 Recreating in the water? Beware of low head dams. Before you head out on the rivers this summer, we encourage you to know before you go. Every year, low head dams claim lives due to their deceptively strong undertows that can trap even the strongest of swimmers. You may not realize the danger until it's too late. Understand the risks before you head out on the water. Read and obey signage and check your route for hazards. Know the dangers of low head dams. Know how to avoid them. Know before you go. This message is from the Virginia Department of Conservation and Recreation.