Boat Detailing Guide: Understand
Clean, Drain, Dry: Stopping Invasive Species on Upstate Lakes
Upstate boaters move between lakes more than most. A weekend on Hartwell, a fishing trip to Keowee, a tournament on Thurmond or Russell, a visit to Murray or Greenwood: every one of those trips is a chance to carry a plant fragment or a few gallons of water from one lake to the next.
That matters because the lakes are not all the same. Some already have hydrilla and other nuisance plants; Hartwell, according to the Corps of Engineers, does not have hydrilla. Clean, drain, dry is the habit that keeps it that way, and it takes about ten minutes at the ramp.
The short answer
Clean, drain, dry means removing every plant, mud clump and animal from the boat, trailer and gear before leaving the ramp, draining all water from the bilge, livewells, ballast and engine, and letting everything dry before launching in another lake. The Corps reports hydrilla in Lake Keowee and Lake Thurmond but not in Hartwell, and South Carolina's 2025 plan lists hydrilla in several Upstate waters, so the routine matters every time you move lakes.
Key points
- The Corps of Engineers says hydrilla has not been located in Hartwell or Russell lakes, but it is in Keowee upstream and Thurmond downstream.
- South Carolina's FY 2025 to 2026 plan lists hydrilla as a problem plant in Lake Keowee, Lake Greenwood, Lake Murray and Broadway Lake in Anderson County, among others.
- State officials say aquatic weed problems are caused primarily by boaters and anglers unknowingly moving plants between lakes.
- Ballast tanks hold more invasive larvae than livewells or bilges in University of Minnesota research; drying for five days or a hot-water flush is the reliable fix.
- South Carolina's Noxious Weed Act allows seizure of listed plants and carries fines and possible jail time.
What is here
Which Invasive Plants Are Actually in Upstate Lakes
The Savannah District of the Corps of Engineers, which runs Hartwell, Russell and Thurmond, states on its Hartwell natural resources page that hydrilla has not been located in Hartwell and Richard B. Russell lakes. It has, however, been found in Duke Energy's Lake Keowee, directly upstream of Hartwell, and in J. Strom Thurmond Lake downstream, where the known area grew from 55 acres in 1995 to about 4,985 acres despite herbicide treatment.
South Carolina's FY 2025 to 2026 Aquatic Plant Management Plan, prepared by the Aquatic Nuisance Plant Program (now part of the South Carolina Department of Environmental Services) and approved by the state's Aquatic Plant Management Council, lists the water bodies where nuisance plants need management. In the Upstate it lists Lake Keowee (hydrilla and slender naiad), Broadway Lake in Anderson County (hydrilla and brittle naiad), and Lake Greenwood (slender naiad, hydrilla, water primrose and eelgrass), along with Lake Murray further down the state. Hartwell is not on the list for that year.
Statewide, the plan names hydrilla, giant salvinia, alligatorweed, water primrose, Brazilian elodea, common reed, water hyacinth and crested floating-heart as some of the most troublesome species. Giant salvinia, found in Lake Marion in 2017, is singled out as a plant that could be transferred by people to other waters.
Why it matters
How Boats Move Plants Between Lakes
Hydrilla spreads from small fragments. A piece caught on a trailer bunk, wrapped around a prop or trolling motor shaft, or floating in a livewell can root and start a new colony. The Corps notes that hydrilla grows fast, forms dense surface mats that interfere with swimmers, anglers and boaters, and is expensive and difficult to control once established; efforts to eradicate it in large Southeastern lakes have proved ineffective.
The state's own boater brochure is blunt about the cause: aquatic weed problems are caused primarily by boaters and fishermen unknowingly spreading weeds from one lake to another, along with people dumping aquarium and water garden plants. The same is true for animals like zebra mussels in other parts of the country, where the larvae are microscopic and ride in any water left aboard.
The routine
Clean, Drain, Dry at the Ramp
Clean before you leave the ramp area
Walk around the boat and trailer as soon as it is out of the water. Pull every plant fragment and mud clump off the hull, transom, trim tabs, prop, lower unit, trolling motor, anchor and rope, and trailer bunks, rollers, axles and lights. Put plants in a trash can, not back in the lake.
Drain every space that held water
Pull the drain plug and let the bilge empty on the ramp, away from storm drains. Empty livewells and bait wells. Run ballast pumps until they stop moving water and drain ballast bags. Tilt the outboard or sterndrive down to let water drain from the lower unit.
Do not move water or bait
Never transport lake water to another lake. Do not release bait, fish, plants or animals into a body of water unless they came out of that same body of water.
Dry before the next lake
Leave hatches, livewell lids and compartments open so they dry. If you are launching in a different lake within a few days, take extra care with any compartment that cannot be fully drained, or flush it with hot water first.
Clean your gear too
State guidance includes anything that touched the water: wading boots, life jackets, tubes, ropes, fishing gear and even dogs.
Wake boats
Ballast Tanks, Livewells and Other Hidden Water
The University of Minnesota's Aquatic Invasive Species Research Center sampled water from 379 boats over two years at two infested lakes and found that the ballast tanks of wakeboard boats carried more zebra mussel larvae than sterndrive engines, bilges or livewells, and that larvae in ballast survived longer than those in smaller compartments. The researchers concluded that cleaning the outside and pulling the drain plug is not enough for large ballast systems. A hot-water flush or about five days of drying were the most practical ways to make sure nothing survives.
Zebra mussels are a Midwest example, but the lesson applies to any organism in any lake: ballast tanks and bags never drain completely. If you run a wake boat on more than one Upstate lake, run the ballast pumps dry at the ramp, open the system per your owner's manual, and plan a few dry days or a hot-water flush before launching somewhere new. Livewells, bait wells and raw-water washdown systems deserve the same attention.
