The park, which was first pitched by Canberra Aqua Park in 2018, will be set up on the lake and at Black Mountain's peninsula from November this year until April 2020.

The obstacle course is set to include tunnels, bridges and slides.

"The addition of this summer activity on Lake Burley Griffin is a welcome one," National Capital Authority chief executive Sally Barnes said.

"The [authority] is keen to see more community use of Lake Burley Griffin and this trial along with the hopeful reactivation of the pedal boats on the lake in the future, will continue to activate the lake for locals and visitors to our fabulous national capital.

"This is a trial and we recognise the community's views and we'll continue to work with the Canberra community and stakeholders that utilise this part of the lake for sporting and recreational purposes to ensure that this site is managed for multi-use."

The authority's public consultation report about the project cited a total of 123 submissions; 25 which were in favour of it, and 34 which supported it but would rather it in a different location.

Another 63 submissions opposed the proposal, with some of the key complaints being about poor water quality, insufficient parking and amenities, ecological and environmental impacts, and a clash with organisations who use the site for events, such as Triathlon ACT. One submission was an advertisement.

"The aqua park will occupy a small portion of the water surface area within the buoyed swimming beach which leaves the majority of space open to public use or other events, including access to the additional fenced children's area," a response from the authority read.

"Based on previous event approvals, and information provided to the [National Capital Authority] Events team from organisations, Triathlon ACT have never incorporated their swim leg in the buoyed swimming area of Black Mountain peninsula, with the exception of the children's swim leg that was undertaken once in 2018."

Executive director of Triathlon ACT, Craig Johns, is disputing the claims. He said the organisation would consider them further over the next few days.

"There's obviously a number of things in there which we would question around the evidence they provided, a number of it which we know is inaccurate in regards to the number of events Triathlon ACT have had there, and also an area at Acton Park," he said.

"It hasn't been approved by ACT government yet - that process for the land still has to go through - but for us we're trying to figure out how we adapt to a changing environment for triathlon."

The report cited additional feedback in support of the park that was left on an article in The Canberra Times; it led to more exposure about it on social media, it said.

The authority was advised by Transport Canberra and City Services that there was enough parking at the site to accommodate all park users, but an overflow carpark would be considered if necessary.

Other sites that were considered for the inflatable attraction included Weston Park, Molonglo Reach, Grevillea Park, Bowen Park, West Basin, Lotus Bay, and Yarralumla Bay.

Canberra Aqua Park's director, William Yeap, told The Canberra Times in May that the attraction would cost about $250,000 to set up and operate. The ACT government and National Capital have not provided any money towards the venture, but will be required to approve various licences to allow it to go ahead.

"We've seen other parks like this in places like Melbourne and I think it's a great way to promote a healthy lifestyle," Mr Yeap said.

With Dan Jervis-Bardy