(b) The establishment or extension of a district shall be based upon the district plan filed in the office of the municipal clerk, except as provided in subdivision (c) of this section.

(c) In any city having a population of one million or more, the district plan shall first be submitted to the city planning commission which shall forward a copy within five days to the city council and to the council member or members representing the council district or districts in which the proposed district is located, to the community board or boards for the community district or districts in which the proposed district is located, and to the respective borough board and borough president, if the plan involves properties located in two or more community districts. Each community board shall notify the public of the proposed plan in accordance with the requirements established by the city planning commission, and may conduct a public hearing and submit a written recommendation to the city planning commission not later than thirty days after receipt of the plan. The city planning commission shall review the plan and recommendations, and, after a public hearing, prepare a report. The city planning commission shall submit its report to the mayor, to the affected borough president, to the city council and to the council member or members representing the council district or districts in which the proposed district is located, together with copies of any recommendation of a community board, within sixty days from the date of expiration of the community board's period for reviewing the plan and submitting recommendations. This report shall certify the city planning commission's unqualified approval, disapproval or qualified approval with recommendations for modifications of the district plan. A copy of this report together with the original district plan shall be transmitted for filing with the city clerk. In the event the city planning commission shall fail to submit its report within ninety-five days of receipt of the original district plan, it shall be required to immediately transmit the original plan to the city clerk for filing and no report of the city planning commission shall be necessary.

(d) All district plans shall conform with the requirements of this article. The legislative body may determine that the plan or any part of the plan, shall be prepared by, or under the supervision of municipal officers and employees to be designated by the legislative body, or by persons or firms to be employed for that purpose, provided, however, that in a municipality having a population of one million or more, such determination and designation shall be made by the chief executive officer. Except as otherwise provided in this article, the expense incurred for the preparation of the plan or part of the plan shall be a municipal charge.

(e) If the municipality shall thereafter establish or extend the district or provide the improvements or additional services or contract for the required services, the expense incurred by the municipality for the preparation of the plan or any part of the plan shall be deemed to be part of the cost of the improvement, or the rendering of additional services, and the municipality shall be reimbursed in the amount paid, or the portion of that amount which the legislative body, at a public hearing held pursuant to this article, shall allocate against the district.