwell, Didcot, Oxfordshire, OX11 ORA,UK. RYEA\18655007\FinaNssue01 Water Resource Management and Desalination Options for Small Communities in Arid and Semi-Arid Coastal Regions (Gaza) A report produced for ODA November 1996 Title Water Resource Management andDesalination Options for SmallCommunities in Arid and Semi- Arid CoastalRe •om Gaza Customer ODA Customer reference ENA 9597966\333 \001 Confidentiality, This document has been preparedby AEA copyright and Technology plc in connection with a contract to reproduction su 1 oods and/or services. File reference Arecons\ ODA\ desalin\ final Reference number RYEA\ 18655007 ETSU Harwell Oxfordshire OX11 ORA Telephone 01235 433128 Facsimile01235 433213 AEATechnology is the trading name of AEATechnology plc AEATechnology is certified to IS09001 Report Manager Name MissG T Wilkins Checked by Name Dr W B Gillett Signature Ov Date , u. Approved by Name Dr D Martin Signature • • Date 111( q Water Management and DeaaMutton (('aza) ItYEA/18655007/finaVissue 1 04/11196 • PREFACE This report was commissioned by the ODA and was jointly funded by three departments within ODA (Engineering Division, Natural Resources and West Asia Departments). The team of consultants and specialists involved in producing this report comprised ETSU, The Institute of Hydrology, The British Geological Society, Richard Morris and Associates, Dubs Ltd and Light Works Ltd. The report aims to assess the viability of water management and desalination options for small communities in arid and semi-arid coastal regions and to identify any necessary developments required for the successful introduction of such options in these areas. Chapter 1 outlines a range of water management options and identifies those which are suitable for small communities in arid and semi-arid coastal regions. An outline methodology is given to aid water management strategy development and to improve the success of schemes. • Chapter 2 describes the desalination processes which have been developed and possible energy resources which could be used to power the plant, giving a brief outline of suitable desalination technology and energy technology combinations. Chapter 3 compares the economics of selected desalination technology and energy technology combinations. • Chapter 4 outlines some of the background requirements for undertaking a water management review and establishing where small-scale desalination plants would be appropriate. • Chapter 5 is a brief case study on water management options for Gaza. Two specific desalination technologies were assessedfor their viability with respect to Gaza (the Seawater Greenhouse - Light Works Ltd and IN powered reverse osmosis - Dulas Ltd). Economic assessments of these technologies can be found in Annex A and Annex B respectively. Chapter 6 contains general conclusions and recommendations for small arid and semi-arid communities in coastal regions and summarises the specific conclusions and recommendations which were made for Gaza in Chapter 5. • • • • • • • • • Page1 Viaftihtimgcmcntandpealinglon(('ra) RYEA/1805007/Final/kwc1 04/11/96 Pageii Water Managnarnt and Draalmanon (Can) It YEA/18655C07/findhlwe 1 i4/11/96 REVIEW OF WATER MANAGEMENT AND DESALINATION OPTIONS FOR SMALLCOMMUNITIES IN ARID AND SEMI-ARID COASTAL REGIONS • EXECUTIVE SUMMARY Background This report was commissionedby the ODA and isjointly funded by three desks within the ODA (the Water, Energyand Palestinedesks). The report aimsto assessthe viabilityof water management and desalinationoptions for smallconununities in arid and semi-arid coastalregions and to identify any necessarydevelopmentsrequired for the successfulintroduction of suchoptions in these areas. A case study has been done on Gaza with an economic assessment of two specific desalination technologies (a SeawaterGreenhouse - Light Works Ltd and a PV powered reverse osmosisplant - Dulas Ltd). • Summary • Water scarcityin semi-aridareasmay often reflectpoor water managementand economic constraints rather than a shortage of water resources. An integrated water resources management strategy appropriate to localcircumstancescan often reducedemandsby making moreeffectiveuse of existing sourcesof supply.Althougha wide range of measuresareavailable,implementingsuch a strategymay depend on institutional,legalor other refomiswhich mayrequire a decade or more beforesignificant improvementscan be made. • In the past, increased water demands were usually met by developing new surface water and groundwater supplies. However, this has often had adverse impacts on the environment and sustainability.Due