City of Morgan Hill Water System Master Plan 2017

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June 2017 6-1 City of Morgan Hill
Water System Master Plan
2017City of Morgan Hill
6.0 CHAPTER 6 - HYDRAULIC MODEL DEVELOPMENT
This chapter describes the development and calibration of the City’s domestic water distribution
system hydraulic model. The hydraulic model was used to evaluate the capacity adequacy of the
existing system and to plan its expansion to service anticipated future growth.
6.1 OVERVIEW
Hydraulic network analysis has become an effectively powerful tool in many aspects of water
distribution planning, design, operation, management, emergency response planning, system
reliability analysis, fire flow analysis, and water quality evaluations. The City’s hydraulic model
was used to evaluate the capacity adequacy of the existing system and to plan its expansion to
service anticipated future growth.
6.2 MODEL SELECTION
The City’s hydraulic model combines information on the physical characteristics of the water
system (pipelines, groundwater wells, and storage reservoir) and operational characteristics (how
they operate). The hydraulic model then performs calculations and solves series of equations to
simulate flows in pipes and calculate pressures at nodes or junctions.
There are several network analysis software products that are released by different
manufacturers, which can equally perform the hydraulic analysis satisfactorily. The selection of
software depends on user preferences, the distribution system’s unique requirements, and the
costs for purchasing and maintaining the software.
The City’s previous model was developed using Innovyze’s (previously MWHSoft) H20Net, which
runs inside AutoCAD and uses the effective EPANET hydraulic engine for processing the
hydraulic calculations. As part of this master plan, the hydraulic model has been updated and
redeveloped into the GIS-based hydraulic model InfoWater by Innovyze. The model has an
intuitive graphical interface and is directly integrated with ESRI’s ArcGIS (GIS).
6.3 HYDRAULIC MODEL DEVELOPMENT
Developing the hydraulic model included skeletonization, digitizing and quality control, developing
pipe and node databases, and water demand allocation.
6.3.1 Skeletonization
Skeletonizing the model refers to the process where pipes not essential to the hydraulic analysis
of the system are stripped from the model. Skeletonizing the model is useful in creating a system
that accurately reflects the hydraulics of the pipes within the system, while reducing complexities