Asset Inventory Collection and GIS Mapping

case study: storm sewer infrastructure inventory collection and GIS mapping

The Region of Peel (population 1,250,000) is centrally located in the GTA and encompasses the Cities of Mississauga, Brampton, and Caledon. The Region covers an extensive area of 1,250 km² with 450 km of major arterial roads. Andrews.engineer (A.E) was retained by the Region to map and document the storm drainage network for the entire 450 km of regional road network. The project required centimetre mapping accuracy for GPS points and high-accuracy rim to invert measurements. Asset mapping is intended to be used for future condition assessment inspections, hydraulic modelling, and ongoing maintenance activities. The inventory collected includes storm sewer pipes, maintenance holes (MHs), catchbasin maintenance holes, catchbasins (CBs), curb inlets, catchbasin leads, and storm water inlets and outfalls.

Inventory collection included the following activities:

• Pre-inspection data preparation, mapping and planning
• Field inventory documentation, measurement and sewer system mapping following NASSCO PACP and MACP standards for all storm water related assets
• Storm water point asset GPS collection utilizing centimeter accuracy GPS units (Trimble Geo7x)
• Field data verification and validation by referencing available as-constructed plans and drawings
• ArcGIS geodatabase development and mapping of collected inventory and storm sewer network

A.E was retained in April 2016 with a mandate to complete all data collection, mapping, validation and final geodatabase creation within an 8-month period. This aggressive schedule required A.E to plan and organize multiple field crews to inspect document and map 11,300 asset points including 5,000 MHs, 6,000 CBs, and 300 outfalls.

Due to the high level of accuracy requirement, A.E developed a variety of techniques to accurately measure sewer depth and performed selective internal data verification to ensure data quality. As-built drawings provided by the client were used to verify all sewer network connectivity and pipe information to ensure system integrity. A.E successfully delivered all of the prescribed work within a 4-month period, 4 months ahead of schedule.