The Oesterdam was necessitated, like the Philipsdam, after the decision was taken to close off the Eastern Scheldt with a storm surge barrier, rather than a solid dam.

The Oesterdam was not originally part of the planned Delta Works, but rather is one of the compartmentalisation dams which became necessary when it was decided not to close off the Eastern Scheldt, but to provide it with a permeable barrier.

[3] The Commissie Compartimentering Oosterschelde (English: Committee for Compartmentalisation of the Eastern Scheldt) was formed under the aegis of the Dutch Minister of Transport and Water Management.

[6] The necessity of this committee arose from the need to maintain a substantial tidal difference at Yerseke and to ensure tide-independent inland navigation between Antwerp and Rotterdam, in accordance with an existing treaty with Belgium.

[1][6][4] In the initial phases, the Bathse spillway channel's dam body was positioned west of the Kreekrak locks, intended to become operational concurrent with the completion of the Oesterdam.

Significant erosion by the Scheldt river had previously formed a valley in the southernmost 100 metres of the works, which had later filled with a complex mix of clay and sand.

Specific requirements were set for dam body construction in transition areas, focusing on maintaining stability and integrity.

Owing to delays and advancements in dredging technology, which offered increased capacities at relatively lower costs, it was later decided to execute the Tholense Gat closure also with sand.

[8] The Bergse Diepsluis, situated at the northern extremity of the dam, stands on the historical site of the submerged city of Reimerswaal.

This centre serves as a memorial and educational point, detailing the history of approximately 250 villages in Zeeland that were submerged in Reimerswaal (in the period 1550-1650) and elsewhere in the province.