Barrie Creeks, Lovers Creek, and Hewitt's Creek Subwatershed Plan

The Barrie Creeks, Lovers Creek and Hewitt’s Creek Subwatershed Plan
4.3.3 Water Demand Estimation
The water demand component of the water budget refers to water taken as a result of an
anthropogenic activity (e.g. municipal drinking water takings, private water well takings, as well
as other permitted takers). The water demand has been estimated from a number of information
sources, including the Permit to Take Water (PTTW) database, population estimates, and water
well records. This section provides a summary of the consumptive groundwater demands for
Barrie, Hewitt’s, and Lovers Creek subwatersheds assessed as part of the Tier Two Stress
Assessment (AquaResource and Golder, 2010).
Consumptive groundwater demand refers to water that is taken and not returned to its original
source (i.e. aquifer) within a reasonable amount of time. Understanding this type of water
demand is critical to the development of a water budget framework. An estimate of the extent
and variability of water use throughout the study area is required to identify the subwatersheds
that may be under the highest degree of potential hydrologic stress, and to guide future efforts
to refine water budget tools in those areas (AquaResource and Golder, 2010).
The consumptive groundwater demand was estimated for both permitted (e.g. municipal,
industrial, and commercial water users) and groundwater takings that don’t require a permit (i.e.
domestic water users extracting less than 50,000 L/day and agricultural water users). Table 4-5
shows the number of groundwater takings by subwatershed and water use sector. Figure 4-19
and Figure 4-20 show the average annual and monthly maximum consumptive groundwater
demand estimates, respectively, for each Tier Two Stress Assessment subwatershed. These
estimates are used to compute the subwatershed potential stress under existing conditions
(AquaResource and Golder, 2010).
Reported pumping rates were used to generate the municipal demand, while other permitted
water demand was estimated by combining the permitted rate with the months of expected
active taking. Non-permitted water demand was estimated by area pro-rating the non-permitted
demand estimate from the Tier One stress assessments (SGBLS, 2009). Future consumptive
demand was also estimated for the subwatersheds not identified as potentially stressed under
existing conditions. After the consumptive demand was estimated a consumptive factor was
applied to determine the proportion of groundwater not returned to the original source within a
reasonable amount of time. Existing and future water demand can be found in Table 4-6. The
consumptive factors used are outlined in Table 4-11.
Table 4-5: Number of groundwater takings by subwatershed and water use sector (AquaResource
and Golder, 2010).
ID
Subwatershed
Agricultural
Commercial
Industrial
Miscellaneous
Recreational
Remediation
Water Supply
Total
28 Hewitt’s & Lovers Creek 0 12 0 0 0 0 5 17
22
Barrie Creeks (includes a small portion of
Willow Creek that contains Barrie Wells)
0 0 1 2 0 5 14 22
Chapter 4: Water Quantity – Surface and Groundwater 172