Protecting Water

Why a bylaw?    To Protect and Restore our Waterways

Calgary has two beautiful rivers running through it - the Bow and the Elbow.  The Bow River is internationally renowned for its trout fishing.

Typically, a large percentage of chemical pesticides and fertilizers used on city yards wash off into gutters, sewers and then into waterways when it rains or when the yards are watered.  These chemicals can be destructive to the ecosystem of life (fish, plants, insects)  in those waterways.

In a U.S. Government survey done from 1992 - 2001, 83 % of urban streams were found to have levels of pesticides that exceeded what was considered safe for aquatic life. The Alberta Government Pesticide Index found that the Bow River’s water quality goes from excellent at Cochrane to fair at the Carseland Weir east of Calgary, after running through Calgary. A 2005 survey of pesticide monitoring in Alberta surface water found the pesticide index was worst for irrigation canals and urban streams, with over 75% of those having poor to marginal levels.

Pesticides are also then found in the drinking water of those downstream from Calgary and while the pesticide levels rarely exceed what is thought to be harmful to human health, an Alberta scientist writes:
"there are uncertainties about how comprehensively pesticide risk in surface waters can be assessed using current guidelines. "

"These uncertainties stem from the unavailability of guidelines for over half of the pesticides detected in Alberta surface waters, the fact that guidelines apply to single compounds, and that many samples have multiple pesticide occurrences or multiple incidences of non-compliance." (3, page iii)

Using natural landscaping practices rather than pesticides can help protect and restore the life in our beautiful rivers and keep them safe for all.


1) U.S. Geological Survey, U.S. Department of the Interior, “Pesticides in the Nations’ Streams and Ground Water, 1192-2001 - A Summary”,
2)  Alberta Environment, “River Pesticide Index”,
3)  Anne-Marie Anderson, “Overview of Pesticide Data in Alberta Surface Waters since 1995”, Environmental Monitoring and Evaluation Branch, Alberta Environment, Nov. 2005.

Click here for more actions you can take to support a pesticide bylaw to protect our waterways.
Click here for how to use natural landscaping practices in your yard.

Brenda Biddell’s son

"I want to live in a Calgary where our landscaping is healthy for our rivers and groundwater"

Brenda Biddell - mother of the backyard swimmer!