Lake Victoria's water levels have surged to their highest level in more than half a century after about eight months of relentless downpours, posing a threat to Uganda's hydropower plants, the country said on Friday.

The east African country relies almost entirely on four hydroelectric power dams on the River Nile, which is fed by the lake, and any threat to this energy infrastructure has major economic consequences.

Uganda's water and environment minister, Sam Cheptoris, said intense rains that started around August last year had raised Victoria's water levels to just under 13.4 meters, a mark last recorded in 1964.

"The increased water level is causing dislodgement of papyrus mats ... resulting into huge mass of floating islands which are dangerous to hydropower infrastructure," Cheptoris said.

On April 14, Uganda lost power countrywide after such islands carried by surging waters clogged the intake gates at two of the hydropower dams in Jinja in the east of the country.

"This cost government a lot of money to remove," Cheptoris said, without giving figures.

Sections of waterfront properties such as luxury hotels, including one belonging to a unit of Nairobi-listed Tourism Promotion Services and a Protea Hotel, part of Marriott International, have become submerged in the last few weeks.

To relieve flooding, Cheptoris said Uganda had more than doubled the volume of water it releases downstream through the gates at the dams at Jinja.

Egypt could be an unexpected winner from the extra volumes as it relies on the Nile for much of its water supplies.

- Reuters