reservoir [reservoirs](large natural or artificial lake used as a source of water supply) noun [UK: ˈre.zəv.wɑː(r)] [US: ˈre.zəˌv.wɑːr]The reservoir is full of water. = El embalse está lleno de agua.
swamp [swamps](type of wetland) noun [UK: swɒmp] [US: ˈswɑːmp]