An "ad valorem" tax is based upon the legal principles of equity and uniformity. That is, everyone must be treated fairly and equally. In special assessments, proportionality is a key element. A special assessment is premised upon the necessity for the public improvement and the fiscal burden imposed must be reasonably proportional to the benefit created. Unlike "ad valorem" taxes,special assessments are not expected to be uniformly levied (the same millage rate for each parcel). The fiscal burden is spread among only those properties within the special assessment district and it is apportioned to each property based upon the unique, specific and direct benefit the property received from the public improvement. Thus, a vacant lot might be assessed the same fee as an adjacent lot which has a million dollar home on it. For example, both the vacant lot and the property improved with a million dollar home, might be assessed Five Thousand Dollars ($5,000.00) for a sewer connection. So, while both properties have identical $5,000 special assessment obligations because sewer installations have been specially assessed, there will be a huge difference in their "ad valorem" tax levies; one "ad valorem" levy will be based upon the value of a vacant lot and the other will be based upon the value of the lot plus the million dollar home.