Big city planning in the Big Apple

The New York Department of City Planning (DCP) has developed a master GIS database that can be accessed by every department in the city. The GeoSupport System allows more than 30 departments – from the police department to the departments of finance and transportation – to update information on constantly changing properties, streets and political boundaries.

The DCP is responsible for land use regulation, environmental review, policy preparation, and providing technical assistance and planning information. For a city the size of New York, constant updates are required to keep the data current. The DCP, which has been using GIS since 1983, has a maintenance team consisting of 32 full-time and several part-time support staff.

The DCP’s Geographic Systems unit maintains two databases: the Linear Integrated Ordered Network (LION) file and the Community Oriented Geopositional Illustration Structure (COGIS) file. The files, which are the basis for the geographic information and computer-mapping capabilities throughout the city, are maintained and updated using software from Cambridge, England-based GE Smallworld.

The LION file is a schematic map that contains street centerlines, address ranges, street names and intersection identifiers. It includes a large number of district boundary overlays, such as police precincts, school districts, fire districts, census tracts and congressional districts, and it allows the city to associate addresses with all of those various districts. The city sells and distributes the LION file and district boundary files under the product name “Bytes of the Big Apple.”

The COGIS file is a graphics-only parcel file containing the outlines of all the properties in the city (approximately 1 million records). COGIS supports the extensive thematic mapping used for planning and information distribution. For planning, city staff members can make color-coded maps that indicate the ways in which land is used.

The GeoSupport System is a city-wide resource, used by all agencies. For example, there are more than three million registered voters in New York. When a voter fills out a registration form, the Board of Elections uses the system to determine the voter’s district. Also, the system is used to issue building permits and to track building code violations, safety inspections, parking meter repairs and street light repairs.

“The current services provided by DCP are vital to effective planning and communication in New York City,” says Richard Steinberg, director of geographic systems for the DCP. “Our system is extremely effective, and we save countless research hours on a daily basis. We are working on developing additional venues for using our data toward enhancing city management functions.”

The DCP is currently working in-house to match the LION data with the city’s new spatially accurate (to one foot) planimetric base map. The department expects to complete work on the project by January 2001.

To match the COGIS file to the base map, the city has contracted with Colorado Springs, Colo.-based Analytical Surveys. As part of the COGIS project, lot dimensions from the city’s tax maps are being stored in the COGIS database, paving the way for automating the tax mapping operations of the Department of Finance. Except for the lot dimension component, the department expects to complete work on the COGIS adjustment by next year. Once the LION and COGIS have been matched to the base map, city agencies will be able to map streets, properties, political and administrative district boundaries, and building outlines.