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Namoi catchment

Environmental watering in the catchment in 2013-14

Watering action Status of Commonwealth action
Lower Namoi River Yet to commence

Planning for 2013-14

Commonwealth environmental water use options 2013-14: Namoi River Valley identifies potential Commonwealth environmental watering actions for 2013-14. Decisions on using Commonwealth environmental water will be made throughout the year based on seasonal, operational and management considerations. If you wish to provide suggestions for Commonwealth environmental water use please contact us at ewater@environment.gov.auor send us your suggestion by visiting: Your suggestions for potential water use options.

Water availability and portfolio management

Namoi catchment water holdings* at 31 May 2014
Location Security Registered entitlements (ML) Long Term Average Annual Yield (ML) Carryover from 2012-13 (ML) New allocations in 2013-14 (ML) Available water transferred for delivery or delivered directly in 2013-14 (ML) Estimated current Commonwealth water account balance (ML)
Upper Namoi General 105 81 5,559 901 0 6,119
Lower Namoi 6,866 5,287
Peel 1,126 292
  Total 8,097 5,659 5,559 901 0 6,119

* Total holdings for Peel, upper and lower Namoi catchments

Subject to water accounting adjustments. Slight discrepancies may exist due to rounding. Allocations of water against entitlements held in regulated systems are made periodically and will depend on factors including seasonal inflows and rules associated with water accounts.

For more information regarding the characteristics of entitlements and the water resource plan held in the Namoi catchment please refer to New South Wales Department of Primary Industries Office of Water

Water trading

From 13-14 March 2014, the Commonwealth Environmental Water Office accepted Expressions of Interest for the sale of this year’s seasonal allocations in the Peel. Within 30 days of the registration of the last trade, the outcomes of this trading action will be made publicly available at Trading Outcomes.

Information on previous trading actions is available at: Trading Outcomes

Information on future trade considerations is available at: Portfolio Management Update

Information on current trading actions is available at: Current Trading Actions

Environmental watering in the catchment in previous years

Environmental watering in the catchment in 2012-13

Watering action Amount of water delivered (ML) Status of action
Lower Namoi River 7,727 Completed
Total in 2012-13 7,727  

No Commonwealth environmental watering has occurred in the Namoi catchment prior to 2012-13.

Catchment profile

Where is it?

The Namoi River catchment is in north-eastern New South Wales, and is based around the Namoi, Manilla and Peel rivers. It is bounded to the east by the Great Dividing Range, the north by the Gwydir, the south by the Macquarie-Castlereagh region and the west by the Barwon-Darling region. The Namoi River and its main tributary, the Peel River, rise in the Great Dividing Range at elevations over 1000 m, falling to 250 m where the two rivers meet near Gunnedah. The river then flows through sedimentary slopes to the open floodplains in the west. Nearly two-thirds of the region is comparatively flat.

This catchment covers an area of 41,856km2 or 4 per cent of the MDB. Other major tributaries of the Namoi River include the Manilla and McDonald rivers, Coxs Creek and the Mooki and Cockburn rivers, all of which join the Namoi upstream of Boggabri. The Namoi River then flows westerly across the western plains and joins the Barwon River near Walgett. Regulation in the catchment includes Keepit Dam (capacity 426 GL), Chaffey Dam (capacity around 63 GL), Split Rock Dam (capacity 397 GL) and a number of weirs.

Northern Catchments page

Legend


Ramsar site


DIWA site

Namoi Catchment

What makes this place so special?

The Namoi catchment is an ecologically significant area because it includes:

  • a wide range of aquatic habitats of ecological importance, including large areas of anabranch and billabong wetlands downstream of Narrabri
  • endangered ecological communities
  • species protected under state legislation, including silver perch, Australasian bittern, Australian bustard, black-tailed godwit, Bell's turtle and brolga
  • a variety of flora including coolabah, river red gum and river cooba, and six vegetation communities including Carbeen Open Forest and bimble box woodland

The only wetland of national importance in the Namoi region is Lake Goran, adjacent to the Liverpool Plains. This lake is situated at the end of an internal drainage basin that does not connect to the Namoi River. Due to this lack of connection it cannot be watered using Commonwealth environmental water.

Another important ecological site is Gulligal Lagoon, near Gunnedah – a semi permanent wetland that is connected to the Namoi River, filling during flood events and from surface flows. The lagoon provides important habitat for native fish species including olive perchlet. This lagoon acts as a drought refuge in the mid-Namoi region and was restocked with breeding pairs of purple spotted gudgeon in late 2009 as part of the Namoi Demonstration Reach project.

What does the latest science say about the ecological health of the catchment?

The Sustainable Rivers Audit (SRA), coordinated by the Murray-Darling Basin Authority, provides scientifically robust assessments of the ecological health of the Basin's river valleys. The overall ecosystem health of the Namoi catchment as reported by the SRA is summarised below.

SRA Report Overall ecosystem health of catchment
SRA 1 (based on data collected from 2004 to 2007) Poor
SRA 2 (based on data collected from 2008 to 2010) Poor

The CSIRO Sustainable Yields Report on the Namoi River catchment identified that the region uses 2.6 per cent of the surface water diverted for irrigation in the MDB. Under the best estimate 2030 climate there would be a 5 per cent reduction in water availability, an 8 per cent reduction in end-of-system flows and a 1 per cent reduction in diversions overall. The region has one of the highest levels of groundwater extraction within the MDB and groundwater use is 15.2 per cent of the MDB total.

Note that the boundaries of this catchment as defined by the Sustainable Rivers Audit and the Sustainable Yields report differ slightly to the boundaries used here.

Environmental water delivery references

Environmental water delivery: Namoi River collates current knowledge of the operational and administrative arrangements for the delivery of environmental water to the Namoi River. The document provides an overview of the environmental assets and potential environmental water use options. This work has been undertaken to support the efficient and effective use of environmental water and to engage communities on how this may best be achieved. This aims to encourage community discussion and feedback on the use of environmental water, to identify future opportunities and recognise operational risks and constraints. Comments on the document are encouraged and can be provided to: ewater@environment.gov.au.