ORS 267.310

For the purpose of establishing a revolving fund to provide money to finance the planning and construction, acquisition, purchase or lease of a mass transit system, a district board may levy an ad valorem tax of not to exceed in any one year three-twentieth of one percent (0.0015) of real market value of all taxable property within the district. The revenue derived from such taxes shall be credited to a revolving fund, and shall be disbursed by the district board and used only for the purpose for which levied.