Improvement in the selection of design storms for the new master drainage plan of Barcelona

In 1988 Barcelona finished its Master Drainage Plan, where a modified Chicago storm of 10 years return period was used. Nowadays, a new Master Drainage Plan has started due to enormous urbanistic changes with the Olympics, the increasing concern for CSO problems, etc. For this Plan the use of a 67 year record from an intensity raingauge, and long-term simulation models allows a change in the traditional concept of design storms, working with historical storms. In spite of that, the complexity of the urban drainage system of Barcelona advises the use of design storms for predesign purposes. Because of that, a study has been carried out to select new design storms to solve the problem that the Chicago storm is too unfavourable as it has all its maximum medium intensities corresponding to a 10-year return period, which is not realistic.