Nebraska's Inland Ocean: Restoring the Saline Wetlands

Aug. 18, 2016, 6:45 a.m. ·

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The water that comes out of the ground around Lincoln can be almost as salty as the ocean. Historically, that created a rare environment for salt-adapted plants and animals. But much of that habitat was lost as the city has grown. A partnership is working to restore it.


Roughly seven miles northeast of Lincoln’s capitol building lies the confluence of Salt Creek and Little Salt Creek. From a high bank overlooking the water, Dan Schulz pointed to the clear water flowing below.

“That's actually base flow or salt water that's being discharged in the bottom of the creek,” he said. Before this property was farmed and used as a hunting club, that salt water made this land something else entirely – saline wetlands and salt marshes.

“Originally there was probably around 20,000 acres of these saline wetlands,” said Schulz, resources coordinator for the Lower Platte South Natural Resources District. “There were large expanses of bare ground that when it was dry enough long enough would actually be white and salt could accumulate on that.” Schulz said that unique landscape is part of why Lincoln is here.

The Saline Wetland Conservation Partnership:

  • Lower Platte South Natural Resources District
  • Nebraska Environmental Trust
  • The Nature Conservancy
  • Nebraska Game & Parks
  • City of Lincoln
  • Lancaster County

“The first people that came here to settle the area were here to prospect mining salt that accumulated in these saline wetlands,” Schulz said. “The success of that was marginal at best.” There may not have been enough salt for a commercial industry, but salt-loving plants and animals flourished. So why is Lincoln’s groundwater so salty?

There are two main kinds of bedrock in eastern Nebraska, explained Dana Divine, survey hydrogeologist with Nebraska’s Conservation and Survey Division. The deeper, older limestone and shale contains a layer of evaporites, basically “thin beds of salt” said Divine. “Researchers now recognize that unit as very likely the source of the salt to the saline wetlands and the whole Lincoln area,” she said.

On top of that limestone sits the Dakota group, which contains layers of impermeable rock called mudstone. “And so that kind of acts like a cap to keep the saline water, the older saline water down,” Divine said.

But as groundwater moves downhill from the Rocky Mountains across the plains, it loses elevation and gains pressure. And in some places in eastern Nebraska that pressurized, saline water finds a way to the surface. Some of the water that comes out of the ground around of Lincoln is getting close to seawater, Divine said. “It's pretty salty.”

Researchers think the saline wetlands and salt marshes formed as that deep salty water repeatedly welled to the surface and spread out. But as the city of Lincoln grew, people changed the landscape.

“Years ago we used to just fill in wetlands, they were more of a nuisance,” said Tom Malmstrom, coordinator of the Saline Wetlands Conservation Partnership, which formed in 2003. He said people began to recognize the value of the saline wetlands in the 1980s, when some of the first saline land was aside.

“They have been identified as one of most fragile ecosystems in the state of Nebraska. It also has an endangered species, the Salt Creek Tiger Beetle. It's the only location where it exists in the world,” said Malmstrom. The U.S. Fish and Wildlife Service has designated 1,100 acres along four streams in the Salt Creek watershed as critical habitat for the endangered beetle.

Today, only about a quarter of the original estimated acreage of eastern Nebraska saline wetlands remains. And many of those have been degraded by human development.

“We've built up the surface and we've lowered the water table, so now it's harder for our pressurized water to get up,” Divine said. Streams like Salt Creek have been channelized, which lowers the water table deeper. Sediment has accumulated on the land surface—from farming, road building, development, and freshwater runoff.

“And so our historic salty soil is now buried, and that salty soil is what the plants needed, what the beetles needed, and it’s buried under fresh new sediment,” Divine said.

Back on the edge of Little Salt Creek, a backhoe moves loads of dirt to lower the elevation of the bank. Schulz explained this is part of efforts to restore some of the natural hydrology.

“Historically little Salt Creek and Salt Creek would have had out of bank events rather regularly,” Schulz said. “So that salt water that was in the creek would spread out across the adjoining banks and the landscape and help accumulate the salt.”

The Saline Wetlands Conservation Partnership is working on restoring and preserving that unique habitat where they can, like this site called Marsh Wren. In addition to lowering the banks, they’ve scraped the ground to remove sediment and installed systems of pipes that allow them to control the flow of water on the entire site. By recreating the saltwater flooding, they hope to reestablish the saline soils that sustained the wetlands, Schulz said.

“I expect the vegetation to change, I hope that we eventually have enough salt accumulate in some of these cells that we can have salt flats again,” Schulz said. This restoration work is adaptive management, he added, “we're going to learn as we go along.”

Federal funding to protect the salt creek tiger beetle has helped conservation efforts, but many other groups have contributed land and money as well. Since the 1980s, the partnership has protected and restored more than 4,500 acres in the Salt Creek watershed. Once construction ends at the Marsh Wren site, it will be open to the public, like many of the wetland properties.

“As we develop more and more of this country for the things that we want to do, there's fewer and fewer places like this that people can access,” said Schulz. “And [that’s] what's great about the saline wetlands--it's in Lincoln's backyard.”