Cal. Gov. Code § 53325.3

A tax imposed pursuant to this chapter is a special tax and not a special assessment, and there is no requirement that the tax be apportioned on the basis of benefit to any property. However, a special tax levied pursuant to this chapter may be on or based on a benefit received by parcels of real property, the cost of making facilities or authorized services available to each parcel, or some other reasonable basis as determined by the legislative body.