Blackwater

Blackwater, the name of numerous rivers and rivulets in Great Britain and Ireland, of which the longest are: (1) The Blackwater of Munster, 100 miles in length, which enters the sea at Youghal harbour; (2) the Blackwater of Ulster, 50 miles long, which falls into the south-west corner of Lough Neagh; and (3) the Blackwater of Essex, 40 miles long, which falls into the North Sea.