of real estate is enhanced due to the influence of a public improvement and in which a tax is apportioned to recover the costs of the public improvement. Individual special assessment levies may be made only in a S.A.D., which is one of two kinds of geographic areas commonly associated with a special assessment levy. The other kind of geographic area is the "service district". Circumstances vary according to laws of various states, but the essential distinguishing feature between these two types of districts is this: a service district is composed of all individual parcels of land that are somehow connected to the public improvement for which the special assessment is to be levied. The special assessment district consists of only those properties which are designated by the applicable law as having received a specific and unique "benefit" from the public improvement. Examples of properties which may be connected in some way to a public improvement and are therefore included within a service district, but may be excluded from the special assessment district are properties associated with a dam and properties associated with a business parking structure. In the case of a dam ... all properties located within a scientifically defined "watershed" and all properties lying within the floodplain of the dam are connected by how water drains from an entire watershed into a lake and how water within the lake may flood specific areas downstream. Since the area of a watershed and the area of a floodplain are often very, very large when compared to the area of a lake, it is possible for some portions of the watershed and floodplain to be physically located in some government unit other than the lake. It is also possible that the government unit authorizing a special assessment levy does not have jurisdiction to include all land within the watershed and floodplain. In this example, the service district would be large enough to include all properties connected to the lake by how water flows. The Special Assessment District would be a smaller area within which the government unit proposing the special assessment has the power to levy a special assessment tax. In the case of an economic development project (e.g. a parking structure for a business district) circumstances which would cause the service district and S.A.D. to have differing geographic boundaries relates to the existing and permitted use of property rather than