Interactive Decision Tree Automates Sewer Rehabilitation Planning

CDM and the City of Columbus (City) developed a comprehensive infiltration and inflow (I/I) remediation plan for a 5000-acre area with historical basement backup problems. This plan identified locations and causes of public and private I/I and provided conceptual designs to reduce I/I and prevent basement backups.The project utilized an innovative, custom GIS application to efficiently summarize sewer defects and provide prioritized initial sewer improvement recommendations. The tools provide a point-and-click interface to a user-defined set of structured query language (SQL) statements that aid analysis and decision-making. The SQL statements are issued against the GIS sewer pipes layer, joined to a CCTV inspection database in NASSCO PACP© format. Selection queries show immediate results in the GIS selection set. Update queries apply weight factors, classifications, or recommendations to pipes that meet criteria as defined in the tree.