GEOGRAPHIC INFORMATION SYSTEMS: Use and implementation options for towns
(from Maine Townsman, June 1999)
By Margaret Allen, (formerly) Information Specialist, Maine Municipal Association

Over the past few years, several Maine municipalities have implemented a Geographic Information System (GIS) to create layered maps and to manage their records and data. A GIS is a combination of computer hardware and software, groups of data, peripheral equipment and users of the system.

The implementation of a GIS usually starts in the assessor’s office (the traditional place for tax maps and data) and then expands into other departments and offices. According to a technology survey conducted by the Maine Municipal Association last January, GIS is currently being used in Maine for assessing, code enforcement, planning, engineering, public works, emergency management, waterfront management, sanitation, water, police, fire and rescue, E 9-1-1 addressing, natural resources management, forestry, economic and community development, administration and airports.


A GIS integrates spatial and tabular data.

Spatial data include any physical features that can be assigned geographical coordinates or "geo-referenced." The geo-referencing can be depicted in state plane coordinates, longitude/latitude points or altitude measurements and can be two or three-dimensional. Spatial data can be stored in different formats, such as points, lines, annotations, polygons and images. On a map, point data could be used for traffic light locations, line data could be used for streets, annotation data could be used for street names, polygon data could be used for buildings and image data could be used for scanned aerial photographs. Spatial data are given coordinates that geographically reference them to the mapping system.

Tabular data are a collection of characteristics or attributes that identify, describe and provide information about a certain geographical location or coordinate on the system. Examples of tabular data used by assessors are map and lot number, address, owner, deed book, deed page, land value, sale date, sale value, ward, census block, school district, acreage and zoning. These data are set up in rows and columns in a database and multiple databases are linked through a common field.

A common field is a field in one database that is identical to a field in another database. Although the two databases contain two different sets of information used to describe the same area, they can be integrated by linking the common field. In this way, a database of demographic data, a database of zoning data and a database of traffic data all can be integrated and layered on a map to better determine road maintenance schedules and priorities.

In a GIS, the different layers of data depicted on a map are called "coverages" and the methods by which different databases are integrated are called "linkages." Since it is estimated that 80% to 90% of local government programs and activities are directly dependent upon geographic information, a GIS is particularly well-suited to providing better information on which to base planning and decision making.

A well-implemented GIS can be used to get a holistic picture of a municipality; manage data and information more efficiently; graphically communicate plans or issues to citizens or developers; reduce redundant work and services performed at various levels of local government; reduce the cost of generating information for public notification and use; and shorten response times to emergencies.


In order to implement a GIS, a municipality must have a relatively powerful workstation, one or more copies of GIS software and a consultant or technically trained staff member who knows how to build coverages and linkages, write customized applications and train users. For the workstation, minimum hardware requirements include a Pentium processor, 64 megabytes of RAM and a 2-gigabyte hard drive.

Municipalities can opt for incremental or full implementation of a GIS.

Incremental implementation is a slower process in which one or two copies of GIS software are purchased and coverages are developed as staff and resources permit. Parcel conversion, the first step in GIS implementation for assessing, is usually done by a consultant through an RFP contract. Training is usually provided for a daily fee that depends on the application. Programming is usually done for an hourly fee. A staff member in the municipality can begin implementing a GIS by choosing one application for which both the need and payback potential are high, such as E 9-1-1 addressing or a revaluation. After an initial application is successful, other departments can gradually develop compatible databases from which to create more coverages for the GIS.

Full implementation of a GIS is more costly, requires more involvement and dedication and brings about quicker change in the way departments manage their records and data.

The following suggestions are made with full implementation in mind, but they will become relevant for incremental implementation as more departments begin getting involved.

Create a GIS Task Force. All department heads should be included. The task force will detect problems, suggest solutions and establish guidelines, procedures and standards. By including all departments, a global view is set from the start and the problem of different departments setting up incompatible databases or systems is avoided.

The most successful task forces are those that have top management support and combine technical with management expertise. It is important to look for potential agreements or partnerships at the start. For example, Bath was able to get aerial photos of the city through a deal with CMP, and Brewer is cooperating with Bangor Gas and Photo Science, Inc. to update its GIS maps with aerial photography and planimetric mapping (mapping that represents only the horizontal position of features). It is also important to research what other municipalities are using for applications and how they are benefiting from them.

