| Historical notes: | The Murrumbidgee area is Wiradjuri country. This was the dominant language of an area of 60,000 square kilometres, extending south of the Murrumbidgee River and westwards to the west bank of the Lachlan River on the Western plains. The river was a source of shellfish and fish, the area provided seasonal food and there were possums, kangaroos and emus all providing a varied and nutritious diet. (Regional Histories, 1996, p. 132) Conflict between the Wiradjuri and settlers was a strong factor in pastoral development of the area in the first half of the nineteenth century; several stations were abandoned in 1839/40 as a direct result of escalations in conflict. (Regional Histories, 1996, p.134) After a brief goldrush and associated boom in the importance of meat production in the 1840s and 1850s the area around Narrandera and Leeton has focussed on wool, fruit and wheat production. (Regional Histories, 1996, pp.134-8) Yanco Creek - not to be confused with Yonco or North Yanco Runs, has been a significant presence for settlers in the vicinity of Narrandera in the eastern Riverina. The creek is one of a number of distributory streams from the Murrumbidgee River which have been altered by canals, dams and other water flow projects to supply the irrigation so important in the area's primary production. The waterways in the area were originally shallow and on permeable soils and frequently ran dry. Between 1832 and 1852 the Yanco Creek ran only once, briefly, during an 1844 flood. The first attempt to improve the Yanco Creek was made in 1855 when one hundred men were employed to cut a canal through the sand choking its intake and let in water from the Murrumbidgee. By October the following year they had cut through to the river. There was celebration and it was renamed the Yanco River. However, when the water ran down the creek most of it vanished into the porous streambed. In 1864 and 1865 attempts were again made to open the creek with a deeper cutting, but were also unsuccessful. It was not until 1879, under a Government scheme, that a reasonable flow was achieved. The ultimately successful cutting increased the creek's flow tenfold, but unfortunately the swift water cut deep into the old bed, destroying the valuable swamps which had lined the waterway. The Yanco Creek also served as part of a natural stock route via lower creeks into Victoria. (Gammage, 1986, pp. 55, 87, 122, 222-3) Through the 1930s the Main Roads System within the Western Division of New South Wales was designed to link main centres of population, to pass through smaller centres, and to provide access to the railways. (DMR, 1976, pp 60-1) Improved roads and bridges facilitated motor transport in general and the road transport of produce. The bridge over Yanco Creek, built in 1940, was one of more than 1,000 bridges built, or under construction, by the DMR between 1925 and 1940, a period in which their engineers were adapting existing standards of bridge design to meet the requirements of improved motor vehicle performance - they were generally wider than previously with an improved load capacity. In many cases bridges began to be constructed on a skew, as the bridge over Yanco Creek is, to fit with improved road alignments. The principal types of bridges constructed in this period were: concrete slab; reinforced concrete beam; steel truss on concrete piers; and timber beam bridges. (DMR, 1976, pp.169, 170, 171) Concrete was favoured in many instances because it was perceived to be a low maintenance material. Based on records available, the extant section of the original bridge built in 1940 covers spans 2, 3 and 4 only. These reinforced concrete spans consist of three beam slabs. The piers at the ends of this section were apparently the original abutments which would have been of the spill-through type. The two piers between are of lighter design, with square columns. In 1954 the bridge was lengthened by the addition of one span to the eastern end and two to the western end, using a similar deck design. The new piers are similar to the original river piers, and the abutments are wall type, all founded on piles. The records indicate that additional piles were added beneath the old western abutment. In 1990 discussions were had as to whether a replacement bridge should be built. The preference was for a new bridge on an improved alignment capable of handling the increased traffic. The likelihood of funding was low and the alternative was to widen the existing structure. The bridge was widened from 6.7 m between kerbs to 9 m between rails on the upstream or northern side in 1993 by the addition of a new column for each pier and using prestressed concrete planks for the deck. At this time the road alignment was slightly modified and the New Jersey kerb with aluminium railing tapers from one end to be inside the bridge width by some 800 mm at the eastern end. (RTA File 14/321.1107) |