It is the policy of the state that a housing authority manage and operate its housing projects in an efficient manner to enable it to set rentals at the lowest possible rates consistent with providing decent, safe, and sanitary housing and that a housing authority may not construct or operate a project for profit or as a source of revenue to a municipality or county. For this purpose, an authority shall set rentals at a rate not higher than the rate necessary, together with other available money, revenue, income, and receipts, to produce revenue that is sufficient to:
(1) pay the principal and interest as it becomes due on bonds of the authority;
(2) meet the cost of and provide for maintaining and operating the projects, including insurance;
(3) pay the administrative expenses of the authority;
(4) create, to the extent determined necessary and advisable by the authority, a reserve for the bonds and to maintain the reserve; and
(5) create, to the extent determined necessary and advisable by the authority, a capital and improvements fund to be used by the authority to accomplish the public purposes of this chapter.