Plains rivers in flood

Press, 14 September 1988, Page 3

Plains rivers in flood

By

NEIL CLARKSON

The main Canterbury rivers were in flood last evening after torrential rain in the catchment areas. The construction engineer of the North Canterbury Catchment Board, Mr Ross Vesey, said all rivers had been monitored throughout the day.

The most serious problem was at the Hurunui River which reached record levels and breached its banks, flooding across State highway 7. The Waimakariri River was in moderate flood but had caused some damage to Catchment Board works on the north bank. Mr Vesey said floodwaters, which were just under 4m deep at the Waimakariri Gorge last evening, had swept away some rock from groyne 18 on the north bank. Groynes are structures designed to keep the river in the middle of

; its bed. 1 Staff early last evening trucked con- ’ crete blocks, each about a cubic metre, on to the groyne and were dumping ' them in a bid to reinforce it and limit - the damage. 1 The Catchment Board issued warnings about floodwaters in most Canterbury rivers on Monday evening. t However, about 5 p.m. yesterday the : board issued a warning to farmers and contractors about rising water in the f Selwyn River.

The warning to move stock and machinery from the riverbed came after the river rose from 60cm to 1.4 m at Whitecliffs. The Waiau River was 6.9 m deep at Marble Point early last evening and showed no sign of dropping. Its worst flood was 7.5 in May this year. The Ashley River was also in flood, measured at 2.6 m at the gorge. It was expected to rise at the mouth overnight. The flooding Rakaia River developed a new mouth during the day, aiding its outflow to the sea.

Mr Vesey said the Rakaia was 4.4 m deep at the gorge last evening and had been about that level most of the day. Stopbanks kept the swollen river from the Rakaia Huts, although the access road was closed by floodwater. Mr Vesey said the river came within 40cm of the top of the stopbank. The opening of the mouth was thought to have lowered the river level at the huts, he said. Residents at Rakaia Huts said the level was 15cm lower yesterday than the May flood.