THE SHANNON BRIDGE.

Shannon News, 25 September 1923, Page 3

THE SHANNON BRIDGE.

ENGINEER’S. REPORT

The repoifc o 1 I.l* engineers, appointed by a conference of local body delegates, interested in the Shannon bridge' .lias been drawn up and will be submitted to a further conference to be held for the purpose of •arriving at a decision on the proposals. ENGINEERS’ PROPOSALS.

■At the conference of the engineers the'following proposals were considered:— (1) To move the h:idge down stream a distance of 25 to 30 chains :

•(2) to lengthen the bridge where.;it now stands; and (3) to. move, it up

stream to a point just below the junction of the Manawatu river and the Tohomaru stream!

After an exhaustive enquiry into the efficacy -of the three proposals it \v;is decided that No. 1 scheme be rejected. The other two were submitted in the-.report with a strong . recommendation in favour of No. 3 scheme.

The> latter provides for one long snan, to be added-and also , for three 30 foot spans. In this scheme the road from Foxton to Shannon will ti~ shortened by about half, .a mile, and it also includes a mile of. road construction. This scheme will have valuable results. The ‘cost of No. 2 proposal is estimated at £9OOO, and that of No. 3 £IO,IOO. It is generally recognised bv the local bodies that it is necessary, for obvious reasons —the dangerous condition of the hr id ee being ■ the most urgent—thafi an immediate decision should be arrive;! at. otherwise the arterial road betwieeri Foxton and Shannon rmv he lost for Avant of a bridge, which, experts have declared will be swept down stream on the rise of llie first big flood. It. is'interesting to .note that thy cost hi replacing the present structure,' if it v-orp dPstroved,. is estimated ah : ''£lsh 000, but. as the existing bridge-ms per- : f'ectiy sound as Regards -the timber, used in its construction, the corHingencv of having to face , such ah' expoo ditu re is to he avoided at aljpostsbv the local bodies. . - :

Erosion is still going on to. an alarm, ing extent, particularly on the : ,AA’.es r tern bank, and the lengineers *' .are' unanimously; of the opinion 'that prompt 'action i ! s nechssiary If hhler bridge is to be saved. CAUSES OF FLOODING.

The idea which many people hold with regard to the flooding of the Manawatu river in believing that it occurs after heavy rains is erroneous, as' the following fads gleaned from the report of the Commission of Enquiry into the question of river control,-which sa+. in 1914, Avould appear to indicate: The rhler drains an, area, of 19.030 snuare miles, equal to 1.235.209 acres. The cause of flooding, the deport states, is due largely, if not wholly, to a coincident-rainfall on the fararua and Ruahine ranges, which feed all the tributaries of the river. An east wind blowing and backing up the spring tide in Cook Straits. Woc-ks' the .'flow of the river at. its mouth and checks the flow, of the dream!, but this tributaries on this side- of the ranges, (adds the report. .have practically no effect, on floods. " . ,