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August 2016
5-3
City of Morgan Hill
2015 Urban Water Management Plan
5.3 BASELINE PERIODS
This section discusses the baseline periods used in the UWMP.
5.3.1
Determination of the 10-15 Year Baseline Period (Baseline GPCD)
Law
To adequately project future water use, SBX7-7 must be considered with the appropriate
reductions. As part of the new requirements for reductions in water use, a range in years needs
to be selected for calculating the base daily (historical) per capita water use.
SBX7-7 allows the selection of either 10 or 15 years as a base period for calculating the average
consumption per capita. If the recycled water use exceeds 10 percent of potable water production,
a 15-year base period is allowed. Otherwise, a 10-year base period should be used. Additionally,
a 5-year base period is to be identified for interim target projections.
The 10- to 15-year base period must end between December 31, 2004 and December 31, 2010;
and the 5-year base period must end between December 31, 2007 and December 31, 2010.
The City’s calculations for the base periods are documented on the following page in
SBX7-7
Table 1
. Since the recycled water usage in 2008 did not account for more than 10 percent of the
total potable water production, the City uses a 10-year base period. The 10-year base period is
selected based on the highest average per capita water use in any 10-year period within the DWR
guidelines.
10608.12 (b) “Base daily per capita water use” means any of the following:
(1) The urban retail water supplier’s estimate of its average gross water use,
reported in gallons per capita per day and calculated over a continuous 10-year
period ending no earlier than December 31, 2004, and no later than December
31, 2010.
(2) For an urban retail water supplier that meets at least 10 percent of its measure
retail water demand through recycled water that is delivered within the service
area of an urban retail water supplier or its urban wholesale water supplier, the
urban retail water supplier may extend the calculation described in paragraph (1)
up to an additional five years to a maximum of a continuous 15-year period
ending no earlier than December 31, 2004 and no later than December 31, 2010.