Urban Drainage Infrastructure Planning and Design Considering Climate Change

Climate change is a reality that planners and designers of drainage infrastructures must consider. The cumulative effects of gradual changes in hydrology due to climatic change are expected to alter the magnitude and frequency of peak flows over the service life of drainage infrastructure. Potential future changes in rainfall intensity are expected to alter the level of service of drainage infrastructure, with increased rainfall intensity likely resulting in more frequent flooding of storm sewers and surcharging of culverts. The expected effects of climate change necessitate a change in the approach used to plan for and design drainage infrastructure. New development should ideally be served by both a minor storm drainage system, such as a traditional storm sewer system, and a major overland storm drainage system designed to convey the excess runoff when the capacity of the minor system is exceeded. The planning and design of new drainage infrastructure should incorporate development features and sustainable urban drainage systems that provide multiple benefits (such as a reduction of localized urban flooding and harmful environmental impacts). Modifications to existing drainage infrastructure in existing development is complicated by the integration of the minor drainage system with other infrastructure and a lack of space for the construction of major drainage system components.