Algae

During the summer months it is common to see algae on waterbodies throughout Strathcona County. This includes on lakes, wetlands, creeks and stormwater management facilities.

Algae occurs naturally during warm summer months and can last into early fall. It is important to keep healthy amounts of algae as they provide oxygen and food to other organisms like fish living in our stormwater management facilities.

Algae and weeds are part of a natural wetland system. However, fertilizers from lawns enter the stormwater ponds when it rains giving the plants extra nutrients to grow beyond their natural size and population. When this excess material begins to decompose, it uses oxygen from the stormwater pond, which can harm fish and other critters living in the water.

Why is the water so blue?

As an alternative to pesticides, which can affect living organisms, a blue, vegetable-based dye is occasionally applied to stormwater management facilities in an attempt to control algae and weeds in the facility.

Algae requires sunlight to grow. The dye temporarily blocks sunlight from the algae, slowing its growth and reducing the occurrence of algal blooms on the pond. Other plants and wildlife, including ducks, geese and pets will not be harmed by the blue dye, but feathers and fur may be temporarily discoloured following contact with the water.

Reducing excess algae growth

Establishing and managing vegetation is essential to how a stormwater facility is designed and works. Naturalized stormwater facilities have shoreline buffers with cattails, shrubs, trees and grasses. With more naturalization, less nutrients are washed into the pond, which reduces algae growth.

Make sure your landscaping is contained within your property, and allow the shoreline of the stormwater facility to naturalize. Adding vegetation like shrubs, trees and native grasses around waterbodies increases shade which lowers water temperatures, these plants also soak up added nutrients that can cause increased algae growth.

Reduce or avoid the use of quick-release synthetic fertilizers and help keep nitrogen and phosphorus from entering waterbodies.  A good alternative is compost which is a slow-release fertilizer for plants that also holds water, making it great for water conservation as well.