N.Y. County Law § 280-D
A petition may be presented to the governing body requesting that a certain area or areas of the county be established as a county district. Such petition shall be executed and acknowledged on behalf of a municipality or existing district, any part of which is included within such area or areas, by the chief executive officer of such municipality, or of such existing district serving a similar function as the district to be established hereunder. In lieu of execution of the petition by the chief executive officer of such municipality or existing district, the petition may be executed and acknowledged by at least twenty-five owners of taxable real property of record situated within such municipality or existing district. Upon presentation of such a petition or on its own motion, the governing body may direct the agency to cause maps and plans to be prepared for a project as requested in the petition or for the establishment of a certain area or areas of the county as a county district, provided, however, that if the petitioning municipality, existing district or owners of taxable property undertake to furnish or pay the cost of such maps and plans at its or their cost and expense, the governing body shall direct the agency to accept or prepare the same. Such maps or plans shall show (1) the boundaries of the area or areas which the agency in its judgment considers will be benefited by the particular project, (2) a description of the area or areas sufficient to permit definite and conclusive identification of all parcels of property included therein, (3) the proposed location of all dunes, bluffs, bulkheads, dikes, groins, jetties, fills and other works, facilities and improvements, (4) a description of the land or water rights to be acquired, and (5) estimates of the cost of construction of the facilities as shown on the maps and plans and the method of financing the same. Such maps and plans shall be consistent with, so far as possible, any comprehensive plan for hurricane protection, flood and shoreline erosion control developed by the state or national government for that purpose.
If the report of the agency required by section two hundred eighty-e of this article shall contain recommendations for the establishment of two or more zones of assessment within a county district, such maps and plans shall show the boundaries of each of such zones and the estimated initial allocation of the cost of the construction of the facilities recommended to be charged to each of such zones.
Where acceptable maps, plans and related data have theretofore been prepared by or for one or more existing or proposed hurricane protection, flood and shoreline erosion control districts, the governing body may, instead, authorize the agency to adopt and utilize such maps, plans and data and, where a county district is thereafter established and facilities constructed thereby on the basis of such maps, plans and data, the agency shall reimburse the municipalities, existing districts or persons who have paid for all or part of the cost of such maps, plans and data in a reasonable amount to be agreed upon among them, which amount shall not exceed their net expenditures therefor, and shall not include any portion of the cost paid from federal or state aid and which amount, when paid, shall be deemed part of the cost of the construction of the facilities by the agency.
N.Y. CountyLaw § 280-D