Ord

A total volume of 3,006,364 ML was provided for environmental benefit in the Ord region during 2009–10. Water for environmental benefit was provided through operating rules for Lake Argyle. Operating rules for Lake Argyle include the release environmental water provisions to protect the current environmental values of the lower Ord River, as defined by the Ord River Water Management Plan (2006). Operating rules for Lake Argyle also require water to be provided to Spillway Creek, at specified lake levels.

The Water Corporation manages the release environmental water provisions from Lake Argyle to ensure that minimum monthly flow rates for the lower Ord River are obtained. These flow rates must be obtained at the Tarrara Bar gauging station in the lower Ord River. Figure 1 compares the actual monthly flow rates at Tarrara Bar to the minimum required flow rates during 2009–10. The monthly flow rates exceeded the minimum flow requirement for all months
during 2009–10.

Graph of the monthly flow rates compared with the required minimum flow rates at House Roof Hill during 2009–10. The figure shows that the minimum flow rates were obtained

The total volume of water that passed Tarrara Bar in 2009–10 was 2,971,718 ML, as calculated for Line item 14.2 Surface water flow out of region.

Environmental water provisions also provide water for social benefit. Water provided for the environment to maintain specific levels in the lower Ord River has the dual purpose of satisfying ecological requirements and allowing access to boats for recreational purposes.

Operating rules for Lake Argyle also allow for provision of water for the environment to Spillway Creek. When the water level of Lake Argyle is between 86.2 m and 92.2 m, water must be released to Spillway Creek. This occurred during 2009–10, resulting in 34,646 ML of water released to Spillway Creek for environmental benefit.

A total of 2,106,596 ML was provided for economic benefit in the Ord region during 2009–10. Water for economic benefit is provided through releases of water from Lake Argyle for hydro-electricity generation, and has the dual purpose of administering water access entitlements for agricultural, mining, and commercial activities downstream. There are also specific releases made from Lake Argyle to support tourism that bypass the hydro-electricity scheme.

A volume of 2,042,807 ML was released from Lake Argyle for hydro-electricity generation during 2009–10. This water has the dual purpose of administering water access entitlements downstream, including bulk irrigation in the Ord River Irrigation Area, and other agricultural, commercial and industrial and mining activities.

The following table shows the 183,358 ML of water that was abstracted under water access entitlements for agriculture, mining, and industrial and commercial activities in the region.

* Water access entitlements administered by the release of water from Lake Arygle for the dual purpose of providing water for hydro-electricity generation.

Water was also provided through an agreement to release water from Lake Argyle to maintain water levels so that tourist boat operators could use the river. This occurred during 2009–10, resulting in 40,186 ML of water released from Lake Argyle for economic benefit.
 

A total volume of 3,091 ML was provided for social benefit in the Ord region during 2009–10. Water for social benefit was provided through administering Water Access Entitlements for the purpose of Public water supply, parks, gardens and recreation, and Stock and domestic.

Environmental Water Provisions also provide water for social benefit. Water provided for the environment to maintain specific levels in the lower Ord River has the dual purpose of satisfying ecological requirements and allowing access to boats for recreational purposes.

Water for cultural benefit requires periods of low flow in the lower Ord River to support traditional hunting and fishing activities. This occurs from time to time when maintenance and inspection work on dam infrastructure is required, however this did not occur during 2009–10.