In addition to the powers conferred upon a housing authority created for a city or county or a regional housing authority by other provisions of law, such authority, in any contract for annual contributions with the federal government, may obligate itself, which obligation shall be specifically enforceable and shall not constitute a mortgage, notwithstanding any other laws, to convey to the federal government the project to which such contract relates, upon the occurrence of a substantial default with respect to the covenants or conditions to which such authority is subject. Such contract may further provide that in case of such conveyance, the federal government may complete, operate, manage, lease, convey or otherwise deal with the project in accordance with the terms of such contract. Any such contract shall require that, as soon as practicable after the federal government is satisfied that all defaults by reason of which it shall have acquired the project have been cured and that the project will thereafter be operated in accordance with the terms of the contract, the federal government shall reconvey to such authority the project as then constituted.