Master Plan Modeling
City of Corvallis, Oregon

West Yost developed a dynamic hydraulic model for the City’s water distribution system. The new model incorporates GIS, geocodes customer billing data to allocate water demand, and was calibrated using an innovative and highly effective tracer analysis.

The dynamic water model was used to optimize water system operations, refine water quality monitoring programs, and will guide future water system expansions and development. West Yost also provided City staff with “hands-on” training and technical support in the use of the dynamic hydraulic model.

A particularly innovative approach used on this project was the use of tracer analysis to help calibrate the model for future water age analysis, ultimately to assist in the confirmation of the City’s existing water quality monitoring sites for future IDSE requirements. Because the City fluoridates, the opportunity existed to perform a tracer analysis study of fluoride in order to dynamically calibrate the movement of water through the distribution system for the purposes of water age analyses and conservative water quality substance transport assessments. The fluoride tracer analysis also assisted in identifying closed valves and incorrect pipeline diameters in the hydraulic model database. Our approach was to curtail the addition of fluoride to the treated water for a period of approximately seven days in advance of the tracer analysis work so that lingering concentrations of fluoride were cleared from the distribution system. Fluoride concentration measurements were then taken every two hours at 28 sample stations over a 72-hour period. West Yost staff evaluated the field data, and adjusted the hydraulic model as necessary to replicate the field observations.

The key to the success of this project was to use the available hydraulic modeling technology in developing and calibrating the City’s hydraulic model to provide the City with a very sophisticated tool at a reasonable price. Our approach became a testing ground for a majority of the hydraulic network development tools available with today’s software programs.

The new model has become an indispensable tool for the City in ongoing system operations, water quality management, and the City’s planning efforts for expansion. We look forward to continuing to use this dynamic tool in our future decision making, planning and operational processes.” —Tom Penpraze, Utilities Division Manager. 

Industry Awards

American Council of Engineering Companies, Oregon
2008 Engineering Excellence Honor Award