Whether it is the Chennai floods or Mumbai getting inundated with water, the message is unequivocally clear that nature is being compromised in our urban areas and we will continue to pay the price unless nature is factored in while planning and managing our urban spaces

Incessant rains over the past two days have brought Mumbai — the maximum city — to its knees with five  people dead, countless stranded and many homes flooded and property destroyed. The India Meteorological Department (IMD) has issued a ‘Red’ warning for the next 24 hours for the city and adjoining areas, indicating that there could be very heavy rainfall over the next two to three days.

According to the IMD, the incessant rain since Monday is a result of westward movement of low-pressure area that had developed over Odisha and south-west Madhya Pradesh. Though these are weather-related events, but it is enough to bring life to a grinding halt for the Mumbaikars as roads become flooded, weak buildings become death traps and the threat of water-borne diseases spiral out of control.

The current rains are reminiscent of the worst floods that hit the city on July 26, 2005 in which nearly 546 lives were lost, besides causing huge damage to property. Just like cases of other urban floods, Mumbai’s flooding woes have their genesis in rapid urbanisation and unplanned development.  While a record 994 mm (37.2 inches) of rain within 24 hours, was a concern at that time, it is the lack of improved rain water drainage system that turned it into a tragedy.

These heavy rains seem to have come back to haunt Mumbai again. According to the Municipal Corporation of Greater Mumbai (MCGM), Mumbai’s official storm water drains consist of road drains, minor and major nullahs and outfall. All are inter-linked, and finally empty into either the Arabian Sea directly or into the four creeks that open into the Arabian Sea.

Inspite of an elaborate sewage and drainage system, the efficiency of the same is very much doubtful since urbanisation and expansion of the city itself is happening on rapid rate and the drainage networks are yet to cater to the newly developed areas.

The suburbs, especially around Mumbai, are developing so fast that the municipality is not able to provide proper drainage for these areas. Also, low-lying areas and old ponds have been filled to make multi-storey buildings and shopping malls.  So, the natural drainage system, of holding ponds and water channels, no longer exists, resulting in flooding of the residential and commercial areas.

Mumbai’s drainage problem is the result of obsessive construction and reclamation activities. The quantity of water falling on the city has not decreased, but the space to flow has, tremendously. Earlier, almost 50 per cent water would seep into the ground, drastically reducing the total volume to be managed. But today the whole city is cemented. Hence, whenever water falls, the ground cannot absorb it. Most drains are encroached upon and choked. They are unable to tackle so much water.

Given these conditions, Mumbai needs to urgently put in place efficient storm water-pumping stations, increase drain capacity and improve floodgates. There is also an express requirement to undertake repairs of dilapidated drains, augment railway culverts and deepen the canals.

The authorities must also ensure that the Coastal Regulation Zone guidelines are properly followed, this by itself will help in protecting the city’s natural drainage system. Also, there should be a check on permitting buildings that are constructed by blasting hills as this has a detrimental impact in permanently altering the natural topography which in turn changes the rain water flows and runoffs.

Similarly, rivers too must not be channelised or forced to change course at the whim of a residential or commercial project. Additionally, it is critical to reduce the amount of cemented areas in the city so that the rainwater can actually seep into the ground. Parts of Mumbai are already facing a saline ingress. Hence, it is important that water percolates into the ground and recharges the groundwater. For this, porous building blocks can be used.

Mumbai needs to desperately protect its fast-dwindling open spaces. Not only do these open spaces act as city lungs, but they are also holding ponds during heavy rainfall. Saltpan lands, which the State Government wishes to open for construction activities, serve exactly the same purpose and should be retained for this alone.

The authorities must also start preparing the land use maps with the local people’s participation. This will help generating public awareness on the nature of land use and assist in protecting those lands, which act as buffer in times of extreme nature events.

Whether it is Chennai floods or Mumbai getting inundated with water, the message is unequivocally clear, that nature is being compromised in urban areas and we will continue to pay the price unless nature is factored in while planning our urban spaces.

(The writer is an environmental journalist)