(1) All stormwater fees collected by the city shall be paid into an enterprise fund which is hereby created, to be known as the "stormwater management fund". Such fund shall be used for the purpose of paying the costs of operation, administration and maintenance of the stormwater drainage facilities of the city and to carry out all other purposes of the stormwater utility. To the extent that the stormwater management stormwater fees collected are insufficient to construct the needed stormwater drainage facilities, the cost of the same may be paid from such city fund as may be determined by the city council, but the city council may order the reimbursement of such fund if additional fees are thereafter collected. When the fund has surplus dollars on hand in excess of current needs, the surplus dollars will be invested consistent with any applicable investment policy established by the city council.

(2) The stormwater fees and charges paid in accordance with this article shall not be used for general or other governmental or proprietary purposes of the city, except to pay for the equitable share of the cost of accounting, management and government thereof. Other than as described above, the stormwater fees and charges shall be used solely for the purposes stated in paragraph (1) of this section.