Claim: There are 17 rivers in Sri Lanka listed to be over 100km in length with Mahaweli River(literally translates to "Great Sandy River") being the longest at 335km (208 mi).
Evidence: Mahaweli River 335 km (208 mi) Malvathu River 164 km (102 mi) Kala Oya 148 km (92 mi) Kelani River 145 km (90 mi) Yan Oya 142 km (88 mi) Deduru Oya 142 km (88 mi) Walawe River 138 km (86 mi) Maduru Oya 135 km (84 mi) Maha Oya 134 km (83 mi) Kalu Ganga 129 km (80 mi) Kirindi Oya 117 km (73 mi) Kumbukkan Oya 116 km (72 mi) Menik Ganga 114 km (71 mi) Gin Ganga 113 km (70 mi) Mi Oya 109 km (68 mi) Gal Oya 108 km (67 mi)