At least half of Australia's special intake of 12,000 Syrian and Iraqi refugees will be settled in one part of western Sydney within 12 months, prompting community leaders to plead for more federal government support to deal with the unusually high intake.

Fairfield City Council, which welcomed 3000 humanitarian arrivals from the two war-torn countries in 2016, has been told by the Department of Immigration and Border Protection to expect the same again. Overall, the council area took in triple their usual annual humanitarian intake last year.

Stephen Bali, the president of the Western Sydney Regional Organisation of Councils and mayor of nearby Blacktown City Council, said local governments need to be properly equipped to meet their settlement and social cohesion responsibilities.

Mr Bali called for detailed demographic information "to ensure councils are investing their efforts in the right kinds of services".