Roadside Guide to Clean Water: Grassed Waterways
Grassed Waterways At a Glance
Grassed waterways (sometimes also called grass waterways) are wide, shallow channels that are installed where water runoff usually concentrates in an agricultural field. They are planted with permanent vegetation, meaning they might be mowed, but the plants are never plowed or killed intentionally. They are designed to carry water down a hill while also preventing erosion. The plants growing in these contoured pathways help slow the flow of water and the plant roots help to hold the soil in place.
How Grassed Waterways Work
As water flows downhill, it tends to gather in natural depressions in the land. Over time, this concentrated flow of water can chisel away at the land, forming small channels called rills, or larger channels called gullies. Oftentimes, this happens when there are not enough plants growing to hold the soil in place. Grass waterways are planted in the natural depressions where water tends to flow. They can either prevent erosion before it happens or fix minor erosion that has already started. They are broad, rounded swales that are planted permanently in grass instead of rotated through crops like corn and soybeans. This year-to-year grass acts as a stable pathway for runoff water to follow. The wide, sloping channel spreads water out as it flows. This reduces the force of the water over the land and therefore reduces erosion. Water quality is improved because less soil and sediment are moved from the field to nearby streams and water enters those streams more gently.
Community Benefits of Grassed Waterways
- Pollution: Reduces pollution
- Climate Change: Promotes climate change resiliency
- Habitat: Provides wildlife habitat
- Savings: Provides cost savings
You can expect to find grassed waterways in rural settings.
How to Recognize Grassed Waterways
