The Suburban Land Agency's board raised the concerns during a meeting in May this year, where it also war-gamed risk mitigation strategies to try to meet the government's profit target while meeting the growing indicative land release program.

Minutes from the May meeting show the board identified a number of risks to the delivery of the $2 billion over four years Mr Barr, as Treasurer, has directed the land agency deliver to the government's coffers.

Among the risks detailed in the minutes were the ability of the agency to actually deliver an accelerated land release program, the market appetite for blocks in each of the precincts earmarked for release and the price impact and associated revenue impact of over-supply.

In the months leading up to the territory budget in June, the government set the controversial four-year revenue target, along with profit margins exceeding 40 per cent in some years, but it also expanded its land release program.

The indicative land release program expanded from the 2016-17 four-year target of releasing 4000 residential blocks around the city to a new target of 4250 over four years in the 2018-19 target, and the agency's board is concerned the added supply could reduce its ability to meet Mr Barr's revenue target.

The board also examined potential issues that may arise during the next four years of land releases in the territory, where the land agency is reliant on other service providers, such as under-grounding power lines and water reservoirs.

While it examined several potential strategies to mitigate against the risks, and meet the new targets, the board ultimately decided in May it was too early to commit to any of the strategies discussed, instead opting to monitor progress and re-examine the issue in the future.

Mr Barr has publicly pledged the new agencies, which replaced the scandal-plagued Land Development Agency last year, would usher in a new era of transparency around the government's land dealings.

But the agency would not answer The Canberra Times'  questions about what the specific risk mitigation strategies the board considered were, nor the exact details of the board's concerns about the land release program and profit margins.

The minutes do show the board decided to ensure the land agency, when providing budget statements to Treasury in the future, to clearly identify the risks to meeting any revised targets.

That would include, the minutes show, the likelihood of the agency being able to deliver the proposed land release program in full, and the likelihood of significant costs and resource increases for the agency to deliver the new program.

The board also considered an additional risk from the potential impact of market forces and matters beyond the agency's control, likely infrastructure-related issues, "that may significantly impact on meeting the delivery timeframe".

An agency spokesman said it was not able to discuss its advice to government on matters associated with the budget process, and its role was to deliver the government's annual land release program.

He said the agency and the government worked closely in the lead up budget to determine the land release program for the next four years and it was important that risks and mitigation strategies were identified to allow targets to be adjusted.

"The [agency] will continue to closely monitor market conditions, release timing and development activity during 2018-19 and the [agency] remains on track to deliver against future targets as listed in the indicative land release program," he said.