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

The Barrie Creeks, Lovers Creek and Hewitt’s Creek Subwatershed Plan
future conditions was computed for only those subwatersheds identified in as having a low
potential for stress under existing conditions. Table 4-6 contains the estimated existing and
future water demand and the percent change from existing municipal water demand.
Future municipal water demand was estimated from a variety of sources. In municipalities with
long term Water Supply Plans, future average daily water demand was obtained directly from
municipalities. For the Innisfil municipal water supply systems, projected average daily pumping
rates were not available, but projected maximum daily pumping rates were presented. The
maximum daily rates, however, do not represent typical long-term pumping conditions and
therefore are not appropriate for use in the stress assessment. For these systems, the
maximum daily rate was scaled down by a peaking factor of 2.5 to obtain estimates of average
future demand. A peaking factor of 2.5 is the average peaking factor (i.e., ratio of maximum to
average demand) for all municipal systems in the Tier Two Stress Assessment where both
average and maximum daily pumping rates were available.
Where future water demand was not directly available, it was estimated by applying either future
population growth estimates, or by applying residential development plans to existing average
daily per capita water use for each municipal water system. Future population estimates were
available for the Town of Innisfil. It was assumed that each residential unit houses 2.6 persons
as per Statistics Canada 2006 Census for Ontario, and that each person uses 348 L/day as per
the combined residential and commercial water use rate for the City of Barrie in the
Environment Canada 2004 Municipal Water Use Database.
Other Permitted Uses
Table 4-5 outlines the number of permitted groundwater takings by subwatershed and by water
use sector. For the Lovers and Hewitt’s Creek subwatersheds the non-municipal permits
account for the majority of permits issued, with the highest number being the commercial sector.
Conversely, for the Barrie Creeks subwatershed less than half of the permits issued are from
non-municipal water uses. Some of these include industrial and remediation.
Some of the water pumped for industrial, agriculture, and golf course irrigation is lost to the
atmosphere via evapotranspiration. While some may infiltrate back to the subsurface as
irrigation return flow, actual consumption (i.e. water removed from the watershed), will differ by
the specific application. In general, reported pumping rates do not consider the consumptive
nature of the taking, as the permit holders are required to report total pumping but not the
returned water volume. As such, in order to obtain consumptive demand, the reported rates
were modified by a consumptive factor, as outlined in Section 4.3.3 and shown in Table 4-11 to
Table 4-14.
Chapter 4: Water Quantity – Surface and Groundwater 187