Irrigation in Australia
Irrigation is a widespread practice required in many areas of Australia, the driest inhabited continent, to supplement low rainfall with water from other sources to assist in growing crops and pasture.
[1] Overuse or poor management of irrigation is held responsible by some for environmental problems such as soil salinity and loss of habitat for native flora and fauna.
Towards the end of the 20th century, environmental problems in the basin became serious as diversions for irrigation approached or exceeded the capacity of natural flows.
[5] A major drought in Victoria from 1877 to 1884 prompted Alfred Deakin, then a minister in the State Government and chairman of a Royal Commission on water supply to visit the irrigation areas of California.
[6] In 1886, the Chaffey brothers came to Australia and selected a derelict sheep station covering 250,000 acres (1,000 km2) at Mildura as the site for their first irrigation settlement.
In 1907, the Victorian government invited American Elwood Mead to become chairman of the newly formed State Rivers and Water Supply Commission of Victoria.
The high hopes for government-controlled irrigation in Victoria owed much to Deakin's earlier efforts, who now as Prime Minister, expected Mead to advise at both national and state levels.
Mead was not content with proposing only higher water rates in attempting to recover maintenance, management, and construction costs.
The Water Act of 1909 was passed despite the fierce opposition of large landowners, and Mead's influence on rural development was greatly increased by his assumption of overriding control in the planning of closer settlement in Victoria's irrigation districts.
Mead rejected plans for further fruit planting, advocating larger dairy farms and improved co-ordination of grazing and irrigation enterprises, which would favour stock fattening and the intensive production of lucerne.
It was further developed during the latter part of the 1930s depression to take unemployed workers to dig and build the extensive irrigation channels in the district.
[11] The management of irrigation, particularly with relation to the problems of the Murray-Darling Basin has long been a politically contentious issue in Australia.
One result was a non-government conference held in Corowa in 1902, which called for government action to manage the waters of the Murray River.
The upstream states, Victoria and New South Wales, favoured the riparian doctrine, under which landowners are free to take water from streams flowing through their property.
Major cotton growing areas in Australia are: In 2001/02 crop size was 420,170 hectares (1,038,300 acres) producing 3,041,000 bales.
All transfers require approval from the various regulatory bodies to ensure it complies with trading rules designed to meet environmental and in some cases socio-economic objectives.
Drip systems are found within most of the high value perennial horticultural crops such as grapes and fruit trees.
In other crops where moisture stress is a complex concern, for example during the growing of cauliflower, water is required to be distributed quickly two or three specific times per day at a rate of about 140% the evaporation replacement rate and for this impact sprinklers set every 12 square metres or butterfly sprinklers set every 6 square metres are required.
[27] Drip sprinklers can be used on many spaced planting locations but typically will be found as gravity fed systems on vineyards.
Most if not all farms employ earthworks such as laser levelling to facilitate drainage and improve water use efficiency and uniformity.
Overuse and poor irrigation practices have led to increased salt content in the soil, reducing the productivity of the land.
The program has returned to production over 2,000 hectares of previously barren farmland and encouraged the regeneration of native eucalypts.
