NSW Premier Gladys Berejiklian this week gave herself an another two years to achieve the key policy pledge.

Wagga Women's Health Centre founder Jan Roberts said targets were difficult to meet when tackling "deep seated" social issues that take place behind closed doors.

She said a five per cent cut would be a more realistic goal for the city over the next three years.

"I think that most governments, when looking at such long-term and entrenched social issues like domestic violence or domestic abuse, they are much too simplistic in how they approach them," Ms Roberts said.

"I'm not saying their solutions can't help, but they are not tackling the underlying causes to get perpetrators to change their behavior.

"There is research to show that males who have perpetrated violence are likely to re-offend."

The health centre along with Murrumbidgee Primary Health Network established 'DVProject:2650' in February to reduce domestic violence rates by promoting gender equality.

Wagga MP and DVProject:2650 committee member Joe McGirr said he there were technical reasons for the government to delay its target, but he was concerned about the potential message it sent.

"The government has made domestic violence rates and re-offending rates a priority, which is good, but pushing back the deadline concerns me," he said.

"It's because I think it reduces the sense of urgency that we need to address this issue."

Dr McGirr said that the DVProject:2650 was focused on preventing initial offending, rather than re-offending, and was not likely to be impacted by the government's changed deadline.

Wagga's rate of domestic assault has increased by an average of 8.4 per cent per year over the past five years.

Ms Roberts said she was not sure if Wagga had reached the point where the rate of domestic assaults would plateau or fall.

"When there is increased support for women who report domestic violence, we will see more domestic violence being reported," she said.

"I don't know how long this increase will go on. That's one of the problems of domestic violence: it happens behind closed doors."

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In the rankings for worst domestic violence prevalence, Wagga City Council has risen from being in the top 25 per cent of local government areas in 2016 to the top one-fifth.

Dr McGirr said the figures reinforced "that we have an issue here".

"We need to keep making it a focus for the community," he said.

There was a rate of 642 'domestic violence related assault' offences recorded per 100,000 people within Wagga council's boundaries in the 12 months to March, according to the latest Bureau of Crime Statistics and Research.

Wagga's violence rate was about half the rate of areas in the top five, but about double the rate of many other areas in the Riverina and Central West.

The rate of offences being reported has increased by 8.4 per cent while the NSW average remained 'stable'.