We have a duty as kaitiaki to share knowledge; we are in a climate emergency.

We must make the lowest-impact decisions accessible. However, detailed calculations of embodied GHG emissions are required on a case-by-case basis. The lowest-impact options are not always intuitive, nor able to be linearly scaled across parameters. For example, there is no single “lowest emission pipe material” because this varies across diameters and pressure classes. Or, when comparing trenchless methodologies to trenched, the emissions are dependent on a range of project-specific parameters. Much like cost estimation, there is no “one size fits all” solution for GHG mitigation, therefore detailed assessments are required.

AECOM partnered with Christchurch City Council to develop a user-friendly tool, called the 3 Waters Emissions Estimation Tool (3WEET). The tool automates and standardises emissions calculations enabling quick comparison of design cases. This enables the user to compare installation methodologies, materials, approved suppliers, or even nature-based solutions versus piped networks.

Eliza Cowey


Eliza is a Senior Water Engineer whose design experience focuses on treatment alongside measuring and mitigating GHG emissions, as well as conveyance for wastewater, stormwater and water supply. She has an additional role as an ‘ESG Influencer’ embedding positive environmental and social outcomes throughout projects while honouring mātauranga Māori.
Concurrent Session B

Kaitiakitanga | Rua

Wednesday 22 May