Copeton Dam, on the Gwydir River, is one of the biggest water storages in NSW. Its 1.3 Million Megalitre capacity captures and stores water for the primary purpose of irrigation.
Since its completion in 1973 Copeton Dam has regulated the flow of water in the Gwydir River and enabled the development of 80,000 hectares of irrigated farmlands downstream of Moree. Nearly all of this water is used to grow cotton, a valuable export for Australia.
At their 2015 Annual General Meeting, Bingara and District Vision 2020 had as their guest speaker, Craig Cahill the Northern Operations Manager for NSW Water. Craig was invited to present at the meeting by V2020 2014 President, Philippa Morris.
The reason for inviting Craig was so that local Bingara people could learn more about how the water in the Gwydir Valley is managed, and how some local issues regarding the Gwydir River might be addressed.
Craig was very open and forthcoming in his explanation of the Management of the Gwydir River’s water. He explained the processes for ordering water, discharging it and charging for its use.
He also explained the accounting system used, the further diversion of water flows by weirs downstream from Bingara, and the allowances made for towns along the river, and for environmental flows and losses, as well as for the irrigation management.
NSW Water has its primary concern the quantity of water in the Gwydir and the other regulated river basins.
They do not manage the quality of that water. Nor are they required, under their charter, to concern themselves with the future environmental and social issues that relate to the provision of water.
Some of the twenty people in the audience at the February 5 meeting were representatives of the Bingara Fishing Club and the Bingara Hatchery Committee. They pointed out that the current system for water releases from Copeton Dam are effectively destroying the Gwydir River.
The water releases for the irrigation of cotton are made during the Spring and early Summer months. This water is released from an outlet tower and valves system that takes water from near to the bottom of the 100m deep storage There the water is very cold, low in oxygen and tainted by decaying vegetation.
Members of the Bingara Murray Cod Hatchery Committee explained that these releases coincide with the breeding season for native fish. Murray Cod, Golden Perch (Yellowbelly) and Catfish are just three native fish that have been greatly reduced in number in the Gwydir since the establishment of Copeton Dam.
Furthermore the volume of releases, often increase or decrease rapidly as orders for water are satisfied. This creates unstable river flows that can enhance bank erosion and siltation. Long time fishers of the Gwydir spoke of the river “slowly dying” in the years since the Gwydir management, principally for irrigation, has been happening.
Craig Cahill could not say if these issues were of concern for those who decide on the Copeton Dam operations. Nor could he say just how many irrigators there were, or the prices they pay for water.
He did, however, offer some ‘light at the end of the tunnel’ possibility for the environmental concerns.
At Burrendong Dam, on the Macquarie River, a similar problem has been successfully addressed by installing a “curtain” on the outlet tower. This device enables water to be released from near the top of the reservoir.
The water is then warmer and more oxygenated.
The V2020 meeting decided to seek more information about this possibility and to support the Bingara Hatchery Committee and the Fishing Club in their efforts to engage with our local member of State Parliament, Adam Marshall. Given that the NSW State elections will be held in March, the same questions will be directed to the other State Government candidates for Northern Tablelands.
Submitted by Rick Hutton
for Bingara & District Vision 2020