FLOOD WATERS INUNDATE HOKITIKA AREA

Greymouth Evening Star, 2 September 1947, Page 7

FLOOD WATERS INUNDATE HOKITIKA AREA

River Blockage Causes Overflow STOCKS DAMAGED IN BUSINESS PORTION OF TOWN

Backed up to a record height, of 16 feet 6ins. above normal low-water level by a sandbank across its mouth, the Hokitika river last night broke its banks and caused one of the worst floods in the recent history of the town. For several hours the water flowed in torrents into the low-lying business area of the town, turning the streets into miniature rivers and inundating shops and homes to depths from a foot to three feet. Fortunately, it was “dead" water and there was no structural damage, but heavy losses occurred through the wetting of business stocks, machinery and household effects. ’

Although a flood had been feared for some time, as a result of the sand accretion at the river mouth, the actual inundation of the town came with dramatic suddenness about 10.30 p.m. and many business houses were caught unawares. In some shops in the vicinity of the intersection of Weld and Tancred streets the water reached almost to the level of the counters and, where stocks could not be lifted in time, heavy damage resulted.

The worst of the flooding was over by 3 a.m., and the waters receded quickly until they reached a depth of about a foot in the parts of the town most affected. From this stage, the recession was slow and at noon today rowing boats were still being used to obtain access to premises in Weld- and Tancred streets. The flooding was severe, but it yesterday’s rainfall had been greater, Hokitika would probably have experienced a major disaster. The flooding resulted from the flow backing up of the river and there was comparatively little flood water. Had a major flood occurred to coincide with the blocking of the river mouth, enormous damage must have resulted/ For the moment, the danger has passed with the sudden widening of the river mouth at 3 o’clock this morning, but with the same set of conditions still liable to recur, Hokitika must remain in fear of a similar visitation.

The cause of the flooding is a sandbank which, for some weeks past has been building up at the mouth of the river, as a result of the littoral drift from the south. The bank has turned the outlet of the river northwards, giving the stream an almost righthanded turn at the mouth and reducing the flow to a comparative trickle. Yesterday, the lower reaches of the river resembled a lake, with the level nearly 11 feet above normal. Even then, the level was still 3 feet 6 inches below the top of the sandbank. Rapid Rise With the heavy rain experienced late yesterday afternoon, the river level rose rapidly but still failed to breach the sandbank. The waters accumulated much faster than they could get away through the small opening at the north end of the sandbank and shortly after 10 p.m. began to lap over the wharf near Wharf street. By 10.30 p.m. the overflow had become a torrent, racing down Wharf street to Camp and Tancred streets and into the centre of the business portion of the town which is several feet below sea level. Revel street, being some feet higher than Tancred and the central portion of Weld street,

escaped the flooding but the low-lying central portion of the town, —a belt several hundred yards wide from the wharf to Hampden street was inundated to depths ranging from a foot to four feet. Waters Sudden Ri-se Once over the river bank, the waters quickly filled up the low-lying streets and householders and business people who had not had prior warning had little time to salvage goods and effects. Staffs and parties of volunteers did great work in many of the shops in hastily removing stocks to higher levels but in some instances the rising waters overtook the workers and stocks were flooded.

About 3 a.m., the pressure of water suddenly widened the northern opening of the sandbank at the mouth of the river and the pent-up waters were given an adequate outlet to the sea. From that stage, the flood began to recede quickly and by daylight the worst of the flooding was over. However, the storm water drains serving the lower parts of the town were overtaxed to carry away the flood waters, even when fall was obtained, and after the first drop the draining process was slow. Boats in Use At noon today, much of the business area of the town, excepting Revell street, was still covered with water up to a foot deep and many of the business premises in Weld street could be reached only by the boats which were being paddled up and down the roadway, in a type of shuttle service.

The danger of further flooding has passed, for the moment, but while the sandbank remains it is still liable to block theTiver outlet and force a repetition of last night’s conditions.

The 1935 Flood

The flooding last night originated much lower down the river than was the case when there was a similar’ visitation in 1935 and there was no flood water in the area east of the Hokitika bridge line. Residents on Gibson quay, however, had a fight to save their properties from flooding. A stop bank had been breached to provide access to the municipal rubbish dump and the residents worked hard to fill the gap with sods and earth before the water reached the level of the gap. Their efforts were successful and there was no flooding in Gibson quay. A similar flood occurred on February 20, 1935, and many business premises were invaded by the waters, but they did not cover an area as great as was the case last evening.