Home
Virginia Review Archives Of Printed Magazine From March/April 2004 to July/August 2008

GIS & GROWTH

Stafford County Manages Growth with an
Enterprise & Integrated GIS

By David Copaz with David Noel and Sheri Stefaniga

Nearly a decade ago, Virginia’s Stafford County was most known for its rural vistas and forests. Today, only 40 miles south of Washington, DC, the county is witnessing an incredible growth rate.

With many residents commuting to the DC area for work, Stafford County is one of the fastest growing counties in Virginia, maintaining a 2005 population of 117,874 (up 28 percent from 2000). As of November 2006, Stafford County’s GIS maintained more than 50,000 parcels (up 25 percent from 2000) and nearly 5,900 road segments (up 52 percent from 2000). The large growth rate is projected to continue well into the next two decades.

To manage the rapid growth and expansion, county officials have turned to the latest geographic information system (GIS) technology, a significant upgrade over its previous system. Today, local governments are challenged to effectively manage vast amounts of information and data while providing quality government services and managing economic development.

These GIS and information technology (IT) solutions help localities organize and manage their facilities and information. Local government professionals maximize productivity in management, development, and planning tasks with advanced GIS applications.

To jumpstart its GIS technology upgrade, Stafford County implemented a complete enterprise GIS that helps county officials and administrators evaluate assets and infrastructure for future development. Converting to an enterprise GIS enables county officials to manage a wealth of information in their daily activities to improve their decision making process through greater support of existing geospatial data.

IT TERMS USED
IN THIS ARTICLE:
Enterprise GIS–a geographic information system that is able to be integrated with other databases in the municipal government like CAMA and asset management systems.
Sync tool–an enterprise GIS based application that copies the tax map from the asset management system to the GIS parcel layer automatically.

As part of the project, the county designed a geodatabase that incorporates geospatial software technology and allows users to efficiently access large, multiuser geographic databases. The geodatabase serves as a data warehouse or repository for county information, like parcel, road, zoning, building, census, and subdivision information that is currently stored in a variety of different formats and locations. Additionally, the geodatabase consolidates, documents, and preserves relevant county information that officials can use to make informed decisions about land development and community planning. It also enables multiple users in remote locations to access data at the same time and provides high quality tax parcel data and associated features, thereby improving analysis capabilities.

THE CHALLENGE

Stafford County’s GIS Staff have very specific roles and responsibilities. As a whole, they are responsible for street and structure updates, parcel, zoning, and land use updates, mobile GIS efforts, site development and administration, and internal and external map requests.

The county’s GIS supports the county government with geographic analysis, survey control information, maps, and data. This information is used to provide improved decision making and information to support county departments, the board of supervisors, and citizens. Additionally, the majority of goals within the county’s comprehensive plan have a spatial component supported by GIS. For example, GIS staff uses aerial photography to locate impervious surfaces, like rooftops, sidewalks, and parking lots, and provides a number of county departments with information related to water runoff and pollution from such surfaces. They also provide training, technical assistance, data organization, quality checks, maps, large format printing, and support to other internal casual GIS users and departments.

Only a few years ago, Stafford County’s GIS used rudimentary technology to conduct a majority of its business functions. Its basic systems provided limited functionality and analysis capabilities. Also, the department’s systems were not easily connected with existing systems used within the county.

Stafford’s early GIS simply digitally tracked land ownership, while edits and updates were made with basic ESRI toolsets. With the exploding growth rate, the county desperately needed an advanced GIS system that enabled staff to work faster and more efficiently. Such a system would permit users to tailor workflows around an advanced GIS infrastructure.

THE SOLUTION

In order to transition the department into an enterprise GIS application–one in which GIS software, GIS components, data, hardware, applications, management, and staff are all working together–a series of structured methodologies were developed.

First, an enterprise geodatabase design document was created that provided a reference for the overall development of the enterprise GIS. The completed document minimizes the learning curve for database administrators, new staff members, and contractors since it categorically describes the nature of the system and its functionality.

The design document also laid groundwork for discussions about the data (both GIS and non–GIS) sources and categorizations based on the requirements of a large user base. It considered all county department needs and grouped it into categories, enabling the GIS staff to effectively plan how to support the diverse needs of its users. It allowed the team to determine feature data sets, data classes, and how the data relates to each other. Additionally, it offered an overview of field properties and documented static domains, like street suffixes. Finally, it established restriction and relationship classes and outlined implementation. Altogether, the design document detailed the individual attributes built into the database.

The second methodology developed was the data adjustment. In order for the data migration to the new GIS to maintain certain levels of accuracy, the data needed to be adjusted. Previously, parcel and structure information was gathered from outdated orthophotography, which is an aerial photograph that has been geometrically corrected so the scale of the photograph is uniform. In other words, the photo is considered to be equivalent to a map. Unlike an aerial photograph, an orthophotograph can be used to measure true distances, because it is an accurate representation of the Earth’s surface, having been adjusted for factors like lens distortion and camera tilt.

Ultimately, newer photography obtained by Stafford County revealed irregularities within parcel and structure information, causing spatial inaccuracy. To correct the problem, county personnel divided the county into several areas and phases. As a result, work could continue, and adjustment rules were established to maintain efficiency. As the technology concurrently improved, the GIS staff remained proactive, ensuring the data that was used and adjusted was as accurate as possible.

Thirdly, the county geodatabase had to be populated. The design document outlined 185 GIS data layers, that were subsequently loaded manually while the topology, relationship classes, and domains were established. The populated geodatabase permitted parcel data to line up correctly, with no overlapping or gaps.

A fourth methodology was to link Stafford County’s existing systems. The county already had a centralized data repository that stored only tabular data, but the challenge was linking it to the newly developed GIS. The solution was the creation of a sync tool that allowed users to attach the GIS data with the attributes from the legacy systems. This created an enterprise GIS database enriched with attributes from various other sources.

The sync tool seamlessly converts information, like street and subdivision data, by building a dynamic domain so a drop down menu is formed. The final result is a stand alone relational table in the geodatabase that allows parcels to have multiple addresses, like condos and mobile home parks.

The sync tool also incorporates parcel attribute data to Stafford’s property assessment system, so users can view information, like street names and lot size, in addition to the property value assessment data. Previously, the assessment system simply contained the parcel ID number. Now, users have access to a wealth of parcel information without obtaining it in the field.

It was important that non GIS users across the county could access the data. To accomplish this, several internal GIS Web applications were developed and are still being enhanced, giving county employees across the board the opportunity to receive parcel information efficiently and fulfill customer requests. The application also enables users to access and print GIS generated tax maps.

Lastly, the data needed to be maintained properly. To accomplish this, the data was migrated to be maintained in one place. Moreover, the majority of attribution is automated, empowering users to engage in more challenging and rewarding work. The data that is used is also real time, enabling county employees to view up to the minute information.

FUTURE OF STAFFORD’S GIS

Through advanced GIS solutions, Stafford County officials have begun to effectively plan for the next generation. The long term project goal is preparation of the data for deployment over the Internet, so the public can have a wide variety of tools at their fingertips. Instead of directly requesting information from the county, like tax parcel information, residents would be able to view information 24 hours a day from any Internet enabled location.

Stafford County also plans to develop customized sites for several departments, as well as implementing a variety of 3D analysis tools.

Altogether, Stafford County’s enhanced geodatabase and Web based application have laid the groundwork to effectively manage and maintain its rapid growth rate in the years ahead.