"The farmland supports some 1,200 families, whose livelihoods and food security now hang in the balance," said the Kenya Red Cross Society (KRCS). About 600 hectares of farmland are under water in the divisions of Rhamu and Rhamu Dimtu, 80km from Mandera town.
The flooding has been attributed to increased run-off from the surrounding hills causing the River Daua to burst its banks.
River Daua originates in neighbouring Ethiopia and covers 230km inside Mandera. Farming activities in the arid region are concentrated along riverine areas.
"In the last two days we have also been experiencing heavy rains," Khalif Mohammed, KRCS Mandera branch coordinator, told IRIN.
The flooding, which is expected to last at least 60 days, has affected recently planted crops as well as maize, vegetables and fruit that were ready for harvesting.
In October, River Daua also burst its banks, displacing thousands of people and submerging hundreds of latrines in Mandera town. The flood followed a long period of drought.
"At the moment no outbreak of diseases has been reported although 68 cases of diarrhoea were treated in October," Mohammed said. "We are also constructing 20 three-unit communal pit latrines in strategic places in the affected areas."
KRCS is also providing non-food items such as tarpaulins and water purification tablets as well as conducting a needs assessment.
Hundreds of people were also displaced by clan clashes between the Garre and Murule groups in the region in October, prompting a government security operation to restore calm.
However, the operation has been criticised by human rights activists who say hundreds of people have been injured by security forces.
"The number of civilians injured in the operation has now increased to more than 300," said Hassan Abdille of the Kenya National Commission on Human Rights. A local herder has also been confirmed dead, Abdille said.
Provincial police officer Stephen Chelimo dismissed claims the man died after being tortured.
However, Chelimo said, the death would be investigated. "We know a certain group of people are determined to stop the operation."
According to Mohammed of KRCS, health teams have been mobilised to assist the local communities. "We suspect that there are a lot of unreported injury cases in the bush."
The security operation has also contributed to population displacement across the border towards Ethiopia and Somalia.
"Most of the locations are deserted and the dispensaries are also closed," he said. "Women and children are the worst affected as most of the able-bodied men have fled or they are the ones with the guns," he said.