Usoro mmiri nke tankị
Usoro cascade tank, ma ọ bụ usoro wewa-ellangava, bụ akụrụngwa ogbugba mmiri n'ubi Sri Lanka oge ochie.  Usoro a bụ netwọk nke obere tankị na-asọba na nnukwu mmiri mmiri na-echekwa mmiri ozuzo na mmiri ozuzo maka iji mee ihe n'ikpeazụ.[1][2]  Malite na narị afọ nke mbụ BC, [3] [4] bụ usoro ihe nketa dị mkpa zuru ụwa ọnụ site na United Nations Food and Agriculture Organisation na 2017.[5]  E mebere njikwa ụlọ ọrụ etiti nke nnukwu usoro site na narị afọ nke atọ ruo na 13th.[2]

. IN'ozuzu Sri Lanka nwere nnukwu dams 80, na tankị 18,000 dị ugbu a, ma ọ bụ wewa.[1]  N'etiti tankị 10,000 na 14,000 na-arụsi ọrụ ike dị ka isi iyi mmiri;  Ọtụtụ n'ime ndị a na-ejide mmiri na mpaghara ugwu-etiti etiti ala ala kpọrọ nkụ.[2][3]

.Ndị na-eme nchọpụta na-eche na evolushọn nke tankị tank malitere site na mmiri ozuzo na-eri nri ma na-aghọwanye ọkaibe na-amalite site n'ịtụgharị rivulets, mgbe ahụ, osimiri na-adịgide adịgide, na-esote mmụba na-aga n'ihu na-ewu nke spillways, weirs na n'ikpeazụ sluices, na-ewu nke reservoirs.  , ruo mgbe, n'oge apogee nke mmepe, ndị Sri Lanka oge ochie nwere ike ime ka osimiri ndị na-adịchaghị mma na-eme ihe nke ọma ma jiri mmiri mee ihe dị ka o kwesịrị ekwesị.[1]  Ojiji akụkọ ihe mere eme nke sistemu ikuku tank gụnyere mkpa mmadụ (mmiri ị drinkingụ mmanya, idebe ihe ọcha, mmepụta nri), ịba ụba gburugburu ebe obibi, mmepe obodo, nhazi ókèala nchịkwa ("ụda mmiri"), na mbelata ọdachi okike.[2]

.A na-arụ ebe nchekwa mmiri ozuzo n'agwaetiti ahụ dị ka 300 TOA—e nwere nkwuputa na ọ bụ ndị mmụọ yaksha rụrụ Sorabora Wewa na Mahiyangana tupu ndị Indo-Aryan kwaga n'àgwàetiti ahụ[1]—na e mere atụmatụ na ngụkọta nke wewa 30,000 bụ.  wuru n'elu akụkọ ihe mere eme nke Sri Lanka