The board annually shall cause to be prepared a written report stating the reasons for and conclusions of the board upon the following, together with any additional information deemed by the board to be relevant to such conclusions:

1. (a) The amount of the total debt service payable by the district for the following fiscal year on any bonded indebtedness incurred pursuant to this chapter, and the estimated maintenance and operation costs of the improvements for such fiscal year.
2. (b) The amount of such total debt service and maintenance and operation costs proposed to be raised in each of the improvement districts established under the provisions of this chapter, in accordance with the estimated benefits to be received by the landowners, water users, and inhabitants of each such improvement district during the following fiscal year.

3. (c) The projected retail water sales within each such improvement district for the following fiscal year, stated by volume and anticipated revenue.

   Such report shall be mailed at least 20 days before the hearing provided for in Section 72074 to (1) each retail water purveyor with a service area wholly or partly within the district, and (2) any other interested party having made written request therefor at least 20 days before such hearing.