Maha Oya River | Ninth Longest River in Sri Lanka Maha Oya (Sinhala: මහ ඔය; Tamil: மகா ஆறு) is a stream that originates in the hilly regions around Aranayaka, Batalegala and Kadugannawa in Kegalle District, Sri Lanka. It is 134 km in length and flows through three provinces (Sabaragamuwa, Central, and Western) and four districts [(Kurunegala, Gampaha, Kegalle, and Puttalam) Palliyaguru et al., 2022; Vithanage, 1988]. After passing several towns such as Aranayaka, Mawanella, Rambukkana, Polgahawela, Alawwa, Giriulla and Badalgama, it discharges water into the Indian Ocean at Kochchikade town near Negombo. Rambukkan Oya and Kuda Oya are tributaries of Maha Oya. River basin Located between 7°0′0″–7°30′0″ N and 79°50′0″–80°35′0″, the Maha Oya River basin is considered one of the major river basins in the country ( Palliyaguru et al., 2022 ). A pproximately 75% of the river basin is located in the wet zone while the other 25% lies in the intermediate zone of Sri Lanka (Palliyaguru et al., 2022). The basin consists of a catchment area of 1,528 sq…
