Ahead of the bulk of the ACT Healthy Waterways project wrapping up on June 30, project heads are ready to celebrate its success, while researchers are scrambling to consolidate their results.
The largest chunk of the $93.5 million in funding has gone towards Lake Tuggeranong, with a total of seven rain gardens, ponds and wetlands constructed along the catchment at a cost of $30.2 million.
The sites are an attempt at filtering nutrients from stormwater drains to combat the lake's intense blue-green algae problem. An additional two research projects, being undertaken by the University of Canberra, seek to find a long-term solution.
The ACT Healthy Waterways project, which began in 2014, was funded for the most part by the commonwealth government, which contributed $85 million. The territory government contributed $8.5 million.
"At the moment we're madly in the stage of doing a bunch of analysis of our results," lead researcher Dr Fiona Dyer said.
"We've had a series of mesocosms, or big plastic tubes in the lake, and we've been trialing four different things in them."
The team at the University of Canberra are testing three different chemical solutions in Lake Tuggeranong, being "Phoslock", "Diatomix" and hydrogen peroxide.
Phoslock is a type of clay that draws phosphorus, an enabler of blue-green algae, out of the water, while Diatomix adds micronutrients that promote the growth of healthy, green algae instead of blue-green.
Hydrogen peroxide is an antibacterial that could fight against the blue-green algae.
"We've also been shading [the mesocosms] to see how important light is at limiting algal growth within Lake Tuggeranong," Dr Dyer said.
"We hope to have [the results of our tests] earlier than June - some pretty good analysis done by between the middle and end of May."
About $51.9 million from the project went to rain gardens, wetlands, ponds and waterway restoration in Fyshwick, Yarralumla Creek, west Belconnen, and the Molonglo Valley. All sites, including those around Lake Tuggeranong, are expected to be finished by June 2019.
Fyshwick received top-end funding with wetlands on Dairy Road, in Kingston and in Narrabundah, totaling $13.2 million.
The Molonglo Valley was at the low end in terms of infrastructure, with just one wetland built in Holder at a cost of $5 million.
The Healthy Waterways project would finish for the most part on June 30, with the exception of plant monitoring until 2021.
"There have been 20 stormwater assets constructed in six priority catchments in the Canberra area, including in the Lake Tuggeranong catchment, Lake Burley Griffin and Lake Ginninderra," project manager Ralph Ogden said.
"We're going to oversee it for another couple of years and make sure [the plants] get established before we hand it over to the Transport Canberra and City Services Directorate."
Funding for the project also went towards public education campaigns, namely H2OK which promotes "only rain down the stormwater drain", and the citizen science Waterwatch program that saw local volunteers test water quality.
"[The result has been] surprising in the sense that if you go out to a random member of the community at the Canberra Show and ask them if they've heard of the program, many of them have," Mr Ogden said.
"Then it's also in terms of people self-reporting that they've changed their behaviours. That's the end game, that people stop blowing leaves into the drain ... and contributing to the problem of water quality."
A business education program was being planned for sometime before June and would be held at the Master Builders Association in Fyshwick.
Funding for water management once most of the Healthy Waterways project stopped in June would be determined in the ACT budget.
Some strategies could be included in the ACT water strategy, which was from 2014 to 2044, ACT director of water catchment and policy Matt Kendall said.