Grassed waterways: A smart investment for landowners

Grassed waterways are one of the most practical and cost-effective conservation tools available to landowners. 

These vegetated channels guide surface water safely across farmland, preventing soil erosion, protecting water quality, and supporting long-term field productivity.

Matthew Patton, Area Engineer with the USDA Natural Resources Conservation Service (NRCS), has spent years designing waterways throughout the northeast Indiana region. He says the value of these conservation practices is clear.

“You’re keeping that gully from getting worse, making sure you’re keeping the sediment out of the creek and that kind of thing,” Patton said. 

Controlling erosion before it gets expensive

When stormwater cuts unchecked across a field, the damage can escalate quickly—taking valuable topsoil and nutrients with it. Patton shared an example that underscores just how much runoff even a modest watershed can produce.

“One waterway we designed had to carry 188 cubic feet per second—more than 84,000 gallons per minute. That’s what was coming off just 200 acres.”

By reshaping narrow gullies into wider grassed waterways, the flow slows significantly. In many cases, velocities can be reduced from over five feet per second down to just one or two—keeping soil in place and runoff clean.

Designing with maintenance and farming in mind

Some landowners worry about losing farmable acres to wide grassed waterways. But according to Patton, smart design can ease that concern while improving long-term performance.

“You’re thinking, ‘Oh, that’s a huge swath of grass, I don’t want to lose that much ground,’” Patton said. 

But Patton explained that the visual size of grassed waterways can be deceiving. Designers make the waterway just a little bit wider than the gully, and usually no deeper. 

A slightly wider design spreads out water flow, reducing velocity. That lowers the risk of erosion, makes the waterway last longer, and reduces future maintenance. It’s a trade-off: a small loss in acreage now avoids bigger losses later from gully formation or sediment build-up.

Wider waterways with gradual side slopes are also easier to cross with modern farm equipment. And good design means less frequent maintenance, even in years with heavy storms.

Flexible designs that fit the farm

Grassed waterways are not one-size-fits-all. Design specifications are guided by NRCS standards, but there's room for customization based on field conditions, equipment size, and producer preferences.

“There are options,” Patton said. “I can design a waterway five different ways. They’ll still meet specs and still work. There are just some tweaks here and there depending on the landowner’s preferences.”

One key factor in the design is the storm event a waterway is meant to handle. In most cases, that means planning for a 10-year storm, or roughly four inches of rain in 24 hours. However, in flatter areas, engineers have flexibility to scale the design accordingly.

“If the slope of that waterway is less than one percent... we can reduce that storm event, and it’s still going to meet our specifications,” Patton said. 

This kind of adaptability helps balance function with field operations, giving landowners a design that works without sacrificing usability.

Early maintenance pays off

Keeping a grassed waterway functioning doesn’t require constant attention, but routine inspection and occasional touch-ups make a big difference. Mowing, checking for sediment buildup, and fixing tile blowouts are all part of the plan.

Catch problems early. If the water isn’t flowing in the middle of the waterway—where it’s supposed to—it’s not just a small issue. It's a red flag that, if ignored, can lead to major damage.

“If this flows like this for two or three years, you may have to come in and redo most of that whole entire waterway,” Patton said. “But if you catch it that first year and get it diverted back in the middle, you’ve saved yourself all that money.”

By doing a bit of maintenance early (like reshaping the inlet or cleaning up edges), landowners can avoid much larger repair costs later on.

Conservation that works above and below ground

Grassed waterways not only protect cropland—they protect water quality across the region. By slowing and filtering runoff, these features reduce sediment and nutrient loads entering nearby streams and rivers.

“That water is going to keep going. If you can slow it down, guide it, and keep it where it belongs, you’re going to protect your field—and the environment.”

For landowners looking to reduce erosion, improve drainage, and protect downstream water quality, grassed waterways offer a proven, flexible, and effective solution.

Ready to Take the Next Step?

If erosion, runoff, or drainage is keeping you up at night—or costing you money—grassed waterways may be the solution you’ve been looking for. They're farmer-friendly, environmentally smart, and proven to work.

Contact your Delaware County Soil and Water Conservation District today to schedule a consultation or learn more about design options and potential cost-share programs. Let’s work together to protect your land, your yields, and your community’s water quality.