Help us protect Tasmanian waterways and parklands

Keep stormwater out of sewer

We live in one of the most beautiful parts of the world and our environment is particularly close to our hearts. Tasmania is home to some of the most stunning waterways and parklands and it is important that we all do our bit to protect the environment.

Stormwater inflow and infiltration

Our sewerage network is not designed to manage the inflow and infiltration of stormwater during rainfall.

Inflow is where stormwater enters the sewerage network, generally via private plumbing that is incorrectly connected to the sewer.

Infiltration is stormwater entering the sewerage network, generally by seeping through cracked, or unsealed underground infrastructure.

Below is a diagram that shows a correctly plumbed and incorrectly plumbed property.

Stormwater out of sewer

The effect of inflow and infiltration

When the amount of stormwater entering the sewerage network exceeds the network's capacity, there is potential for the following:

  • overflows to creeks, rivers and parklands
  • increased risks to the health of our waterways and local environment
  • increased sewage pumping and treatment.

Recent activities

Triabunna

Investigations of Inflow and Infiltration issues in Swansea and Triabunna discovered fifteen sewer maintenance holes with unsealed lids that were at, or below the level of the surrounding ground. These unsealed lids were a source of stormwater inflow into the TasWater sewer network during rain events, as pooled water on the surface entered via the lid. These photos show a maintenance hole in Triabunna having the old lid replaced with a new lid that sits proud of the ground level, preventing water from entering during rain events.
Recent manhole works at Triabunna
Recent manhole works at Triabunna
Recent manhole works at Triabunna
Triabunna works
Triabunna works