Newtown Geographic Information System Brings Local Data Online

By Andrew Gorosko

The town’s electronic compilation of municipal information keyed to local geography, known as the geographic information system (GIS), is now available to the public on the Internet.

Assembling that information has been a complex task, which has been in the development stages for more than a decade.

Scott Sharlow and others have been compiling a range of municipal data in an electronic format intended to make the GIS information accessible and useful.

Mr Sharlow is the town’s technology and GIS director. Steven Birney is the town’s GIS software specialist.

GIS is an electronic mapping system designed to provide a wealth of planning information to its users through its cross-indexed, digitized format.

GIS mapping collects and unifies both broad geographical information, such as the course of rivers and layout of road networks, as well as fine details, such as the location of individual utility poles and stormwater catch basins.

The system incorporates many electronic “layers” of information within a unified format, within which layers may be added, subtracted, or recombined to produce customized electronic maps. Those maps are specified to depict a desired level of detail and also list the type of detail that is required for a particular planning project.

GIS mapping stores information on individual land parcels, roads, railroads, brooks, ponds, wetlands, open space, trails, public utilities, industrial development, and land use zones.

It includes information on property boundaries, zoning boundary lines, topographic contours, tax assessments, property ownership, building sizes, and land record references, plus other data.

Computerized GIS mapping may be used by every municipal department that stores information that can be keyed to geographic locations, such as street addresses, or lines of latitude and longitude.

Until now, much of the local GIS data has only been available to town employees via an internal municipal computer network.

But recently that information became widely available through a hyperlink posted on the town’s homepage on the Internet that connects to a municipal information portal. The town’s website address is: www.newtown-ct.gov/Public_Documents/index.

Under the “News and Announcements” section of the homepage, the hyperlink to GIS is: “Newtown Geographic and Property Information Online.”

Features

Besides local tax assessment data, the portal contains interactive mapping, GIS data downloads, and a map gallery.

The GIS information portal allows Internet users to perform searches for information on individual properties contained in the town assessor’s information database. The electronic indexing system allows data searches to be made in multiple ways. There are 11,144 parcels listed in the database.

The assessor’s online database, which is linked to the GIS system, provides a set of tools that may be used to perform real estate sales history searches based on a variety of criteria including: dates of sales, sale prices, land area, building sizes, category of construction, and building type, among others  

Layers of information listed in the GIS mapping include: zoning districts, floodplains, trails, elevational contour lines, police patrol sectors, fire districts, water districts, sewer districts, historic districts, school districts, voting districts, open space, wetlands, aquifer protection areas, aquifer recharge areas, fire suppression facilities, surface water quality, and groundwater quality.

Planimetric base mapping, as well as 2007 color aerial photography and 2002 black and white aerial photography, are key aspects of the GIS mapping.

Besides “overhead” aerial photography that was produced for the town, the system offers hyperlinks to “oblique” color aerial photography produced by other sources. Such oblique photography provides angled views of surface features which makes the view appear three-dimensional.

The town may produce another set of color aerial photos of the local terrain in April 2012, which would be added to the GIS network.

The town’s GIS information portal provides users with access to hundreds of mapping files listed on the state Department of Environmental Protection’s (DEP) GIS data homepage, including information on the environment, water depths, ground elevations, geology, endangered species, topographic maps, natural resources management, recreation, soils, watersheds, trails, place names, and others.

On the local level, the GIS system offers mapping on local open space areas, indexed street mapping, and zip code mapping.

Because the map information is easily scalable, users can view broad sections of town or focus in on small areas.

Work In Progress

Mr Sharlow said that the town’s GIS network is a “work in progress” that will be continually modified in seeking to make it as useful as possible. “We try to make it as simple as possible,” he added.

The town has waited until now to make the GIS network available to the general public because it wanted to provide a reliable system for general use, he said.

“The more information the public is able to get, the better,” Mr Sharlow said.

 “[GIS is] always open, but town hall is not,” he noted.

In providing the public with its GIS contents through the Internet, the town is acting progressively, he said. Other municipalities in the general area with comparable GIS projects include Greenwich, Stamford, Ridgefield, and Danbury, he said.

Although the mapping included in the Internet-based GIS network will print well on home printers, if people need large, high-quality maps printed on heavy stock, they can submit a map printing order to the town to obtain a map for a fee.

“All GIS data is a constant work in progress,” Mr Sharlow said in asking that GIS users contact the town’s GIS office or the assessor’s office to verify the accuracy of specific data.

Having direct public access to the town’s GIS data via the Internet benefits citizens at large, Mr Sharlow said. Those who will particularly benefit from the GIS network are people working in the field of real estate, including property title searchers and attorneys, he said.

Having so much municipal information available on the Internet is partially intended to reduce the foot traffic at town offices where public records are kept. For example, the town clerk’s website allows Internet access to certain land records, maps, and registered trade names.

Mr Sharlow points out that the information contained in the town’s GIS network is not as accurate as that produced by surveyors’ field surveys. The GIS data is intended for general planning purposes, Mr Sharlow said.

The town website contains disclaimers concerning the accuracy of the GIS data.