The construction of small wetlands along the edges of Fountain City Lake is getting underway this week.
In May, City Council unanimously authorized a $249,000 contract to construct the wetlands – the final step in the City’s long-range plan to upgrade the lake’s infrastructure and improve its water quality.
Savannah, Tenn.-based Ronald Franks Construction Co. will be building the wetlands over the next four months. The project is anticipated to be completed by late fall 2017.
This week, the water level in the lake is being lowered, and the walkway around the edge of the lake will be closed due to the construction.
The aim is to improve circulation of water in the lake, and deepen the lake, to discourage algae from forming.
City stormwater engineers and Lions Club members opened up the outlet apparatus on Monday to begin drawing down the water in Fountain City Lake. Construction will begin soon on new wetlands aimed to improving the lake's water quality.
The project basically involves creating a small wetland on a western patch of the lake and a larger wetland on the northeastern edge. Each wetland will be strategically placed to eliminate shallow, stagnant zones of water that for years have encouraged the growth of thick algae. The wetlands will total less than a fifth of the 1.1-acre lake.
Each constructed wetland will incorporate a gabion, rip rap stone base and gravel filtration layer, topped with native wetland plants.
The deeper lake will allow less sunlight to penetrate the water to the floor; both the depth and the lake’s cooler temperatures make it less conducive for algae to form. The lake’s water will circulate better, flowing from springs on the northwestern end to the outlet across the lake, without the two stagnant zones where water doesn’t churn. In addition, the new aquatic plants will suck up nutrients in the water – mostly from waterfowl feces – that now accelerate algae growth.
The wetlands construction is the last major step in a three-year series of infrastructure investments, totaling about $500,000, made by the City.
Previously, the City and its contractors have repaired a leak in the earthen berm that surrounds the lake, allowing the water to deepen to healthy levels. Crews have repeatedly drained, cleaned and treated the lake, and inappropriate species of fish have been relocated. Algaecide has been sparingly added.
Last year, work was completed on the lake’s fountain system and pumphouse to increase aeration, which helps control algae growth by adding oxygen to the water, agitating the water and reducing stagnation.
Construction of wetlands is expected to help reduce algae growth in Fountain City Lake. This photo was taken Monday, as the water drawdown was beginning to accommodate the wetlands project. The walkway circling the lake will be closed through late fall 2017.
Parks and Recreation Director Joe Walsh observes the Fountain City Lake drawdown on Monday. Temporarily draining the lake is necessary as crews begin construction on small wetlands, aimed at improving the lake's water quality.