Attanagalu Oya

The Attanagalu Oya is a river in Sri Lanka's Gampaha District. The river has a length of about 76 kilometers and a drainage basin of 727 square kilometers. It rises in the Galapitamada area of Kegalle district and flows as Dandugam Oya into the Negombo Lagoon. In the Gampaha district, the river is a frequent cause of flooding in low-lying areas.

The river originates in the Galapitamada area of Kegalle District's lower peneplains. The left tributaries Basnagoda Oya and Waharaka Oya join it in Karasnagala, and Algama Oya joins it lower downstream near Attanagalla town.

In Gampaha, Oruwal Oya and Diyaeli Oya join the Attanagalu Oya. The river then runs north, joining Kimbulapitiya oya and Mapalan oya in Madawala (near Katunayake) to form the Dandugam, Attanagalu, and Dandugam Oya river system, which subsequently drains into Negombo Lagoon in Dandugama Area, where Muthurajawela meets Negombo Lagoon. It is also joined by Ja-Ela, which is a diversion of the Oruwal Oya, near its mouth.

Length: 76 kilometers