Combining CAD and GIS data before and after design creates an efficient cyclic process.

Project
Vistancia master planned community in Peoria, Ariz.

Civil engineer
Stanley Consultants, Phoenix

Product application
Implementing GIS technology as a data and document management system improves communication with developers and contractors.

Using geographic information systems (GIS) technology for site planning is an effective way to assemble existing data before incurring the cost of creating new data (see "GIS for site planning," CE News, July 2006). Many savvy firms search their local, state, and federal agency websites for GIS data, including cadastral information, aerial imagery, and topographic maps. Without leaving the office, engineering professionals and other personnel can access and use this data during the pre-design phase to answer the following questions, among others:

• Where is the site?
• Where are recorded survey monuments?
• What sort of topography exists on the site?
• How will site topography affect radio and satellite coverage for GPS survey?
• Where are wetlands?
• How vegetated is the site?
• Who owns the surrounding land?
• Where are environmentally sensitive areas and protected species habitats?

It’s simply good business to leverage existing data instead of paying to have it created. However, to draw upon the full potential of GIS technology, completed CAD design data can and should be exported to the GIS. This step transforms a traditionally linear design process into a cyclic design process that is more efficient, more productive, and more profitable.

A linear design process (Figure 1) begins with a planning phase where an artistic rendering of the site usually is done by hand. During the data-capture phase, GIS and CAD technicians assemble and correlate existing GIS, CAD, survey, and photographic data before they decide if they need additional topographic, cadastral, or aerial surveys.

Figure 1: In a linear design process, design and as-built data are archived indefinitely.

Pre-design analysis is typically completed using both CAD and GIS tools. During this phase, many questions about the site can be answered and addressed. Decisions made during pre-design analysis are used during the design phase, which is completed almost exclusively using CAD applications.

During the construction phase, the proposed design is built. Finally, because most private civil engineering firms do not have GIS departments, design and as-built data are typically archived indefinitely. The public sector for the most part has GIS departments, but the value of the design data is either not apparent or dismissed because of misconceptions about compatibility. Many GIS technicians overlook the value that CAD data generated by surveyors and civil engineers present to a GIS.

In a cyclic design process (Figure 2), design data and any as-built data are entered into a GIS after the construction phase. GIS data, for the most part, have only been accurate to within 10 feet to 20 feet, whereas CAD software provides data that are accurate to 16 decimal places. Furthermore, interoperability between CAD and GIS data formats is already available, so exporting the CAD files (along with their inherent accuracy) into the GIS is easy to do.

Figure 2: A cyclic design process makes design data readily available during a project and for use in future projects.

In time, the once semi-accurate GIS maps evolve from map grade to survey grade, and everyone involved in the process benefits from this change. Adding this extra and very logical step to these time-honored methods transforms the linear process to a cyclic one.

Master planning
Two years ago, the Phoenix office of Stanley Consultants, an international engineering firm, faced the challenge of developing a GIS site for Vistancia, a large master planned community in Peoria, Ariz. Stanley Consultants determined that incorporating a GIS department into the business could improve its efficiency and bottom line, not only for this project, but also for others in the future. CAD applications create abundant useful survey-grade data. By slightly altering the way it creates that data and by implementing GIS technology as a data and document management system, the firm could move away from paper-based means of exchanging information. Furthermore, Stanley Consultants could use the GIS technology as a central repository for all relative design data and make that data available to any authorized person.

The firm selected Autodesk MapGuide for its GIS system because it is web-based and fully compatible with existing CAD applications. A MapGuide site can be made available to anyone with Internet access.

Digital CAD files, ordinarily plotted, stamped, and archived indefinitely, are now added to the firm’s GIS. The GIS is used to manage all CAD drawings, construction documents, permits, and correspondence throughout the construction phase. For security purposes, access to any part or parts of the GIS can be locked down with logins and passwords. This change has vastly improved communications between the developer, the firm, and the contractors.

Figure 3: Stanley Consultants’ GIS page shows current projects in the Phoenix area.

Figure 4: Stanley Consultants’ GIS showing a land ownership theme.

By using a GIS for document and data management, the firm can post all of its design data to the GIS and give access to all other consultants involved in projects. In the case of the Vistancia project, when new phases were added to the master planned community, the firm knew where everything was located and could easily access this data.

Figure 5: A GIS overlay shows a rendering of the Vistancia community master plan.

Figure 6: A lot report in the GIS created for the Vistancia development contains photos, as well as links to deed and lease information.

Not only has Stanley Consultants derived benefits from having the MapGuide site, but also during this project, the master developer of the 3,000-lot subdivision, Vistancia, LLC, was thrilled to have it available. The man-hours and money saved by having all parties looking at the same data was significant. Furthermore, Vistancia, LLC, reduced its plotting costs by 35 percent. Almost all regular overnight shipping and faxing were eliminated. When anyone involved in the Vistancia project wanted an update on permitting, construction progress, access to plans, progress of the next phases of the design, and other related information, they simply accessed the GIS to find what they needed and then plotted, printed, or copied it. Vistancia, LLC, was even able to use the GIS for managing and selling the lots as they became available.

Meanwhile, following implementation of the GIS system, Stanley Consultants received new revenue streams from GIS management fees.

Pete Kelsey is the technical evangelist for Autodesk’s Civil Engineering solutions. He can be contacted at pete.kelsey@autodesk.com or on his blog at www.autodesk.com/petekelsey.