Town of Willington, CT
Des Lauriers was contracted by the Town of Willington, CT to convert the town’s sixty tax maps from analog to digital GIS format. The project involved scanning and tracing the original tax map images as well as incorporate one year of sub-division changes to the tax maps to bring the map to current year.
The Town of Willington’s tax maps presented a unique challenge, because the town’s tax maps are overlaid on aerial photograph taken prior to the creation of original mylar tax maps.
The first step was to extract the line works from the individual tax maps. With the assistant of the town’s Assessor, many unclear issues were resolved through research to find submitted plans. The second step was to obtain a more recent set of aerial photographs. These aerial photographs was registered to CT State Plane NAD27 Feet. Then the individual digitized tax maps were overlaid on the aerial photographs and positioned using major identifiable features such as street intersections, street right of way, etc to rectify the tax maps. Edge matching was then performed to ensure no gap exists across multiple tax maps to create a town wide seamless tax map. Each parcel is tagged with an attribute to provide a link to the Assessor database. All text was manually entered and double checked for accuracy. The parcel area was extracted from the Assessors database and entered directly into the map automatically. Finally, the town accepted our recommendation to add a Map number above every parcel number to identify the map in which the parcel resides.
Using AutoCAD’s paper space, individual updated tax maps including the aerial photographs was reproduced from the town wide map. This method reduces multiple editing work required for future maintenance.