Utilities Data Conversion – Case Study

Project Background

The Town had the opportunity to develop infrastructure design and maintenance for their water and sewer facility network. The scope of the project was to convert the existing storm and sanitary sewer maps to digital GIS database using the provided Mylar maps, having sewer subdivision updates and digital basemap as reference. The Town sought a comprehensive and updated central database of all assets related to sewer and drinking water in a format that enabled efficient tracking and management of assets, and improved decision making and e-governance. The database also served to help the planners and designers for future planning of assets and assessing the condition of sewerage and water supply services.

Project Scope

Sanborn executed the conversion of the Town’s infrastructure to a comprehensive GIS database by scanning and registering the Sewer map to the base map. Using heads-up digitization, all the storm and sanitary features were captured using the CAD environment, ensuring the flow direction. The project also included assigning pre-defined attribute information to Pipes, Manholes, Catch basins and Outlets by referring to the existing Mylar Maps. The data was subjected to quality control processes to ensure proper network connectivity and flow direction was maintained. After validation, the final database was delivered to the Town as per the required format.

Additional Services

Sanborn provided parcel mapping for unincorporated areas of the Town of Mamaroneck, the Village of Larchmont and a portion of the Village of Mamaroneck. In total, 8,596 parcels on 272 Mylar tax maps were vectorized into an AutoCAD format. The maps were edge matched to create a seamless mosaic. Block centroids were generated and attributed with PIN which would be used to link to the Town’s RPS database. Additionally, over 200 easements were digitized using COGO methodology.

Individual layout tabs were created with the AutoCAD file which allowed the Town to perform any edits to the mosaic and plot scaled reproductions of the original tax maps. Each plot contained an overlap of adjacent tiles which were shaded to emphasize the data within one particular map. The parcels and centroids were imported into a custom geodatabase. The resulting feature class was linked to the Town’s RPS database.