§ 1561. Imposition of tax. Notwithstanding any other provisions of law to the contrary, any designated community, acting through its governing body, is hereby authorized and empowered to adopt a local law imposing in such designated community a tax on each conveyance of real property or interest therein where the consideration exceeds five hundred dollars, at a rate of up to two percent of the consideration for such conveyance; any such local law shall fix the rate of such tax. Provided, however, any such local law imposing, repealing or reimposing such tax shall be subject to a mandatory referendum pursuant to section twenty-three of the municipal home rule law. Such local law shall only be submitted for the approval of the electors at a November general election. In addition to the filings required pursuant to article three of the municipal home rule law, the local law shall be filed with the commissioner within twenty days of its approval by the electors. Notwithstanding the foregoing, prior to adoption of such local law, the designated community must establish a community preservation fund pursuant to section six-s of the general municipal law. Revenues from such tax shall be deposited in such fund and may be used solely for the purposes of such fund. Such local law shall apply to any conveyance occurring on or after the first day of a month to be designated by such governing body, which is not less than sixty days after the enactment of such local law, but shall not apply to conveyances made on or after such date pursuant to binding written contracts entered into prior to such date, provided that the date of execution of such contract is confirmed by independent evidence such as the recording of the contract, payment of a deposit or other facts and circumstances as determined by the treasurer.