"There were people who were there constantly," he told the ABC. "In fact there was a tent pitched." Mr Ord said the problem had existed for 18 months and there had been several attempts to organise alternative housing through the Salvation Army. "The people that were staying there regularly said that they didn't want that kind of support," he said. With the arts centre featuring a dance studio, many users were young females "so our concern was the duty of care for them" and cleaners who were finding themselves "accosted" by homeless people trying to use the toilets, Mr Ord said.

"If this was a situation outside an education facility, I'm sure the public would justifiably ask the Department of Education to try to find a way of finding these people an alternative place," he said. Earlier, the St Vincent De Paul Society described the use of water treatment on vulnerable people in the city as "disgusting". St Vincent De Paul's WA chief executive Mark Fitzpatrick told Nine News on Wednesday homeless people were just looking for somewhere to sleep for the night. "It's disgusting to think we are treating people who are already down on their luck and less fortunate than you and I in such a way, when all they are trying to do is get a safe night's sleep," he said. "It's cold out here this morning and it's going to be bad when the water goes on and someone is sleeping underneath it."

Mr Fitzpatrick called for the "sprinklers", which operate from the second storey of the arts centre, to be pulled down immediately. "We think it's an abhorrent way of actually trying to deal with a problem that is a lot broader than where someone is sleeping at night. So they need to pull them down," he said. "Most homeless people just want to be left alone and find somewhere they can actually feel safe and secure and actually get a decent night's sleep just like anyone else." In a letter obtained by Nine News and reportedly distributed to tenants around the centre by the DCA, the homeless people had been referred to as a "larger than anticipated problem" and "uninvited guests". According to Nine News reporter Scott Cunningham, the DCA's deputy director-general David Ansell had not seen the sprinkler in action until filming for the bulletin.

He initially described it as a misting system but then conceded vision he was shown of it appeared to be something more hefty. "It didn't appear [to be a mist]," he said. "So whether it's malfunctioned or by the time it gets closer to the ground it is a mist, that's something we can investigate." He said the water system, along with timer-controlled lighting, was installed to curb "anti-social behaviour" in Munster Lane, off King Street.

"Things such as smoking implements, alcohol, some urination as well," he said. But Mr Fitzpatrick hit back at Mr Ansell's claims that homeless people were creating problems in the arts precinct. "The majority of people we help in that situation won't be actually creating problems, they want to get away from a lot of people and get somewhere quiet," he said. "It's hard to believe this is the only issue surrounding this. We would love to get some contact from the department so we can actually assist them in dealing with what is a broader issue, rather than putting in something like a sprinkler system. "The solution for different people is different things. What we would rather do in terms of this particular location is come and have a chat to us to start with and we can work out how they can connect with different services that already exist and help people that are sleeping rough on the streets of Perth."

The CEO of Shelter WA, Chantal Roberts, whose organisation offers housing for homeless people, said spraying people sleeping rough was really cruel". "It is totally unwarranted," she said. "There are other ways to deal with homelessness. I didn't thinking laying or sitting in a public place was illegal." Rob Philbrick, who lives on Munster Lane, said the sprinklers were a "little extreme". "The two guys that normally sleep their aren't the problem," he said.

"It's the other guys they attract that are a major problem. I've had to pick up needles and I've had to clean up defecation." Tessa Bontempo, from the Bontempo Investment Group which owns property around the King Street Arts Centre, said neither she nor any staff in the group's Perth office had sighted the letter sent by the department. She said she was appalled by the sprinkler system. "We don't want to see people treated like that," Sydney-based Ms Bontempo said. "We believe a viable solution to the problem, which we previously had suggested to the Perth City Council, is to utilise several of their 32 undercover carparks which generate over $70 million per annum in income to provide shelter for the homeless to sleep in the evenings."

Etro Cafe manager Henry McAlpine said spraying homeless people was not going to solve the issue. "I am slightly apprehensive some of the students might be getting hassled, but they [homeless people] don't disturb me," he said. "The guys that sleep outside are not the issue, it's the associates they attract that are the problem." Ted, who said he had battled homelessness for 15 years, told Nine News he and others who sought shelter in Munster Lane weren't creating trouble. "We sleep here, we don't bother anyone but they've put sprinkers here to get rid of us," Ted said.

The San Francisco Archdiocese was on the receiving end of flack earlier in the year when it was revealed it had installed a similar sprinkler system to deter homeless people from sheltering in the doorsteps of St Mary's Cathedral. The Archdiocese removed the system after the backlash, saying that it recognised the concept was "ill-conceived". - with AAP Follow WAtoday on Twitter