THE ACCIDENT TO THE YAN YEAN AQUEDUCT NEAR MELBOURNE.

New Zealand Times, Volume XXXIII, Issue 5306, 28 March 1878, Page 3

THE ACCIDENT TO THE YAN YEAN AQUEDUCT NEAR MELBOURNE.

During the recent heavy floods in Victoria serious damage appears to have been caused in various parts of the colony, especially in the vicinity of Melbourne, Am accident which •courred to the Van Yean aqueduct cut off the whole of the main water supply to the city. The following particulars of the occurrence appear in the Argus of the 18th instant; The actual occurrence of the accident—which took place before daylight on Saturday morning—was not, so far as could be learned, witnessed by anyone; but when the embankment gave way the noise caused by the bursting of the embankment and the carrying away of the great ma a of masonry soon drew those living near to the spot. The Plenty had been steadily rising all the previous afternoon and, before this, had caused a large amount of damage to the farms on its banks, several of the - farmers and their families between Whittlesea and Morang being flooded out, and having to take refug.on the higher lands. It was observed during Friday afternoon that the river was bringing down a much larger number of trees and other dehria than during the flood of 1863—probably owing to the extension of settlement along the upper course of the river and its tributaries. It is to this fact that, in all probability, may be attributed the disastrous result of the present flood in the river. Although the accident was not seen, the large trees scattered by the flood along the banks near the river supply the cause of the catastrophe. After a careful examination of the present state of the bridge and embankment the theory of the officers of the department is that the arch of the bridge, from its small span, became choked with the downcoming trees, and the waterway, already inadequate for such a torrent, became almost completely obstructed. The embankment and the bridge itself thus acted as a dam, holding the waters back until they rose to the parapet. Some of the floating matter brought down —a large tree or two probably then struck the parapet and carried it or a portion of it away. The aqueduct, being on a level with a parapet wall, was the next object of obstruction, and even its solid mass could not resist the force of the concussion. Once the water got over the parapet wall it soon worked a slight opening in between the connection between the bridge and the earthen embankment. As soon as this was done the embankment was, of course, soon swept clean away. The broken side of the embankment—which displays its whole composition—shows that it was not so compactly constructed as it ought to have been, as large quantities of loose rubble and spall are revealed which should never have been allowed a place in it. This is only mentioned by the way, however, as no embankment, however faithfully constructed, could have remained intact under the circumstances. As a contrast, the accident revealed the splendid workmanship in the construction of the aqueduct walls, and the manner in which the remains of these lay about also served to show what must have been the terrible pressure of the water. Although the walla of the aqueduct could not withstand the stream, and although masses of the stone were carried many yards down the river, the excellence of the masons’ work was shown by the fact that in some cases as many as sixteen blocks—forming three courses of the wall—remained uosevered. If any error was made in the construction of the aqueduct at this point it was not on the part of the workmen. After the accident no doubt the thought presents itself whether it was wise to trust to the old embankment, and whether the restriction of the water-way, rendered evident by the flood of 1863, should not have been considered. On the other hand, however, the fact that the bridge and embankment had offered a successful resistaace in 1863 was undoubtedly deserving of due weight, and no doubt, also, the expense of building a completely new structure over which to carry the aqueduct was a very important consideration with the Government. That so apparently impregnable a mass would be swept away by any rise that could occur in so seemingly unimportant a stream as the Plenty perhaps never entered into the calculations of the Yan Yean Water-supply Department ; but in whatever permanent plan replaces the means of crossing the river that has now proved a_ failure, the liability of the Plenty to rise into a rapid and tremendously powerfully torrent will have to be taken into consideration. Prompt measures are being taken to repair the damage. A number of carpenters and other workmen were despatched to the spot immediately, and timber and other materials were supplied without delay. The Argus of the 19th instant says ; —Mr. Davidson (the engineer) expresses the most confident hope to have the connection re-established by midnight, so that a full supply of water will he available in Melbourne to-morrow (Wednesday) morning. For the purpose of meeting immediate requirements, the Hon. Henry Miller yesterday waited on the Commissioner of Public Works

and offered to place the large reservoir on his estate at the service of the public, if the department' could convey the water into the aqueduct ; but as Mr. Miller s reservoir was found to be half a mile from, tlie lino of the conduit, his offer could not be availed of.