Unusually high tide raises brows

Grace Chua Straits Times 1 Jan 12;

High tide at East Coast over the Christmas weekend. The canals that drain into the sea were nearly full as the tide on Christmas Day was 3.4m, which is 0.2m higher than the predicted level. -- ST PHOTO: CORRIE TAN

Beachgoers at East Coast over the Christmas weekend might have been surprised by unusually high tides, which ran up the beach and filled the canals that drain into the sea.

The recorded tide on Christmas Day was 3.4m, said the Maritime and Port Authority of Singapore. That is 0.2m higher than the predicted level, which is based on the movements of the moon and sun, it added.

'It is normal to record a higher spring tide during the north-east monsoon and the difference is mainly due to meteorological factors largely due to strong or prolonged winds,' a spokesman said.

A spring tide occurs when the moon is full or new, the moon and sun are aligned, and the gravitational pull of both is strongest; at those times, maximum tides are very high and minimum ones are very low.

The highest tide recorded here was 3.9m, on Feb 9, 1974. Despite the lack of rain, parts of the island were flooded.

Civil engineer Tan Yew Meng, 55, who was cycling with his family at East Coast Park on Boxing Day, was startled by the tide.

'This is the highest tide I've seen,' he said.

'The canal was almost full to the brim - if it rains, that would mean it cannot contain more water and would cause flooding.'

Since 1991, the Government has mandated that new reclaimed land be 1.25m above the highest recorded tide, but many of the recreation areas at East Coast, West Coast and Changi were reclaimed before then.

Last year, national water agency PUB also revised its drainage code for better protection against floods.

Building platform levels must be 60cm above the highest recorded flood level or 30cm to 60 cm above ground level, and the new minimum level for reclaimed land is about 1m higher than current standards.

Grace Chua