1. a channel or passage designed to carry floodwater away from populated areas
Usage: engineering; urban planning
2. the part of a river valley where floodwater naturally flows during periods of high water
Usage: hydrology

Examples

• The city built a concrete floodway to protect downtown buildings from river overflow.
• Engineers designed the floodway to handle water from a 100-year flood.
• Houses were relocated outside the natural floodway to reduce flood damage.
• The floodway successfully diverted water during last spring’s heavy rains.
• Urban planners mapped the floodway before approving new construction.
• The river’s floodway extends several miles beyond its normal banks.