The city's drainage system, built in the British era, is more than a hundred years old. It was built to drain around 25 mm of rain per hour. Though the Brihanmumbai Municipal Corporation (BMC) has so far spent more than Rs 10,000 crore on widening it to carry 50 mm of rainwater per hour and constructing six stations to pump out water during high tide, the improvement is invisible. Heavy rains and high tide are still blamed for flooding.
The city is a 'heavy rainfall' area and receives over 2,200 mm rain over the four months of monsoon, while the annual average rainfall for India is 300-650 mm.
According to data from teh meteorology department, Mumbai gets 10% of its total rainfall in a single day almost every year, which flood the city. The civic body spends crores of rupees every year but the number of flooding spots doesn't come down.
After the city was flooded in 1985, Watson Hawksley was appointed as consultant to improve the drainage system in 1989. The project, which included bigger drains, setting up of pumping stations, construction of a five-metre-wide road alongside nullahs to remove silt, removal of slums, was submitted in 1993.
The civic body started some of the work but the whole project was shelved due to its massive cost. But after the July 26, 2005 deluge, the Chitale committee report recommended implementing the Brihanmumbai Storm Water Drain (BRIMSTOWAD) project.
Its cost has since escalated from Rs 60 crore to Rs 1,800 crore. In 2007, the Centre sanctioned Rs 1,200 crore for it. The BMC has constructed six out of four pumping stations worth Rs 700 crore in the last 12 years. Mahul and Mogra-Andheri pumping stations remain on paper to date.
The BMC replaced pipelines in the island city and set up new lines in many suburbs. But it couldn't remove slums near the nullahs and rivers. The road alongside drains remains a distant dream. BMC claimed flooding at Hindmata in Parel would be solved after its Britannia pumping station, but it hasn't.
Now the civic body started a three-stage project worth Rs 53 crore which requires another three years to complete. Works of laying new lines has stopped many times due to utility cables and gas pipelines, denial of permission from traffic police, construction of Metro and roads.
"The BMC has completed 80-85% of the work under BRIMSTOWAD. Pumping stations at Mahul and Mogra are incomplete due to permit issues and land disputes," said additional commissioner Vijay Singhal. "Six stations pumped 13,694 million litres into the sea which is equal to the combined capacity of
Vihar and Tulsi lakes. Still, there was waterlogging!"
But the CAG report has disputed the civic body's claim. Its report says that there was a delay of six years in updating the BRIMSTOWAD master plan and even then only 48% of nullahs – 25 of 53 – had been upgraded to carry 50 mm per hour. It also cited poor workmanship and lack of attention to drainage repairs by utility providers and poor structural conditions as deficiencies in storm water drain management.
"Why does the biggest corporation make a fuss about heavy rains and high tides every year? It is their duty to improve the system so it can withstand heavy rains during high tide," said activist Nikhil Desai, 67, who is a retired mechanical engineer.
