Katwijk aan Zee, Uitwateringskanaal, Berghaven and Binnenwatering. The Uitwateringskanaal was commissioned in 1807. The mouth of the Old Rhine became blocked in the 12th century, excess water was discharged via the Spaarne and IJ, but the need for additional discharge remained and plans for additional drainage were made as early as the 17th and 18th centuries l © 14 sept 2020 Aerophoto-Schiphol