Floodways

What is a Floodway?

A Floodway is a specifically designated part of the floodplain, typically the central channel alongside rivers or streams, where water flows with the highest velocity during flood events. FEMA identifies floodways to manage these critical areas, allowing floodwaters to move efficiently without causing an unexpected rise in water levels that could worsen flooding elsewhere. These designations are essential in floodplain management for protecting property and lives from the most intense parts of a flood.

Characteristics and Importance of Floodways

1. High-Velocity Flow: Floodways carry the fastest and most intense water flow, presenting increased risks to any structures within this zone.
2. Clear Floodwater Path: As the primary channel for floodwater, keeping floodways unobstructed prevents additional backwater effects that could elevate flood levels in surrounding areas, thereby reducing the risk of unexpected flooding in adjacent properties.
3. Building and Development Restrictions: FEMA imposes a no-rise requirement within floodways, meaning any construction must demonstrate it will not cause an increase in flood levels. Any development requires specific permits and hydraulic analysis to confirm it will not obstruct floodwater flow.
4. Regulatory Boundaries and Compliance: Floodway boundaries are determined through hydrologic studies. Local governments enforce floodway management ordinances in line with the National Flood Insurance Program (NFIP), ensuring compliance to maintain federal flood insurance eligibility for the community.