The threat of flooding in a small N.W.T. community, perched on the bank of the South Nahanni River, is subsiding. After watching the river swell over the past week — quickly at first, and then more slowly — people living in Nahanni Butte noticed water levels drop an inch or two on Tuesday morning. About 24 hours later, Burton Campbell, one of the community's 93 residents, said it had gone down by eight inches.