Upon institution of proceedings pursuant to Section 19160, if the governing body determines that it will be just and equitable and in the public interest for the additional cost, if any, of installation and maintenance of additional lights to be paid by the district as a whole, it shall immediately estimate the cost of installing and maintaining the additional lights, and shall use such reserve funds as may have been accumulated for such purposes to the extent necessary. In the regular tax levy for the first fiscal year in which it is possible to do so, the governing body shall include a tax upon the taxable property within the district at the equalized value thereof, or an assessment on each parcel of real property within the district on the basis of the estimated benefit to the parcel, sufficient to pay the cost of installing and maintaining for one year the additional lights. If sufficient reserve funds are available or will be available from the tax or assessment levy already made, or after the tax or assessment levy has been made, the governing body shall proceed with the installation of the additional lights.