Under the new model, local districts North West and West will merge, covering suburbs from Wembley Downs to Two Rocks.
The North West Metropolitan District will form in December.
It will include Cottesloe, City Beach and Floreat subdistricts from the existing Central district.
Each of the new districts will have a minimum of 500 officers whose roles will be divided into response, local policing teams and investigations.
There will also be a 24/7 District Control Centre that prioritises and develops local strategies.
Police Commissioner Karl O’Callaghan said collapsing the metropolitan area into four districts would reduce the number of administrative positions.
‘We can convert those positions to people on the street which is really what the community wants’