River Management after 1800: Complete Regulation and Canalisation

In the traditional agricultural society of the Delta the new technological progress got under way relatively late. Developments in river management in the 19th century were a continuation of a strategy that had inspired and stimulated the inhabitants of the Delta for millennia: the use, maintenance and improvement of their waterways as economic arteries. For ages waterways were the most important routes for transport of humans and goods, and by dogged perseverance attempts were directed to serve the joint interests of safety and navigability. Safety against flooding demanded regulated rivers, strong and high dykes and straight river channels without obstacles, sandbanks, etc., especially to avoid damage caused by drift ice. Effective transport demanded also a continuous, navigable shipping channel, reliable at low water and at high discharges, used by ships ever-increasing in size.

But the rivers in the Delta did what all lowland rivers do: they silted-up. Where the narrow, fast-flowing Rhine and Meuse rivers in Germany and Belgium entered the wider lowland of the Delta, the currents slowed down and sand and silt settled in the riverbed and in its floodplains. Local dredging could not cure that problem; it only meant a displacement of the sedimentation process. At the end of the 18th century, after a centuries-long process of river regulation, embanking and draining the river polders, the constricted and silted-up river channels became unmanageable.

In this chapter the rigorous measures, especially taken in the 19th and early 20th century, to ‘normalise’, i.e. completely regulate and canalise the riverbeds, are described. The removal of numerous meanders and sandbanks, the building of hundreds of groynes, the digging of lateral canals and bypasses and the building of weirs and ship-locks fully canalised the Meuse and large sections of the Rhine (Nederrijn–Lek). The Waal and IJssel have long been the only free-flowing river branches, but since the 1950s the flow of the IJssel can be regulated by the weirs in the Nederrijn–Lek. The flow in the Waal was restrained in 1971 by the building of the main tap of the Rhine, a large weir system, the Haringvlietdam, close to the North Sea. Awaking interests in recreation and nature conservation in the 20th century did not play any role in the decision-making processes.