Tonkin Hwy Water Monitoring



Arup Pty Ltd

Project Value



One Year

Services Provided


Project Description

Main Roads Western Australia (MRWA) proposed to upgrade a six-kilometre (6 km) section of the Tonkin Highway from south of Roe Highway to Kelvin Road from four to six lanes and to a freeway standard.

A pre-construction water monitoring program was required to establish baseline conditions of the water resources in the vicinity of the proposed works, including groundwater, wetlands, waterways, and open drains.

A baseline water monitoring program is required to identify the water discharges and the receiving water quality conditions before the works commencing.

The section of road proposed to be upgraded is situated within the City of Kalamunda (CoK) and the City of Gosnells (CoG) local government areas (LGA).


The ultimate aim of the monitoring program, be it, pre- or post- development, should be to collect and analyse robust and accurate data to assess the development’s potential environmental impact (or lack thereof).

The best technique to achieve this aim is to monitor locations upstream and downstream of the development. Given the current monitoring, locations will be removed during the project’s construction; new monitoring wells will need to be installed post-construction to monitoring groundwater quality.

Installing these monitoring wells now will allow a direct comparison between pre and post-development water quality data. Robust and comparable data will stand up to scrutiny should any suspected problems be arising from the development in the future. The methodology produced here can also be used to develop and refine monitoring programs for future infrastructure projects.


360 Environmental have completed the first round of the pre-development monitoring program.

The monitoring programme is expected to continue during construction and post-construction to determine the newly established conditions are still in compliance with the licencing requirements.

2021-02-10T12:45:34+08:00February 9th, 2021|