Lagoons 411

By Lynn Lewis - lynnl@landings.org
Communications Manager

When many people look at The Landings’ 151 lagoons, the first word that comes to mind is beautiful, but for The Landings Association’s Public Works Director Sean Burgess, the first word that comes to mind is functional.

“The lagoon system serves a multitude of functions for the community beyond aesthetics,” he said. “They were designed by engineers to provide proper drainage for the island. This was especially helpful during 2016’s Tropical Storm Hermine and Hurricane Matthew, as well as 2017’s Hurricane Irma.”

Of the 151 lagoons, 54 have water control structures whose primary function is to control water levels and storm water overflow. These water control structures have an estimated lifespan of 30 years each and are evaluated annually by Public Works staff in conjunction with the Thomas and Hutton Engineering Study of Lagoons, Dikes, and Structures.

Burgess said it is very important to keep a close eye on all 151 lagoons year-round, but especially during certain seasons such as summer.

“The summer season historically is the most difficult time to manage the lagoons, as plant growth increases with water temperatures,” he said. “In addition to increasing water temperatures during the summer, other weather factors can immediately and dramatically impact a lagoon’s water chemistry.”

During the summer, it is common to experience heavy rainfalls. Burgess said this rain results in an increase in the amount of nutrient runoff from the turfed areas of the community. This nutrient-rich runoff causes an increased growth of filamentous algae, which is one of the most recognizable plants in the lagoons during this time of year.

“These algae mats grow on the bottom of the lagoon and trap gasses from the sediment, which causes them to float to the surface,” he said. “Herbicide treatments will remove the majority of the mats floating on the surface. However, these treatments are not intended to control any future infestations. In addition, herbicide treatments become less effective this time of year as plants reach the top of the water column. Submerged vegetation which has reached this stage is less likely to uptake the herbicides since they become semi-dormant in their growth.”

The Landings Association employs two spray technicians dedicated to lagoon maintenance. These technicians treat all lagoons within the community on a two-week cycle, with lagoons that have recurring problems being treated more often. If your lagoon is experiencing this summertime algae growth, please contact the Association’s Public Works Department (598-5509).

Burgess said another interesting occurrence affecting lagoons during summer months is higher-than-normal tides. “This results in brackish lagoons being inundated with saltwater,” he said. “The mixing effect of the saltwater rushing into the brackish lagoons causes the ponds to turn over, resulting in a depletion of available oxygen, a drastic increase in salinity, and the ponds turning a milky brown color with sediment.”

He added this dramatic change in the lagoons’ water chemistry causes many of the baitfish and some game fish species to die.

“In instances such as this, staff clean up and remove all dead fish from the lagoons to prevent further oxygen depletion through decomposition,” Burgess said. “Oxygen and salinity levels in these lagoons will stabilize naturally. We want everyone to know we always are working to make sure our lagoons are both pleasing to look at and functional. Although some of the seasonal impacts are beyond our control, when they occur, we do everything possible to get our lagoons restored to their former beauty as quickly as possible.”

For more information about The Landings’ lagoons or to report a problem with a lagoon near you, please call The Landings Association’s Public Works Department (598-5509). You also can report the problem via SeeClickFix.

If you have yet to create an account, there is no better time to do so than today! The mobile app is available for download on Android and iPhone by searching for The Landings Association in the respective app store. In addition to the mobile app, residents can send reports via website (http://en.seeclickfix.com/landings-association) or by clicking Report an Issue/SeeClickFix on the Association’s homepage (www.landings.org). The customized app also gives residents the option to access The Landings Association’s website (www.landings.org) and social media accounts (Facebook, Twitter, YouTube, and Instagram).