Water Line

The Atlantic Wall as a defensive water line. The achilles heel of a linear defense line made of concrete and steel, such as the Atlantic Wall, was its cross-sectional dimension. The Germans recognized this fact as early as 1942. Consequently, provisions were made in low-lying areas (e.g. the Dutch polder landscape) to protect the Atlantic Wall in the rear by inundations and water obstacles. The water defense consisted of two concentric “zones”. The Vordere Wasserstellung [forward or first water position] was an area of inundation created by flooding polders immediately inland of, and parallel to the Atlantic Wall. In this way, the cross-sectional dimension of the Atlantic Wall could be extended to 20 to 30 kilometers. This defense line was aimed at halting enemy paratroopers who might have landed on or very near the coast. Beyond the Vordere Wasserstellung was a second defensive water line: the Hintere [rear] Wasserstellung. It roughly traced the course of the Oude Hollandse Waterlinie, or old Dutch Water Line, dating from the 18th century. This hintere Wasserstellung, as well as the so-called IJsselstellung [a similar line projected along the river IJssel], were never realized due to a lack of man power, equipment and materials.

Work on the Vordere Wasserstellung started in July of 1942. Many of the fortifications and works of the existing water lines were refurbished and  a few new defense works were added to create an interconnected and coherent system. Most of the structures were earthworks and trenches in higher ground, such as dikes and the embankments of overpasses and bridges. Only a few light concrete structures were built. In addition, a number of works making up the Stelling van Amsterdam - the old Defense Line of Amsterdam - were put back in use. These included the Slotertocht casemates, theAalsmeerderweg battery, the fortress at Aalsmeer, and the trenches in the Geniedijk [dike] surroundingthe Haarlemmermeer polder.  By an order of 21 June, 1944, boats of all sizes along this route - canoes included! – had to be moved east of the then-named Merwede Canal (now the Amsterdam-Rijn Canal to prevent, one must assume, enemy troops from using the vessels to cross flooded land.

Between April 1944 to May 1945, the entire forward water line was protected by inundations. Only the Haarlemmermeer polder was not flooded, although explosive charges were put in place around Lisse, Hillegom, Halfweg and Burgerveen in case a sudden (explosive) breach was needed. Thus, the southern part of the polder could be flooded if needed. A new dike in the polder was not built. Explosive charges were also installed around another polder, the Wijde Wormer and these were used: as evidenced by the fact that the polder was under water in December of 1944. Also, in the sea wall at Schellingwoude (north-east of Amsterdam) wells were dug and readied to receive explosive charges for inundation. However, they were not used. In some areas, such as west of the town of Alphen aan den Rijn, in the Haarlemmermeer polder, south of Fliegerhorst [airfield] Schiphol and near Leimuiderbrug, anti-tank ditches were dug.

The Germans had prepared for the large-scale inundation of the western Netherlands, i.e. the provinces of North and South Holland, Utrecht and Zeeland. In anticipation of this flooding, the water level in the IJsselmeer was kept high and explosive charges were installed in pumping stations, locks and electric power plants.  “Sprengkommandos” [blasting commandos] were ready and set to blow everything up but it never came to this.

The spatial consequences of the inundations were felt most acutely towards the end of the war. In one extremely important case, water served not only as a defense mechanism but was also used as an offensive strategy by the Allies in the attack on the Atlantic Wall: in the Battle of the Scheldt in the fall of 1944. The prolonged inundation of the Walcheren peninsula with (salty!) sea water, had far-reaching consequences for the post-war agricultural landscape and local water management. Closing the breaches in Walcheren’s dikes was accomplished by using caissons, foreshadowing the methods for dike repair that would be employed following the catastrophic flood of 1953 and during construction of the dams of the Delta Works. After the dikes had been closed, extensive land consolidation was carried out, whereby the small-sized farmland of old was replaced by an agricultural landscape with a much larger scale.