floodwater

Floodwater is water that covers normally dry land during flood events. It may originate from rivers overflowing their banks, heavy rainfall producing runoff, storm surges along coastlines, or dam or levee breaches. The composition can vary, ranging from fresh to saline, and often includes sediment, organic matter, debris, and dissolved contaminants.

As a hazard, floodwater can circulate with strong currents and variable depth that can sweep people off their feet. Submerged obstacles, hidden channels, and collapsed structures present physical danger. Contamination is common; floodwater may carry pathogens from sewage or animal waste, chemicals, fuels, and pesticides, posing health risks to contact and ingestion. Electrical hazards may exist from downed power lines. Exposure can cause skin irritation or infection.

Environmental and public health impacts include degraded water quality, spread of invasive species, erosion of banks, deposition of sediment in waterways, and damage to crops and infrastructure. Floodwater can overwhelm wastewater systems and contaminate drinking water supplies, requiring monitoring and treatment.

Management and safety involve warnings and forecasts issued by authorities, and flood risk reduction through land-use planning, levees, retention basins, and early warning systems. When encountering floodwater, avoid entering it if possible; do not drive through it; turn around. If evacuation is necessary, move to higher ground and seek shelter. After flood events, assume water is unsafe until tested, avoid contact with standing water, and follow public health advisories.