The rules
What South Carolina and the Corps Ask of Boaters
- The Corps of Engineers asks boaters to make sure the boat, trailer and livewell are free of aquatic plants before leaving the launching area of any lake, and to put removed plants in a garbage container rather than back in the lake.
- South Carolina's Noxious Weed Act gives the state powers to seize, quarantine, treat or destroy listed noxious weeds, and violations can bring fines and up to a year in jail.
- South Carolina's noxious aquatic plant list includes hydrilla, Eurasian watermilfoil, water hyacinth, water lettuce, giant salvinia, slender naiad and others.
- Report suspected new infestations in public waters to the state's aquatic nuisance plant program so they can be checked early, when control is still realistic.
Boat care
Clean, Drain, Dry Is Also Good for the Boat
The same habits that keep plants out of the next lake also keep the boat in better shape. Water left in livewells and bilges goes stagnant and smells. Damp compartments and carpet grow mildew quickly in Upstate humidity. Plant debris trapped under trailer bunks holds moisture against the hull and stains gelcoat.
Make the ramp routine part of your after-trip rinse: pull plants, drain everything, then at home rinse the hull and trailer with fresh water, open lockers and livewells, and let the boat dry before covering it. Use a mild, phosphate-free boat soap if you wash at the ramp, sparingly, and keep runoff out of the water.
| Water body | Listed problem plants | Source |
|---|---|---|
| Lake Hartwell | Hydrilla not located, per the Corps; not on the state's FY 2025 to 2026 problem list | Corps of Engineers; state plan |
| Lake Keowee | Hydrilla, slender naiad | State plan |
| Broadway Lake (Anderson County) | Hydrilla, brittle naiad | State plan |
| Lake Greenwood | Slender naiad, hydrilla, water primrose, eelgrass | State plan |
| Lake Thurmond | Hydrilla | Corps of Engineers; state plan |
| Lake Russell | Hydrilla not located, per the Corps | Corps of Engineers |
Plant distributions change from year to year. Check the current state plan and lake office before assuming a lake is clear.
Clean Boat, Clean Lakes
Clean, drain, dry is the boater's job at the ramp. For a deeper clean of the hull, waterline, deck, vinyl and storage compartments, The Auto Show in Anderson quotes boat detailing one boat at a time. Tell us what you have and where it is kept.
Common questions
Is hydrilla in Lake Hartwell?
The Corps of Engineers, which manages Hartwell, states that hydrilla has not been located in Hartwell or Richard B. Russell lakes. It is present upstream in Lake Keowee and downstream in Lake Thurmond, and the state's FY 2025 to 2026 plan lists it in several other Upstate waters. Because fragments travel on boats and trailers, cleaning and draining between lakes is what keeps Hartwell clear.
How long should a boat dry between lakes?
University of Minnesota research on zebra mussel larvae found about five days of drying, or a hot-water flush, reliably killed larvae in ballast tanks. Plant fragments on a hull and trailer dry out faster in summer sun, but compartments that hold water stay damp much longer. If you cannot wait, remove every visible plant and flush water-holding spaces with hot water.
Do I need to drain my livewell when I leave the lake?
Yes. Livewells and bait wells carry lake water and anything living in it, so empty them on the ramp before you drive away and leave the lids open so they dry. Never dump livewell water or leftover bait into a different lake. Rinse and dry the livewell at home to prevent odor and mildew as well.
What should I do if I find a plant I think is hydrilla?
Remove it from your boat and trailer, put it in a trash container and do not throw it back. If you see what looks like a new patch in a public lake, note the location and report it to the state aquatic nuisance plant program or the lake's managing agency, such as the Corps lake office for Hartwell, so it can be checked.
Sources
- Hartwell Dam and Lake: Natural Resources (aquatic plant management), U.S. Army Corps of Engineers Savannah District, archived copy (https://web.archive.org/web/2026/https://www.sas.usace.army.mil/About/Divisions-and-Offices/Operations-Division/Hartwell-Dam-and-Lake/Natural-Resources/), accessed October 2026
- FY 2025 to 2026 Annual South Carolina Aquatic Plant Management Plan, Part II, South Carolina Department of Environmental Services (https://des.sc.gov/sites/des/files/Documents/BOW/AquaticScience/2025PartTwo_Draft.pdf), accessed October 2026
- South Carolina Aquatic Plant Management Plan 2025, Part I (Procedural Plan), South Carolina Department of Environmental Services (https://www.des.sc.gov/sites/des/files/Documents/BOW/AquaticScience/2025PartOne_Draft.pdf), accessed October 2026
- Invasive Aquatic Plant Management in South Carolina (brochure and noxious weed list), South Carolina Department of Natural Resources Aquatic Nuisance Species Program, hosted by SCDES (https://des.sc.gov/sites/des/files/DNR/plantmgmtprogrambrochure.pdf), accessed October 2026
- Zebra Mussels' Best Friend: Wakeboard Boats, New U Study Finds, Minnesota Aquatic Invasive Species Research Center, University of Minnesota (https://maisrc.umn.edu/news/wakeboats), accessed October 2026
- Clean Boating Tip Sheet: Vessel Cleaning and Maintenance, Maryland Department of Natural Resources (https://dnr.maryland.gov/boating/Documents/ts1vesselm.pdf), accessed October 2026
Boat detailing is quoted per boat, so this guide does not list boat prices. Product directions and warranty terms come from the manufacturer: follow your boat builder’s care instructions where they differ from general advice here.