NORTHERN MAIN DRAIN STORMWATER MODELLING AND WATER RESOURCES REPORTING
Perth Airport Pty Ltd
Water Resources Reporting
Optimisation of Stormwater Detention
Perth Airport Pty Ltd (PAPL) plays a significant role in the Western Australia (WA) economic, social and cultural activities by facilitating travel and employment, connecting people and places, providing support for communities.
PAPL has recently completed over a $1 billion capital works program. A new wave of investment over the next decade includes investment in a new runway, a significant expansion of the International Terminal, and the consolidation of the Qantas services into the Central Terminal Precinct.
Currently, PAPL is assessing the development of the Airport North Precinct (ANP) as described in the Perth Airport Master Plan 2020 (PAMP). As part of the development, the Northern Main Drain (NMD) needs to be upgraded to a higher standard with storage areas added to detain runoff from proposed aeronautical and non-aeronautical developments on the estate.
The NMD is located north of the Terminal 1 (T1) area and runs along the northern boundary of the ANP. The proposed development will cover an area of 277 hectares.
PAPL required an expert analysis and optimisation of land required to detain the stormwater runoff and prevent flooding from a 1% Average Exceedence Probability (AEP) rainfall event.
Thus, PAPL commissioned 360 Environmental Pty Ltd (360) to undertake hydrological and hydraulic modelling of the NMD and proposed associated stormwater detention for a range of rainfall events.
Subsequently, 360 was engaged to prepare a water resources report to identify the hydrological regime of the site and analyse the potential implications of the proposed development on surface water, groundwater and wetland resources on and adjacent to the site and identify measure to mitigate the impacts.
Due to time and budget constrains, a detailed hydrological and 1-dimensional (1D) hydrodynamic drainage model was developed to assist in the assessment of the development.
The modelling was completed to determine the land area required for the NMD upgrades and associated detention storages.
Several recommendations were made.