The bombings created major gaps in the dikes at four primary locations, breaching the coastal defences against The North Sea and allowing seawater to flow unchecked into inhabited areas of land.

Whilst the bombings achieved the immediate military objective of forcing a retreat of the occupying forces of Nazi Germany, who had used Walcheren to control the Western Scheldt and access to The Port of Antwerp, the subsequent flooding caused by the breaches had profound effects on the island infrastructure and local population.

[14] In the non-fiction novel Het verjaagde water by A. den Doolaard about the reclamation works, Jansen features prominently under the pseudonym Van Hummel.

[15] Jansen successfully managed the completion of the works, overcoming several technical and equipment-supply issues, including the fact that many dredgers were still located in areas of the occupied Netherlands, and around 25% of the Dutch dredging fleet had been confiscated and transported to Germany.

[20] After the devastating effects of the North Sea Flood of 1953 on The Netherlands, Jansen had an advisory role in the closure of the various dike breaches across the country.

He played a particularly important role in the creation of the Combinatie Speurwerk Baggertechniek (Dredging Techniques Research Joint Venture).

[5] Jansen also provided support for research into new coastal erosion protection techniques, and the introduction of mathematical models for tide calculations.

[22] In 1955, Jansen was appointed as chairman of the Commissie voor het onderzoek naar de spanningstoestand in dijken (Commission for the Investigation into the State of Stress in Dikes).

[5][23] After the breach of a quay in Tuindorp-Oostzaan in 1960, Rijkswaterstaat identified that many secondary barriers, which were not part of the Delta Works, were insufficiently robust.

In order to address the situation, the Technische Adviescommissie voor de Waterkeringen (TAW - Technical Advisory Committee for Flood Defences) was created in 1965.

This organisation had a more permanent nature than the aforementioned commission, and was also explicitly tasked with issuing guidelines for the design and testing of water barriers.