Prakasam Barrage in Vijayawada is where the water will be stored and diverted to irrigate paddy crop on seven lakh acres in the Krishna, West and East Godavari districts.
At 9 pm on Wednesday, the waters of the Godavari flowed into the Krishna, linking two big rivers, a 50-year-old dream come true for Andhra Pradesh.
Chief Minister Chandrababu Naidu performed puja at Ibrahimpatnam near Vijayawada. He then switched on a pump, commissioning an irrigation project that will pump Godavari waters into a canal 4 km away. From there, it will flow 174 km to meet the Krishna river.
Mr Naidu's Telugu Desam Party promptly credited him for the historic moment.
"Many great people thought of linking these rivers for so many decades. Chandrababu Naidu's vision for the future has made this possible,'' said the state's irrigation minister Devineni Uma Maheswar.
Prakasam Barrage in Vijayawada is where the water will be stored and diverted to irrigate paddy crop on seven lakh acres in the Krishna, West and East Godavari districts, often called the rice bowl of the country.
It will also provide water to some coastal towns and cities.
The parched Anantpur, Kurnool and Kadapa districts that make up the Rayalaseema region hope to benefit too, as there will be more water available to be stores upstream at the Srisailam with pressure easing on the Krishna river to irrigate the lower riparian districts.
Rayalaseema is always short of water but earlier this year, there was an acute water shortage in the Krishna delta with farmers even declaring a "crop holiday" or growing no crop.
Mr Naidu, who is an ally of the BJP, recalled that former Prime Minister Atal Bihari Vajpayee had initiated the scheme to link rivers and criticised the Congress-led regimes that followed at the Centre for "ignoring" the project.
Several projects, including one worth thousands of crores called Polavaram, have been delayed by years. The TDP government has cleared several legal hurdles to use the Pattiseema lift irrigation project to connect the two rivers.