How Operations Collaboration Lead to a Successful Unidirectional Flushing Program

Last Modified: Aug 10, 2018


  • Troy McPherson, Kyle Ballance - Hazen and Sawyer
  • Shane Majetich - Hydromax
  • Will Morris - City of Portsmouth

The City of Portsmouth’s existing Unidirectional Flushing Program was a paper-based program developed in 1998. The City’s distribution system consists of over 400 miles of water mains, approximately 2500 fire hydrants and over 5000 valves, of which over 60% is fully depreciated. The last execution of unidirectional flushing was during the 1999 to 2001 period. With limited resources, hard copy records and a schematic hydraulic model, the City recognized the need to update their program and systems to facilitate long-term maintenance and regular updates.

This presentation describes a team effort that included close collaboration with field operations staff to effectively convert an existing hard copy system to a GIS based system with mobile access while simultaneously performing condition assessment of valves and hydrants, hydrant testing, hydraulic model development and calibration as well as capital improvement planning budget projections.

This presentation will help other water utilities navigate the challenges of updating and implementing a Citywide UDF program, recognize potential problems and implement proven strategies and solutions.

To date, the project team has performed and documented condition assessment on 8,600 valves, and 2,500 hydrants, converted system wide hard copy records and operational data to electronic format, developed and calibrated a comprehensive extended period water model and began development of flushing logs and field execution. Project is schedule to be complete in August of 2018.

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