Floating Wetlands at Sequiota Park Lake are Designed to Reduce Algae Growth

May 9, 2018

Sequiota Park, off Lone Pine Ave. in southeast Springfield, is a popular place to walk, bike or just hang out.  But in the summer, algae blooms on the lake can make the experience not-so-pleasant.

"The unsightliness of the algae just really detracts from what would otherwise be just a nice scenic view of some nice clear water," said assistant director of Springfield-Greene County Parks, Miles Park.

According to Park, algae has always been present in the lake at Sequiota Park, but, "the last couple of years has been quite a challenge to keep that algae bloom in check, particularly during the summertime when algae continues to grow very very aggressively," he said.

Algaecides are used, but they haven’t eliminated the problem.  So, the Park Board teamed up with the City of Springfield to come up with a solution.  Last week, city and parks employees gathered at the park to launch a pilot project.  They placed 30 floating wetlands into the Sequiota Park Lake.

"The idea with the floating wetlands is we're planting them with aquatic plants, and algae is caused by a combination of warm temperatures, sunlight and excess nutrients in the water, and so the plants that we're putting in the floating wetlands will help to absorb excess nutrients out of the lake," said Carrie Lamb, water quality compliance officer with the City of Springfield.

According to Lamb, the goal is to see if the floating wetlands will be another tool in the city’s toolbox to help reduce algae.

The 4’ X 8’ cedar structures hold together recycled plastic bottles with caps on for floatation inside recycled burlap cocoa bean bags donated by Askinoise Chocolate, two layers of coconut fiber, which provide the plant medium and recycled plastic mesh, holding the fiber layers in place.  Each frame contains several aquatic plant starts that are native to Missouri:  rushes, irisis and hibiscus.  Lamb says they’ll provide habitat for pollinators as well as help control algae.  And fish will benefit as the plants will provide dissolved oxygen in the lake as well as shade and shelter in the root masses. The floating wetlands are surrounded by chicken wire to keep out waterfowl.

"There's a lot of geese and ducks here at the park, and they actually contribute to the algae problem as well.  All of the waste from them is a source of nutrients as well,  But, yeah, they would probably like to eat the little plants in the floating wetlands, so we've put mesh around each one to help keep them off of the floating wetlands," said Lamb.

The hope is that eventually the plants will take root in the substrate of the lake, and the wooden structures will no longer be needed.  Lamb said they don’t expect to entirely eliminate algae in the lake, and visitors might not see a reduction at all the first year.  She says the plants need time to grow, but they hope to see a noticeable reduction in algae growth over time. 

This is one of a few things that have been tried to reduce the amount of algae in the lake at Sequiota.  Not too long ago, the lake was dredged, and jetties of rock were placed just below the water surface around the waterway to try to prevent stagnant areas.

Lamb said the excess nutrients causing algae growth come from duck and geese droppings as well as non-point source pollution such as stormwater runoff.

She reminds residents that there are things they can do to reduce stormwater pollution such as getting a soil test before fertilizing their lawns.  According to Lamb, the City of Springfield offers free soil testing.

A sign has been placed at Sequiota Park Lake to let visitors know what the floating wooden structures are.