Issue link: https://read.dmtmag.com/i/59336
City Infrastructure CITY OF MONTREAL Setting Practical Goals The centralized GIS for water and wastewater network asset management provides a global view of the net- work, and eliminates redundancies and discrepancies among data sources. The goals for the network GIS were clear: • Geo-referencing of legacy documentation and drawings of the utility networks • Centralization of information regarding water and wastewater networks • Maintenance of an up-to-date inventory of utility net- works and their associated descriptive datasets • Definition of unique feature IDs • Association of descriptive terrain-pipe analysis data with existing features • Maintenance of data integrity • Performance of spatial analysis, including net- work analysis The project team for this ambitious undertaking comprised 50 people at its peak, including field data collectors, GIS technicians, land surveyors and engi- neers. Building the spatial database was just part of a series of integrated activities associated with the intervention plan. The biggest challenge was to cre- ate a database that would answer and anticipate the needs of a majority of users, and be flexible enough for future applications. Building the Spatial Database The water and wastewater networks include more than 5,000 kilometers of water-distribution pipes, 7,000 kilometers of wastewater-collection pipes, 40,000 valves and 30,000 fire hydrants. Building the spatial database entailed activities ranging from feasibility studies to the collection, analysis and integration of spatial data. Before digitizing all the available information about the network, the city conducted a rigorous analysis to identify only the most-accurate data. The extensive inventory of existing information also provided city planners with a useful tool for all levels of intervention. For network mapping, Bentley's MicroStation was used to integrate 245,000 georeferenced field points and 220,000 photogrammetric points as well as geo- reference 100,000 paper plans. Data integrity was maintained through digitizing procedures and rules for data-drawing consistency as well as pre-defined value domains associated with each descriptive field (which is essential for efficient SQL queries). Creating the topology was a challenge, because the geometric properties and spatial relationships of objects initially weren't well defined or consistent. The solution was to create a series of validation rou- tines using FME Workbench to automatically correct 16 GEO W ORLD / MARC h 2O12 lThe georeferenced network helps city workers locate equipment and reduce the risk of breaking pipes when digging with heavy machinery. certain errors and flag objects to be manually vali- dated by a technician. The database resides on Oracle Spatial, and geom- etry and attribute data are updated on a daily basis using Bentley Map. In this project, the ProjectWise Connector for Oracle provides seamless data integra- tion between Oracle Spatial and Bentley Map, and the connector supports a multi-user environment. Oracle Spatial provides stability, flexibility and easy data, and the ProjectWise Connector for Oracle enables users to work in long-transaction workflows where necessary. ProjectWise also provides a set of reconciliation tools that allows version reconciliation, data inspection, and conflict visualization and resolu- tion for geometric and descriptive data.