Design Criteria


  • Regulate river water level upstream of barrage;
  • To mitigate fluvial and tidal flooding in Kuching;
  • Protect Kuching water supply and quality of water upstream;
  • Allow passage for river traffic; and
  • The desiltitation of river upstream of the lock.


  • Barrage consist of 5 radial gates and 1 lock with 2 radial gates, all of which are hydraulically operated.
  • The 5 gateways, numbered 1 to 5 from the north side, are all for the purpose of water control and the lock is for the passage of river traffic to and from Kuching.
  • The design allow for the No. 5 gate to be used for the passage of river traffic for emergency purpose only.
  • The weight of each of the barrage gate is approximately 168 m/tons and the shiplock gate is approximately 180 m/tons.
  • The regulated level upstream of the Barrage is designed to the Land and Survey +0.5 meter or +8.5 meter at the Barrage yard stick.
  • This level will be maintained for most of the time except during flooding-in and total flush-out.
  • Flooding-in is being carried out twice (2) a week that is on Monday and Friday (time depend on tide).  This is for purposes of ship repair, tributaries/drain flushing etc.
  • During this process, traffic is stopped because current speed can reached up to 4 meter per second which is dangerous for vessel to maneuver


  • Total flush-out is recommended to be carried out 14 times a year is also a process of flushing-out silt and refreshing the river system.  This process is done by building up the water level up stream of the barrage to +9.5 meter to 9.8 meter.
  • During the ebb/down tide, when the head difference is 1.0 meter lower on the down river side, the 5 barrage gates are fully open for water to gush out until the lowest tide level.  The gates will be closed and level will build-up with down flow water from the catchment.