The 10 year struggle of the Rijkswaterstaat (State Department of Public Works) and contractors with the task to build a permeable sea defence structure in the Oosterschelde, has been registered in sixteen successive project reports which contain thousands of documents. These documents are sometimes complete part-project papers and sometimes not more than minutes of a meeting or time-scaled diagrams. This documentation contains all elements which belong to a design report and a project plan. That in this way a successful construction project did come about, does not lessen the need of the PGS (Management Team Oosterschelde Project) for an integrated design plan. In this design plan, the conSistency of the design is visible and can be tested, even for those who were not participants in the project. Because of the fact that the construction was designed while it was being built, the design plan was ready only when work was finished. And since writing of it had to take place during construction, often priority was given to construction instead of writing. Therefore writing of the design plan was more difficult than if it had been done before construction started. In the knowledge that this reversed procedure should not be repeated, the PGS is satisfied that a design plan did come about atal!. The report will provide the manager of the storm-surge barrier, and those who are interested, with an insight into the chosen starting-points. It is hoped that the report will also be an encouragement and a comfort to all those who may be involved with similar constructions in the future. Encouragement to make a design plan and a project plan before construction starts, and the comfort that when necessary it can also be done without these. But then it becomes crucial to have the commitment of all participants in the project to work closely together with mutual trust.