Lake Hartwell is one of the Southeast’s most beautiful recreational lakes, spanning the Georgia–South Carolina border and supporting fishing, boating, and wildlife habitat. But beneath its calm waters, an ecological threat continues to grow: invasive aquatic plants. These non-native species can quickly take over coves, choke out native vegetation, and disrupt the lake’s natural balance.
Knowing how to spot invasive plants early is the best way to stop them from spreading. Here’s what to look for and what to do if you find one.
Why Early Identification Matters
Once invasive aquatic plants establish themselves, they can be nearly impossible to eliminate. According to the U.S. Army Corps of Engineers’ Aquatic Plant Management Plan for Lake Hartwell, mapping species distribution and abundance is key to managing these infestations effectively.
Misidentifying invasive plants, or confusing them with native look-alikes, can delay management efforts. That’s why the Center for Aquatic and Invasive Plants at the University of Florida (IFAS) emphasizes learning the unique features of the most problematic species in your area.
Common Invasive Plants Found in Lake Hartwell
Several invasive or non-native aquatic plants have been documented or are of concern in the lake, including hydrilla, parrotfeather, water primrose, and water pennywort.
Let’s take a closer look at a few of the most concerning species:
Hydrilla (Hydrilla verticillata)
Hydrilla is one of the most aggressive aquatic weeds in the U.S. Its leaves grow in whorls of five, with small serrations along the edges—a key feature that separates it from native look-alikes like elodea. Hydrilla grows rapidly and forms dense mats that block sunlight, deplete oxygen, and restrict boating access.
Parrotfeather (Myriophyllum aquaticum)
Parrotfeather stands out for its feathery, bright-green leaves that extend above the water’s surface. It forms thick mats that can clog waterways and alter oxygen levels in the water.
Water Primrose (Ludwigia peploides)
This invasive plant floats or creeps across the water’s surface, with long stems and bright yellow flowers. It can spread quickly across shallow areas, limiting space for native vegetation.
Water Pennywort (Hydrocotyle ranunculoides)
Water pennywort has small, round leaves on long stems that resemble miniature lily pads. It creates floating mats that can block sunlight and reduce water flow.
What About Algae and Blooms?
While not technically plants, harmful algal blooms (HABs) are another growing issue at Lake Hartwell. The Lake Hartwell Association has reported the presence of algae species such as Microcystis and Dolichospermum, both of which can produce toxins dangerous to humans and pets.
If you see a bright-green “paint spill” appearance on the surface of the lake, avoid contact and report it immediately to the South Carolina Department of Health and Environmental Control (DHEC) or the Georgia Environmental Protection Division (EPD).
How You Can Help Protect Lake Hartwell
- Inspect your boat and equipment.
Before launching or leaving the lake, always Clean, Drain, and Dry your gear to prevent spreading plant fragments. - Avoid planting non-native species.
Choose native shoreline and aquatic plants that won’t threaten the lake’s ecosystem. - Document and report invasives.
If you spot an unfamiliar plant, take clear photos and note its location. Send your findings to the Lake Hartwell Association or local environmental agencies. - Participate in lake monitoring programs.
Citizen reports help guide management decisions and strengthen early detection efforts.
Protecting Hartwell’s Future
Lake Hartwell’s beauty and biodiversity depend on collective stewardship. By learning to identify invasive plants and responding quickly when you spot them, you play a crucial role in keeping the lake healthy for generations to come.
For more information or to report a potential invasive plant, visit www.lakehartwellassociation.org.