Tens of thousands of people have fled their homes
Floods are wreaking havoc in large areas of eastern Africa, ending a harsh drought.
The floods have killed at least 40 people in southern Ethiopia, officials say.
Another 40 people have died in Kenya, according to Red Cross figures.
Tens of thousands of people across the region have fled their homes.
And aid agencies warn the worst may be yet to come as rain continues to fall across the region.
Ethiopia's Mines Minister Mohamoud Dirir Gheddi on Wednesday told the BBC the government was unable to cope.
"For the last two years people have been praying for rain... Very unfortunately according to what I have seen... villages have been virtually submerged," he said.
"Houses have been destroyed... People have fled to the mountains... they have been left with virtually nothing."
In western Kenya some 60,000 have fled rising waters, according to the Kenya Red Cross Society.
Kenya: 60,000 displaced, 40 dead
Ethiopia: 100,000 displaced, 40 dead
Somalia: Thousands displaced
"It is just the beginning of the rainy season so we should be prepared for a deterioration of the situation," their secretary general said in a statement.
On Monday, Kenya's Government declared the floods a national disaster. They are appealing for international assistance and the army have been deployed.
A United Nations report says refugee camps in north-eastern Kenya have also been severely hit.
The BBC's Ishbel Matheson in Nairobi says the Kenyan authorities have been caught unprepared by the scale of the flooding.
In the Busia area of western Kenya, earth dykes, built only last year, have been swept away.
Houses and crops have been submerged.
Villagers have been heading to higher ground where they are finding shelter in camps set up by aid agencies.
In the capital, Nairobi, roads have flooded and stranded cars are causing even bigger traffic jams than usual.
The rains are being described as the heaviest for several years.
In Somalia, the lower Jubba River and the middle Shebelle regions have been affected with thousands displaced.
An aid agency official in Bu'aleh told the BBC said that 21 out of 33 nearby villages had been abandoned because of the floods and people were now suffering from lack of food, shelter and medicine.
However, he said water levels had now begun falling.
In Ethiopia, about 96,000 were forced to flee their homes after the Shebelle river burst its banks, flooding lowland areas of the country's Somali region.
Delivering help has been difficult because bridges and roads have been washed away and the usual sources of drinking-water have been contaminated by the floods
Rescue workers are operating in the area, providing the people with medical supplies, plastic shelters and cooking equipment.
The towns of Kelafo and Mustahil have reportedly been hardest hit.
A senior representative of the UN children's fund Unicef, Marc Rubin, said the situation was "very serious and worse than any year before".
"We are very concerned about the humanitarian situation. They have no food, no clean water and the health service has been destroyed," he told the UN information agency Irin.
At least five health centres and two schools have been destroyed, and dozens of villages have been cut off.
The area has been receiving food aid due to the severe drought that has hit some 12.6 million people in the country.
The UN's World Food Programme (WFP), which is in Kelafo, has warned that food needs may have to be reassessed because of the flooding.
"Flooding is needed in the area for flood-recession agriculture, but there will be an immediate negative impact on the population," said a WFP representative quoted by Irin.