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August 2017
6-9
City of Morgan Hill
Sewer System Master Plan
During the V&A flow monitoring program; three rain gauges was set up in the City to record storm
events during the monitoring period shown on
Figure 6.2
. Data from the V&A flow monitoring
effort, as documented in the 2014 V&A Flow Monitoring Program, was used in this analysis to
calibrate the computer hydraulic model to average dry weather flow (ADWF) and peak wet
weather flow (PWWF) conditions.
6.3.3
Dynamic Model Calibration
The calibration process was iterative as it involved calibrating each of the 10 flow monitored sites
and for the three calibration conditions: 1) peak dry weather flow, 2) peak wet weather flows from
storm rainfall Event No. 1, and 3) peak wet weather flows from storm rainfall Event No. 2.
The rain events of February 26, 2014 to February 27, 2014 (Event No. 1) and February 28, 2014
to March 1, 2014 (Event No. 2), as listed on
Table 3.4
, were used to calibrate the hydraulic model
to the wet weather conditions. The diurnal curves for each of the 10 sites were extracted from the
2014 V&A Flow Monitoring Program and the data was used for comparison purposes with the
hydraulic model predictions. The calibration effort continued until it yielded acceptable results for
each site and for each of the three calibration conditions.
The calibration results for each flow monitoring site are documented in
Appendix B
. These
results indicate the calibration effort yielded reasonable comparisons between the flow monitoring
data and the hydraulic model predictions at the 10 sites. Representative extracts from
Appendix
B
are shown on
Figures 6.3
and
6.4
. After each of the calibration process has been completed,
the hydraulic model was benchmarked for further analysis and evaluation.
6.3.4
Use of the Calibrated Model
The calibrated hydraulic model was used as an established benchmark in the capacity evaluation
of the existing sanitary sewer system. The model was also used to identify improvements
necessary for mitigating existing system deficiencies and for accommodating future growth. The
hydraulic model is a valuable investment that will continue to prove its worth to the City as future
planning issues or other operational conditions surface. It is recommended that the model be
maintained and updated with new construction projects to preserve its integrity.