There is created a fund to be known as the "payroll fund," into which fund there may be placed from time to time such amounts from any funds available as the city council shall in its discretion direct, and upon which fund warrants may be drawn and cashed for the purpose of paying any moneys due city employees for salaries and wages. Appropriate accounting records shall be kept to show the department or departments and the various amounts to which payments from the payroll fund are properly chargeable.