To defray the cost and expenses of required and necessary services rendered by the offices of the Director of Finance, the Clerk of Council, the Director of Law and other officers and offices in the planning, preparation, execution and completion of various public improvements, programs and undertakings of various departments of the City, the proper officials shall ensure that the General Fund of the City shall be credited in the amount of three percent (3%) of the total cost of such improvement, program or undertaking, chargeable to the proper department or fund.