ˈkälməd.ij noun
( -s )
Etymology: French, from colmater to impound silt-laden water (from colmate silt, from Italian colmata, from colmare to heap up, to build up by silt-laden water, from colmo top, summit, from Latin culmin-, culmen ) + -age — more at hill
New Zealand : the impounding of silt-laden water to build up low-lying areas