to the rapid increasein population,risinglivingstandards,industrialisationand the degradation of existing sources, water resourcesmanagement must also consider the role of less conventional sourcesof supply,such asdesalination,or importingsuppliesfromelsewhere.Validcost comparisonsbetween conventional and non-conventionalsourcesshould take account of the water resourcesavailableto future generations. There are a variety of technologiesavailablefor the desalinationof seawateror brackishwater using renewable energy (RE) sources. Numerous researchand demonstration plantshave been built with a view to overcoming the problems of matching a discontinuous energy source to a desalination process,which in all casesare best suited for continuous operation. However, there is stillmuch to be done before suchplantscan be classedasbeingcommercial. • Seawater ismuch more expensiveto desalinatethan brackishwater. The costof water produced by desalinationtechnology using conventional fossilfuelsis usuallymuch higherthan most economies can afford and much higher than naturally occurring water. Hence the only countries that have invested seriouslyin desalinationare the oil rich Gulf countries. The costof water produced by desalinaonti usinga renewable energy source isnormallymore expensivethan using a conventional fossilfuel if an electricgrid is alreadyin place. However, renewable energydriven desalinationcan bc competitive in remote areaswhere there is no developedelectricalgridor where fossilfuel prices are high. The energy efficiencyof desalinationprocessesis improving andthe costsassociatedwith Pageiii Water Management and Desalination(Gan) RYEA/18655O07/Final/nsue I 04/I I/96 renewable energy are falling, and are expected to continue to fall, which will make RE powered desalinationplant more viable in the future. In the absence of grid electricity or waste heat, the most likely renewable energy souras to be coupled to desalination plants using current technology arewind, solarenergy and combustion of municipal solid waste or agricultural waste (biomass). Solarenergy plants tend to cover Largeareas which can be a problem on small islandsor in areaswhere landprices are high. The availabilityof biomass is questionable if there is a lack of water for agriculture,as given the cost of the water produced by desalinationsystemsit is unlikelythat it can be usedfor agriculture. But, there can be a good market for smalldesalinationplantsusingrenewableenergysourcesin specificremote locations. In remote coastalcommunities, without accessto alternativewatersuppliesand without accessto grid electricity, the PV/wind reverse osmosis(RO) and the SeawaterGreenhouse conceptsdeveloped for desalination using alternative energy may prove cost effective. Longer term, vapour compression (VC) processescould be developed with lower energyconsumption than RO. The viabilityof the Seawater Greenhouse will depend on the specific topography of the coast, its climate and local demand for, and pricing of, horticultural produce. Oceanic islands with seasonaldemand from tourism will probably be currently the most appropriatetargetsfor the technology.Asthe technology isdeveloped they may have wider application. General Recommendations Whether water scarcity is already existing, occurring occasionallydue to drought or due to foreseeablerisingdemands, it isrecommended that: an integiated water resourcesmanagement strategyshouldbe developed forareassubjectto water scarcity in order to reduce demands. An integrated strategymakes more efficientuse of existing water resources, and considers the potential contribution from lessconventional and external sources of supply. The integrated planning and managementstrategyshould cover the following areas: fiscal policy, legal matters, institutional structure, infrastructural needs, environmental management, water demand and supply issuesand the availabilityand costsof energy for water pumping and treatment. the strategyshould identify any constraintson its implementation,a timescalefor its introduction and take account of cost-benefits, the equitable distribution of supplies and intergenerational transferof resources. whilst a range of demand reduction and water supplymanagementmeasuresare available,further work is needed to identify the cost-benefitsand water savingsfor individualmeasuresas well as combinations of measures. A water management planning manual containing information on these aspects,on the factorsto be considered,and thc planningstepsto be taken would aid those responsible for water management in developing countries. It would also be