Development of Model Calibration Guidance

As application of hydraulic and water quality modeling of distribution systems continues to increase, there is a need for guidance on best practices for developing, calibrating and using the models. Data collection technologies are rapidly evolving with the implementation of GIS and SCADA systems at many US water utilities. While many utilities are developing and using skeletonized and all-pipes hydraulic models, relatively few have fully implemented more advanced applications like water quality or real-time modeling. The use of advanced optimization algorithms for design and calibration applications remains largely in academia at this time. In a project sponsored by the American Water Works Association Research Foundation (AwwaRF), we have worked with industry leaders and academic partners to develop guidance on current modeling practices. This guidance covers the gaps between textbooks and real-world modeling applications, aimed at providing practical and helpful advice for modelers ranging from beginner to advanced levels. This paper will include discussion of the development of guidance for model input data, calibration data collection, and goodness of fit for calibration. These criteria were developed for models in several categories: master planning, water quality, and advanced applications. A Model Planning Matrix was developed to assist utilities in understanding the range of options for data collection and calibration for each model application category. This matrix provides a linkage so that users can understand how lack of data or poor calibration could impact the ability to use the model for different applications. Furthermore, the range of options provided in the matrix allows users to determine where additional investment in data collection or model calibration could increase the quality of the model for the desired application.