Stormwater is any water that flows over land and impervious surfaces during rainfall and snow melt events. In natural environments, stormwater is filtered by vegetation and “infiltrates”, or seeps into the ground. These processes slow runoff rates and remove pollutants before stormwater returns to surface and groundwater sources.
As natural areas become urbanized, changes in landscape properties and land development contribute to increased runoff rates, larger stormwater volumes, and the accumulation of pollutants and sediments. This is largely because impervious surfaces such as parking areas and roads prevent the water from infiltrating the ground. As this runoff flows across the land, water quality deteriorates as sediment, heavy metals, hydrocarbons, pesticides, and other pollutants accumulate.
Increased runoff rates and pollutants in stormwater can also increase the risk of flooding, damage property and infrastructure, increase the frequency of sewer overflow events, degrade water quality, reduce available groundwater, compromise the health of aquatic habitats, decrease biodiversity, increase erosion and sedimentation rates, and disrupt water flow patterns.
These impacts are very concerning to municipalities across Alberta. For this reason, AUMA has developed stormwater policies and assembled examples and resources to assist with stormwater management and infrastructure issues.
Graphic Source: Puget Sound Partnership
Graphic Source: North Carolina Department of Environment and Natural Resources
AUMA policy on stormwater management
To create an enabling environment for improved stormwater management, AUMA has developed the 2014 Municipal Water Policy on Stormwater. These policies address challenges identified through member outreach and include policy solutions on areas such as stormwater reuse, urban flooding, climate change, low impact development, and infrastructure management.