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Streams of conscientiousness.

Now there's an extra half-mile reach of Hotophia Creek to fish in. And the fishing gets better each year, thanks to an ongoing Demonstration Erosion Control project.

Known as DEC, this project is an collaborative effort among Agricultural Research Service scientists at the National Sedimentaion Laboratory (NSL), the Vicksburg District of the U.S. Army Corps of Engineers, USDA's Soil Conservation Service, and the U.S. Army Engineers Waterways Experiment Station of the Corps.

The project is a congressionally mandated effort to find environmentally sound solutions to problems caused by flooding, erosion, and sedimentation within one of the most channel-erosion-prone areas in the United States - Mississippi's Yazoo River basin.

Says nearby Batesville resident, D.R. Roberts, who is retired from USDA's Soil Conservation Service, "I caught a lot of bass in Hotophia Creek last spring. My friend owns these fields, and he lets me come down here and fish. This year, the fishing has improved considerably. I'm catching mostly what I call Kentucky bass - the largest about 2-1/2 pounds."

ARS hydraulic engineer Doug Shields works at the NSL, which is located at Oxford, Mississippi. He says, "Hotophia Creek may not be the fishing mecca of the United States, but our sampling shows the number of catches increased from 162 to 746. And the fish caught were to times heavier, with twice as many species in the catch. And even more important, fish length almost doubled, on average, in just one year."

Like many streams in this part of the state, Hotophia Creek is wide, shallow, and sand filled downstream. Upstream, the channel is relatively narrow and deeply incised, with bank heights often exceeding 20 to 30 feet. Because of erosion that followed unwise land management practices, reservoir construction, and straightening and deepening of channels, many present-day channels in northern Mississippi are as much as 10 times wider than they were in the 1930's.

Bed and bank instability are major problems.

Hotophia Creek, which is in Panola County between Oxford and Batesville, drains about 22,400 acres - 35 square miles. Last year, a section of it became part of an experiment to discover how best to restore fish and wildlife to stream habitats.

According to Shields, "Before the channel stabilization work began, Hotophia Creek was yielding thousands of tons for sediment per mile of channel. With time, restoration will reduce this to more acceptable levels."

Why a Sedimentation Lab?

According to ARS hydraulic engineer George Foster, director of the National Sedimentation Laboratory, "When the lab opened in 1959, its mission was to find solutions to environmental problems caused by soil erosion, poor water quality, and sedimentation - especially those problems related to agriculture.

"Recently, emphasis on water quality, ecology, and environmental protection has increased. The stream habitat restoration work on Hotophia Creek is a good example of this.

"One of the greatest stream pollutants, by volume, is sediment from field and channel erosion, and Mississippi is the nation's worst-case scenario," says Foster. "Each year, the Mississippi River carries over 300 million tons of sediment to the Gulf of Mexico. Such eroded sediment does irreparable damage. It clogs streams and ditches. bottomlands become flooded, and, as water quality declines, fish and wildlife habitats degrade or disappear."

The NSL is strategically located in the northern part of the state, within the Yazoo River Basin, in the hills, above the Mississippi River alluvial plain. Conservation principles shown to work in this area will help in stabilizing eroding streams in many other geographic areas, as well.

Soil Conservation Service (SCS) agronomist Bill Lipe, who has worked with ARS scientist at the NSL for 4 years and is the SCS liaison there, says, "Much of the pioneering work on agricultural pollution was done by National Sedimentation Laboratory scientists. In the Southeast, the lab has long been a leader in research on the movement of pollutants from the land to streams and lakes."

Foster adds, "The DEC project started with six watersheds in 1984. Today, the $30 million-per-year project has expanded to 15 watersheds. It is one of NSL's most important and impressive research projects, involving thousands of miles of streams. And it's an excellent example of ongoing, directly applied research and technology transfer."

Keeping Sediment Out of Channels

One of DEC's missions is to reduce erosion and keep sediment out of Delta streams and lakes. Stream channel control measures include constructing spur dikes, grade control structures, riprap bank protection, and small flood-control reservoirs.

