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

The Barrie Creeks, Lovers Creek and Hewitt’s Creek Subwatershed Plan
3.3.2.2.
Chloride
The main source of chloride, in its various compounds, in the environment is from road salt
(Environment Canada, 2001). It enters the environment through runoff from roadways as well as
through losses from salt storage and snow disposal sites. Due to its high solubility, chloride very
easily contaminates both surface and groundwater.
High levels of chloride, such as those found in runoff water draining from roads and salt storage
yards, can damage the roots and leaves of aquatic and terrestrial plants, and can also have
behavioural and toxicological impacts to animals. Continued exposure to high chloride levels
can cause a shift from sensitive communities to those more tolerant of degraded conditions
(including a number of invasive species that are able to thrive).
Chloride loads have been modelled for Lovers Creek, using the data from water quality samples
combined with flow data, as well as a few other tributaries for comparison. Lovers Creek, as
shown in green in Figure 3-18, had increasing loads from 2001-2006, after which there is a
decrease the following year (chloride loads for 2007-2010 are currently being analyzed and will
be included in updated versions of this report). The other three subwatersheds also saw a
decrease in chloride loads during the 2006-2007 sampling period. Given that the urban area of
the subwatershed is anticipated to expand in the coming years, it can be expected that these
loads will also continue to increase unless new practices are instituted to reduce them.
Figure 3-18: Modelled chloride loads for several Lake Simcoe subwatersheds (tonnes/year) (1998-
2007)
3.3.2.3. Sediment
While a certain amount of sediment input is normal in a natural system, in larger amounts it
begins to cause a number of problems. Many contaminants, including phosphorus, bind
themselves to soil particles, and eroding soil acts as a vector for introducing these particles to
an aquatic system. There are also impacts to aquatic biota, which are discussed in greater
detail in Chapter 5 - Aquatic Natural Heritage.
Chapter 3: Water Quality – Surface and Groundwater 108