THE SHANNON BRIDGE

Manawatu Herald, Volume XLV, Issue 2585, 26 May 1923, Page 3

THE SHANNON BRIDGE

EFFECT OF BANKING SYSTEM.

CONFERENCE CALLED OF INTERESTED BODIES.

At Wednesday’s meeting of the Horowhenua County Council, tlie question of erosion in connection with the Shannon bridge over the Manawatu river, came up for discussion. The chairman (Cr. G. A. Monk) mentioned that he had since the recent heavy floods, in company with Cr. Barber and the County Engineer, visited the bridge. There was no foundation, lie said, for the wild rumours that there was danger of the bridge being washed out to sea. There certainly had been some slight erosion on one side, and the piles supporting one span appeared to have sunk slightly, but not seriously. There was no doubt, however, that the Makerua drainage scheme would in the future, greatly endanger this structure. If the whole force of the water in the river is confined to the stream instead of, as formerly, spreading over a large area of swamp, a vastly increased strain is going to be imposed on the bridge and on the hanks in the vicinity. He did not think, however, that there would be any use in erecting works to strengthen the banks at the bridge. The question was a larger one than that, and really concerned all the local bodies concernned in the drainage scheme, and directly interested in the bridge. It was not fair that the Horowhenua County should have to bear the whole burden of this work, which was due to the operations in banking the river. If they were to erect protective works at the bridge now, the probable result would be that the first big flood would undo the whole work.

Several other councillors spoke in a similar strain, and the following resolution, proposed by the chairman and seconded by Cr. Ryder, was carried: “That a conference of the following local bodies: Shannon, Borough, - Foxton Borough, Manawatu County, Horowhenua County, Makerua Drainage Board, Manawa-tu-Oroua River Board, together with representatives of the Public Works Department, be held at Shannon to consider the matter of the bridge over the Manawatu river at Shannon; the chairman to arrange date.” COUNCILLORS VISIT BRIDGE. POSITION NOT AS BAD AS STATED.

After the meeting the .Council paid a visit to the scene in order to view the position. Their observations bore out the chairman’s statements. Erosion is taking place at a point considerably above the bridge, but the Engineer’s opinion, which is supported by most of the councillors, is that the next flood will remove a point of land there and that the main stream will then flow straight beneath the bridge. The position is a very complicated one, however, by reason of the Makerua banking system now in progress. It is stated, for instance, that whereas formerly it took 48 hours for a high flood to travel from the Fitzherbert bridge at Palmerston to the Shannon bridge, the water now came down in 26 hours, showing that the velocity had greatly increased with a corresponding effect on the banks. On the other side of the river, the Manawatu County Council has sevven or eight scoops at work building u new bank designed to protect the main road to Foxton, which runs parallel with the river for a short distance. Already two previous banks have been built, but have been cut through by erosion, and the banking system there would not appear to have any finality. Under the circumstances it seems

that the Horowlienua County’s policy is the wisest. The Council aims at keeping the bridge open for traffic for the present, and the road span is to be strengthened with that object in view. Until the full effects of the banking system are apparent it would be simply waste of money putting expensive protective works that might be useless under the new conditions created by the banking scheme. Statements siieh as that made recently, that the bridge will be washed out to sea, are to be deprecated. ‘They do not contribute anything to the solution of the problem, which is one for patient investigation rather than hasty recrimination. The conference that the Horowlienua County Council is calling should enable the views of different bodies interested to be stated and a course of action decide upon—Levin Chronicle.