Analysis and Calculation of Design Flood

6.1.1 Design flood shall correspond with the annual highest flood discharge and the discharge hydrograph associated with the specified frequency indicated in Clause 1.0.8 of the Specifications. If the structure is designed by water level control, the design of flood level shall comply with the annual highest flood discharge with the specified frequency shown in Clause 1.0.8 of the Specifications. If design flow is calculated according to storm runoff, the rainfall intensity or precipitation shall comply with the assigned frequency in Clause 1.0.8 of the Specifications.