Pauline

Yanco Weir

Rice growing began in Australia in the early 1920's near the townships of Leeton and Griffith in the NSW Riverina. A number of dams and weirs were constructed on both the Murray and Murrumbidgee rivers.

During 1927/28 the NSW Water Conservation and Irrigation Commission constructed the Yanco Creek weir on the Murrumbidgee River just downstream from their junction. The object was to divert water from the Murrumbidgee into Yanco Creek to supply settlers to the south of the river.

The weir was constructed by driving stel caisson-type piles into the riverbed and backfilling with soil high in clay content. Concrete was set on the top of the steel piles and earth dam to form the actual spillway.

The weir was also of great importance to the poeple in the Leeton, Narrandera and Yanco townships, not only from the point of view of the irrigation provided, but also because it became a much-favoured resort for swimming, boating and picknicking. The weir was put into use on 9^th February 1928 and subsequently the nearby riverbanks were grassed and trees planted. Often many people visited this spot on most weekends during the summer months.

Some 30 or 40 years on, possibly due to a higher flowrate in the river due to the Snowy Mountain Scheme, a small Anna-branch of the river bypassed this original weir. To control this branch, in the early 1980's, a more modern floodgate weir was constructed. This reinforced concrete structure has steel lift gates which control the flow of water through the weir, and hence the water level behind it.

When we inspected the weir on 22 March 2004, the water level was about one metre below the top of the original spillway. After crossing the artificial "island" to the new weir we saw that the lift gates were in a raised position, allowing enough flow to maintain this upper level height.

Reference: "A Brief History of Leeton", A. E. Bowmaker, 1968

Alf

SunRice Visitor Centre, Leeton

The SunRice factory is located on Calrose Street in Leeton, NSW, and processes between 1.2 and 1.75 million tonne of paddy rice grown annually by some 2500 SunRice shareholders. Access to the factory was not possible because of OH&S restrictions and public liability concerns, however, our group visited the display centre where the products and activities of SunRice are promoted. Long term employees Lynne and Eleanor proudly presented a video tape and confidently answered our many questions.

Heads of rice formed as tiny clusters of flowers in the base of the rice plant during early January develop as they travel up through the centre of the plant to emerge in early February. The small green shell that is the flower opens and, ideally, all flowers are pollinated within a week. The fertilized flower then closes to a protective "hull" which the plant fills with liquid starch and protein. Over the following forty days the liquid consolidates to form a starchy inner grain attached to seed embryo, all encased in nutrient, enzyme and oil rich layers. The complete grain, including the hull is the product delivered to the mill by growers and called "paddy rice" in the industry.

In the first stage of milling, paddy rice is passed through rubber faced rollers to split the hull and allow separation of "brown rice" grain from the hull material. The hull material, high in silica (from entrapped soils?) is inedible for humans. Unground hull is useful as horticultural mulch and extending stock feed. Many inventive uses have been found for otherwise unwanted hull material, one ingenious application displayed uses hull as the fibre reinforcing in a product used for road marker posts, cargo support blocks and building boards.

Brown rice is perfectly edible, but many cultural tastes demand separation of the internal "white rice" from the enclosing bran layers. These nutritious layers are removed as "rice bran" during later stages of milling and sold as a granulated food or on-processed to be included in, for example breakfast cereals and crispbreads. It is also valued as a constituent of livestock feed.

White rice (polished rice) in wholegrain form is more rapidly cooked and is the most common form of rice for world wide human consumption. Broken grains produced during the milling process are further processed for use in many other food products.

The industry, sensitive to criticism about its use of water, has actively promoted changes in farm management to improve water use efficiency by 60% over the past ten years. This includes effectively re-using water on secondary crops. It has also privately funded research ($80m per year) leading to the development of new grain varieties to further extend available water. One variety introduced in 2003 uses 10% less water than traditional rice. The group is continuously developing new strains to satisfy market demand and claims to produce more rice per Hectare and use less water than international benchmarks. It was the first Australian company to introduce a Greenhouse gas policy.

The presentation climaxed with a meal based on rice products, which was greatly appreciated by an audience, obviously hungry for more than information.

John M

Murrumbidgee Irrigation Limited, Leeton : Presentation

After Sturt mapped the Murrumbidgee in the 1830's, squatters began to arrive, most farming sheep. Sir Samuel McCaughey bought up land in 1860, and using bores and tanks for stock watering, built up a famous Merino stud. After he bought another property at North Yanco in 1899, he built miles of irrigation channels from a dam and a pumping station above his property. He grew lucerne and fodder crops over the thousands of acres that he had irrigated. Because of McCaughey's success a government survey was carried out and in 1906 several major constructions were started; Burrinjuck Dam was built to store water, Berembed Weir, the Main Channel and a network of smaller canals to convey water to farms were dug, the allotment of farms, establishment of towns and services began. In 1912 the Murrumbidgee Irrigation Area was officially opened at Yanco and The Water Conservation and Irrigation Commission was established to control all water projects in N.S.W. including the M.I.A.

