undredged

Undredged describes a body of water, channel, or harbor that has not been dredged—that is, not cleared of sediment, mud, or debris from its bottom.

Waterways that remain undredged may become too shallow for boat traffic or develop accumulated silt that affects water flow.

The undredged canal had silted up to the point where only kayaks could pass.

The term appears most often in discussions of harbor maintenance and navigation.