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

The Barrie Creeks, Lovers Creek and Hewitt’s Creek Subwatershed Plan
Key points – Current Hydrogeologic and Water Quantity Status:
• The physical properties within a watershed, such as drainage area, slope, geology
and land use can influence the distribution of the water and the processes that
function within a watershed.
• Monitoring groundwater levels can characterize baseline conditions, and assess
how groundwater is affected by climate change, seasonal fluctuation, land and
water use. Monitoring groundwater levels can help identify trends and emerging
issues, and can provide a basis for making informed resource management
decisions, measure the effectiveness of the programs and policies that are
designed to protect these groundwater resources.
• A refined understanding of the aquifer systems and groundwater flow as part of the
subwatershed components and processes is vital in maintaining the ecological
balance and sustainability of resources within a watershed.
• The water level maps for the subwatersheds show that there are cross boundary
groundwater flows within the major aquifer systems that support the City of
Barrie’s main aquifer system.
• Groundwater discharge is the main component of streamflow during dry periods
and as such maintains an environment that allows cold water fish to survive even
during the dry summer months.
• Groundwater recharge can be described as areas that can effectively move water
from the surface through the unsaturated soil zone to replenish available
groundwater resources. The mapping of these recharge zones show that the most
significant recharge within the subwatersheds occur within the western portion of
the subwatersheds and is associated with high permeability (sand & gravel)
materials.
• Surface water flows are a function of overland runoff and groundwater discharge
(baseflow). The hydrographs for Lovers and Hewitt’s Creeks show that both
systems demonstrate a rapid response to precipitation events and typically short
recession to baseflow conditions, likely due to the relatively high degree of
urbanization, increased slope and small size/lack of storage of the Lovers Creek
and Hewitt’s Creek watersheds compared to other Lake Simcoe Watersheds.
• An examination of the Baseflow Index at a yearly scale shows that greater than
60% of the flow in the Lovers Creek comes from baseflow as opposed to surface
runoff. This suggests that groundwater discharge is a substantial contributor in this
subwatershed and is a good indication of stable year round flow, which is
important for maintaining the ecological functions of the Creek.
• The ESGRA areas are seen to loosely correlate with the areas of mapped SGRAs.
In both Hewitt’s and Lovers Creeks, ESGRAs are dispersed around their
catchments roughly extending to the tips of the headwater tributaries; whereas in
the Barrie Creeks area, little of the recharge that occurs in the catchment is
modelled to discharge in any streams.
Chapter 4: Water Quantity – Surface and Groundwater 184