Spur dikes are fingers of stone that extend into the creek. Grade-control structures, made by driving sheet piling across a stream and placing rockfill downstream, create small waterfalls and control channel erosion upstream. Riprap revetments are layers of large stones, or facings, placed along stream-banks to prevent erosion and instability.

Foster says one dramatic success story is the 8.3-square-mile Goodwin Creek Research Watershed, located in one of the original project watersheds that predates DEC. About 20 miles west of Oxford, its 14 fully instrumented gauging stations - each costing a quarter of a million dollars - were built by the Corps. It's one of the best instrumented and most intensively studied watersheds in the United States. The information gathered from studies at Goodwin Creek on rainfall, runoff water, sediment yield, and land use supports sediment transport research at other DEC project watersheds.

For every storm, each gauging station collects a variety of data, such as temperature, amount of water generated, and movement of gravel in the stream. Each station has a system to automatically collect discharge samples used to calculate sediment concentrations and sediment yield. Microcomputers relay this information back to the NSL every 30 minutes. Samples are bar-coded at the collection site and analyzed back at the lab.

"Goodwin Creek shows us how to do the best job of preventing erosion along channels at the least cost," Foster adds. "Data gathered there will be used as prototype data for all future DEC activities."

Like Hotophia Creek, the lower end of Goodwin Creek is getting a facelift. Between gauging stations 1 and 2 on Goodwin in Creek, part of the DEC project team is working on measuring surface water quality and restoring streams to stable ecosystems. ARS ecologist Charlie Cooper leads an aquatic ecology group that includes Doug Shields and ARS ecologist Scott Knight.

According to Shields, DEC streams don't usually have harmful water quality. The constraints on the aquatic habitat are more physical: Erosion causes the streams to be too shallow and sandy and makes the hydrology too flashy, so flows peak and fall too rapidly.

Says Cooper, "Early in our DEC evaluation, we found that the lack of stable habitats limited fish populations. During heavy rainfalls, habitats are scoured or hollowed out, covered with silt or sand, or moved. Because suitable habitats are lacking, entire annual hatches of fish are missing. And during dry periods, the water level is too shallow to support fish populations."

Shields, who studies stream restoration, was with the Corps for 12 years before coming to the NSL in 1990. He says, "What we're trying to correct is an environment that has been severely traumatized. When we looked at habitats created by structures used to stabilize against erosion, we found the structures were not really optimal for restoring stream channels."

Even after channels are stabilized, many of the streams in DEC watersheds are extremely shallow and have little tree canopy. Shields says, "From an environmental standpoint, we'd like to see occasional deep pools with lots of shade canopy and woody debris.

"So we designed a study of seven stream reaches - each about 6-tenths of a mile long. Hotophia, Goodwin, and Martin Dale Creeks are being restored. Peters Creek, Bobo Bayou, and Martin Dale Tributary were left untreated. And Toby Tubby Creek, which was not badly eroded and flows through forested wetlands, is being used as a reference site."

Goodwin Creek landowner William E. Leigh, whose property surrounds the DEC stream restoration site, says, "Goodwin's a little creek most of the time, except after a heavy rainfall. It's too soon to tell how well the restoration will work, but I think it'll do the job. Already, plenty of beavers have been busy, damming up the lower end of the creek and making an even deeper pool." Leigh worked for the Corps for 15 years as a mechnical and electrical engineer before retiring.

Knight finds that "one of the most rewarding aspects of DEC is the intermingling of engineering and environmental expertise to benefit both aquatic habitat and channel stability."

To restore habitats along Goodwin Creek, Shields and the other researchers used three techniques. "We put in spur dikes, pointing them alternately up and down the stream, added a low ridge of stone along the sandbank, and then planted 3,400 willow tress along the stream.

The spur dikes have increased deep-pool habitats by 200 percent.

"We sampled fish in the spring and fall of 1991, before the restoration, and again 1 year later," says Shields.

