India Floods – Mumbai and the Mithi River 9 Years On

It’s been 9 years since the 26 July floods in Mumbai, when the Mithi river broke its banks flooding some of the city’s most densely populated areas. The poor state of the Mithi was blamed by many for the disaster. Sadly, Mumbai’s residents are yet to see any significant changes in the state of this notorious river…

“The Mithi River used to serve as an important storm water drain but has been reduced to a sewer over the years” – Mithi River Development Authority (MRDA)

26 July 2005 Floods

In Mumbai, if you mention the date 26 July, many of those old enough will assume you are talking about the day in the great Indian city was brought to a standstill by severe flooding.

As many as 5,000 people were killed in the floods across the state of Maharashtra, many of them in Mumbai. Torrential rain hammered the state for 4 days. In Mumbai, as much as 994 mm (39.1 inches) of rain fell in just 24 hours. Trains, airports, roads, subway, hospitals, schools and even mobile telephone networks were in chaos.

Much of the flooding in Mumbai occurred along the 18 km long Mithi River, a river in Salsette Island which merges into the sea at Mahim creek. The downpour increased levels of Lake Powai, which started to overlow, spilling vast amounts of water into the Mithi.

powai lake mumbai floods 2005
Starting to Flood – Powai lake, Mumbai 26 July 2005

As the quote from MRDA above points out, the river usually served as a storm water drain and would enable excess rainwater from Lake Powai and around the city, to drain quickly away into the Arabian Sea. In 2005 this was far from the case. The river was so blocked with sewage and waste of all kinds, there was no way through for the flood water from the lake. Instead of flowing downstream to the Arabian Sea, the flood water, along with 1,000 of gallons of sewage and industrial waste from the Mithi, flowed into Mumbai’s streets.

The whole situation was made worse by the fact that the heavy rain and flooding rivers and lakes coincided with a high tide. Mumbai’s 100 year old storm water drainage system had no chance, especially since it, like the Mithi, was also blocked with garbage and silt in several places.

The Mithi River – Mumbai’s Open Drain

The Mithi River runs through densely populated and industrial areas of Mumbai and carries the overflow discharges of Powai and Vihar lakes to the Arabian Sea at Mahim Creek. It’s about 18 km long and has a catchment area of 7,295 hectares. The river is supposed to serve as a natural drainage channel that carries excess water during monsoons.

The poor state of the Mithi river (also known as Mahim River) in 2005 was blamed by many for exacerbating the flood disaster. The river had long been heavily polluted, at times looking more like an open drain than a river. It was then, and still is today, used as a dumping ground for sewage, industrial waste and all types of garbage from those living along its banks.

Mangrove Flood Defences

The river’s capacity for dealing with larger amounts of water caused by the monsoon rain had also been dealt a blow by the destruction of many of the mangrove ecosystems alongside the river. Mangroves normally served as a buffer between land and water. Without them, the river’s banks were unable to withstand pressure from increased water flow. It is estimated that Mumbai lost about 40% of its mangroves between 1995 and 2005. Some have been destroyed by the dumping of sewage and garbage, but many of them were claimed for building land, such as the Bandra Kurla Complex.

2006 Mithi river in Mumbai. with the Bandra Kurla complex opposite. Photo:  Joe Athialy
2006 Mithi river in Mumbai. with the Bandra Kurla complex opposite

The Mithi River Today

It’s been 9 years since the 26 July 2005 floods but sadly Mumbai residents are yet to see any significant changes in the state of the river. It remains pretty much as it was in 2005; an open drain.

According to Mithi River Development Authority (MRDA):

Development of suburban areas along Mithi River in last 25 years has drastically degraded water quality of Mithi River. Mithi River used to serve as an important storm water drain but has been reduced to a sewer over the years. The Mithi River is being used by locals to dump raw sewage, industrial and municipal waste. Today the river is full of sludge, garbage and vegetation growth. This has resulted in contamination and stagnation of water which is the prime reason for mosquito’s menace and stench emanation along the entire stretch of the river.

Mithi River in 2007. Photo: Global Reach Out
Mithi River in 2007
Dredges of Dharavi's recycling industry overflowing onto the banks of the river, 2012. Photo: bmw guggenheimlab @ flickr
Dredges of Dharavi’s recycling industry overflowing onto the banks of the river, 2012

Just after the floods, in August 2005, the Mithi River Development and Protection Authority was set up to develop a plan to improve the state of the river (called Mithi River Development Plan), working under both MMRDA and Municipal Corporation for Greater Mumbai (MCGM).

Sadly the Mithi River Development Plan is running way behind on any proposed work to improve the river and mitigate flooding. Part of the plan was simply to clean the river, but also to desilt, widen stretches of the river, and build new roads and bridges. Initially work was to be completed by 2010. MRDA say it should be completed later this year, although that may seem overly optimistic.

Cleaning the Mithi River. Photo: MMRDA
Cleaning the Mithi River. Photo: MMRDA

There has been some developement, however. The MRDA have recently approved plans to increase the catchment height of Powai lake by up to 4 metres in places. This may well keep flood water awy from the river in times of heavy rainfall. But the MRDA also intend to use the extra capacity to store monsoon rainwater which, when circumstances permit, will later be released into the Mithi with the hope that it will help “flush out” the polluted river.

Photo credits: Powai Lake; DharaviMithi River 2006; Mithi River 2007; Cleaning the Mithi