70 ILCS 3710/10

The board of trustees may levy and collect other taxes for corporate purposes upon property within the territorial limits of such water service district, the aggregate amount of which including the tax levied for payment of any bonds issued for each year, shall not exceed .125 per cent of value, as equalized or assessed by the Department of Revenue. The foregoing limitation upon tax rates may be increased or decreased under the referendum provisions of the General Revenue Law of Illinois.