Municipal

Background Towns and cities use water from rivers, lakes and/or groundwater sources. While we have come to accept that there are seasonal changes in both the supply and municipal need for water, it is becoming clear that climate change will also influence water levels and create uncertainty for the future of Alberta’s freshwater resources. There is also concern that municipalities may not be completely successful in their attempts to treat the water that returns to the rivers via household drains and storm sewers. Despite best efforts, high levels of nutrients, sediments, and bacteria can still reach the rivers. If Alberta’s water supply is to remain a sustainable resource for the future, city residents will have to become more sensitive to the ways that their water use might harm downstream ecosystems Facts Approximately 15% of the water drawn from Alberta’s waterways is for municipal use. Learn more Concerns A growing human population and the impacts of climate change on river ecosystems will put a bigger burden on Alberta’s freshwater resources. Learn more Urban stormwater returned to the rivers may contain high levels of nitrogen, phosphorous, suspended sediment, and bacteria. Learn more EXPLORE some FACTS about Municipal Water Use: More about municipal water use: About 15% of the water that is “allocated” in Alberta is used by the two million people who live in Alberta’s towns and cities. Water allocation refers to the water that is designated for a specific human use (e.g., used in and around the home). Most of the water allocated is derived from rivers, but some also comes from lakes, groundwater, and man-made reservoirs. Treatment is required both before and after water use because about three-quarters of the water is returned to the land. This effluent can have a large impact on the receiving water body since nutrients, chemicals, metals, and pathogenic organisms may be present depending on the discharges and effectiveness of treatment. Many improvements have been made to existing wastewater treatment facilities in order to account for the growth of cities. Resource: An 18 page document produced by Alberta Environment, How We Use and Influence Aquatic Ecosystems. EXPLORE some CONCERNS about Municipal Water Use: More about the future of Alberta’s freshwater resources: As the population of Alberta grows, there will be larger demands placed on municipal water supplies. Sixty-seven percent of the water flowing in the South Saskatchewan River basin has already been allocated for human use. Work is under way to monitor and examine the impact of climate change on the Bow and other glacier-fed watersheds. This work is trying to determine what impact climate change will have on the seasonal variations in the amount of water that is held in the rivers and groundwater. Some think that as the glaciers shrink in size, glacier-fed rivers such as the Bow River will experience lower summer-time flows. Lower flows would have an impact on the quality and availability of aquatic habitats. Presumably, lower flows would also mean that streams and rivers would drop some of the sediment that they would normally be able to carry. Clearly, there is an uncertain future for Alberta’s freshwater resources. However, monitoring programs are in place to detect changes and to provide data that will help solve specific problems such as increased sedimentation. Resource: A web page produced by the Government of Alberta, Alberta’s Water Resource More about urban stormwater: The water that runs off our lawns and streets comes into contact with fertilizers, gasoline, car exhaust and all sorts of “nasties.” When this stormwater returns to Alberta’s rivers it tends to contain nitrogen, phosphorous, suspended sediments, and bacteria. Not surprisingly, these excess “nutrients” have an effect on river ecosystems. The fertilizers and “nutrients” encourage the growth of algae. These mats of algae (“algal blooms”) cover the water surface and block sunlight. Eventually the algae dies and as it decomposes it gives of foul smelling gases and uses up oxygen that is dissolved in the water. Starved for oxygen, fish and other organisms also die off along with the algae. Chemicals and pollutants in the water can also chemically bind with sediment and be transported downstream. Clearly, deteriorating water quality in any river should alert us to the need for better treatment systems and better efforts by city residents to keep unwanted nutrients and chemicals out of the stormwater. Resources: A web page produced by the Bow River Basin Council, Emerging Water Quality Issues in the Bow River Basin.