Building a Comprehensive Stormwater Asset Inventory

The City of San Antonio (COSA) initiated a multi-year stormwater investigation and mapping program to facilitate a proactive asset management program for its 100-year old storm sewer system. Storm sewers, manholes, inlets, and catch basins, citywide, are being inspected and mapped. NASSCO standards developed for sewers are being used to grade defects in the system with risk analysis being used to formulate recommendations based on the need for maintenance planning and capital budgeting. The updated GIS is serving as the foundation for the City's preventative maintenance program. 

• The GIS integrates storm sewer schematics with condition assessment data, risk scores, and inspection video.
• Risk analytics provided the foundation for developing a citywide televising master plan that will drive ongoing CCTV programs. 
• Identified and integrated 74.2 miles of unrecorded stormwater pipeline into COSA's GIS database, through as-built research and video inspection review
• An alternatives analysis evaluated available rehabilitation options—cured-in-place pipe, sliplining, spray-on lining, or invert paving—and found the recommended methods provided savings averaging $196/LF; a 39% reduction in total cost compared to the City's original approach
• Decision trees automate the selection of the best rehabilitation method for corrugated metal pipe maintenance.