The structure of the Prakasam Barrage stretches 1223.5 m across the Krishna River connecting Krishna and Guntur districts. The barrage serves also as a road bridge and spans over a lake. The three canals associated with the barrage run through the city of Vijayawada, crossing it and giving it a Venetian appearance.
The idea of constructing a dam across the river Krishna dates back to 1798. It began in the hands of captain Buckle and was revised in 1839 and 1841 by Captain Best and Captain Lake. After the endorsement of Major Cotton, the board of Directors of the East India Company approved it on 5 January 1850. The dam was started in 1852 and completed in 1855. It cost Rs 1.75 crore in those days and seems to have paid the then government a return of 18%. It used to irrigate 7 lakh acres.
Later, the State Government constructed a bridge that was named after Tanguturi Prakasam, the first Chief Minister of Andhra . Completed in 1957, it helps to irrigate over 1.2 million acres of land. This barrage also supplies water to Buckingham canal which was initially constructed as an inland navigation canal but was later used as an irrigation water supply canal. One of the first major irrigation projects of South India, the Prakasam Barrage in Vijayawada was completely successful in its mission.
Andhra Pradesh largely owes its rich agriculture to the Prakasam dam as the project facilitated the irrigation of large tracts of farmland. The dam provides views of the lake. It has become a tourist attraction of Vijayawada. The barrage has 76 pillars in total; 70 pillars belong to Guntur district and 6 belong to Krishna district.