The State of the Service report, released this week, showed six of the territory government's seven directorates faced skill shortages, gaps in workforce capability and difficulty attracting Aboriginal and Torres Strait Islanders, people with disabilities and gender and diversity applicants.

The concerns follow high turnover and shuffling of senior executives in the Barr government's bureaucracy, including light rail boss Emma Thomas' move to head up the combined Transport and City Services directorate, David Dawes departure from the Land Development Agency, Dave Peffer's move from Community Services and the May 2016 axing of three senior executives in the former TAMS directorate.

The report found:

One directorate said its problems retaining senior public servants with specialist skills was attributable in part to the age profile and retirement factor of these employees.

To counter the problem, public servants identified the need to more effectively target succession planning among staff and provide better leadership capacity building.

The Community Services Directorate said it faced challenges attracting and retaining health officer employees, in part due to the increased demand on the services of Child and Youth Protection Services.

It has moved to pay employees above base salary when they start in the roles, better manage advancement and recognition opportunities and provide improve study assistance.

The directorate is conducting bulk recruitment rounds to attract a broader field of applicants and has improved screening of applicants.

The average age of ACT public servants was 42.5 years in 2016-17, with an average length of service of 8.8 years.

Its workforces makes up 10.1 per cent of the local labour force, totalling 21,791 people, an increase of 531 people since 2015-16.

Permanent jobs grew by 233 positions to 16,534, with 3785 temporary employees and 1472 casual.

The 30 to 39 years age group represented the largest share of the workforce at 26.1 per cent, followed by employees between 40 and 49 at 25.8 per cent.

A further 22 per cent of staff were aged 50 to 59, while 17.1 per cent were 29 or younger and 9 per cent were 60 or older.

Women represent 64.9 per cent of ACT public servants, while people from culturally and linguistically diverse backgrounds make up 18.2 per cent.

Just 2.3 per cent have a disability and 1.6 per cent are Aboriginal and Torres Strait Islanders.

The report found a gender pay gap of 3.1 per cent, down by 0.5 per cent since June 2016.

As of June, the average salary of women employed by the ACT was $89,356, compared with the average salary of men was $92,170.

Womens' average salary has increased by 14.9 per cent since June 2013, while mens' salaries have grown by 14.3 per cent in the same period.

Over the five years, overall average salaries have increased by 14.7 per cent, and average salaries are about equal to the ACT average of $90,844 in November 2016.

ACT public servants are paid about $10,000 more than the average salary of average Australian workers.

"It has been identified that gender pay gaps are lower in those organisations with higher representation of women in executive leadership roles," the report said.

"This is certainly the case for the ACTPS with 44.7 per cent of the Senior Executive Service being women. It is important to note that in the ACTPS, women and men doing the same job receive the same remuneration."

From June 2013 to June 2017, the average salary for female employees increased by 14.9 per cent, slightly higher than the increase for average ACT public servants during the same period.

"The average salary of female employees continues to sit slightly under that of the average ACTPS salary, a trend that is likely attributable to the proportionally larger number of female employees choosing part time work across the ACTPS," the report said.