Stage one of Canberra's Boundless National Children's Playground is on track to open in June, thanks to strong community, public service and government support, its organisers have said.

Boundless board member Kristen Connell said the project was being developed in three stages and, once complete, would be a public asset worth about $4.5 million.

The first stage, which includes constructing all the underground services and other infrastructure, is the most expensive at $2.8 million.

Ms Connell said early completion of stage one had been made possible by the ACT government advancing loans of $2.5 million.

''The ACT government, like Boundless, doesn't want the people of Canberra to have to wait for years before this is finished,'' Ms Connell said.

''The money is a loan; there is a loan agreement and it will be paid back. It is important for people to realise that they shouldn't stop fund-raising when stage one opens; it still has to be paid for.''

ACT Chief Minister Katy Gallagher has supported the project since its inception. ''The ACT government realises the importance of Boundless Canberra and that is why we have decided to make available this extra funding in the form of a loan,'' she said, announcing an additional $1.5 million last month.

Ms Connell said support, including from within the public service in the parliamentary triangle, had been strong.

''We have only been at this for two years and we have raised $1.2 million [in cash and kind] already,'' she said.

This consists of more than $850,000 worth of donated labour and other resources by the territory building sector; $250,000 in public cash donations, about half of which has come from the public service, and a $50,000 community centenary initiatives fund grant.

The land on which the playground stands, made available at no cost by the National Capital Authority, is literally priceless.

Donations have come in many forms, ranging from a few dollars a child may have saved from their pocket money, to $13,000 cheques from organisations such as the Master Builders Association, which last week donated the proceeds from its annual golf day and dinner.

The need for such a playground was noted more than five years ago by an investigation into the lack of an ''all-abilities'' playground in the territory.

An all-abilities playground is one in which all the equipment can be used by children, regardless of any vision, hearing and mobility impairments or autism spectrum disorders they may have.

Parents of children with disabilities are delighted there will soon be a place where all their children can play in the same place at the same time.

Project manager Franco Frino said until Boundless opens there is nowhere like that for people to go. ''This is a gift to the ACT from the people of the ACT. It is a legacy project, built for the long haul.''