This project consisted of building a concrete dewatering structure for dewatering the bottom ash from Units 3 & 4 of the Colstrip Power Plant located in Colstrip, Montana. The structure is approximately 180’ wide and 300’ long. The base slab ranged from 18” to 24” thick. The walls were 15’ tall and 24” thick. The structure also has 3 settling basins and 1 clearwell.