The restoration techniques worked. Before restoration, the largest spotted bass weighed less than half an ounce; a year later, the largest was 2 pounds. The largest long-ear sunfish weighted 1.5 ounces before the restoration, and 10 ounces afterwards.

Knight adds, "The number of species increased, too. Before restoration, we found 15 species of fish; afterward, 24. New species included smallmouth buffalo, channel catfish, and largemouth bass. And we've found five different species of catfish and four of gar."

Near some stone projections, the scour holes that developed were 1 to 4 feet deep and about 8 feet across. "Stream areas classified as pools nearly doubled, and these pools made all the difference," Shields says. "Had we pushed the system further, the biological response could have been even greater."

Adds Knight, "We have found that dikes are better for fish habitat than other types of bank protection structures used in the DEC program. They promote waterflow patterns conducive to a wide range of water depths and velocities.

To collect data on fish populations, the team uses an electrical stunning device, collects the fish in nets for examination, and releases then as soon as possible. Workups on larger fish typically include identification; a visual inspection for hybridization, lesions, other anomalies, and length measurement. The team preserves and bags smaller fish for laboratory workups.

But this "electrofishing" may soon be passe, replaced by state-of-the-art acoustical sensing. The NSL has a cooperative research agreement with the University of Mississippi's Jamie Whitten National Center for Physical Acoustics at Oxford.

A Biotic Inventory

Says Cooper, "As part of our long-term evaluation of the effects of DEC channel stabilization, we're also characterizing - that is, keeping data describing the environmental changes that occur on - thousands of stream miles. We use the data to develop an index of biotic integrity."

This index is a measure of stream health based on samples of fish populations. Since fish are sensitive to their environment, the index reflects water quality and physical stream characteristics such as water depth and velocity, channel width and depth, streambed composition, and bank vegetation. Because the index is computed from several different variables that describe a fish sample, it's much more sensitive to changes than any one measure.

The scientists have detailed 44 sites on 15 different watersheds, including Hotophia and Goodwin Creeks.

Sam Testa, an ARS biologist who works with Cooper, adds, "As part of this work, we sample different plant and animal habitats. When we sample invertebrates, we take gravel and sand cores from stream bottoms and measure the organisms they contain. We also scrape the rocks, looking for invertebrates such as mayflies. The number and types of animals indicate their tolerance of pollutants or to the harshness of environment."

The ARS team is working with fish biologist Steve Ross at the University of Southern Mississippi, Hattiesburg. Ross is compiling a database of state fishes. The team hopes to collect enough information so future efforts can be measured against this database.

The team also cooperates with the Mississippi Department of Wildlife, Fisheries, and Parks. "Any unusual catches are preserved and sent to the state museum at Jackson," Knight says.

An anticipated result of this project will be the adoption of these stream restoration practices as a routine part of DEC projects. So in the DEC and similar projects, instead of simply combating erosion, construction can also include stream corridor habitat restoration with little additional cost.

"In fact," says Cooper, "as a result of our study, the Corps has already modified standard designs in DEC and extended the tips of spur dikes to improve habitats. And both the U.S. Department of the Interior's Bureau of Land Management and the Tennessee Valley Authority have asked for help in transferring the technology to improve their unstable streams."

Shields says that sport fishing is one of the most popular activities in the United States. And fishermen prefer stream fishing to lake fishing, according to a public opinion survey by state fishery biologists.

"Southeastern streams are harbors of ecological diversity - much like the tropical rainforests. Even if we don't develop a sport fishery here, the taxpayer will benefit, because what we learn about ecology and species diversity has a value in and of itself.

"Each year, stream habitat restoration is growing in popularity around the world. Some western states have an adopt-a-stream program to clean up and restore the health of streams. This restoration project put the DEC program in the forefront of a research area with worldwide interest.

"Now that Hotophia and Goodwin Creeks have been restored, Martin Dale Creek is scheduled next. It's already about 15 feet deep and not very wide, so all we're going to do there is plant willows along the banks. That will begin next spring."

