Comprehensive flood master plan for Chennai on anvil as monsoon nears

CHENNAI: With the unscientific construction of stormwater drains constantly putting the metropolis under threats of floods and claiming lives during the construction of stormwater drains, which takes place every year, the Tamil Nadu government is in the process of preparing a Comprehensive Flood Control Master Plan in Urbanized River Basins in Chennai.

According to a Chennai Corporation official, the project of preparing the master plan is being assisted by Japan International Cooperation Agency (JICA)and will be completed in 2024.

"Unless the usual studies, the master plan will be prepared using Digital Terrain Models (DTM) also called Digital Elevation Models (DEM). This will provide the elevation details of the city's terrain," the official added.

A few days ago, a meeting was conducted at the Secretariat to review the progress of the master plan preparation in which the officials from municipal administration and water supply department, Chennai Corporation and others took part.

A JICA document pointed out that the Chennai metropolitan area experienced major floods in 1943, 1976, 1985, 1998, 2002, 2005, and 2015 due to cyclones and heavy rains. "In particular, the December 2015 floods claimed 289 lives, inundated a large number of houses (about 500,000), disrupted power and communication services, and halted transportation by air, rail, and road, causing extensive economic damage, including damage to public and private property."

Explaining the need for a master plan, the document pointed out that the Chennai metropolitan area does not have an overall master plan for flood control, and as a result, the State government and donors have not been able to implement projects aimed at drastically reducing flood risks. Due to this, they have been implementing symptomatic measures based on projects that are easy to start without considering overall optimisation.

"In addition, in the Chennai metropolitan area, development on flat terrain with high flood risk and inhabitants has led to the accumulation of assets in flood plains, increasing the potential for damage from future flooding. Furthermore, recent development has led to a decline in the natural flood control functions that existed in the past," it read.

Flood forecast system on anvil:

Apart from the master plan, the Commissionerate of Revenue Administration has already begun preparing an early flood forecasting system and geospatial digitisation. "During the earlier monsoon seasons, the system was used on a pilot basis. The system will be used during the upcoming monsoon. Using the system, we can forecast the possibility of flooding three days in advance," a consultant said.