What are the effects of chemicals frequently used by Melbourne Water along waterways on aquatic ecosystems?

Understanding ecological risks from pesticide spraying activities on or near waterways and suitable management alternatives 

Background

This project seeks to understand the environmental risks of chemicals used by Melbourne Water on or near waterways, as well as potential alternatives. Melbourne Water manages diverse and complex environments. Vegetation management in these areas is essential to protect local biodiversity and maintain assets. Herbicides, particularly glyphosate, are used in vegetation management globally, however, growing concern about the potential risks of glyphosate has led Melbourne Water to reassess the risks of glyphosate use and investigate reduction opportunities. This work will inform Melbourne Water’s herbicide use policies and practices and support obligations under the EPA Act General Environmental Duty. This project continues to evolve from A3P1.

Approach

This research will be delivered in two studies. Year 1 will focus predominantly on Study 1, with some initial data synthesis around spraying activities at Western Treatment Plant also undertaken for Study 2. Year 2 would then focus further on Study 2.

Study 1: Assessment of alternative instream vegetation management activities in Westernport 

Complementary assessments of the impacts of alternative management practices, identified by Jacobs, to waterway health will be undertaken. Measurements may include chemical concentrations in water and sediments and assessments of biological measures e.g.: macroinvertebrates, functional bioindicators. 

Study 2: Assessment of risks from herbicide spraying to waterway health and environmental values at Western Treatment Plant