Create a Strategic, Cohesive Plan. The plan should incorporate all departments and include the following:

• An outline of current work resources, processes and costs;

• An outline of work resources, processes and costs re-engineered through the use of a GIS;

• An inventory of current technological equipment and data resources;

• Identified links or enhancements to existing systems;

• Hardware and software platform alternatives that provide expandability and long-term use;

• General and application-specific goals, uses, needs and requirements;

• A cost-justification process that quantifies expectations and measures costs and benefits over time. Costs may include personnel; equipment; training; and back-file cleanup and conversion. Benefits may include time saved by expediting work processes; reduction of redundant operations; savings in costs associated with paper storage, retrieval and distribution; and the enhanced products of a GIS;

• A realistic assessment of funding and potential agreements or partnerships needed to sustain the plan over time (3 to 5 years into the future, if possible);

• A designation of who will coordinate the GIS effort, procure equipment and technical support, integrate hardware and software and perform system testing;

• A realistic schedule for procurement, negotiations and implementations. The schedule should also include the total duration of the project, long-term strategic goals and approximate annual costs;

• An RFP process and evaluation package;

• A pilot project that tests the new system before implementation;

• Enough flexibility so that the plan can accommodate changes in organizational needs and/or technology;

• Methods for handling resistance to change, such as ongoing communication, workshops, support and training; and

• Clearly assigned procedures, standards, tasks and responsibilities.

Incremental Implementation in Bath

According to City Tax Assessor Paul Mateosian, the introduction of a GIS has been incremental in Bath. "Your maps are only going to be as good as your data. You have to think about building up accurate and current data sets incrementally, using existing resources and personnel. Each data set has to be developed and maintained by someone. It’s a slow process," says Mateosian.

Instead of determining a price and going out to bid, Bath started by purchasing two copies of ArcView (a GIS software package from ESRI, Environmental Systems Research Institute, Inc.) and hiring a contractor to create custom scripts, add coverages and provide training on an as-needed basis. One of the scripts allows Mateosian to recreate tax maps from the AutoCAD files Bath began creating in 1994 when it first went from a paper to digital format.

GIS was first used in Bath to generate tax and zoning maps. The second use was economic development.

"The city manager has been very supportive from the start and likes the GIS because it allows him and the city planner to ‘show and tell’ more easily to potential developers," says Mateosian.

For example, they can now use a GIS to show developers a pin map of commercial property that includes sale prices and assessed values.

"You get a much clearer picture using a GIS than just looking at a bunch of tables and charts," says Mateosian.

The next logical steps of implementation in Bath are to incorporate public works data, such as sewer lines, pipes, road signs and street maintenance; and then to involve the police and fire departments in incorporating their data. Each of these databases would have to originate from its respective department and be in a compatible format.

Mateosian has been working with a GIS in Bath for almost two years. The city spends between $3,000 and $5,000 per year on the GIS. Mateosian is planning to develop a digital orthophoto layer in the near future.

Orthophotography is the making of a photographic reproduction in which the displacement of images due to camera tilt and terrain relief has been removed so that the photograph has a uniform scale and the same metric properties as a map. Bath has aerial photographs of the city that will be digitized, scanned and incorporated into the GIS to produce maps of aerial views, or photogrammetric maps.


Brewer is aiming for full implementation of a GIS this year, the first year of its implementation plan. About two years ago, the city hired a contractor for $18,000 to do introductory demonstrations and training, to conduct departmental needs assessments and to come up with a three-year implementation plan. The city council approved $84,000 for the first year of implementation and will be voting on $100,000 for the second year.

Brewer formed a GIS team made up of the technology coordinator, assessor, public works director, two engineers and the assistant to the city manager.

The city bought 11 copies of ArcView and acquired more equipment and training through a Local Government Start-up Grant from ESRI. Within the second year of the plan, the city will spend $30,000 on updating its tax and zoning maps and $35,000 on a GIS Web server so that maps and data files can be put up on the Web for economic development purposes.

"Just from some informal surveying I did, it seems that GIS in local government is getting started in the assessor’s office," says Technology Coordinator Mary Stuart.

