GIS for site planning

July 2006 » Feature Articles
How can due-diligence information be obtained in a format that everyone can understand and in a quick time period? A comprehensive site analysis can be completed in less than two days using GIS technology.
James J. DeVellis, P.E.

Improving speed and precision

GISConsider the following scenario: A meeting with potential business partners to get their buy-in on developing a parcel of land. A site walk reveals a potential resource area onsite, and although assessor's maps and record plans provide some insight, many questions remain unanswered. How can due-diligence information be obtained in a format that everyone can understand and in a quick time period? A comprehensive site analysis can be completed in less than two days using Geographic Information Systems (GIS) technology.

Not only does GIS accelerate the site-analysis process, it also allows site design and engineering professionals the ability to create a recognizable base to which property owners and developers can relate. This base can be made up of several media, including aerial photos, topographic maps, CAD plans, and electronic assessor's maps. An abundance of relevant data can then be overlaid onto this image to paint a picture of the site, clearly illustrating its opportunities and constraints.

Armed with this complete and legible due-diligence packet, property owners and developers can present more confidently the site's potential to business partners or other constituents. In addition, moving forward, site designers and civil engineers can design the project from these base maps created with GIS.

GIS appeal Although GIS technology for site planning has been available for many years, it is just now gaining ground. Even one year ago, many cities and towns did not have GIS capabilities, and many engineering firms were just starting to implement this technology for site planning and due diligence.

Now, cities such as Boston have converted all public data to GIS format.

Additionally, engineering firms are relying on GIS for almost every project. Civil engineers and planners see it as an essential tool for discovering red flags on a site early in the planning process.

For a property owner who wishes to know the development possibilities of a site, a developer with a project but no land to build it on, or a building owner planning an addition or renovation, GIS is an invaluable resource. Although such site analysis is possible without GIS, it often can be completed more quickly and with a higher degree of accuracy using GIS.

On the fast track

Before GIS, a comprehensive site analysis was a week's worth of gathering information and record plans, which in many cases do not reveal all the answers. Also, this type of information gathering often produced a large stack of papers with no cohesion between them. In addition, all this data was confusing for a property owner to understand.

With GIS, designers and engineers gather most data digitally from a predesigned database, resulting in legible results obtained quickly. Between its comprehensive database and the ability to convert data to CAD format for the design phase, GIS puts projects on the fast track.

For the College of the Holy Cross's Fitton Field renovation in Worcester, Mass., the speed and precision GIS afforded engineers and site designers was remarkable. Just six months before opening day for the Worcester Tornadoes, a Canadian-American league baseball team, Fitton Field had to be re-designed, permitted, and built. To meet this timeframe, the engineers and site designers had to rely heavily on GIS, using it to create maps on which the design, permitting, and ordering of materials was based.

Since GIS is not site specific, it cannot take the place of a field survey, so the engineers had to move ahead with the design before getting the survey. Once the timeline allowed, site planners backtracked and implemented a field survey, which proved the GIS information to be highly accurate.

By using GIS to this extent in the design and permitting phases, the engineers shaved three months from the schedule and had the field built in time for the Tornadoes' opening day. Project participants felt rewarded for their efforts when the team won the division championships that year.

GIS technology also helped put a private elementary and high school on the fast track when the school decided to expand. Plans for the school, located on Boston's north shore, included the addition of a new sports complex building, dining commons, classrooms, and a soccer field. As GIS identified onsite constraints early, attention was directed to off-site possibilities. Luckily, a nearby parcel of land went up for sale that could suit the expansion.

However, before the school could purchase this parcel, it had to evaluate the site's development capabilities and constraints. Because the parcel was located in a desirable waterfront location, the site analysis needed to be completed within 24 hours before another buyer came along and made an offer. Using GIS, the site planners checked the wetlands, zoning, and other characteristics of the parcel and, by the end of the day, determined that the site was viable for a soccer field. Therefore, the school quickly made an offer before other abutters, and purchased the parcel for the new soccer field.

