Emergency call-outs about domestic violence have soared by a third in just over 2½ years, with police attending almost 40,000 incidents in WA last year.
Officers found evidence of crimes committed in 15,065 of those incidents.
Alcohol abuse, mounting financial pressures and the growing use of amphetamines were to blame for the increase in the number of domestic violence incidents, according to the WA Police Union.
Police attended 39,297 domestic violence incidents last year, compared with 30,933 in the year to March 2009 and 35,027 in 2010.
Det-Sgt Ryan Murphy, from WA Police's family violence State co- ordination unit, said population growth and community awareness of domestic violence were behind the increasing number of reports.
"Most assaults against women, where the victim knows the offender, go unreported," he said. "The challenge is to find ways of intervening early before the violence escalates."
Det-Sgt Murphy said domestic violence was a police priority because of the impact on vulnerable victims and children who witnessed the crime.
"It is known that many young people have witnessed acts of physical domestic violence against a parent, which is a concern for them, their families and society as a whole," he said.
Russell Armstrong, outgoing president of the Police Union, said the increase in domestic violence incidents was significant but he did not know what could be done.
"It is a crime that's happening in our society and our officers are certainly under pressure because of these terrible assaults and domestic violence," he said.
Mr Armstrong said there were many homes in the metropolitan area that police were going to "constantly" in response to reports of domestic violence.
Supt. Peter Halliday, of the Rockingham and Peel police district, said domestic violence formed a significant part of his officers' workload.
He said there was a continuing problem of some victims not wanting to press charges against their attackers.
In 2010 police brought in a threshold of six emergency call-outs for a victim to try to halt the escalation of violence and reduce demand on resources. Once officers have been called out six times, a file is started and shared with other authorities.
Supt Halliday said the system had helped to involve other agencies, such as the Child Protection Department, in domestic violence cases though in itself it was creating more work for police.