Licchavi Lyceum


Licchavi Lyceum

Drainage System of Tamil Nadu

In this article, we will discuss the Drainage System of Tamil Nadu. The state has a well-developed drainage system that plays a crucial role in managing water resources and preventing waterlogging. The state’s drainage system is primarily natural, comprising rivers, lakes, and other water bodies.

Drainage System of Tamil Nadu
Drainage System of Tamil Nadu


Cauvery River: The Cauvery River is the largest and most significant river in Tamil Nadu. It originates in Karnataka and flows through Tamil Nadu, providing essential water for agriculture and other purposes.

Cauvery River
Cauvery River

Vaigai River: Another major river, the Vaigai, flows through the southern part of the state, supporting agriculture and serving as a source of water. It originates in the Western Ghats and flows eastward across the state before ultimately reaching the Palk Strait in the Bay of Bengal.

Vaigai River
Vaigai River

Thamirabarani River: The Thamirabarani is a major river in southern Tamil Nadu. It originates in the Western Ghats and flows into the Gulf of Mannar. The river supports agriculture and is important for the socio-economic life of the region.

Palar River: The Palar River flows through the northern part of Tamil Nadu before entering Andhra Pradesh. It is a seasonal river, and its flow is largely dependent on rainfall. The river is essential for agriculture and groundwater recharge.

Bhavani River: The Bhavani River is a tributary of the Cauvery and originates in the Nilgiri Hills. It flows through the western part of Tamil Nadu, contributing to the Cauvery’s water flow and supporting agriculture in the region.

Noyyal River: The Noyyal is another tributary of the Cauvery, originating in the Western Ghats. It flows through the Coimbatore district and is important for agriculture and water supply.

Kaveri (Kollidam) River: The Kollidam is a distributary of the Cauvery River that branches off near Grand Anicut (Kallanai). It flows eastward and eventually merges with the Bay of Bengal. The Kollidam plays a crucial role in draining excess water from the Cauvery during periods of heavy rainfall.

Adyar River: The Adyar River flows through the city of Chennai and is relatively short in length. It has been subject to environmental challenges, including pollution, due to urbanization and industrialization in the Chennai metropolitan area.

River Basins as the base of Drainage System of Tamil Nadu

River basins are geographical areas drained by a river and its tributaries. Tamil Nadu is divided into several river basins, including the Cauvery, Vaigai, Thamirabarani, Palar, and others. These basins contribute to the overall drainage pattern of the state.

Cauvery River Basin: The Cauvery River Basin is the most prominent and extensive river basin in Tamil Nadu. It covers a large portion of the state, originating in Karnataka and flowing through Tamil Nadu before reaching the Bay of Bengal. The Cauvery Delta, formed by the Cauvery River, is highly fertile and supports extensive agriculture.

Vaigai River Basin: The Vaigai River Basin is located in the southern part of Tamil Nadu. The Vaigai River originates in the Western Ghats and flows eastwards, serving as a significant water source for the districts it traverses, including Theni and Madurai.

Thamirabarani River Basin: The Thamirabarani River Basin is situated in the southernmost part of Tamil Nadu. This basin is characterized by the Thamirabarani River, which originates in the Western Ghats and flows towards the Gulf of Mannar. The river basin supports agriculture in the districts of Tirunelveli and Thoothukudi.

Palar River Basin: The Palar River Basin spans the northern part of Tamil Nadu, extending into Andhra Pradesh. The Palar River is a seasonal river, and its basin is essential for agriculture in districts like Vellore and Kanchipuram.

Bhavani River Basin: The Bhavani River, a tributary of the Cauvery, has its own basin. Originating in the Nilgiri Hills, the Bhavani River Basin covers areas in the western part of Tamil Nadu, including Coimbatore and Erode districts.

Noyyal River Basin: The Noyyal River Basin is associated with the Noyyal River, a tributary of the Cauvery. This basin covers parts of the Coimbatore and Tiruppur districts. The Noyyal is important for the agricultural activities in the region.

Water Divides

  • The Western Ghats act as a significant water divide in Tamil Nadu. The rivers originating in the Western Ghats flow towards the east and west, influencing the drainage pattern in the state.
  • The Palghat Gap, a low-lying pass in the Western Ghats, serves as a crucial water divide. It allows the flow of southwest monsoon winds and influences the distribution of rainfall on either side of the Western Ghats.

Understanding these river basins and water divides is essential for effective water resource management, as it helps in planning for irrigation, flood control, and sustainable utilization of water in Tamil Nadu.

Role of Lakes and Tanks in Drainage System of Tamil Nadu

The state has numerous lakes and tanks (artificial reservoirs) that serve as water storage facilities. These water bodies are crucial for irrigation, especially during the dry season. Examples include the Chembarambakkam Lake, Puzhal Lake, and the Veeranam Lake.

Canals: An extensive network of canals has been developed to distribute water from rivers and reservoirs to agricultural fields. These canals aid in irrigation and contribute to the overall drainage system.

Coastal Drainage: Tamil Nadu has a long coastline along the Bay of Bengal. The coastal areas have a network of rivers and estuaries that facilitate drainage into the sea.

Drainage into the Bay of Bengal: Several rivers, including the Cauvery and the Tamiraparani, drain into the Bay of Bengal. This drainage into the sea helps prevent waterlogging and ensures proper water flow.

Water Management Structures: The state has various water management structures, such as check dams and anicut (small dam-like structures), to regulate the flow of water and recharge groundwater.

Challenges to the Drainage System of Tamil Nadu

Despite the well-developed drainage system, Tamil Nadu faces challenges such as water scarcity, especially during periods of drought. Additionally, the state experiences occasional flooding during heavy monsoon rains.

The Tamil Nadu government, through its water resource management policies and infrastructure development projects, continues to focus on sustaining and improving the state’s drainage system for agricultural, domestic, and industrial purposes.