The Holderness coastline suffers the highest rate of coastal erosion in Europe: 2 metres a year on average or 2 million tonnes of material a year. Some of this is transported by longshore drift with about 3% of material being deposited at Spurn Head spit, to the south. The coastline has retreated noticeably in the last 2,000 years, with many former settlements now flooded, particularly Ravenser Odd and Ravenspurn, which was a major port until its destruction in the 14th century. Erosion is an ongoing concern in the area. The East Riding of Yorkshire Council has been carrying out cliff erosion defences between Sewerby and Kilnsea since 1951. The Holderness area drains mostly into the Humber and the eponymous River Hull drains the area north of Hull.