InChinawaterresourcesareunevenlydistributed.Ingeneral,waterresourcesareabundantinthesouthbutdeficientinthenorth.Withtheincreaseofpopulationandrapideconomicdevelopment,theproblemofwatershortageinthenorthisgettingmoreandmoreserious.Onesolutionistodivertwaterfromonedrainageareatoanother,alsoknownastheSouth-to-NorthWaterDiversionProject.Therearethreeroutes.TheeasternroutewilltransferwaterfromthelowerreachesoftheYangtzeRivertonorthalongtheBeijing-HangzhouGrandCanalandthroughatunnelundertheYellowRiver,fromwhereitcanflowdownhilltoreservoirsnearTianjin.ThecentralrouteisfromDanjiangkouReservoirontheHanriver,abranchoftheYangtzeRiver,toBeijing.Thewesternroute,alsocalledtheBigWesternLine,aimsatdivertingwaterfromtheheadwatersoftheYangtzeRiverintotheheadwatersoftheYellowRiver.