It is hereby declared to be the policy of this State that each housing authority shall manage and operate its housing projects in an efficient manner so as to enable it to fix the rentals for dwellings at the lowest possible rates consistent with its providing decent, safe and sanitary and affordable dwellings, and that no Housing Authority shall construct or operate any project for profit, or as a source of revenue to a city, village, incorporated town or county. To this end an Authority shall fix the rentals for dwellings in its projects at no higher rates than it shall find to be necessary in order to produce revenues which (together with all other available moneys, revenues, income and receipts of the Authority from whatever sources derived) will be sufficient (a) to pay, as the same becomes due, the principal and interest on the bonds of the Authority; (b) to meet and provide for the cost of maintaining and operating the projects (including the cost of any insurance on the projects or bonds issued therefor) and the administrative expenses of the Authority; (c) to create (during not less than the ten years immediately succeeding its issuance of any bonds) a reserve sufficient to meet the large principal and interest payments which will be due on bonds in any 2 consecutive years thereafter, and to maintain a reserve; and (d) to create a reasonable reserve solely from any contributions or grants to the Authority from the federal government, the State, or any political subdivision of the State for the purpose of meeting the cost of maintaining and operating the project and of paying the principal and interest on its bonds. The management of low-rent public housing projects financed and developed under the U.S. Housing Act of 1937, as now or hereafter amended, shall be in accordance with the provisions of that Act. The provisions of this Section 24 shall not apply to any project undertaken pursuant to the additional powers conferred in Section 8.2 upon housing authorities in any municipality or county having a population in excess of 1,000,000.