The Clarence River catchment is located in the state of New South Wales (NSW), on the east coast of Australia. The lower Clarence Valley is an area covering approximately 1000 square kilometers and is located on the downstream part of the Clarence River. Due to heavy rainfall, the Clarence River discharge can increase from an average 160 m3/s to 20000 m3/s. As a result, water levels rise significantly leading to severe floods in the Clarence Valley. The main urban areas in this region, Grafton, South Grafton and Maclean, are located in narrowing river bends which makes them particulary vulnerable to flooding during high water levels. The main goal of this report is to present flood mitigation measures to reduce the impact of flooding in the urban areas of the Clarence Valley, based on the Duthc flood mitigation strategy called 'Room for the River'. Consequently the following research question was formulated: How can the impact of flooding on the urban areas in the Clarence Valley be reduced by increasing the storage capacity of floodplains? In order to answer the research question, the following project approach is applied. Six areas were identified, based on a fieldvisit and an extensive preliminary study, to implement flood mitigation measures and assess existing flood defences. Part of these flood defences are the Swan Creek Floodgate and the reinforced concrete levee wall of Maclean, which will be investigated on their performance. A fully calibrated numerical floodmodel provides input for the hydrological analysis. The model represents the current situation in the Valley. Scenarios are created by applying topographic adjustments. The new scenarios are implemented into the numerical model and the effectiveness on flood mitigation in urban areas is assessed by comparing the results of a 5, 20 and 50 year Average Reccurance Interval flood event to the current situation during one of these flood events. By making use of the proposed floodplains and improving the performance of existing flood defences, the flood defence system of the Clarence Valley can be extended. It can be concluded that it is possible to reduce the impact of flooding in the urban areas of the Clarence Valley by increasing the storage capacity of floodplains around Grafton. Therefore, the usage of a ’Room for the River’ strategy can be a solution to the problems the Clarence Valley is facing, and possibly might be applicable to more flooding-vulnerable areas in Australia.

The use of the Classical Laminate Theory (CLT) is limited to laminates where all the fibres in a ply are oriented in the plane of the laminate. In some applications, it is possible that the plies will start at the bottom of a laminate and end at the top of the laminate. This means an inclination is added to the plies, which creates an extra rotation in the fibre direction with respect to the plane of the laminate. Such a laminate with inclined plies is found for example in the skin of InfraCore panels. In the regular CLT, this extra rotation cannot be taken into account, thus the elastic behaviour of a laminate with inclined plies cannot be described properly. The extra rotation that occurs in a laminate with inclined plies has analytically been implemented in the regular CLT to obtain a modified CLT, which has been verified using Finite Element analyses. Using the modified CLT, a reduction in equivalent stiffness can be observed for a single unidirectional ply with an inclination in the fibre direction. The exact value of stiffness reduction strongly depends on the material properties and the lay-up of the laminate. For InfraCore skins, the stiffness reduction is very small (0.15%). Due to the inclination in the plies, the lay-up of the laminate differs along the length of the plate. As a result, the output of the modified CLT is only applicable to one location along the plate. Due to the lay-up differences, the equivalent stiffness will also differ along the inclination direction. The in-plane equivalent stiffnesses will be the highest for symmetric laminates, where the flexural equivalent stiffness will be the highest when the plies with the stiffest fibre direction are located on the outside of a laminate.