Modelling the solution to a local river’s pollution problems

The first pipes in Launceston’s combined drainage system were installed in the 1860s, which means the oldest network parts are now over 130 years old.

In northern Tasmania you’ll find the city of Launceston, perched on the banks of the North Esk and Tamar rivers. It’s home to the last combined storm water and sewerage drainage system of any significant size still operating in Australia. Launceston’s communities believed that this system, plus its overflows into the Tamar river, were responsible for the majority of the river’s pollution problems.

To understand the impact of the drainage system on its surrounding environment, a long-term strategy was developed that focused on understanding the frequency, extent and environmental impacts of the overflows. It also examined potential upgrades to the system to lessen the risks of the issues raised.

A strongly stakeholder-focused strategy ensured that key stakeholders were engaged throughout the process and able to have their say on findings and proposed upgrades. Workshops were run, and regular communications shared.

In the end, TasWater received clear evidence that the combined system overflows were not the key contributor to river pollution. This meant that what was initially a popular option within the local community (separating the combined stormwater and sewerage system) was passed over in favour of more cost-effective options.