Maritime Board has predicted a rare 5.05-metre high tide,57 cm higher than July 26,2005
This years monsoon could bring back memories of the deluge of 2005,with the Maharashtra Maritime Board predicting a rare high tide level of 5.05 metre on July 24.
At 2.03 pm on July 24,the tides are expected to rise to 5.05 metre about 57 cm higher that the high tide on July 26,2005 according to the Maritime Board’s tide predictions. The high tide recorded during the 26/7 floods,caused by a record rainfall of 944 mm within 24 hours,was 4.48 metre.
Dr Kapil Gupta,professor,Department of Civil Engineering,Indian Institute of Technology,Bombay,who has published a study on flood resilience,planning and management based on the 2005 deluge,said,The high tide level for July 24,2009,is probably the highest in a decade,and if rains persist that day,flooding is likely in low-lying areas like Juhu,Kurla,Kalina,Hindmata and Dadar.
According to Gupta,with high tide levels at a maximum of 5.05 m inland,even water from a moderate rainfall would have difficulty in draining out. It all depends on the weather system that day, he said,however,even if it doesnt rain,flooding cant be ruled out in areas near tidal outlets,for example,Juhu.
Gupta cited the example of a June 2008 incident,when,despite sporadic showers,the highest high tide of the season at 4.86 metres saw areas of Juhu inundated for nearly half an hour.
However,he said the rescue personnel are better prepared this year. With the online rainfall monitoring systems installed by the BMC providing real-time information on rainfall and water levels every 15 minutes,the authorities will have regular rainfall and water level information from the 35 rain gauges across the city and one flow gauge at Powai on the Mithi river, he said.
It was a similar tidal occurrence coupled with an unprecedented cloudburst that caused the 26/7 floods in 2005. As much as 944 mm of rainfall was measured at Santacruz,from 8.30 am on July 26 to 8.30 am July 27,that year. At Vihar lake,a record 1,011 mm rainfall was documented. Over 405 casualties were reported in Mumbai itself.
However,assuring that the situation is not as dire as 26/7,B G Save,deputy hydrographer of the MMB said,Though the highest high tide of the month falls on July 24 ,it also comes in the spring tide period,during which the ebbing of the tides touch the lowest level. For example on July 24,when the tides will rise to 5.05 m,its corresponding low tide at 8.09 pm is predicted to be a low 0.77 m. In laymans language,even though the tides will rise,when ebbing begins six hours later,the water will be pulled back far away from the land.