Prakasam Barrage, Tidal barrage and road bridge across the Krishna River in Vijayawada, Andhra Pradesh, India

Prakasam Barrage is an irrigation structure across the Krishna River in Andhra Pradesh, India, regulating water flow through a series of gates. The structure spans the full river width and connects both banks with a roadway running along the top of the construction.

A first dam at Vijayawada was built in 1853–54, 1,132 m long and 4 m high, after the 1832–33 famine showed the Krishna's water went unused; it was supervised by Major Charles Orr. Floods in 1952 destroyed it, and the new barrage, begun on 13 February 1954 a few metres upstream on sand foundations, opened to traffic on 24 December 1957 at a cost of Rs 2.78 crore. It is named after Tanguturi Prakasam, the first Chief Minister of Andhra.

The barrage is named after Tanguturi Prakasam, the first Chief Minister of Andhra state, which was formed in 1953 and became Andhra Pradesh in 1956. Its three canals cross Vijayawada itself, a layout often compared to Venice. The road deck carries National Highway 16 between Chennai and Kolkata, with a 24-foot carriageway and five-foot walkways on each side.

The barrage carries National Highway 16 between Chennai and Kolkata, with a 24-foot-wide roadway and five-foot-wide footpaths on both sides. The three canals it feeds cut through Vijayawada, so the structure is reached from the city side. The maximum flood flow recorded was 31,000 cubic metres per second on 5 October 2009.

The barrage is the last dam on the Krishna before the river splits into two branches and reaches the Bay of Bengal at Nagayalanka and Koduru. Its 24-foot-wide roadway carries National Highway 16 between Chennai and Kolkata, with a 5-foot footpath on each side.