Irrigation tank is a small reservoir constructed across the slope of a valley to catch and store water. The water stored in the tank is used for irrigation. It is a common structure prevalent in India, Sri Lanka, Indonesia. As per the estimate, there are more than 39,000 tanks in the Tamil Nadu state of India, managed by Public Works department (PWD) of the state Government and local administrative body of the state. The agriculture activity of tank command area depends on water available in the tanks. The water distribution is liked with efficiency, inequality and poverty of the farmers in the state. The book measures the above aspects and results are presented.