Gunidgera Weir Raising

Gunidgera Weir Raising

About the project

WaterNSW is raising Gunidgera Weir to improve water delivery in the Gunidgera—Pian system in the Namoi valley.

Located on the Namoi River, the Gunidgera Weir is approximately six kilometres west of Wee Waa. The Gunidgera Weir and upstream regulator enable water flows to be stored, controlled and released from the weir pool into Namoi River and Gunidgera - Pian Creek.

Constructed in 1976, the Gunidgera Weir allows for control and regulation of water. The Project will increase the maximum diversion capacity from the Gunidgera Weir pool into the Gunidgera - Pian Creek system from 1230 megalitres per day (ML/day) to 1650 ML/day. This will increase WaterNSW’s ability to meet customers’ water needs in times of peak demand.

The proposed upgrade works will occur in two stages:

Stage 1 - Raising of the Gunidgera Weir by 0.47m and minor works at the Gunidgera Regulator and erosion control/protection works at Cotton Lane and Cudgewa Lane, within the first 12 km downstream of the Gunidgera Regulator.

Stage 2 - Monitoring, and where necessary, rectification works on the Gunidgera – Pian Creek System to manage the additional flows.

Stage 1 works will occur on land owned by WaterNSW, Council and Crown Lands. Access for construction will be through Cotton Lane and Cudgewa Lane.

Construction works will be postponed to 2023, after the peak irrigation season, due to the continued rainfall and high river flows in the Namoi river.


The Project will have a range of benefits that include:

  • Improving water delivery to Gunidgera-Pian customers during peak demand periods
  • Increasing capability for on-time delivery to customers
  • Limiting environmental impacts by maintaining the existing channel width (a previous option considered was widening the channel).

Project schedule

The construction works at Gunidgera Weir will be scheduled after the peak irrigation season in 2023 to minimise service delivery impacts as far as possible.


Customers have been consulted through the Namoi Customer Advisory Group (CAG) and River Operations Stakeholder Consultation Committee (ROSCCo).

The following stakeholders and government agencies have also been included in discussions:

  • Natural Resources Access Regulator (NRAR)
  • Department of Planning, Industry and Environment
  • Department of Primary Industries – Fisheries
  • Narrabri Shire Council

We will provide you with further information through project fact sheets and website updates.

Project updates

Contact details

For more information about Gunidgera Weir raising email us at or call 1300 662 077.

Project Manager: Sarinda Wickramasinghe


Tuesday 17 May
2,573,926 ML
2,581,850 ML
9,342 ML
1,335 ML
50,768 ML
Tuesday 17 May