Case Studies

Assessment Roll Tracker

Providing Real-time tools for local government agencies, allowing them to accurately project their respective agency’s income.


California’s San Mateo County Assessor is responsible for determining the assessed value of all taxable property located within the County. There are approximately 236,000 assessments each year, with a total assessed value topping out at more than $100 billion.


Every local agency (city, school district, special district), as well as the County, itself, relies on the property taxes collected on these assessed values. The Assessor wanted an application that would give local agency fiscal officers real-time access to property tax roll data in order to accurately project their respective agency’s income and thereby make sound budget and policy decisions. Additionally, the new application had to work with the Assessor’s existing hardware, software and databases, as well as meet privacy law compliance standards.


Nimbus Design created the Assessment Roll Tracker (ART) application, comprised of five modules, to meet the challenge. The Land & Improvements Module provides the most critical data – the year-to-date, “real time” assessed valuations of the property within each jurisdiction and the County as a whole, along with comparative prior year roll data. Users can open views that show the secured land and improvement values, the Redevelopment Area (RDA) values and the values net of the RDAs.

The Appeals Module provides a listing of all the properties, by jurisdiction, with open, unresolved appeals before the Assessment Appeals Board (AAB). This allows fiscal officers to track the amount of the assessed value at risk by viewing the Assessor’s valuation, the appellant’s opinion of value and the difference between the two. Critical to budgeting is the Module’s inclusion of an AAB adjustment factor, which is a complex calculation created every year by the Controller’s Office to incorporate the impacts of assessment appeals decisions.

This is a very important feature because the impact of tax refunds based upon an assessment appeal decision is felt countywide; the tax refund is not specific to the location of an appellant’s business or residence. Having the AAB adjustment factor


We are proud to report the Assessment Role Tracker received a standing ovation when previewed to the SAMFOG (San Mateo County Fiscal Officers Group) city managers and fiscal officers. Now that it is in place and works as previewed, the satisfaction of these various governmental agency fiscal officers continues – especially in light of today’s economy.