(a)      Except as provided in § 20, all bonds issued by any code county pursuant to this subtitle shall constitute pledges of the faith and credit of the issuing county to the prompt payment, from the taxes and other revenues described in the public local law authorizing such bonds, of the principal of and interest on the bonds when due.

      (b)      If at the time of the issuance of the bonds there is no statutory limit on the power of the code county to levy property taxes, this pledge constitutes a covenant on the part of the county issuing the bonds to levy upon all real and tangible personal property within its boundaries subject to assessment for unlimited county taxation, ad valorem taxes in rate and amount sufficient in each year in which any of the bonds are outstanding to provide for the payment of the principal of and the interest on the bonds.

      (c)      If at the time of issuance of the bonds there is a statutory limitation upon the power of the code county to levy property taxes, this pledge constitutes a covenant on the part of the county to levy ad valorem taxes as above described within the limitations so prescribed by law.

      (d)      No statute adopted or enacted after the date of issue of bonds of the types described in subsections (b) and (c) above, which places a maximum limit on the rate at which property taxes may be imposed by the county, or which removes any limit theretofore existing, shall be taken or construed as impairing or in any manner affecting the covenants of the county with respect to its bonds outstanding at the time the statute becomes effective.

      (e)      No bonds shall be issued by a county pursuant to the provisions of this subtitle, if, by the issuance thereof, existing maximum limits on the power of the county to incur indebtedness fixed by statute shall be exceeded, but no such maximum limitation imposed subsequent to the issue of the bonds shall be taken or construed as impairing or in any manner affecting the obligation thereof, nor shall the obligation of any outstanding bonds of a county be taken or construed as having been impaired or in any manner affected by the issuance of bonds pursuant to an increase in the maximum limitation on the power to incur indebtedness, or the elimination of the maximum limitation, enacted subsequent to the issue of the outstanding bonds.

      (f)      Any code county, in addition to the pledge of its faith and credit and taxing power for the payment of the principal of and interest on the bonds, may secure the payment by the additional pledge thereto of any other revenues of the county, including payments to the county from the State or federal governments and special benefit assessments, taxes, fees, or service charges which the county is authorized and empowered to impose, levy, or charge; and to the extent that the revenues are sufficient in any year to provide for the payment of the principal of and interest on the bonds to which they are pledged, the county shall not be obligated in that year to levy property taxes also pledged thereto; and the failure of the county to levy such property taxes, so long as the additional revenues are sufficient to satisfy the pledge, shall not be taken or construed as a breach of any of the above-described payments of the county.