THE SHANNON BRIDGE.

Shannon News, 25 May 1923, Page 3

THE SHANNON BRIDGE.

■ - IT' ' EFFECT OF BANKING SYSTEM.

CONFERENCE CALLED OF INiER-

ESTED BODIES

At Wednesday’s meeting of the Horowhenua County Council, the 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, he said, for the wild rumours that there wa s 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 tlte 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 tlhe banks in the vicinity. He did not think, however, that there would be any use in erecting works lo strengthen the banks at the bridge. The question was a larger one than that, -and really concerned all the local bodies concerned in the drainage scheme, arid directly interested in the bridge. It was not lair 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, Manawatu-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 I the position. Their Observations bore I out the chairman’s statement. Erosion is taking place at a point considerably above the bridge, but Hit Engineer’s opinion, which is support- I ed by most of the cduficillors, is that j the next flood will remove a point j of land there and that, the main J stream will then flow straight beneath the bridge. The position is a i very complicated one, however, bv reason of the Makeriia hanking system. now in progress. Tt is stated, for instance, that whereas formerly it took 48 hours for a high flood to Irav'eTtrom the Fitzherbert bridge at Palmerston to the Shannon bridge, j 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 seven or eight scoops at work building a 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 hanking system there would not appear to have any finality.

Under the circumstances it seems tliiit ine Horowhenua County’s policy I is Uie wisest. Tlie Council aims at keeping the bridge open for traffic, for the present, and the road span is to he strengthened with that object in view. Until .the full effects of the hanking system are apparent it would be simply waste of money putting expensive protective tvorks that might be useless under the new conditions created by the hanking scheme. Statements -such 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 Horowhenua County -Council is calling, should enable the .views of different bodies interested to be stated and a course of action decided upon.