While sorting through the mountain of environmental information that I collect from Credit Valley Conservation (CVC), I came across the Watershed Report Card from earlier last year.
It got lost among the press releases, other reports and more urgent news. It is still of interest though, a snapshot of data collected from 2007 to 2011. The river changes slowly, even with climate change.
It’s not exactly news that the Erin environment is superior to that in Brampton and Mississauga, but there are concerns that put us at less than top grade.
Both climate change and increased urbanization are a threat to water quality, forests and wildlife says the Report Card, available at www.creditvalleyca.ca.
“Between 1996 and 2006 the population in the Credit River Watershed grew from 573,000 to 758,000 and this growth continues,” it says. “Responsible development practices, such as minimizing the amount of impervious cover and implementing innovative water technologies, are needed to limit the impact of land use change on Credit River ecosystems.”
The western part of the Town of Erin is in the Grand River watershed, while Hillsburgh and Erin village are part of the Upper Watershed of the Credit River, with the water flowing east towards Caledon. The area south of 10 Sideroad is part of the Credit’s Middle Watershed, where water flows towards Georgetown.
Much of the Upper area had a C grade for Surface Water Quality, based on measurements of phosphorus (from fertilizer and septic systems), E. coli bacteria and populations of invertebrates in the river. A large part of the Middle area had a B grade on the Report Card.
CVC advocates further improvement in farming methods and urban stormwater management to preserve and improve surface water quality.
When CVC studied the river for the Servicing and Settlement Master Plan (SSMP), they reported in 2010 that the surface water was relatively good, with only slight increases in pollution levels since the mid-1970s, and still below limits considered acceptable by the federal and provincial governments.
For Forest Conditions, the Erin portion of the Upper Watershed had good riparian (riverside) coverage, but ended up with a C grade. That is based on the overall percentage of forest cover, and the amount of “interior” forest (excluding a 100-metre outer perimeter) which is required or desirable habitat for some plants and animals.
Much of Brampton and Mississauga got a D or F grade for Surface Water and Forest Cover.
“Restoration and protection of natural habitats, particularly the few existing large forest patches, should continue to be encouraged to ensure ecosystem integrity is maintained and over time improved,” the Report Card says.
Ratings for Groundwater (aquifer / well water) were based on measurements from test sites – one bedrock well near Erin village and a pair of overburden (shallower) wells near Hillsburgh. They measured nitrogen and chloride, which are naturally occurring, but can be elevated due to human activity. High nitrogen can come from fertilizers and septic systems, while chloride can be elevated by road salt and water softeners.
The Hillsburgh test wells got an A grade for chloride, but a C grade for nitrogen. The Erin test well got a B grade for chloride, and an A grade for nitrogen.
This is not an issue for municipal water. The Hillsburgh drinking water system, for example, just got a 100% inspection rating in December from the Ministry of the Environment for water quality monitoring and other procedures.
Various testing, including the CVC report for the SSMP, has indicated that the deep groundwater that supplies the Erin village and Hillsburgh municipal wells has no impact from septic systems, no organic contaminants and no trace of other chemicals such as pesticides.
The Report Card has this disclaimer: “CVC monitors groundwater quality as part of the Ministry of Environment Provincial Groundwater Monitoring Network. The results presented here do not necessarily represent the quality of municipal drinking water sources.”
Water quality in private wells can vary depending on local conditions, with shallower wells at greater risk of contamination. Owners of private wells should ensure that the nearby ground surface drains properly, and take advantage of free bacteria testing offered by the Health Unit. Many also use ultraviolet and filter systems for added safety.