SAN ANTONIO – An invasive plant, water hyacinth, has taken over Elmendorf Lake next to Our Lady of the Lake University.
In 2012, voters from the City of San Antonio approved a bond of $14.25 million to make improvements to Elmendorf Lake Park. Some improvements included bioswales and aerators that help reduce surface runoff of containment and sediment and oxygenate the water for fish and other wildlife as part of the project.
Over the summer ’19, the invasion of water hyacinth made its appearance in Elmendorf Lake causing negative impacts to life in the lake. The invasion of the plant takes away from the benefits of the project.
Water hyacinth is native to areas in the Amazon and according to gardeningknowhow.com the plant can double its size every 8-to-12 days and needs full sun and hot summer temperatures.
“No one can be sure where it came from, but it was likely brought to Elmendorf Lake from an animal that ate their seeds, likely a bird,” said Briana Salas Ph.D., Assistant Professor of Environmental Science. “It is illegal to possess water hyacinth in Texas because of its invasive tendency.”
Salas claims the water hyacinth has no benefit to Elmendorf Lake and is a real problem that poses negative impacts on life in the lake.
“In addition to blocking sunlight, I am concerned with the effect the hyacinth will have on oxygen concentrations in our lake,” said Salas. “Once the plants begin to dieback they will begin to get broken down by bacteria and invertebrates, which will use up most of the oxygen in the water and could cause hypoxia/anoxia.”
The process is called eutrophication—when oxygen content gets too low, it can cause many of the organisms living in the lake to die.
Catalina Sanchez, a public relations sophomore, reflects on the beauty of Elmendorf Lake when first attending OLLU in fall 2018.
“When first attending OLLU it [Elmendorf Lake] was beautiful, I would listen to music and walk around the lake and the water was filled with ducks and everything was just beautiful,” said Sanchez. “Coming back for my second year, the up-keeping of the lake is slowly declining, my escape is deteriorating because of the disgusting weeds.”
Salas stated she spoke with someone from San Antonio Parks and Recreation and they are aware of the problem and trying to fix it, and according to Connie Swann, marketing manager for the department, the city has begun manual removal of the plant.
“The manual removal of the plant started on July 18 and no chemicals will be used in this process,” Swann wrote in a statement. “Our team will continue to remove the plant from Elmendorf Lake until the project is complete.”
Salas added the issue has the potential to be devastating to our lake and easily spread to other waterways in San Antonio if not taken care of.
“They also have to properly dispose of the plants they remove from the lake because birds can just continue to eat the plants that were removed and spread them even more,” said Salas.
Since Swann’s statement, the invasion of the plant continues to spread.
Salas suggests emailing and calling your local representative and putting pressure on them to urge the city to find a solution.