Stormwater
What is stormwater?
Stormwater is rain and snow melt that runs off impervious surfaces such as rooftops, paved streets, highways, and parking lots.
As water runs off these impervious surfaces, it can pick up pollution such as oil, fertilizers, pesticides, soil, trash, and animal waste.
The water might flow directly into a local stream, bay, or lake. Or, it may go into a storm drain and continue through storm pipes until it is released untreated into a local waterway. Untreated and unmanaged stormwater can rapidly degrade water quality and create flooding hazards.
Urban Stormwater Issues
Urban stormwater can be seen as a water resource or a nuisance that should be directed off the property as fast as possible.
Stormwater that is untreated can cause human health issues, degrade water quality, increase flooding and erosion, and damage fish and wildlife habitat. The following describes some of these issues:
Human Heath Issues:
Untreated stormwater is often unsafe, is not suitable drinking water, and is not recommended for swimming. The main human health concerns in stormwater are pathogens and bacteria that can be transported from lawns, sidewalks and streets. Bacteria associated with stormwater can lead to the closure of swimming beaches and shellfish harvest because it can contain harmful bacteria and viruses. Untreated stormwater can also trigger toxic algal blooms, contain toxic metals, and organic compounds.Degrades Water Quality:
Stormwater could decrease water quality by contaminating it with oil, fertilizers, pesticides, dirt, trash, metals, and animal waste containing harmful bacteria.Increased Flooding and Erosion:
Urban areas have a lot of impervious surfaces (such as roof tops, driveways, walkways, and even compacted lawns) which increase stormwater runoff. The increase in runoff causes flooding and erosion along streams banks, altering the configuration of watersheds.Impaired Habitat:
Harmful stormwater can pollute streams and alter the streams that provide valuable habitat for fish and wildlife. Altering watersheds by clearing all shrubs and trees, and replacing those areas with pavement and other impervious surfaces increases the rate and amount of pollutants entering our local streams and lakes. This results in degraded water quality and even a loss of habitat not just in the water but on the land as well.To learn more about stormwater in the Anchorage area, visit the Watershed Management Services website at http://wms.geonorth.com/Home.aspx.