In Brewer, each department will be building data sets with database software (Microsoft Access) and the databases will be linked with the Assessor’s database, using map and lot number as the common field.

The assessor, code enforcement officer and city planner are using the GIS for zoning and wetlands maps, abutter notification, deeds, site assessment, sales/ratio and a public kiosk. The fire department would like fire hydrant data to be part of the system and has started gathering data on commercial properties. The fire department is also interested in putting computers with GIS in their trucks so that, in emergencies, they will quickly be able to retrieve details about the structure or area to which they are going.

The engineering and public works departments will be updating and maintaining their data using a Global Positioning System (GPS) and the technology department will be responsible for managing and coordinating the GIS effort.

Stuart envisions that every department will be using the GIS, whether for information or application purposes.

Brewer has taken advantage of its close working relationship with its school system by sharing the GIS with the school’s technology coordinator and students; adopting the school’s technology benchmarks for city employees; installing a fiber optic network that connects city offices, public buildings and schools; sharing file servers and equipment; and training city employees in the school’s computer lab.


The Maine Office of Geographic Information Services (OGIS) is working with the Maine Department of Public Safety to support a statewide implementation of Enhanced 9-1-1 service using a GIS. The OGIS offers free technical support to municipalities undergoing E 9-1-1 addressing and has so far worked with all but 30 of Maine’s 494 municipalities.

OGIS begins by using a municipality’s tax maps and data to produce a base map that includes road names, rivers, lakes, ponds and borders. The municipality can review the map and request changes, such as public or private roads that should be added or deleted.

The office then schedules a Global Positioning System (GPS) collection in which a contractor visits the municipality and inventories all the structures, streets, intersections and address ranges. To assist the contractor in navigating the area, the municipality must provide a "guide" who knows the community.

After the GPS collection, OGIS technicians create an updated map and digital file of GPS data for that municipality. The new map will include structure locations and mathematically calculated address numbers. The data will include road names, directionality, address ranges, lengths and other attributes. The municipality then has a "working map" it can download, review and correct.

The free service is for cleaning up street naming problems and bad addressing and for clarifying emergency response areas. The office encourages municipalities to work with police and fire chiefs, paramedics, neighboring municipalities and the local postmaster throughout the process to ensure that all needs and special requirements are met.

Most of the OGIS technicians’ work is done in ARC/INFO (also a product of ESRI) and the data are kept in Shapefile format so that they can be easily imported into ArcView, which is the GIS software package that most municipalities are currently using. Municipalities without a GIS can download the shareware, ArcExplorer, which is a free piece of software used to view Shapefiles and available on the OGIS Web site.


Many municipalities are getting GIS assistance from their local council of governments. GIS staff at the Androscoggin Valley Council of Governments (AVCOG), headed by Fergus Lea, has provided mapping support to six towns for comprehensive planning over the past two to three years. The GIS staff collects data from the municipality as well as from state and federal sources, like FEMA (for floodplain data) and USGS. Other projects include digitizing tax maps using AutoCAD and building layouts from them in ArcView. Its first pilot project, started three years ago, was building sewer, water and zoning coverages for the eight-town region of the Oxford Hills Growth Council. The AVCOG has a 50-50 program whereby members can get project support at 50% of the cost.

The Greater Portland Council of Governments (GPCOG) has provided assistance to most of its members in Cumberland County, including Freeport, Portland, Westbrook, Cape Elizabeth, Scarborough, Gorham and Windham. Lately, the COG has been helping Long Island and Frye Island in setting up a GIS by supporting them through the RFP and selection process and proofing the data once they are on a PC. As part of their dues, member municipalities receive free on-site technical and data management support and special projects are done on a fee-for-service basis at a member rate. GPCOG is concentrating a lot of its efforts on standardizing formats, protocols and documentation for data release to the public and helping municipalities project nonstandard data into standard state plane coordinates. The COG has a three-member GIS staff, headed by Kris Sommer.

Both the Maine OGIS and the Maine GIS User Group provide links to vendors and consultants on their Web sites. The Maine GIS User Group, managed by Dan Walters of the Maine OGIS, is a good place to start learning about GIS. The user group has a long list of members made up of water and wastewater districts, COGs, towns, cities, state departments and agencies, commissions, libraries, development corporations, schools, vendors, contractors and individuals.