In 1956 work began on the Snowy Hydro Scheme and Lake Eucumbene was completed in 1958, Tantangara in 1960 and Blowering Dam in 1968. Water from these storage dams flow down the Murrumbidgee and Tumut Rivers to the Berembed Weir, taking 5 days, where water is diverted to the M.I.A. The water is then split at the Yanco Regulator into the Main Canal and a supply to the Gogeldrie Branch Canal, which supplies farms on the western side of the M.I.A. The Main Canal feeds the supply, channels which bring the water to the farms. The M.I.A. is a gravity fed system of regulators, canals and channels.

In 1989 the M.I.A. community developed the Land and Water Management Plan, this plan is being implemented across the area but is now called M.I.A. Envirowise. This plan is concerned with ensuring the environmental and economic sustainability of the region. In 1999 management and the responsibility of irrigation of the area was passed from government to irrigators and Murrumbidgee Irrigation Limited now operates as a public company owned by its customers as shareholders and employing over 200 local people.

M.I.L. provides water effectively and efficiently to irrigation customers. This role includes water management and pricing, infrastructure maintenance and development as well as upholding M.I.A. Envirowise principles.

Because all ordering and allocation of water is now done by computer much more efficient control over supply can be made. Water is ordered 7 days ahead of usage so if there is local rainfall or demand changes, excess water can be diverted into several storage facilities where it can be released if and when needed. Staff can also adjust channel flows to meet changing needs of their customers.

M.I.A. Envirowise promotes water use efficiency programs designed to more accurately measure water supplied to crops and decrease the water entering the underground system. This includes encouraging farmers and helping them gain financial assistance to convert to drip irrigation systems, soil testing and overall farm planning of suitable crops. They are also committed to improving drainage disposal and flood management. Drainage is now via Mirrool Creek, which traverses the M.I.A. and drains into Barren Box Swamp where it eventually is recycled into other smaller irrigation areas. Education and awareness programs about the environment, organising tree planting, wetland management and monitoring of water quality and biodiversity changes are all the responsibility of Murrumbidgee Irrigation Limited.

Lee

Murrumbidgee Irrigation Limited, Leeton : Inspection Tour

This tour was in the Yankoo and the Leeton areas, where we followed the main canal, some 23m wide and 2.5m deep to one of its side canals, only 10m wide. The side canals are controlled by lock gates which can be operated from the MIA office in response to water orders received 7 days previously from the irrigators. The whole irrigation system can be likened to a tree, with the main canal - the trunk, and the side canals and subsequent smaller canals reducing down to the irrigation ditches beneath the citrus trees - the branches and twigs of the tree. Water usage has been measured by an Australian invention - the Deighton Wheel, being phased out and being replaced by an accurate probe in the water stream using the Doppler effect to measure the quantity of water passing this probe at the irrigators inlet metering point. The meters are read each 14 days to ensure that the quantity of water supplied is what was ordered and meets MIA allocations.

The MIA is allocated 1.2 million mega litres of water each year, that is after the SA's allocation of water has been taken out of the flow. Each irrigator is allocated a quantity of water according to the type of crop that is being grown and the total amount of water that is available to be distributed, the formula used to determine the final allocation was established in1983. In times of drought, the allocation is reduced and has been only 5% or7% of the irrigators entitlement. This has forced the irrigators to become more and more efficient in their use of water. Flood irrigation is only used when necessary, for example when rice is being sown from the air. The ditches are kept clear free from weeds, silt and any other material that can cause water loss. Where there is seepage into the ground, the ditches are often lined with concrete. In more difficult soils, pipes are installed to reduce water loss even further, however such methods of piping requires pumping and hence an extra cost to the irrigator. Citrus trees may be watered by small micro sprays under the tree foliage, rather than flood or ditch irrigation methods. With the earlier methods of irrigation, it took over 2 or 3 mega litres of water to grow 1 tonne of rice, with the new methods of irrigation, only 1 mega litre of water is used for 1 tonne of rice; of course, this can vary with the type of rice grown and the weather.

The area which the MDSG studied was first recognised in 1891 by Sir Samuel McCaughy and a State sponsored survey was carried out in 1896, with approval to implement the proposed plan in 1902. The Burrinjuck dam, the Berembed weir, main and subsidiary canals taking the water to the many farms which had been surveyed and even the establishment of the towns was so far advanced , that in 1912 the scheme was officially opened by the Minister of Works the Hon Arthur Griffin. There are now some 2000 commercial farms, 1000 being large mixed farms of 250 to 300 hectares and 10000 farms being horticultural farms 10 to 50 hectares.

The water is diverted from the Murrumbidgee River into the Berembed weir upstream of Narrandera and the Gogeldrie weir near Leeton. Any excess water from the irrigation and that which is caused by storms are all collected and allowed to run into the Barren Box Storage just west of Griffith which serves as a storage for other customers further down stream. No water is allowed to run back into the living waters of the Murrumbidgee River.

The MDSG were well looked after by MIA personnel, who provided us with plenty of information and were most cooperative in answering our many probing and often difficult questions.

Terry