View Photo(s) of Award Presentation

Project Goal

1. Build and efficiently maintain the most complete, current, and accurate real property data within our CAMA and GIS systems that time and staffing allows including inventory, sales, cost tables, permits, lease, rental, appraisals, structure photos, aerial photography, exemptions, abatements, land use, and data provided to the Assessor by the public during revaluations, valuation protests and throughout the year.

2. Incorporate GIS data provided by other government agencies that may influence assessed values such as the Soil Survey Geographic (SSURGO) provided by U.S. Department of Agriculture, zoning data provided by area zoning agencies, and traffic counts provided by the Iowa DOT, and digital FEMA flood zones.

3. Use the real property data to model property value, calculate equitable assessed values, and give the public and other government agencies reasonably easy access to the GIS and CAMA data, not confidential under Iowa law.

Learn more about us

Learn more about our application: Site 1

Business Problem Solved

1. Used ESRI Spatial Analyst to develop a response surface model “location adjustment factor” used on the 2005 residential land values. See Site 1 for a detailed description.

2. Provide multiple forms of access to the Assessor’s data through public terminals, web site, phone, and public access counter. Provide an easy to use, understandable web page interface for queries on property characteristics and structure characteristics maintained in the CAMA system reducing customer trips to our office and calls with routine questions.

3. Provide multiple formats of current data from the CAMA system available on the web site in the form of delimited text files customizable by the user to meet their individual needs.

4. Provide other governmental agencies free GIS data with associated attribute files, currently in the ESRI shape file format, accessible from the Assessor’s web site. (A supplement to the MicroStation design file format provided by the Polk County Auditor’s Office.)

5. Use GIS applications to efficiently determine agricultural values based on soil productivity. Use GIS applications to improve analysis of sales and time adjustments to older sales. Use GIS applications to easily visualize the spatial relationships inherent in real property data.

Technology Implemented

1. CAMA software: developed in house using Informix and Perl

2. GIS software: ESRI applications, Arc Info 9.1, Arc GIS 9.1, Arc SDE \ SQL Server, Extensions: Spatial Analyst, Geostatistical Analyst, 3D Analyst, Arc Publisher

3. CAD software: Bentely applications: MicroStation 7.0

4. GIS component of the web page: A Perl script is used to read and composite aerial tiles, MicroStation design files, ESRI shapefiles, and Informix database attributes (labels and symbology) into a JPEG map converting the coordinates requested on various web pages. It also handles scale, location, and theme settings when they are adjusted by the end user. A second Perl script handles user clicks on the map to identify the selected parcel polygon and display a new page containing information about the selection.

Development Team Biography

LaRayne Fenton, Database Specialist
Ruth Larsen, Database Administrator
Jerry Leibold, Consultant
Jill Mauro, Computer Support Specialist
Terry Powell, Mapping Specialist
Randy Ripperger, Residential Deputy Assessor
Ray Willis, GIS Coordinator