An Unwelcome Guest

It can grow more than ten feet tall, it’s narrowing the Platte River, and everyone’s talking about… phragmites.

Phragmites choking the valley as seen from the Cozad bridge

Phragmites choking the valley as seen from the Cozad, NE bridge. © Rich Walters/TNC

Rich Walters grudgingly admits it’s an amazing plant.

"Phragmites can outcompete most any plant in drought conditions. It’s extremely hardy and it spreads very quickly,” said Walters, The Nature Conservancy’s outreach specialist with the Platte Habitat Partnership in Nebraska.

Phragmites are also Walters’ sworn enemy. For many years purple loosestrife was the invasive of greatest concern on the Platte River, but that has changed in the past five years.

“I can’t say why it happened,” said Walters. “Many think the past few years of drought conditions is the cause.”

Impacts to the system

Whatever the cause, the impact of the phragmites on river flows has been more pronounced in recent years because there has not been enough water to have spring and summer flows. Heavy stands of the plant create thick choke points and cause the stream to narrow.

“A pulse of water like that eight-inch rain we had in the spring increased the flood stage a lot more quickly than we’d normally see,” said Walters.

Because native plants are choked out by phragmites, the bird population is affected. Phragmites reduce the amount of available habitat and migratory waterfowl go elsewhere in search of open sandbars.

Finally, phragmites use a lot of water.

Partners finding solutions

The Conservancy is working with 15 counties in the Platte Valley and West Central Weed Management Areas with private landowners, the U.S. Fish and Wildlife Service, the Nebraska Game and Parks Commission, the Platte River Whooping Crane Maintenance Trust, the Central Platte Natural Resource District, the Nebraska Public Power District, Central Platte Irrigation and many others.

Together, the group obtained grant funding to remove phragmites from the Platte River. A recent award from the Nebraska Department of Agriculture has enabled aerial spraying on approximately an 85-mile section of the Platte River between Hershey and Elm Creek.

Walters works with landowners to obtain permission to spray. "Landowners are the most important partner in this, and it’s been very easy to get agreement. They laugh when I ask permission. They say, ‘Please, get rid of it! Do what you need to do!’”

The EPA aquatic-labeled chemical Habitat is used on phragmites because it only affects enzymes found in plants—not in humans, animal, birds, fish or insects. It is absorbed through leaves, stems and roots. Treated plants stop growing soon after spray application.

“Using helicopters is actually better because the size of the droplets can be larger. That helps control the application. You get very little chemical in the river—it all goes into phragmites,” said Walters. It costs about $134 per acre.

Then what?

“The application of chemical prevents the infestations from getting worse. It stops the seeds from spreading down the river,” said Walters. “Next we will need to clear it through mechanical means—like mowing or diskings.”

Walters hopes that as a result of this positive first contact, landowners will consider participation in more projects like slough restoration or tree clearing. “If we can get rid of the phragmites, it is a win for wildlife and for people,” said Walters.