Improvements to Stormwater, CSO, and Drinking Water GIS
The City of Burlington selected Weston & Sampson to update and improve their existing stormwater, combined sewer overflow, and drinking water geographic information system (GIS). The objective of this project was to review and improve the existing stormwater GIS by increasing spatial accuracy and expanding attribute data fields of existing features as well as capturing new features and data. Weston & Sampson verified, completed, and/or expanded the existing data sets for the infrastructure-related data in conformance with the city’s existing GIS. When the location of stormwater system features could not be obtained from ortho-photographs, Global Positioning System (GPS) and/or Real Time Kinematic (RTK) GPS was utilized. All manholes, catch basins, outfalls, and drain pipes were updated to have accurate data attached to a unique identifier.
When the GIS was sufficiently updated and the extents and limits of both the separated and combined systems were clear, the firm delineation of the sewersheds draining to the various lakes, rivers, and brooks was established for the Municipal Separate Storm Sewer Systems (MS4s). The tributary areas’ limits to each of the stormwater outfalls have been delineated as a layer within the GIS. The same has been completed for the combined sewer system, except that the tributary areas are the pipelines that drain to each of the three wastewater treatment plants.
Data relationships (domains, topology, attribution, and geometric networks) and management of the stormwater infrastructure inventory have been developed or confirmed as they are essential for operation, maintenance, and hydrologic/hydraulic modeling. We also provided evaluations and recommendations for asset management solutions and system hydraulic modeling. Considerations for this project include ease-of-use for city employees, maximum data accuracy, and, in general, ensuring the City’s smooth transition to using GIS as a planning and evaluation tool.