Father-of-seven Dah Toubada Kadapia stood on a stack of homemade sandbags in his backyard in Chad's capital N'Djamena, surrounded by floodwaters that locals say have risen higher than past years, causing more damage than ever.

Residents of Chad, Mali, and Niger waded through flood waters or used boats along submerged streets in recent weeks. They are among 6.6 million people affected by West and Central Africa’s monsoon. Over 8.