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June 2017
6-3
City of Morgan Hill
Water System Master Plan
6.4 MODEL CALIBRATION
Calibration is intended to instill a level of confidence in the pressures and flows that are simulated.
Calibration generally consists of comparing model predictions to field measured results and
making necessary adjustments.
6.4.1
Calibration Plan and SCADA
In order to calibrate the hydraulic model pressure SCADA data was collected for points throughout
the water distribution system, as well as water level data for the City’s storage reservoirs. City
staff provided 15-minute pressure data for each groundwater well and booster station as well as
15-minute water level data for the City’s storage reservoirs, for a portion of the month of August
2014. The locations that were included in the calibration for tanks, booster stations, and wells
were identified on
Figure 6.1
.
In addition, pressure loggers were installed throughout the system in an effort to enhance the
calibration effort and document system conditions away from the vertical infrastructure. Three
pressure loggers were placed at various intersections for a one-week period before moving to new
locations. In addition to these three rotating pressure loggers, one pressure loggers was placed at
a fixed point for the duration of the pressure logging program. The periods of installation for the
pressure loggers are summarized on
Table 6.1
, while
Figure 6.2
documents the points used in
the calibration of the hydraulic model.
6.4.2
EPS Calibration
Calibration can be performed for steady state conditions or for extended period simulations (EPS).
In steady state calibration, the model is compared to field monitoring results consisting of a single
value, such as a single hydrant test. EPS calibration consists of comparing model predictions to
diurnal operational changes in the water system.
The calibration process for the hydraulic model was extensive, and involved an iterative process
which resulted with satisfactory comparisons between the field measurements and the hydraulic
model predictions at each well site and the water tank. The calibration results were graphically
summarized for each site and included in
Appendix A
.
Representative extracts from
Appendix A
are shown on
Figure 6.3
for calibration points at Diana
Well Number 1 and the Edmundson tank.
6.4.3
Use of the Calibrated Model
The calibrated hydraulic model was used as an established benchmark in the capacity evaluation
of the existing water distribution system. The model was also used to identify improvements
necessary for mitigating existing system deficiencies and for accommodating future growth. This
valuable investment will continue to prove its value to the City as future planning issues or other
operational conditions surface. It is recommended that the model be maintained and updated with
recent construction to preserve its integrity.