Centreville, AL – The Cahaba River National Wildlife Refuge will be dedicated this weekend. The ceremony will be held Sunday. The Cahaba River has more than 150 miles of free flowing water. It's one of the most diverse rivers in the country, and conservationists believe at least 69 species are threatened by construction and pollution. The preserve will contain the world's largest remaining stand of the Cahaba lily. The tall, white plant blooms on the shoals in mid-May. They once thrived in rivers throughout Alabama and the South, but dams wiped out many of those clusters.