Beautification work using tiles without enough provision for stormwater drainage is a major cause for flooding in the city, according to the Irrigation Department.
A preliminary report furnished by the department on back-to-back flooding in the city between October 21 and 31 indicated that holes provided underneath paved footpaths were too small to drain out water. The report, prepared at the instance of Irrigation Minister K. Krishnankutty, was submitted to the Chief Minister.
It said the drainage facility was totally inadequate to handle the severe waterlogging caused by 200-mm rain recorded on October 23. According to the report, the 10-cm diameter pipes provided at six-metre intervals were too small to drain stormwater.
Meanwhile, the department has constituted a special team to prepare a comprehensive report on urban flooding.
The preliminary report said it was possible that no cleaning had been done in the past one year, the period when most beautification projects were implemented. Since beautification work involves laying tiles covering the existing drainage slabs, cleaning was next to impossible, the report said.
According to the department, the size of manhole is 60 x 60 cm, and it cannot be utilised to clean up all drains. Cleaning can be done only in their immediate surroundings, it observed.
Yet another observation was that there was no way water from roads could directly enter the drainage as the flow was blocked by kerbstones.
All major government institutions involved in various projects, including the Kochi Corporation, GCDA, and the Kochi Metro, have been blamed for overlooking serious lapses while taking up beautification work on roads.
While many believe that the city was inundated due to lack of cleaning of canals, the department said the water level in canals was low after October 21.
All the above aspects will be studied before tabling a formal report, according to senior officials.