All in the details

Before GIS was widely in use, developers and engineers could reach the permitting stage for a site before discovering a slight zoning change, remote wetland area, or other such inconspicuous but plan-altering constraint. By conducting a comprehensive overview using GIS, these issues potentially can be avoided, which is another reason why GIS has become a popular site-planning technology.

One way GIS allows for a comprehensive view of a site is through the use of aerial photography. Detailed aerial photographs bring a site into context for property owners and, when overlaid with available data layers, can help to identify features such as rivers, streams, aquifers, overlay districts, wetlands, and others.

At Hebrew Senior Life's 150-acre intergenerational senior campus community in Dedham, Mass., the site planners used GIS to create an initial overview of the property.

During this analysis, they found rare vegetation in a remote area of the large site that they may not have discovered during the site walk. Armed with this level of detail, the planners were able to identify this area when visiting the site and plan around the vegetation accordingly.

Another example of how GIS helped to uncover important details about a site was during the renovation of Cronin Skating Rink in Revere, Mass. A creek adjacent to the existing rink was identified to be a body of water with tidal influences, which changes the regulatory process on the site significantly.

Therefore, civil engineers directed botanists and surveyors to implement more resource area delineation and research of historic coastal mapping than would have been necessary for a non-tidal area. With this information, the engineers were able to determine the necessity for uncommon state and federal permits.

The site is potentially subject to regulations that require public access to coastal waters (altering the design of the site), and that can delay a project severely, particularly when discovered months into the design. GIS kept the project running on time by providing an early warning regarding the tidal waters.

A selling tool

Not only does GIS allow property owners to understand their site for development, but it also is beneficial when it is time to sell by illustrating development opportunities to prospective buyers, developers, and other business partners. For example, during the school expansion project on Boston's north shore, the school also had a piece of land it needed to sell. Using GIS, site planners analyzed what types of building projects would be viable for the land. School representatives used the data to highlight the selling points of the parcel to potential buyers.

GIS is also especially useful for creating clear graphic representations of a site for people who are not familiar with reading traditional site plans. The maps created with GIS helped the site planners for the school expansion project convince school board members to approve funding for the project.

During the master planning process, the planners created a map of the proposed expansion using GIS and sent it electronically to the board members. They clearly understood the expansion plan and the amount of funding needed.

Additionally, the maps produced with GIS technology are useful for presenting a project to town officials or abutters who, in many cases, can be a deciding factor in the fate of a project. For example, a project's impact on open space is often a matter of concern among abutters. Using a GIS aerial map overlaid with a proposed site plan can clearly and accurately show which spaces would be impacted by development and the amount of open space that would remain untouched.

Proper use and obstacles

GIS is the answer to many site-planning challenges, but it does not take the place of design. Because the product created from GIS technology can look like design, some members of the team (architects or developers) may misidentify the maps as design plans and build from them. Site planners must be careful to explain that the GIS maps are only a picture of the existing property data.

Another challenge in relation to GIS is the reluctance some public agencies and private companies are showing to release electronic copies of their comprehensive regional map. For civil engineers using GIS to identify existing utility lines to create a comprehensive utility inventory, this obstacle especially can be frustrating.

At the Massachusetts Water Resources Authority, water and sewer line electronic data is now kept under lock and key because of terrorist concerns. Post-Sept. 11 fears are hindering the release of GIS data without significant security hurdles at many similar agencies across the country.

Therefore, to identify infrastructure quickly, engineers must return to pre-GIS days and pull paper plans to generate maps from scratch. With the time saved on other aspects of a project through the use of GIS technology, however, creating utility maps from paper plans is a minor setback.

With its time-saving features and clear and presentable end product, GIS will no doubt continue to be an invaluable resource to site planners and engineers.

Although many larger cities and towns have converted data to GIS format, many smaller communities will not have GIS capabilities for another five to 10 years. But as more cities and towns transform public data into GIS format, site planning with GIS will become even more efficient and accurate.

James J. DeVellis, P.E., is a partner at Geller DeVellis Inc., which provides landscape architecture, site planning, and civil engineering services to clients nationwide. He can be reached via e-mail at jim@gellerdevellis.com.


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