Tax Maps: From Fabric to Digital Mapping

Amanda-Paton_3x4 Tax Maps: From Fabric to Digital Mapping
Amanda Paton, GIS Technician, Maser Consulting PA

Property taxation in the United States dates back to the original pilgrims at Plymouth, Massachusetts. They created a set of laws regarding taxes and assessments of their part of the fort that they built to protect them from the perceived threat of the native Americans.  The first tax mapping originated in the 1670s in Boston where the assessors listed assets and value.

In the early stages of development, these maps detailed the metes and bounds of each property. They were drawn manually and many times were printed on animal skin (vellum) or linen fabric. As time moved on, maps were drawn on linen fabric or Mylar which had the risk of a decline in durability and readability as time passed. Additionally, the risk of human error also contributed to some inaccuracies since maps were drawn by hand while walking in the field which could potentially skew the courses. Storing these records was also problematic since they were cumbersome, large, space-eating records that were rather impractical by current standards.  Today, the use of digital tax mapping performed with Computer Aided Design/Drafting (CADD) and more recently, Geographic Information Systems (GIS), has advanced the tax map system in both practicality and accuracy.

New Jersey is a very diverse state with an ever-changing landscape and new development happening everywhere you look. Property boundaries are constantly being maneuvered to accommodate consolidation and/or subdivision. In this State, the use of tax maps is required to assist with the assessment and taxation of property. It’s important that these property records are maintained with as much accuracy and consistency as possible so property owners can be properly taxed. To assist in this process, the New Jersey Division of Taxation has prepared a manual outlining the regulations and standards of tax mapping to ensure the consistency of tax maps between NJ municipalities.  The Manual also outlines requirements such as what information must be included on each tax map and how it is displayed such as line weights and text styles.

The City of Elizabeth, one of New Jersey’s largest cities, is a great example of the diverse environment the state has to offer. The City combines small streets for houses, larger areas for industrial facilities, a few main roads for retailers and scattered parks, all split up by main highways and the Elizabeth River. A large section of the City is dedicated to the Newark Liberty International Airport, the Port of Elizabeth and a large network of railroads. For a city as established as this one that is constantly redeveloping, it is more important than ever for tax maps to be easily accessible and updated.

The New Jersey Division of Taxation’s standard has been mainly CADD-based which utilizes the accuracy of a computer while allowing for the digital storage of maps. Going digital has been a big step forward in tax mapping toward both accuracy and practicality. Of course, it’s necessary to keep a printed set of each city’s tax map, but keeping digital copies of outdated, historic versions is more practical.

Taking the ease of use and accuracy a step even further has been the introduction of Geographic Information Systems or GIS. Relatively new to the state as a means to prepare tax maps that meet NJ State standard, GIS is a more forward-thinking technology in comparison to CADD that even furthers the advancement of creating tax maps. Not only does it continue the accuracy and practicality that was observed with CADD mapping, GIS combines the power of a database linked to the mapping which enables each parcel to have its own specific features recorded right in the data including the block number, lot number, area, and almost any other detail you want.

As one of the few companies in New Jersey currently using GIS to create tax maps, Maser Consulting’s GIS team employed powerful Esri parcel fabric technology to develop a plan to convert the City of Elizabeth’s 229 detail sheets. Esri, an international supplier of geographic information system software, web GIS and geodatabase management applications, developed a means to migrate the City’s data to this parcel fabric as one continuous dataset that can be used to create tax map sheets in GIS that comply with New Jersey’s Division of Taxation’s Tax Map Regulations and Standards.

The parcel fabric offers a way to maintain a seamless surface of connected parcels in one dataset. This ensures that there are no gaps or overlaps in the parcel data. Parcel polygons consist of lines that are plotted using coordinate geometry based on the legal description in the deed. Each parcel can be associated with a deed or record plan as the source document, therefore tracking the accuracy and source of the data. Another benefit of the parcel fabric is its ability to track historic parcel data. As lots are consolidated or subdivided, the original lot is given an end date and is stored within a historic parcel layer. This provides a way to view the history of the parcel dataset, an essential tool when redevelopment is always occurring.

The parcel fabric leverages Esri’s Local Government Information Model providing a standard data model for maintaining important attributes for each parcel. These attributes allow the parcel dataset to be linked with the City’s tax assessment database. A major benefit of the seamless parcel fabric in GIS is that it is georeferenced to real-world coordinates which enables it to be overlain with other GIS data such as Flood Hazard lines, which are to be shown on the tax maps according to the Division’s standards.

The parcel fabric technology offers an effective way to create, maintain, and share parcel data and digital tax maps. GIS has inevitable potential to be the new standard for tax maps.