Floodway (road)

This article is about floodplain crossings for roads. For shallow waterway crossings, see Ford (crossing). For areas that are reserved for flood flows, see Floodplain § Flood control.

A floodway is a flood plain crossing for a road, built at or close to the natural ground level.^[1] It is similar to a causeway, but crosses a shallow depression that is subject to flooding, rather than a waterway or tidal water.^[2]

A floodway on a gravel road

They are designed to be submerged under water, but withstand such conditions. Typically floodways are used when the flood frequency or time span is minimal, traffic volumes are low, and the cost of a bridge is uneconomic^[2][3] – in most cases, in rural areas.

Floodway on Great Northern Highway, Western Australia

Floodway and signs, eastern side of Southern Cross, Western Australia

Floodway (road goes across the photo) in Baja California, Mexico. Note bridge behind it.

See also

• Flood control channel
• Glossary of road transport terms
• Low water crossing