(CNN) -- Ravaging floods killed dozens in Nigeria and displaced tens of thousands of residents as crocodiles, hippos and other water animals washed into homes.
The floods have left 148 people dead and affected 21 of the nation's three dozens states, according to the local Red Cross.
"Torrential downpours in recent weeks have caused widespread destruction and forced many families into makeshift camps," the aid agency said on its website. "An estimated 134,000 people have now been affected by the floods and concern is growing about the spread of waterborne diseases."
The floods have affected a series of states, including Bayelsa and Benue.
In Bayelsa state, an official said the area's terrain has intensified the effects of the downpour.
"It is like Florida ... swampy with a lot of sea water mixed with fresh water because we are close to rivers and the Atlantic (ocean)," said Tam Alazigha, the chief economic adviser for the state.
"A lot of people have been displaced. Snakes, crocodiles and hippos have been displaced and are ending up in people's homes. Everyone has been displaced."
Alazigha said more rain is forecast and authorities are evacuating residents to shelters that have been set up in schools located on higher ground.
"The bad part is ... there is no relief yet," he said.
State officials are working to enhance drainage around the buldging rivers, according to the adviser.
"Our main goals are to help settle the displaced people and improve on the drainage," he said. "Our hope is that when the drainage gets better and the waters subside, we can deploy more resources to see how much we can save."
Alazigha said the amount of rain was unexpected.
"It took us by surprise," he said. "We need help from those agencies that are out there that usually help out in situations like these. All hands are on deck, but it is quite a challenge."
In the state of Benue, more than 25, 000 people were displaced after a local river overflowed, the National Emergency Management Agency said.
Nigeria's rainy season occurs between May and October. Torrential rains are especially hard on communities in rural areas, where drainage is inadequate or nonexistent.
Last month, authorities urged residents living along River Niger to move to higher ground. The evacuation order affected the states of Niger, Kogi, Kwara, Kebbi, Anambra and Delta.
CNN's Hamdi Alkhshali contributed to this report