The　Taihu　Basin　is　one　of　the　most　economically　developed　regions　in　China,　but　the　problems　of　quality-induced　water　shortage　and　water　environment　deterioration　are　very　serious.　At　the　end　of　1999,　80%　of　river　network　was　subject　to　pollution　of　varied　degrees.　The　water　quality　of　Taihu　predominately　features　water　of　Class　IV,　and　more　than　70%　of　the　water　is　eutrophic.　Water　pollution　has　become　a　constraining　factor　in　economic　and　social　development　of　the　basin.　In　order　to　improve　the　water　environment　in　Taihu　Basin,　TBA　has　carried　out　the　long-term　work　of　leading　other　rivers　into　Taihu　since　2002---Water　Diversion　from　Yangtze　River　to　Taihu　Basin　through　Wangyu　River　and　supplying　water　to　the　downstream　through　Taipu　River---and　has　achieved　significant　effects.

　　Because　the　water　pollution　in　Taihu　Basin　was　serious,　TBA　tried　Water　Diversion　from　Yangtze　River　to　Taihu　through　Wangyu　River　in　2000,　which　achieved　some　effects.　Later,　complying　with　the　spirit　of　the　instructions　proposed　by　national　leaders,　i.e.　“to　control　the　static　with　dynamic,　to　dilute　sewage　with　clean　water,　to　enrich　the　depleted　with　the　rich,　so　as　to　improving　the　water　quality”,　TBA　decided　to　carry　out　a　two-year　pilot　projects　of　Water　Diversion　from　Yangtze　River　to　Taihu,　and　determined　the　overall　outline:　Water　Diversion　from　Yangtze　River　to　Taihu　and　river　networks　by　using　the　existing　hydraulic　system,　and　supplying　water　to　the　surroundings　of　Taihu　and　downstream　areas　through　the　Taipu　River　Sluice　Station　and　doors　of　other　lakes　to　accelerate　the　water　flow　in　the　basin,　to　increase　the　carrying　capacity　of　water　bodies,　to　promote　self-purification　capacity　,　and　to　improve　basin-wide　water　environment.

　　Diversion　test　of　Water　Diversion　from　Yangtze　River　to　Taihu　was　officially　launched　on　the　30th　of　January　in　2002.　After　two　years　of　operation,　it　is　proved　that　this　project　could　accelerate　the　flow　of　river　networks　and　lake　water　in　the　basin;　increase　the　amount　of　the　quality　water　in　the　basin;　improve　the　effective　supply　capacity　of　water　resources　and　make　significant　improvement　in　water　quality　of　the　intake　area.　However,　because　the　problems　involved　in　Water　Diversion　from　Yangtze　River　to　Taihu　were　complicated,　some　water　of　the　rivers　and　lakes　in　the　basin　that　could　not　flow　orderly,　and　the　water　quality　was　poor　and　the　carrying　capacity　of　the　water　environment　kept　low.　In　order　to　activate　the　water　of　river　networks　and　lakes　in　the　basin,　and　to　further　improve　the　water　quality,　it　is　necessary　to　continue　to　implement　and　expand　the　diversion　pilot　project　of　Water　Diversion　from　Yangtze　River　to　Taihu.

　　In　2004,　the　project　of　expanding　the　diversion　test　of　Water　Diversion　from　Yangtze　River　to　Taihu　was　launched.　Its　aimed　to　expand　the　range　of　the　diversion　test,　to　intensify　the　efforts　of　discharge,　and　to　further　research　and　explore　and　use　the　hydraulic　system　to　improve　the　capacity　of　the　water　environment;　to　increase　water　supply,　and　to　shorten　the　changing　water　cycle　in　the　basin;　to　drive　the　river　networks　by　utilizing　key　rivers,　to　lead　the　water　in　the　basin　to　orderly　flow,　to　increase　self-purification　capacity,　to　improve　the　water　environment,　and　to　promote　the　restoration　of　the　water　ecology　in　the　basin.

　　Water　Diversion　from　Yangtze　River　to　Taihu　has　been　into　long-term　operation　since　2005,　especially　after　2007,　as　an　important　measure　to　comprehensively　treat　the　water　environment　in　Taihu　Basin,　the　working　efforts　of　Water　Diversion　from　Yangtze　River　to　Taihu　continue　to　increase,　and　the　outcome　is　very　significant.

　　According　to　the　statistics,　from　January　of　2002　to　June　30th　in　2014,　the　total　amount　of　water　that　has　been　led　into　Taihu　Basin　through　the　Changshu　hydro-junction　of　Wangyu　River　is　***　hundred　million　square　meters;　the　amount　through　the　Wangting　hydro-junction　is　***　hundred　million　square　meters;　combined　with　the　utilization　of　rainfall　and　flood,　the　water　supply　to　the　downstream　through　the　of　the　Taipu　River　Sluice　Station　increases　***　hundred　million　square　meters.