Water from the Challawa and Tiga dams has swept through rural Jigawa state, bordering the nation of Niger, said Umar Kyari, a spokesman for the state governor. Kyari said the rising waters have affected about 5,000 villages in the typically arid region approaching the Sahara Desert.
"They released water indiscriminately," Kyari said.
It wasn't immediately clear whether residents received a warning or if anyone was injured or went missing in the flooding. Officials typically open dams seasonally in the region, but it appears far more water flowed out than residents expected.
Jigawa is home to 4 million people, so half of the state's population has been displaced by the flooding.
Nigeria, an oil-rich nation of 150 million in West Africa, has strong seasonal rains that wash through the country. However, this year has seen particularly strong rains in the north that already have broken a dam and flowed over levees in another northern state.
Local officials had begun putting displaced families in rural schoolhouses and other government buildings out of the reach of the floodwaters, Jigawa state information commissioner Aminu Mohammed said. However, Mohammed said the water had reached the border with neighboring Yobe state.
"The flood has washed away all the farms and houses," Mohammed said.
Officials with the agency in charge of the dams in neighboring Kano state could not be immediately reached for comment Friday night.
Jigawa state sits about 870 miles from Lagos in Nigeria's Muslim north.
Mohammed said the flooding has grown progressively worse since August, reaching its height Friday. He said more than 34 square miles of farmland have been washed away by the flooding, as well as millions of dollars worth of cattle.
The commissioner said the state has yet to receive significant aid from the federal government.
Typically, the water released yearly from the dams flows into farm fields across the region known as the Sahel, a band of semiarid land stretching across Africa south of the Sahara. There, farmers use the water in the region's brief fertile season to grow corn, rice and a variety of vegetables. However, rains this year have been unusually strong, putting pressure on the reservoirs and dams in the area.
In Nigeria's northwest state of Sokoto, floodwater topped levees and a dam failed during recent flooding, spilling water into surrounding villages. Local newspapers reported as many as 40 people died.
Seyi Soremekun, a spokesman for the Nigerian Red Cross, said officials were working on casualty figures from the flooding. He said volunteers already reached Jigawa and Sokoto states to offer assistance.
"I think the most pressing need is how to put the victims, those affected, in shelter from the harsh weather," Soremekun said. "They need blankets; they need some personal effects to at least deal with or absorb the shock of displacement."
The rains come as neighboring Niger faces what international aid experts warn is the worst hunger crisis in its history following a prolonged drought and poor growing season last year. One of the poorest countries in Africa, Niger now has more than 7 million people - almost 50 percent of the population - suffering from a lack of food, officials say.
Nigeria, Africa's most populous nation, last saw serious flooding in 2007, when 68 people died and 50,000 were affected.