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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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