canal in eastern Andhra Pradesh state and northeastern Tamil Nādu state, southeastern India. It was constructed section by section between 1806 and 1882 along the backwaters of the Coromandel Coast, which extends for a distance of 680 miles (1,100 km) from Cape Comorin northward to the Krishna and Godāvari deltas.

Although the canal was extensively rebuilt after 1880, it is of poor workmanship, and the expense of repairs is always high. It cannot be used by craft drawing more than 3 feet (1 m). Even so, it is the only main route by which bulky commodities, such as fuel, salt, and dried fish, can be profitably brought to the city of Madras in Tamil Nādu state.