The local bodies were entrusted with the task of providing the amenities of water supply and drainage schemes initially.

Then arose the necessity for an organisation of fully trained and experienced personnel on the Government side for the execution and maintenance of water supply and drainage schemes at satisfactory standards and minimum cost.

Hence the Sanitary Engineering Branch of the Madras Public Works Department was entrusted with the task of the investigation, design, execution and maintenance of the water supply and drainage schemes of all the local bodies in the state.

The Government of Tamil Nadu constituted, the Tamilnadu Water Supply and Drainage (TWAD) Board as a non-statutory body during 1969.

TWAD Board undertakes investigation, execution and maintenance of any scheme for the provision of watersupply and sewerage facilities, to meet the needs of any industries or institutions within the area of the local authority on the direction of state Government.

The watersupply and sewerage schemes undertaken by TWAD Board are handed over to the respective local bodies for maintenance on completion.

The headquarters at Chennai co-ordinates with all the regional offices and government agencies for effective implementation of various watersupply and sewerage projects through the following units :