Attanagalu Oya (Sinhala: අත්තනගලු ඹය) is a river in Gampaha District, Sri Lanka.[1][2]

Attanagalu Oya
Attanagalu Oya, near Dandugama
Native name	අත්තනගලු ඔය  (Sinhala)
Location
Country	Sri Lanka
Physical characteristics
Source	Kegalle District
• location	Galapitamada
2nd source	Indurana Ela
• location	Indurana
Mouth	Negombo Lagoon
• location	Dandugama
• coordinates	07°10′N 79°53′E
Length	76 km (47 mi)
Basin size	727 km2 (281 sq mi)
Discharge
• average	40 m3/s (1,400 cu ft/s)
• minimum	20 m3/s (710 cu ft/s)
• maximum	100 m3/s (3,500 cu ft/s)

The length of the river is approximately 76 km, with a drainage basin of 727 km².[1][3][4] It originates from Galapitamada area in Kegalle district and drains into the Negombo Lagoon as Dandugam Oya.[5][6] The river is often a cause of floods to low-lying areas in the Gampaha district.

Hydrology

The river originates from lower peneplains of Kegalle District in Galapitamada area. It is joined by the left tributaries Basnagoda Oya and Waharaka Oya in Karasnagala and later joined by Algama Oya further down stream close to Attanagalla town.

Oruwal Oya and Diyaeli Oya joins the Attanagalu Oya in Gampaha. The river then flows in a northerly direction and joined by Kimbulapitiya oya and Mapalan Oya in Madawala (near Katunayake) and forms Dandugam Oya, Attanagalu Oya-Dandugam Oya river system then finally discharges into Negombo Lagoon in Dandugama Area where Muthurajawela meets Negombo Lagoon. Close to its mouth it is also joined by Ja-Ela which is a diversion of the Oruwal Oya.

Tributaries

• Left
  • Basnagoda Oya
  • Waharaka Oya
  • Oruwal Oya (sometimes referred to as Uruwal Oya)
  • Ja Ela
• Right
  • Algama Oya
  • Diyaeli Oya
  • Kimbulapitiya Oya/ Dunagaha Ela
  • Mapalan Oya [5][4]

References