Mapping Site for Abandoned Properties Visualizing the most current data on the Web By Chris McCoy, City of Chula Vista, California Dead grass, overgrown bushes, and trash scattered across the front yard—these are the telltale signs of a house in foreclosure. To combat the negative effects of distressed properties on other homes in the neighborhood, the City of Chula Vista, California, passed an ordinance requiring that foreclosed properties be maintained. Code enforcement officers use a Web mapping application to track distressed properties so information is available in the field as well as the office. During the past decade, the City of Chula Vista has been among the fastest growing cities in the United States. With a current population of about 200,000, Chula Vista experienced a significant increase in the number of singlefamily homes built during this period. At the height of the 2004–2006 building boom, it was not unusual for the Planning and Building Department to issue more than 2,000 building permits per year. In recent years, the cooling housing market has led to a decrease in permits issued and an increase in foreclosures. These vacant houses have a negative impact on the surrounding neighborhood and the community as a whole. Many homes in the foreclosure process remain vacant and are not maintained for months. Blighted properties can discourage potential buyers of adjacent properties and reduce property values in a neighborhood by thousands of dollars. To combat problems associated with unmaintained properties, city leaders approved the Residential Abandoned Property (RAP) ordinance in October 2007. It requires the financial institution foreclosing on a property to maintain the vacant house to neighborhood standards. The Code Enforcement Division is charged with enforcing compliance with this ordinance. To manage more than 2,000 foreclosed properties, enforcement staff must identify where the highest concentration of foreclosure activity is occurring and quickly monitor data both in the office and field. 18 ArcUser Summer 2009 Although Code Enforcement Division staff maintained RAP data in Permits-Plus, the city's permitting system, they preferred a system that could visualize property locations. Code enforcement staff approached the GIS team and requested a digital map to identify these foreclosure locations. This would allow them to see clusters of foreclosures and help determine where to focus resources. In 2005, Chula Vista built CVMapper, a custom ArcIMS viewer for city staff to display and query common GIS layers. Initially, the GIS team discussed adding the RAP data directly to the ArcIMS viewer as a separate layer. Although this was a workable solution, code enforcement staff preferred a simple, lightweight map interface that would display up-to-date property locations. A key component of the project was furnishing current, accurate data. When code enforcement officers returned to the office from field inspections, the Web site would require updating to reflect the latest inspection data and current inspection status of each property. Another key consideration in the Web site design was the sensitivity of the data. The RAP database contains phone numbers, e-mail addresses, and other personal data that should only be available to the Code Enforcement Division. The GIS team ultimately decided to build a Web site based on ArcGIS Server, using ArcGIS JavaScript Extension to the Google API and the ArcGIS API for JavaScript. "We thought this was a great opportunity to take advantage of the mashup capabilities of ArcGIS Server and create a simple Web page that merged the locations of foreclosure properties on top of a Google map," said Bob Blackwelder, the GIS manager for Chula Vista. Since Chula Vista maintains its GIS data in ArcSDE using a Microsoft SQL Server enterprise geodatabase, staff can easily integrate GIS data with other city databases, including the RAP data, which is also stored using Microsoft SQL Server. The first step in creating the Web site was to spatially enable the RAP data. The GIS staff created a simple ArcSDE database view using the city's parcel layer. Using Microsoft Visual Studio, the view was modified to include the RAP program data. The modified ArcSDE view linked each record in the RAP database to a parcel feature based on the unique assessor parcel number (APN). Since the database view retrieved data directly from the Permits-Plus database, this also ensured the RAP locations and property status were always current on the Web page. The ArcSDE database view data was added to an ArcMap document along with a few additional GIS layers. These layers, including parcel boundaries, city boundary, census tracts, and ZIP Code boundaries, were added to provide reference and background information for the digital map. The ArcMap document was then published as a map service and embedded into a Web page. Using the ArcGIS JavaScript Extension www.esri.com