Water sampling goes auto

A new approach to water quality monitoring could be a game-changer for how we manage catchments in the ACT and region.

Automated equipment is being installed at 11 sites across the region to take water samples during that first flush of rain when the bulk of the contaminants – like sediment, phosphorous and nitrogen – are washed into our waterways.

Why is this significant? Water Scientist with the ACT Government, Dr Danswell Starrs, explained that the unpredictable nature of storms means there is a gap in the data collected by various government agencies and volunteers.

“To really understand the nutrient load in stormwater, we need to sample at the start of a storm or downpour when pollutants are moving off the land and into the water. Rain events are often unpredictable and short-lived which makes the manual collection of samples during that first flush really challenging,” said Starrs.

The samples collected using the new automatic sampling (during event flows) will be combined with those collected manually (base flows) to provide a more accurate picture of the overall quality of the water that flows into our creeks and waterways.

But there’s more to it than that, as Starrs explained:

“We also want to measure how different types of land use affect water quality and to what extent. The stormwater running off conservation areas like Namadgi National Park is, of course, cleaner than the run-off from commercial or industrial areas in the city but we don’t yet have the detail to really understand those two extremes and everything in between.”

As a result, locations for the automatic sampling equipment have been carefully chosen to ensure the full range of land uses is covered: conservation areas, rural grazing land, urban, residential, commercial and industrial areas as well as new developments.

The final step is to create models, bolstered by improved data, to help us understand how our waterways are likely to respond to changes in land use.

“With the right data and the right software, we can predict the likely effect of land use and water management decisions on water quality before we make them,” said Starrs.

This work is funded by ACT Healthy Waterways, a joint Australian and ACT government initiative to improve the quality of water entering our waterways and flowing downstream into the Murrumbidgee River system. The wider project also includes the construction of water quality infrastructure - like wetlands, ponds and rain gardens - as well as an education campaign and research trials.