Skills for Study Level 2 Teacher's Book - Cambridge University Press

deGroup discussionAnswers2.7Type of water source Problems BenefitsDig / drill forgroundwaterLarge-scalewater engineeringprojects – dams,river diversions,canals, etc.DesalinationRecycling wastewaterShipping waterby tanker / othermeansWater harvestingTakes a very long time toreplenish. The deepest ofgroundwater is a fossilresource and will never bereplenished; they are thereforea non-sustainable resource.Ease of access to thissource means it tends toget overused, and the waterbecomes contaminatedquickly.Need to relocate populationfrom area of planned works.Diversion / damming of waterimpacts the environment.Large reservoirs have beenassociated with an increasein earthquakes. Creation oflarge bodies of water in humidregions can also introducewater-borne disease.Must be near the coast.Until recently, too expensive tobe feasible.Public aversion to drinkingtreated sewage.Puts water supplies at themercy of other nations.Local level / small-scalesolutions, which may not beenough to guarantee a reliablesupply.Still depend on precipitation,which is low in arid / semi-aridregions.Plentiful supply,relatively easilyavailable.Provides amassive andreliable supply ofwater. Can helpwith economicdevelopment aswell.Can make freeuse of abundantseawater.Costs are fallingrapidly.Technology todo this existsand is proven inSingapore.Large volumescan be movedrelatively easily.Low environmentalimpact.Don’t need tocost much.Make maximumuse of availablewater withoutwaste, thereforesustainable.Unit 2 Part A ∙ Understanding spoken information 43