Durdent (river) Durdent (river) The river Durdent is one of the many small coastal rivers that flow from the plateau of the Pays de Caux into the English Channel. The river rises just northwest of Yvetot, near Héricourt-en-Caux, at the meeting of the two streams, the Saint-Denis and the Saint-Riquier, then takes a north-northwest route, typical of the rivers of the Seine-Maritime department. It passes through the villages of Robertot, Sommesnil, Oherville, Le Hanouard, Clasville, Grainville-la-Teinturière, Cany-Barville, Vittefleur and Paluel and empties into the English Channel at Veulettes-sur-Mer. In earlier times, it powered many watermills along its course. The Durdent valley is
Blackadder Water and joins with that river at the village of Allanton, where Blackadder House and its estate once stood. The Whiteadder then crosses the English Border below Edrington where it joins the Tweed which empties into the North sea at Berwick-upon-Tweed. Blackadder Water Blackadder Water () is a river in Berwickshire in the Scottish Borders area of Scotland, forming part of the River Tweed system. Rising in the Harecleugh Forest plantation just south of the Twin Law cairns, north of the village of Westruther, the headwaters of the Blackadder join with those of the Wedderlie, Edgar, and Fangrist Burns, before reaching