During a media briefing Tuesday, April 8, the U.S. Army Corps of Engineers provided a closer look at two sandbar habitat projects south of Vermillion, near the
Highway 19 bridge. The sandbars cover a total of 118 acres at a total project cost of $5.6 million.
Contractors working for the Corps began building three emergency sandbar habitat complexes in the Missouri National Recreational River last summer, according to Omaha District Commander Col. David C. Press.
The Corps is implementing the sandbars to meet the U.S. Fish and Wildlife Service (USFWS) Biological Opinion, Press said in a news release. The biological opinion covers the Missouri River main stem system.
"These complexes provide nesting habitat for the least tern and piping plover, two bird species protected under the Endangered Species Act," Press said.
Contractors are working to finish by the time the birds arrive for the summer, said Kelly Crane, the Corps' emergent sandbar habitat manager from Omaha.
"We have a couple of plovers already spotted at River Mile 791 (below Gavins
Point Dam at Yankton), and there are others up on (Lewis and Clark) lake," she said. "They start showing up now and come in heavy during the last week of April and the first week of May. The birds are usually here from April 15 to August 15."
The 44-acre sandbar, located about a mile downstream of the bridge, is made
up of 220,000 cubic yards of sand, Crane said. The construction cost is $1.4 million. The project should be completed within the next three weeks.
The 74-acre sandbar – a $4.2 million project, including 15 acres of backwater – is located 1-1/2 miles upstream of the bridge, Crane said. The project is comprised of 500,000 cubic yards of sand and should be completed within the next week.
Another 60,000 cubic yards may be added to that project, adjacent to the Frost Wilderness Game Production Area, Crane said.
The Emergent Sandbar Habitat Program follows the USFWS recommendations in
its biological opinion, Crane said. The acreage goals equate to about 11,900 acres by 2015 on the entire Missouri River system.
"One of the ways we create habitat is mechanically by dozers and dredges," she said. "Another way is to remove vegetation off an existing sandbar."
Besides meeting the Endangered Species Act, the Corps' sandbar project also meets one of its missions from Congress, Crane said. The Corps' missions on the Missouri River include hydropower, navigation, recreation, fish and wildlife, flood control and irrigation, she said.
For safety purposes, public access to construction and staging areas has been restricted, with recreation and hunting disallowed until April 15, Press said.
Sand used to construct the sandbars was taken from the adjacent river bed at each location, Crane said. Sediment from a historic river channel on the Frost property was also used as an alternative borrow source.
"When we selected the sites, we chose areas of the river that tend to naturally accumulate (sand)," she said. "The river has been changing daily. It is eroding and depositing sand in those areas that seem to have sandbars over time."
The Corps began its current emergent sandbar habitat projects in 2004 and 2005, in response to the USFWS biological opinion, Crane said. However, the Corps has drawn on data dating back two decades, she said.
"We have been monitoring the birds' use of these sandbars since the late 1980s," she said. "They seem to gravitate toward these kinds of areas, which is why we chose the sites for construction."
The sandbars are not meant to become permanent, Crane said. However, the sandbars do change over time and could become islands if they develop extensive vegetation, she said.
Crane said the tern and plover "are responding with a pretty significant use."
The two species prefer a barren sandbar, meaning less than 10 percent vegetation, Crane said.
"They like it barren, so the predators don't have a place to hide," she said. "The plovers also forage along the weathered perimeter of the sandbars. They need a straight shot so they don't go through weeds."
The Corps experiments with different types of sandbars, Crane said.
"The river used to form new sandbars every year, but we now have the dams," she said. "We try to recreate what formerly happened physically, and (the birds) respond to the new barren sandbars."
Researchers have banded the piping plovers to track their migratory patterns, Crane said.
"They do have some indications that birds return to the sites," she said. "Since we are not banding every single bird, there is no way of knowing (exact numbers). Generally, they come back to the area."
The sandbar projects are also a response to another long-term concern – drought.
"We had a great deal of habitat created during the flood year of 1997," Crane said. "That habitat has been steadily decreasing since then, and there is really a shortage of habitat on the river. The whole ecosystem has been affected by this drought."