Resilient Infrastructure Case Studies in the Scenic Rim

Abstract

The Scenic Rim Region experiences frequent severe weather events including floods and storms. Over the last 15 years, the region has been activated under NDRRA and DRFA over 20 times, and total damage to Council assets has reached the $100s of millions. Council manages a network of nearly 1,000km sealed and 800km unsealed roads, 130 bridges, 260 floodways and 244 major culverts. The region has over 1,000 points of intersection with identified streams or waterways and an estimated 6,000 plus locations where water may cross a road during intense rainfall, each with varying degrees of immunity and vulnerability. As well as residential access, this road network is the ‘first and last mile’ of the freight network for a wide range of agricultural products. During and following an event, road closures result in risk of injury or death, but also prevent access by residents, businesses and visitors to their homes, places of work and access to services. This results in significant social and economic impacts on the region. As assets are replaced, designs aim to reduce the risk of inundation such as through lifting bridge decks, realigning sections of road or improving drainage systems, but there are many roads and structures in the region where the risk of inundation will never be removed due to cost and topography constraints. Over many years, Council has developed designs, details and technical standards which have enhanced the resilience of Council’s assets, in order to continue to provide a local road network which aims to meet Council’s target of an ‘accessible and serviced region’ providing access to all parts of the region for residents, businesses and visitors. There are often also cost efficiencies in maintenance during non-disaster periods. These innovations have been workshopped with technical and operational personnel, performance has been monitored in the field, and partnerships with universities have been established to study outcomes. These resilient infrastructure designs focus on reducing the frequency and duration of road closures, as well as reducing the work required to reopen a road following an event. Reducing the frequency of closure enables residents, businesses and visitors to continue to move around the region. Reducing the duration of closure reduces the social and economic impact of the flood event on the region’s community. Strategies include incorporating scour resistant pavement materials, rock armour, cut off walls, and designs to reduce the impact of debris. This presentation will detail a number of case studies of assets which incorporate resilient infrastructure.