Morland Development Co., Inc., and New-comb Cleveland (appellants) own a tract of land within the corporate limits of the City of Tulsa (appellee or City). Appellants’ land is situated in the flood plain of Mingo Creek, an area subject to periodic flooding. Prior to February 2, 1973, appellants’ land was zoned CS, light commercial, a zoning which permitted appellants to conduct landfill operations.
In 1970, City enacted comprehensive Floodway Zoning Ordinances. In reality, these comprehensive ordinances zoned no land but established the public purpose and procedure for specific floodway zoning. The specific zoning was accomplished by subsequent ordinances referred to as Flood-way Supplemental Districts (FD). On February 2, 1973, the FD zoning affecting appellants’ property was enacted by the City. Under this FD zoning appellants were not permitted to continue their land-fill operations without the approval of the city engineer. However, appellants continued to conduct their land-fill operations after the FD zoning was enacted without securing the engineer’s approval.
In 1975 City commenced proceedings to enjoin appellants from continuing their land-fill operations in violation of the FD zoning ordinance. Appellants, in their answer and counter claim and amendments thereto, requested the court to declare the FD zoning unconstitutional and unenforceable. Appellants also placed in issue the validity of the ordinance as to their property because City failed to give proper notice *1257of the “change” of zoning as prescribed by 11 O.S.1971, § 405.1
The facts were submitted to the trial court without any material dispute and both parties filed motions for summary judgment. The trial court granted City’s request for a permanent injunction, and appellants appealed.
Appellants first contend that the FD zoning ordinance was invalid and unenforceable against their property because City failed to comply with the notice requirements of section 405. City contends that the notice requirements of section 405 are not applicable but that 11 O.S.1971, § 404, prescribes the necessary notice in these proceedings. Section 404 provides:
“The legislative body of such municipality shall provide for the manner in which such regulations and restrictions and the boundaries of such districts shall be determined, established and enforced, and from time to time amended, supplemented or changed. However, no such regulation, restriction or boundary shall become effective until after a public hearing in relation thereto, at which parties in interest and citizens shall have an opportunity to be heard. At least fifteen (15) days’ notice of the time and place of such hearing shall be published in an official paper or a paper of general circulation in such municipality.”
Section 405, supra, provides in part:
“Regulations, restrictions and boundaries of cities and incorporated towns may from time to time be amended, supplemented, changed and modified or repealed. .
In addition to the notice provided by § 404 of this title, notice of public hearing of any zoning change shall be given by mailing written notice * * * to all owners of property within a three-hundred-foot radius of the exterior boundary of the subject property * *
It is conceded that City complied with the notice requirements of section 404, but no written notice was mailed to appellants as prescribed by section 405. The trial court found that the record did not show there had been a “change” of zoning within the meaning of section 404, and therefore written notice to appellants was not necessary.
City argues that the creation of an expansive floodway zoning area, encompassing many square miles, is the institution of a new comprehensive zoning plan, thus falling under the notice provisions of section 404. Additionally, City points out that compliance with the notice provisions of section 405 which would require written notice to all affected land owners would be costly, time consuming and generally cumbersome to implement.
A fair reading of sections 404 and 405 indicates the Legislature intended that zoning in most instances would be a two-step procedure. First, a comprehensive zoning plan would be adopted which would be a matter of general public interest. For a comprehensive plan, section 404 provides for notice to the public at large by publication. This plan, in the area of floodway zoning was first adopted by City in 1970. Under the guidelines therein established, the second phase of the zoning came into being, i. e., separate Supplemental Flood-way Districts were created. In February, 1973, City enacted the specific Supplemental Floodway District which rezoned and changed appellants’ land from CS to FD. Appellants’ land-fill operation did not violate City’s zoning ordinance until this FD zoning ordinance was adopted. Under the new ordinance appellants could not conduct their operation unless their plans were approved by the city engineer.
Section 405 provides that in addition to the notice provided by section 404, “notice of public hearing of any zoning change *1258shall be given by mailing written notice * * * to all owners of property * We hold that the enactment of the FD zoning order constituted a “change” of zoning and that the notice provisions of section 405 were applicable. The admitted fact in the ease at bar is that no written notice of the proposed “change” of zoning was given to appellants. In the absence of such written notice the ordinance may not be enforced against appellants’ property.
In O’Rourke v. City of Tulsa, Okl., 457 P.2d 782 (1969), we held that an aggrieved party may challenge the constitutionality of a zoning ordinance by petition in the district court without first exhausting his administrative remedies. It is admitted appellants did not seek any administrative relief. Although appellants’ argument that the ordinance is invalid because of improper notice is not premised on a constitutional infirmity, it does attack the validity of the ordinance itself. As a prerequisite to the City receiving the requested injunctive relief there must be a valid ordinance prohibiting the activities of the appellants. This notice argument goes to the validity of the ordinance, and appellants were entitled to show that invalidity without seeking administrative relief.
On the basis of the undisputed facts, the specific ordinance zoning the appellants’ property as FD was not enacted according to the required statutory notice, and the trial court’s judgment in favor of City is in error. Appellants were entitled to summary judgment and injunctive relief from enforcement of this invalid ordinance.
Although raised by Amicus Curiae, this Court will not address the issue of whether a municipality has authority pursuant to the Oklahoma statutes to enact flood plain zoning. Amici Curiae must accept the issues as made and cannot raise constitutional questions not presented by the litigants. Davis v. McCasland, 182 Okl. 49, 75 P.2d 1118 (1938); State v. Ford, Okl., 434 P.2d 934 (1967).
CERTIORARI GRANTED: DECISION OF THE COURT OF APPEALS VACATED; ORDER OF THE DISTRICT COURT REVERSED; AND CAUSE REMANDED WITH INSTRUCTIONS TO GRANT REQUESTED RELIEF TO APPELLANTS.
LAVENDER, C. J., and HODGES, DOO-LIN, HARGRAVE, and OPALA, JJ., concur. BARNES, J., concurs specially. WILLIAMS, J., dissents.. Although our statutes in reference to zoning have been amended since 1971, the 1971 zoning laws govern the issues presented here.