Challenges in Modelling Energy Losses in Hydraulic Structures

Kedan Li (Auckland Council), Jahangir Islam (AECOM)

Increased rainfall intensity and variability due to climate change along with increased intensification in Auckland Region have profound effects on increased risk of flooding and operation of water infrastructure, such as stormwater drainage collection and flood management systems. Hydraulic modelling software such as InfoWorks, MIKE URBAN, MIKE11 are widely used to develop hydraulic drainage network models to assess the effectiveness and performance of the existing drainage systems, and to assist in design and planning for adequate future drainage infrastructure. The primary or formal drainage system comprising manholes, pipes, culverts, bridges, weirs and other hydraulic structures are essential components in most drainage network models. They serve both stormwater conveyance and hydraulic controls and represent key roles in flood risk management. Hydraulic modelling at Auckland Council shows that accurate modelling of hydraulic structures is a challenging issue and one of the major sources of uncertainty across all modelling software.