A torrent of water surged recently into Sudan's Blue Nile river at the launch of the expanded Roseires dam, which officials say should help develop one of the country's poorest regions where insurgents are fighting the government.
A strategically-important structure, the 66-year-old dam is already a major power generator for a Sudan struggling with economic crisis since South Sudan separated last year with most of the country's oil production.
It is located on the Blue Nile near Ethiopia and the expansion has cost $460-million.
After four years of work and the resettlement of 20,000 families, Roseires dam now stands 10 metres (33 feet) higher, doubling its storage capacity to allow additional power generation and agricultural irrigation, officials said.
"The significance is very huge," Industry Minister Abdulwahab Mohammed Osman told on the sidelines of the ceremony held to mark the country's 57th independence day.
He said millions of feddans (acres or hectares) of land will be irrigated or provided with additional water because of the project.
The dam's capacity has risen to 7.4 billion cubic metres.
Sudan has been aggressively trying to tap its abundant Nile waters for power generation and agricultural development.
In 2009 it opened the $2-billion Merowe dam north of Khartoum and is also building the connected Atbara and Seteet hydroelectric projects in Gedaref and Kassala states.
The government sees agriculture as one way of trying to boost revenue after the separation of South Sudan, following a 23-year civil war, deprived the north of most of its export earnings and precipitated an economic crisis with soaring inflation and a sinking currency.
When President Omar al-Bashir arrived to open the Arab-funded, Chinese-built expansion before thousands of dancing and flag-waving residents, an arc of water surged through the flag-draped dam, sending spray into the air and rapids surging into the river.
Military helicopters flew low overhead and troops were stationed throughout the area.
Insurgents, which Sudan says are backed by South Sudan, have been fighting government forces in Blue Nile state since September 2011.