LAKE NAIVASHA:Months of sustained torrential rains have caused a lake in Kenya's Rift Valley to flood its banks, forcing hundreds of people to flee their homes and farms, in what officials say shows the devastating impact of climate change on East Africa.

Lake Naivasha has expanded to 173 square kilometres, from 112 square kilometres just 10 years ago, mainly due to increased rainfall and siltation, which pushes the waters outwards, said Cyrus Oguna, the Kenyan government spokesman.

In many other parts of the East Africa region too, heavy rains have ravaged crops and rising waters from lakes and rivers have destroyed shoreline communities.

"This is a global phenomenon which has come to Kenya now. Climate change is now affecting the East African region," said Festus Ng'eno, the executive in charge of water in Nakuru county, where Lake Naivasha is situated.

Ruth Wanjiru, forced to leave her home in the shoreline village of Kihoto in May, said she had lived in the area for nearly three decades but had never seen flooding on this scale.

"It all started in April. The water started rising, coming to the residential areas. It got worse and I had to move out," said the 47-year-old mother, one of around 500 people displaced by the flooding from Lake Naivasha.

She watched crestfallen as five young men waded through thigh-high waters to salvage windows and doors from the house she had to abandon.

"I am now trying to save the little that I can," said Wanjiru, adding that she would sell retrievable parts of the house for food and other essentials.

Ten small rental houses she had built in the area have also been abandoned, depriving her of her primary source of income.

Some residents are afraid of wild animals that now roam about the area.

"We are now having hippopotamuses right before our eyes," said Esther Gichuki. "We cannot walk around after 7 p.m."