The ACT Healthy Waterways Project is a joint initiative of the Commonwealth and ACT governments to improve long-term water quality in the ACT and further downstream in the Murrumbidgee River system.

Part of the Murray-Darling Basin Plan and with a budget of  $93.5 million, the project is 90 per cent funded by the Commonwealth, the remainder by the ACT.

It involves the construction of a range of infrastructure - ponds, wetlands, rain gardens and swales as well as waterway restoration that will prevent harmful runoff as well as solid rubbish from entering the lakes and rivers and reduce the risk of problems such as blue-green algae outbreaks.

The scale of the project is considerable, with Healthy Waterways project manager Justin Foley saying about 1 million water-based plants, alone, will be put in the ground to bring the wetlands and other projects to life.

"It's really the plants which will be stripping out the pollutants, the nitrogen and phosphorous,'' he said.

The big-picture aim is to improve the quality of the water in Canberra's lakes and river systems but the campaign has its roots in the humble gutters and driveways of the national capital's suburbs.

The focus is on improving water quality higher up in the catchment where rainwater becomes stormwater. That means physical infratructure to filter the stormwater, but also a campaign to change the mindset of Canberrans, to help them understand that blowing leaves down the gutter or hosing off the driveway sends pollutants ultimately to our waterways.

The biggest cause of water pollution in lakes and waterways is contaminated stormwater run-off from  streets, house blocks, development sites, retail and industrial areas.  Leaf litter is one of the biggest contaminants, overloading waterways with nutrients, contributing to the blue-green algae outbreaks.

The ACT Government says "every house in Canberra is uphill from our waterways so every drop of water we use as well as all the rainwater that falls ends up in the lakes''.

"We're retro-fitting older suburbs where in the 1950s and 1960s, the focus of stormwater management was on mitigating the risks of flooding,'' Mr Foley said. "But its become clear that we needed to deliver a better water quality outcome and we all have a role to play in that.''

Wetlands under construction at Holder, off Dixon Drive, is one of the 19 projects. The finished wetlands will eventually contain about 2.4 million litrees of water, about the same as an Olympic swimming pool.

Water will be diverted from existing stormwater pipes in the area to the wetlands before flowing into Weston Creek and the Molonglo River.

The stormwater will pass through gross pollutant traps first to collect larger rubbish, collected ultimately by maintenance crews . It will also travel through ponds where sediment will settle on concrete bottoms and be collected and disposed of using a bobcat, likely ending up in landfill. Then the water will pass through the wetlands where plants will filter out the nitrogen and phospherous, before going into Weston Creek, a lot cleaner than it started.

The wetlands will not be filled with water until the plants are established. At Holder, construction is due to finish mid-year but the wetlands won't be fully functional for another two years after that. The wetlands are gravity fed and will be filled by the stormwater, once the timing is judged to be right to open the pipes.

Other projects include rain gardens  which "look like a garden on the surface but have a storage and filtration structure underground that reduces nutrients from stormwater before it enters the drainage system''.

Another major wetlands project is at Isabella Pond in Tuggeranong, which will eventually be stocked with native fish.  Almost 1.6 tonnes of carp were removed from Isabella Pond 12 months ago.

Mr Foley said the projects would also add to the amenity of the areas. Wetlands built in Dickson in 2011 had attracted birds, animals and reptiles and were used by the community for walking, riding and other recreation.

Twenty-one projects have been selected for the funding, 19 infrastucture and two research: