City of Morgan Hill Sewer System Master Plan 2017

City of Morgan Hill Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study

RESULTS AND ANALYSIS Rainfall: Rain Gauge Data

V&A utilized rain data from rain gauges maintained by local weather enthusiasts. While V&A performed QA/QC analysis to ensure, to the extent possible, the quality of the rainfall data from the three rain gauges used, it is noted that V&A has no direct control over these gauges. There were five rain events stacked over seven days from February 26 to March 5, 2014. The largest individual rain event occurred on February 28, 2014 and this event was used for infiltration and inflow analysis for this study. Table 5 summarizes the rainfall data collected for this study. Figure 10 graphically displays the rainfall activity recorded over the flow monitoring period (average of the three rain gauges shown).

Table 5. Rainfall Events Used for I/I Analysis

RG WEST Event Rainfall (in)

RG EAST Event Rainfall (in)

RG SOUTH Event Rainfall (in)

Rainfall Event

Event 1: February 28 – March 1, 2014

1.74 3.16

2.16 3.34

2.26 4.06

Total over Monitoring Period

Total Rainfall over Period: 3.52 inches

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55

2.05 inches

1.17 inches

Rain (inches per hour)

1-Mar

2-Mar

3-Mar

4-Mar

5-Mar

6-Mar

7-Mar

8-Mar

9-Mar

10-Mar

11-Mar

12-Mar

13-Mar

14-Mar

15-Mar

16-Mar

25-Feb

26-Feb

27-Feb

28-Feb

Figure 10. Rainfall Activity over Flow Monitoring Period (Avg. of Rain Gauges)

12-0248 AEG CofMorganHill FM Rpt.docx

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