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Water: Nonpoint Source Success Stories

Iowa: Brown Trout Return to Iowa Streams - The Coon Creek Story


Recent stream surveys by the Iowa Department of Natural Resources indicate that trout are once again reproducing in some northeastern Iowa streams. A 1994 survey of 15 streams in Allamakee, Clayton, and Fayette Counties found natural trout populations in seven streams, including (in two streams) the state's first documented reproduction of rainbow trout.

Natural trout have not yet been observed in sufficient quantities to support heavy fishing pressure, so the practice of stocking hatchery-raised trout will continue. Brown trout reproduction is, however, extensive in the upper portion of French Creek, and here stocking has been discontinued.

Lost spawning grounds

Sediment frequently enters Iowa's trout streams, much of it carried in runoff from eroding croplands. When it settles, this sediment covers the gravel beds that trout use as spawning grounds and alters the stream's overall characteristics. For example, sediments often create wide, shallow streams that warm rapidly and provide habitat conditions unfavorable for trout survival.

In recent years, significant progress has been made to control soil erosion in Iowa's watersheds much of which can be credited to conservation provisions in the 1985 and 1990 federal farm bills, especially conservation compliance and continuance of the Conservation Reserve Program. Other Iowa streams, for example, Coon Creek, have been further protected through participation in state and federally funded water quality projects.

During the 10-year period ending in 1995, sediment movement into Coon Creek was reduced by 42 percent annually.
Coon Creek, a small coldwater stream located in Allamakee and Winneshiek Counties, illustrates the progress that these combined programs have made in protecting and improving many of Iowa's trout streams and other water resources. During the 10-year period ending in 1995, sediment movement into Coon Creek was reduced by 42 percent annually (from an estimated 24.5 thousand tons per year in 1985 to 14.1 thousand tons per year in 1995). The conservation provisions of the farm bill were responsible for most (nearly 90 percent) of this reduction.

Then, from 1992 to 1994, a water quality project funded by the 319 program took place at Coon Creek. This project, too, was highly successful. It helped install 11 settling basins, three manure storage structures, and 1,500 feet of clean water diversions. These structures were used for animal waste treatment; specifically, they helped treat the animal waste from 35 percent of the livestock produced within 0.5 miles of Coon Creek. The treatment reduced manure movement into the stream by an estimated 1,330 tons annually. In addition, the project prevented livestock from having direct access to the stream, particularly in areas where their access had already caused significant water quality problems.

CONTACT: Ubbo Agena
Environmental Protection Division Iowa Department of Natural Resources
(515) 281-6402

Sny Magill Creek -
The New Standard Agricultural Practices

Sny Magill Creek, one of 25 coldwater streams identified by the state of Iowa as a priority, has impaired water quality primarily resulting from nonpoint sources, particularly agricultural nonpoint sources such as sediment, animal waste, nutrients, and pesticides.

Sny Magill Creek is also one of the more widely used streams for recreational trout fishing in Iowa. It drains a 22,780-acre agricultural watershed consisting of row crops, pasture, forest and forested pasture, and farmsteads. Approximately 140 grain, dairy, beef, and swine producers live and work in the watershed.

The watershed is characterized by narrow, gently sloping uplands that break into steep slopes with abundant rock outcrops. Up to 550 feet of relief occurs across the watershed. The stream bottom (of Sny Magill and its tributaries) is primarily bedrock and gravel with frequent riffle areas. Along the lower reach of the creek where the gradient is less steep, the stream bottom is generally silty. Sny Magill Creek empties into the Wildlife and Fish Refuge part of Effigy Mounds National Monument.

Sediment reductions

Estimates based on the Universal Soil Loss Equation suggest that landowners' use of best management practices (BMPs) has decreased sediment delivery to Sny Magill Creek by over 40 percent since 1991. The BMPs preferred by landowners are contour terraces, water and sediment control basins, contour stripcropping, and conservation tillage.


Streambank revetments

Streambank erosion is a major source of sediment. Demonstrations that use multiple bank-stabilization techniques, ranging from willow posts to rock riprap, are being installed. Many landowners have adopted animal waste management systems because they are not expensive and they provide an economic benefit from nitrogen and phosphorus crediting in an overall nutrient program. About 30 animal manure utilization plans have been developed since the demonstration projects began.

Integrated Crop Management

Integrated Crop Management (ICM) is a method used to help producers balance nutrient and pesticide applications with plant and soil needs. For example, a project coordinator served as a crop consultant and hired a crop scout to make field observations. By recommending the use of pesticides and herbicides only as needed and using soil tests to balance fertilizer applications with plant needs, applications within the watershed have decreased by 39,450 pounds of nitrogen, 33,625 pounds of phosphate, and 28 pounds of corn rootworm insecticide. ICM activities, in fact, produce savings for the farmer of about $13.85 per acre.

The project has developed an education-based Nutrient and Pest Management Program to help smaller producers refine their ICM systems on their own. Workshop sessions instruct producers on proper soil-sampling techniques, soil-test interpretation, manure nutrient management, fertility planning, and pest management. Producers then independently develop and implement their own crop management plans.

CONTACT: Ubbo Agena
Environmental Protection Division Iowa Department of Natural Resources
(515) 281-6402

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