By Del Marks
AMES, IA--Cooperative efforts between residents of many Iowa watersheds and public agencies are succeeding in solving Iowa's water quality problems, according to Iowa State University specialists who are tracking the progress being made.
Statistics compiled by the Iowa Department of Natural Resources indicate more than 110 water quality projects have been funded since the late 1980s.
John Creswell, nutrient management education coordinator for Iowa State University Extension, says, "Producers have made a major commitment, assisted by state and federal conservation programs, to control soil erosion and surface runoff on erodible land, using practices such as terraces, grassed waterways, buffer strips and reduced tillage/no-till farming."
"Our next great challenge," says Susan Brown, watershed specialist for Iowa State University, "is to control nonpoint sources of nutrient and microbial pollution and still keep agriculture profitable. As for soil erosion, these problems are the combined result of thousands of individual management decisions. Fortunately, Iowa watershed projects also have demonstrated that local partnerships can foster change and lead to innovative solutions."
The Big Spring groundwater basin project in Clayton County is one of Iowa's premier water quality efforts. Groundwater nitrate had increased from the 1960s to the 1980s with increasing fertilizer use and corn acreage. In 1981, the Iowa Department of Natural Resources began an intensive monitoring program. The Big Spring Basin Demonstration Project, with field leadership by ISU Extension, assisted producers with on-farm demonstrations and crop management information. The result was significant improvement in nitrogen management. Between 1981 and 1993 annual nitrogen fertilizer input decreased by nearly 2 million pounds--while corn yields were not reduced.
Another watershed success in northeast Iowa is Bigalk Creek. Bigalk is one of only three Iowa coldwater streams where natural reproduction of rainbow trout has been reestablished. The Natural Resources Conservation Service estimates that management practices such as sediment retention ponds and contour farming have reduced soil erosion by approximately 5,000 tons per year in the 11,300-acre watershed.
In south west Iowa, the Three Mile Lake--a new 880-acre reservoir in Union and Adair counties--is a drinking water resource for a seven-county area. It has also become a popular recreation site. In 1991, the Three Mile Lake project began as one of the first pre-emptive watershed projects funded by USDA and Iowa Department of Agriculture and Land Stewardship conservation programs. Local planners determined to reduce sediment and nutrient runoff before the lake was completed, rather than allow costly water quality problems to develop later.
By the end of the project in 1999, soil erosion rates were reduced to tolerable soil loss levels or below on more than 80% of the watershed. A third of the producers in the watershed producers voluntarily took part in a program sponsored by ISU Extension to refine their fertilizer and pest management. Long term demonstrations showed that planned grazing increased carrying capacity and reduced soil erosion on pastures.
In central Iowa, producers in the Union Grove Lake watershed in Tama County made major changes in farming practices to protect water quality. From 1990 to 1995 conservation practices reduced potential soil erosion to 5 tons per acre per year or less on 100% of the watershed's crop acres--a decrease of more than 30,000 tons annually compared to erosion rates before 1990. Fine-tuning fertilizer and pest management was shown to increase profitability an average of $15.79 per acre annually while reducing potential pollution.
Creswell says, "These are just a few examples of how Iowa producers and their neighbors have worked in partnership with agencies all across the state to make our lakes and streams cleaner and Iowa's economy stronger. Challenges lie ahead, but past watershed successes show us how we can continue to improve."