DAR ES SALAAM, Oct. 20 (Xinhua) -- A power supply crisis is looming large in Tanzania as incessant drought has caused the water levels in reservoirs to go down with one already at its record low, local press reported on Wednesday.

The water level at the Mtera hydropower dam dropped to an all- time low of 690.42 meters, according to newspaper Daily News. The level of 690 meters is the working permit for the turbines to keep running.

If no rain comes soon, the Tanzania Electric Supply Company will have to switch off the turbines at the hydropower plant and to start power rationing on the national power grid.

As an emergency measure, the power supply company has turned to gas turbines which are now being installed in a couple of power plants in the country.

With an installed generating capacity of 318 megawatts, hydropower already falls short of Tanzania's national maximum demand of 500 megawatts at the time being.

Upon completion, the two additional gas turbines will not only increase the country's total number of gas turbines to six but will also up the country's gas fired generating capacity from 112 megawatts to 178 megawatts. And the power generated by gas fired turbines is expected to further rise to 300 megawatts with the installation of powerful transformers.

Though rich in hydropower, Tanzania still has to import electricity to meet its ever-increasing requirement. It imports some 50 million kilowatt-hour per year.