Project to boost water storage and flood mitigation in Chennai


In a significant move to address water scarcity and recurrent flooding in Chennai and its surrounding areas, the Tamil Nadu Water Resources Department has proposed a Rs 22,004-crore project. Announced by Minister Duraimurugan in the Assembly on Friday, the project aims to boost water storage capacity by 20.50 thousand million cubic feet (tmc ft) and ensure permanent flood mitigation.

The project, named Chennai City Water Supply Augmentation and Flood Mitigation Resilient to Climate Change, is designed to enhance flood mitigation and rainwater conservation for deficit years in and around Chennai. Minister Duraimurugan stated that this initiative would create additional storage capacity sufficient to meet the city’s drinking water needs and provide lasting flood solutions.

Currently, the combined capacity of the six reservoirs supplying drinking water to Chennai is 13.222 tmc ft, while the city’s annual demand is about 22 tmc ft. With the new project, storage capacity is expected to increase to 32 tmc ft by 2035, accommodating the projected population growth.

The necessity of protecting Chennai from recurrent flooding and water shortages was highlighted in the 2023-24 policy note. The policy outlines both short and long-term flood mitigation measures, underscoring the urgent need for action following the devastating December floods and the ongoing impacts of climate change.

To ensure effective drainage before the monsoon, pre-monsoon work costing Rs 30.5 crore is already underway. This includes desilting four waterbodies in Chennai, which is expected to increase storage by approximately 1.904 tmc ft.

Additionally, a new reservoir has been created by upgrading the Kattur and Thattamanji twin tanks in Tiruvallur at a cost of Rs 62.36 crore. This enhancement will not only bolster Chennai’s water resources but also provide irrigation for 5,804 acres.