Most of the large sloughs around the Bay have been diked or leveed.
During the 1970s, the area that would become Grand Cote Refuge was cleared and leveed for agricultural purposes.
That, however, did not prevent the corps from transforming the Missouri, once a meandering river with countless braided channels that sheltered fish, birds and riverine plants, into a leveed-line ditch.
Delta smelt are threatened with extinction due to anthropogenic alterations to their ecosystem, including urbanization, non-native species, water diversions, contaminants, and the conversion of complex tidal habitats to leveed channels.
In 1956, both the " The Clarion-Ledger " and " The State Times " newspapers reported that the area just to the east of Jackson had been carefully leveed to sustain industrial development.