Significant water events
The upper Ord and Negri rivers contribute most of the inflows to Lake Argyle. The location of these rivers is provided in the Surface water section of the 'Contextual information'.
Total annual flows in these rivers were below average during the 2012–13 year, and almost half that recorded during the 2011–12 year. The 3-month period between January and March is usually when the majority of the total annual flow occurs in these rivers. Flow during this period was well below the long-term average (figures W1–W2), which contributed to the overall below average annual flow during the 2012–13 year. December 2012 was the only month with above average flow in these two rivers.
Figure W1 Total monthly flow along upper Ord River during the 2012–13 year compared with the long-term average and percentiles for the river
Figure W2 Total monthly flow along Negri River during the 2012–13 year compared with the long-term average and percentiles for the river
Streamflow in the lower Ord River below Lake Argyle is measured at Tarrara Bar (Station 809339). The location of this station is provided in the Surface water section of the 'Contextual information'.
Total annual flow during the 2012–13 year in the lower Ord River was the lowest on record for the entire period of record (1998–2013). The 4-month period between January and April is usually when the majority of the total annual flow occurs in the lower Ord River, primarily due to unregulated catchment inflow (not storage releases). Flow during this period was well below the long-term average (Figure W3), which indicates that few high magnitude flood events occurred in this part of the region during the 2012–13 wet season.
The below average flow in the Ord region, both upstream and downstream of Lake Argyle, reflects the below average rainfall observed throughout the region during the 2012–13 year (see Climate overview), particularly during the middle of the wet season (January–March).
Figure W3 Total monthly flow along lower Ord River during the 2012–13 year compared with the long-term average and percentiles for the river
Major water initiatives
The Ord–East Kimberley Expansion Project is a major initiative of the Western Australian Government. The State committed $220 million from the Royalties for Regions fund under the Ord Irrigation Expansion Project and a further $195 million was contributed by the Australian Government via the East Kimberley Development Package.
The first stage of the expansion will develop 74 km² of irrigated farmland known as the Goomig farmlands (Figure W4). Construction of the irrigation infrastructure commenced in 2010 and is scheduled to be complete by the end of 2013. In November 2012 the state government also announced it would develop approximately 10 km² of irrigated farmland in the Ord West Bank area (Figure W4) during the next few years.
The Ord Irrigation Cooperative currently holds a licence for diversion of 335,000 ML/year from the Ord River for the Ivanhoe and Packsaddle irrigation districts (see Water entitlements and other statutory water rights). Additional water demand from the Ord River to support irrigation development in the Goomig farmlands and the Ord West Bank area is expected to be 80,000–170,000 ML/year and 16,000–25,000 ML/year respectively.
There are proposals to develop other irrigated areas in the Ord region, such as the Carlton Plain and the Mantinea areas, the Knox and Keep River plains and areas alongside the Packsaddle Plain (Figure W4). Development of these areas could take place in the next 5–10 years. Further details on these potential irrigation areas are given in Chapter 3 of the Ord Surface Water Allocation Plan.
Figure W4 Map of Ord River Irrigation Area expansion
Further information on the Ord–East Kimberley Expansion Project can be found at the following Government of Western Australia websites: