- SPECIAL REPORTS
- THE MAGAZINE
Cadastral surveying, including the development and management of cadastral information, provides the basis for land titling and ownership. As property values increase, the importance of the cadastre increases as well. In Utah, private surveyors and state and county agencies are seeing the value of combining cadastral management and positioning systems into a single well-coordinated effort.
With roughly three million people occupying more than 1.3 million legally defined parcels, Utah has a clear need for consistent, easily accessible land information. Like other states, cadastral information in Utah goes back for decades and beyond, with much of the information in the form of paper records kept in county courthouses. By the late 1970s, Utah had begun to implement electronic geographic information technology. In 1981, the state formed the Utah Automated Geographic Reference Center (AGRC) to coordinate the state’s GIS and serve the interests of geospatial users. Since then, AGRC has emerged as a key part of the Utah’s strategy for geospatial infrastructure.
In 2005, the Utah legislature enacted a law to further improve the cadastral efforts within the Utah AGRC, a part of the state’s Division of Technology Services. The AGRC was given the tasks to (1) create a statewide parcel layer in its GIS, (2) create a statewide GNSS reference network, and (3) densify and enhance the PLSS in the state. The law also established a position for a licensed surveyor within AGRC. The surveyor’s role is to coordinate and facilitate work across the state to bring cadastral information into the GIS. The center’s current efforts are concentrated on collecting field data, and on maintaining and distributing accurate cadastral information.
In addition to cadastral and property surveys, the Utah GNSS network is used by surveyors and contractors in engineering and topographic surveys, GIS data acquisition, and construction. Many users access TURN GPS to conduct RTK surveys, receiving correction data via mobile phones. In areas of limited cellular coverage, surveyors use CORS data from TURN GPS to establish local control points via static GNSS and post-processing.
The AGRC task to enhance the Utah PLSS includes recovery, restoration and preservation of section corners and other cadastral monuments. In addition to positioning, the work entails keeping detailed records. AGRC provides a web application that lets users log in to submit PLSS information. As an example, Fernandez says that a surveyor can capture the position and information for a PLSS monument and complete the monument form online. “I think it is important that surveyors evolve into a GIS realm so that they can stay current and be able to better utilize their profession,” he says. “That’s where AGRC comes in. We understand the legal aspects of surveying and the need for high accuracy, as well as the importance of evolving to a GIS in order to obtain good attributes on the data we are collecting. GNSS is an evolving technology, and TURN GPS is making it faster and easier to obtain precise measurements and attributes.”
Fernandez describes the AGRC as a “one-stop shop” for geographic and land information in Utah. In addition to information about PLSS monuments, the center has gathered aerial imagery, General Land Office (GLO) notes and information from the U.S. Bureau of Land Management (BLM). “Much of what we’ve been able to accomplish is due to the ease of collecting the data,” he says. “We have actually developed a statewide parcel layer for private ownership. We are now working to merge that with our federal and state ownership layer. Because we are now on the same coordinate frame, it’s a lot easier to bring all of it together.”
A large part of AGRC’s funding comes from federal grants. The money is intended to clarify the boundaries between federal and privately owned lands. In some cases, counties hire third-party surveyors to go through their records, create parcel data and deliver it to AGRC. For PLSS data, either in-house county surveyors or third parties collect PLSS data and submit it to AGRC. AGRC processes the information into its database and forwards it to BLM where it is added to the Federal Geographic Coordinate Database (GCDB).
AGRC is also collecting subdivision information down to the local level. The data includes the subdivision plats with polygons, parcel numbers, addresses and locations. Beyond this, AGRC leaves the data management to the counties. County assessors or surveyors manage local information including zoning, valuations and assessments.
Not all field information coming into AGRC is done with survey-grade equipment. Preserving the existing monuments is important, and the accuracy of GPS mapping systems is often sufficient. Olson says that the Horrocks Engineers GIS department uses Trimble GeoXH handheld receivers in conjunction with TURN GPS to collect mapping information down to a few centimeters. Fernandez even hopes to get geocaching and recreational GPS owners into the act by collecting rough positions and photos of section corners. “We can at least have it in our database,” he says. “The low-accuracy information tells us what the point is, what it looks like and a general position. Eventually we can send surveyors out to improve the accuracy.”
AGRC illustrates how modern technology and a well-planned system can streamline the processes for gathering, managing and sharing cadastral information. Burton Christensen, survey manager for Sunrise Engineering in Draper, Utah, says he submits survey data directly to a county and AGRC at the same time, using a standard format defined by AGRC. The information includes coordinate data for the cadastral control and the individual monuments. Monument reports--including photos and descriptions--can be included as well. Christensen is a frequent user of TURN GPS, both for real-time corrections and in creating control for local RTK. Either way, his objective is to be able to provide SPC on any type of survey.
As part of Fernandez’s one-stop concept, Christensen notes that parcel descriptions entered at the county level are shared with AGRC, and that AGRC maintains a database of all PLSS section corners in the state. “The taxpayers shouldn’t pay twice for anything,” says Fernandez. “We’re able to bring data together across political boundaries, and the cadastral information will match up from city to city. By providing a single cadastre, we help people make better decisions based on accurate information.”
Looking forward, Fernandez and Buscaglia expect to see even wider access for cadastral information. As bandwidth for Internet access increases in the field, Web interfaces for cadastral data will move onto handheld data collectors. Fernandez hopes to see standard feature code libraries and procedures built into field applications for cadastral data collection. He envisions the ability for surveyors to access property records in real time, documenting updates and revisions while tying property markers directly to the geodetic reference frame. Over time, the cadastre will blend information about land usage and physical markers into the GIS layers, with a gradual resolution of gaps and overlaps between parcels. Buscaglia emphasized the importance of surveyors in the cadastral GIS, as evidenced in Fernandez’s success in Utah. As more agencies adopt the model of automated, GIS-based cadastral management, it will create additional work and opportunities for surveyors with good GIS skills.
In the end, it’s not much different from what land surveyors have been doing for centuries. What’s changed is how they are doing it. “Construction normally can’t begin until the property rights are addressed,” Olson says. “When looking for information on PLSS markers, we used to only be able to get the information needed by going to counties, the BLM or GLO for notes and descriptions. Now, we can go to one place for this information, regardless of where we are working in the state. It saves a lot of time and money.”