What's the Impact, Overall?

Restoring stream habitat isn't the only new and innovative technology being used in the DEC project. NSL soil scientist Earl Grissinger is an expert on DEC and its history. He looks at how changes in land uses affect water quality and at indicators of channel erosion. And he works closely with the U.S. Army Engineers Waterways Experiment Station in developing plans and procedures for long-term monitoring of the efficiency of the DEC program.

Grissinger explains that the NSL is involved in promoting more efficient use of existing data to meet the streambed and channel construction design needs of action agencies that build waterway structures. Modelers will be able to use DEC data in simulations of channel processes - anywhere in the United States.

To better organize and integrate the enormous amount of data collected from the DEC projects, the scientists are planning to use Geographical Information Systems. GIS is a grid-based system that uses computers to combine extensive data on diverse features, including soil type and land- use characteristics into spatial databases. This facilities model simulation, as well as better collection and organization of new data for use by action agencies.

A data set complementary to LANDSAT is currently under development to aid in interpreting land-use data and other needed information, and video and laser technology are being adapted to NSL needs. ARS pioneered the agricultural application of video imaging technology at the agency's Remote Sensing Laboratory in Weslaco, Texas.

Grissinger says, "Scientists can now fly over DEC project areas and remotely collect and record, in minutes, data that would have required thousands of hours of manual labor."

This past spring, NSL hydrologic technician Keith Parker, hydrologist Bill Blackmarr, and geologist Joe Murphey spent several weeks aerially videotaping all the streams in the DEC project watersheds - more than 1,100 miles of restored channels.

According to Murphey, "The videotape records allow us to monitor the performance of the various channel protection measures installed by the Corps and SCS in the DEC project watersheds from Memphis to Vicksburg."

For all the DEC watersheds, the general problem areas have been characterized and classified as to their severity. These include urban flooding, sedimentation in the floodplain, channel filling and obstruction, upland erosion, and bank caving.

"Many of these problems are interactive," Grissinger explains. "For example, sediment from severe upland erosion - if deposited in critical channel reaches - can cause flooding." To monitor sediment, the U.S. Geological Survey is currently collecting discharge samples from 12 of the 15 DEC watersheds.

"The charge given to DEC is unique, emphasizing as it does evaluation of procedures in use today and practical demonstration of research findings. And DEC offers a unique opportunity to assess the strengths and limitations of current action agency procedures for abating watershed-scale problems."

Filming a Bird's-Eye View

National Sedimentation Laboratory scientists use a Panasonic 3CCD S-VHS camera to videotape each segment of every creek in the DEC project area from a height of 2,400 feet, at a speed of about 100 miles per hour.

At full-lens field of view, this gives a 2,000-foot-wide film path with a resolution of 2.86 feet per pixel (data point in the picture element).

At full 16-X telephoto magnification, the flight film path width can be reduced to 125 feet, with a resolution of 2.25 inches per pixel.

Where precise measurements are needed, individual scenes are geo-referenced using Global Positioning System procedures.

According to ARS soil scientist Earl Grissinger, LANDSAT satellite imagery record the average spectral characteristics of a 30- by 30-meter area (about a 100-foot square).

He says that for a lot of applications, this is very satisfactory. It's sufficient for broad land classification for large areas. Where more detailed information is needed, CCD-type video imagery is being used.

Video imaging has the advantage of being operator dependent. Data can be collected at any scale - within reason - that is needed.

Grissinger says, "These pictures, taken at 1/2000-of-a-second shutter speed, can then be frame grabbed, downloaded at the National Sedimentation Laboratory, geo-referenced, and analyzed for such things as channel plugging, widening, deepening, land-use changes, and structural performance.

"Theoretically, under ideal conditions, we can detect the movement of a single piece of riprap."
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Title Annotation:includes article on aerial filming of streams; stream restoration
Author:Becker, Hank
Publication:Agricultural Research
Date:Oct 1, 1993
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