Siak River
| Siak Sungai Siak, Siak rivier | |
|---|---|
| The Siak River flows through the city of Siak. | |
| Location | |
| Country | Indonesia | 
| Province | Riau | 
| Physical characteristics | |
| Source | |
| • elevation | 0 m (0 ft) | 
| Mouth | Malacca Strait | 
| Length | 370 km (230 mi) | 
| Basin size | 10,423 km2 (4,024 sq mi) | 
| Discharge | |
| • location | Siak Delta, Malacca Strait | 
| • average | (Period of data: 2009–2013)720 m3/s (25,000 cu ft/s) | 
The Siak (Sungai Siak) is a river of Riau province, in the east of Sumatra, Indonesia, about 1000 km northwest of the capital Jakarta. Approximately 370 kilometres in length, the Siak is a blackwater river which owes its brown color to dissolved organic matter (DOM) leached from surrounding, heavily disturbed peat soils; it is heavily polluted, notably by the petroleum industry. It flows through the town of Pekanbaru before emptying into the Strait of Malacca.