Record low water levels at Iraq's largest hydroelectric dam have ground turbines there to a halt, amplifying a power shortage that led to riots last summer, a top official said on Thursday.

Adel Mahdi, advisor to the electricity minister, said water levels at the Mosul dam on the Tigris River had fallen to 298 metres (977 feet) above sea level.

"It is the first time since 1984 when the dam was built that water levels have fallen this low," Mahdi told AFP.

"The installed power generation capacity of Mosul's hydroelectric plant is 1,175 megawatts, but the current production is zero, because the turbines need a minimum water level of 307 metres (1,007 feet) to operate," he added.

He said half of the water to the dam was coming from Turkey, and the rest from Iran and the mountains of Iraq.

The Tigris and Euphrates which gave Iraq its ancient name of Mesopotamia, meaning "land of two rivers," reach Iraq through Turkey.

The Tigris flows directly from Turkey, and the Euphrates goes from Turkey through Syria, then flows to Iraq. Water projects in the two countries have had a severe impact on Iraq.

Mahdi said Iraq also was eyeing with extreme worry Turkey's controversial Aliso dam on the Tigris, work on which began in 2006.

"If Aliso is completed, it will finish with the Tigris in Iraq completely," Mahdi said.

Mahdi said hydropower from Iraq's Haditha dam on the Euphrates was also operating at less than 50 percent of capacity because of water shortages due to irrigation and dam projects in Turkey.

He added that Iraqis will have to endure power outages next summer as well, because additional supply would be matched by an expected 10 percent rise in demand, leaving Iraqis with an average of eight hours of power per day.

Mahdi said the situation would not improve before 2013, when projects in the pipeline now would add another 10,000 megawatts to the grid.

He put overall Iraqi electricity demand at 15,000 megawatts, and supply at 8,500 megawatts.

Due to the shortfall, homes and businesses nationwide suffer daily cuts and rely on private generators to fill the gap, as the war-ravaged country struggles to boost capacity.