COLUMBUS, Neb. (AP) — Over his 28 years of service, Assistant Highway Superintendent Fred Liss said he's watched Platte County's land and 500 bridges come under increasing stress from stream beds that are washing away.
"Oh, there's no question about it," Liss told the Columbus Telegram (http://bit.ly/14p1zv9). "It's something that I've seen over the years, the last 10 years especially."
The problem is especially pertinent to our area given that Platte County has the third most bridges in the state — only Saunders and Cass counties have more crossings.
The county is hoping to come up with some solutions to the issue of streambed degradation by joining a coalition of Nebraska counties to form a coordinated effort.
Mark Mainelli, Gage County highway consultant and one of the primary organizers of the coalition, said 36 counties with degradation issues have been identified. Of those, 30 have passed resolutions to support the coalition. A couple others have given verbal support for the coalition.
Mainelli explained that as streams have been straightened, or channelized, they have deepened and widened under the bridges that have, obviously, remained the same length. A channelized stream can provide some increased land for farming and provide greater flood control, but the straighter streambed causes water to run faster washing away not only topsoil but other earth that makes contact with the stream as well.
Mainelli estimates that for every foot a stream drops, it widens 4 feet.
"You hear these old farmers say, 'When I was a kid, I used to be able to hop over this,' and now it's, you know, 15 feet across," Mainelli said. "In your area, Shell Creek would be a prime example of a stream that's been degraded."
He's part of a group that went to Congress to get federal funding sources secured for the coalition through a line item in the Farm Bill.
That way, Nebraska could receive some federal aid to tackle this problem like they did in western Iowa. The Hungry Canyon Alliance was formed in the neighboring state in 1992 to address a 23-county area affected by streambed degradation.
The project has thus far created 350 grade control structures — a Google image search turns up shots of rock-based dams as well as concrete walls that slow flows, according to John Thomas, Hungry Canyons Alliance project director.
Price wise, Thomas said $40,000 could get you a weir structure — a low wall going across the stream level with the water surface that allows the river to pool behind and run over it at a diminished speed — at the end of a small flow, one with less than 10 square miles.
For a bigger stream — greater than 150 square miles — you'd be looking at perhaps a $150,000 grade control structure.
Thomas said these structures deliver big returns. For every dollar invested in these projects, the alliance estimates the state saves $4.20 in infrastructure costs and retains one ton of soil.
The four state area — Nebraska, Missouri, Kansas and Iowa — has been aware of the streambed degradation issue since the 1980s, Thomas said. While the numerous studies Nebraska has done on the issue show a strong interest in addressing the problem — and a few small stream reinforcement projects have been done — Thomas said there needs to be a coordinated effort like the one Platte County will support for there to be real gains.
Information from: Columbus Telegram, http://www.columbustelegram.com