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Water: Nonpoint Source Success Stories

Iowa (Section 319I - 1994)

Iowa's Nonpoint Pollution Control Program combines public information and education, demonstration projects, technical assistance, and financial incentives to encourage farmers to voluntarily control agricultural pollution. The progress in protecting the public water supply in West Lake Reservoir documents the program's success in reducing nonpoint source pollution.

Pesticide Reduction Helps Ensure Safe Drinking Water

Just a few years ago, sediment, pesticides, and nutrients were major pollution problems in the West Lake Reservoir. Today, sediment delivery and herbicide levels have been substantially reduced, proving that watershed management is a promising alternative to treating water supply reservoirs.

West Lake is the surface reservoir for Osceola and Woodburn, cities located in south-central Iowa. The lake covers 306 acres and has a 6,340-acre drainage area. Of the 4,188 acres of cropland, approximately three-fourths is primarily in corn-soybean rotation.

Sediment is rapidly reducing the reservoir's capacity, damaging filtration and pumping equipment, increasing maintenance costs, and making additional water treatment necessary. Increases in row crop acreage have caused an increase in annual soil loss in the watershed.

In 1987, sampling by the Osceola water treatment plant detected atrazine and cyanazine levels above the federal drinking water standards; concentrations remained high in 1991. Also in 1991, to comply with federal and state requirements to upgrade the water treatment plant, the Osceola utilities conducted pilot tests using a treatment of powdered activated carbon to absorb the herbicides. Installing this kind of additional water treatment can be an expensive operation for city utilities.

For watersheds dominated by agriculture, an alternative is to use best management practices such as no-till and integrated crop management (ICM). If properly applied, these BMPs have significant impacts on reducing the amount of pesticides available to contaminate the water supply.

In November 1990, Clarke County Soil and Water Conservation District developed a watershed management plan. The goal of the five-year project is to preserve, protect, and improve the West Lake Reservoir for use as a municipal, industrial, and rural water supply and as a fish, wildlife, and recreational resource for Clarke County. This requires reducing sediment and sediment-attached nutrient and pesticides that negatively impact the lake. Since 1990, financial assistance from the section 319 program totaling nearly $170,000 has been used for program staffing, implementation, and establishing BMPs. In addition, Iowa's Resource Enhancement and Protection (REAP) Program has provided $165,326 through the Water Protection Program to pay for incentives, travel, training, education, supplies, and equipment. Section 319 funds of $47,000 have been approved for FY 1994.

Under the plan, 41 landowners representing 2,500 acres of the most highly erodible cropland were offered - incentives. They included financial payment for acres contracted into soil conserving practices, soil fertility analysis, sprayer calibration, evaluation of land use, assistance in implementing reduced or no-till systems, and fertility and crop pest consultation. New pasture and grazing incentives are targeted towards improving management and use of pastures and hayland. Beginning in 1994, the program is offering technical and financial assistance to keep marginal lands out of row crop production.

In 1991, project staff working with area farmers prompted a number of farmers to voluntarily agree to reduce or eliminate their use of atrazine and cyanazine. For the farmers cooperating in this voluntary program, the number of gallons of atrazine applied dropped from 443 in 1991 to 8 in 1992. For the entire watershed, the use of atrazine was nearly cut in half, going from 1,159 gallons in 1991 to 638 gallons in 1992; cyanazine use decreased from 3,281 in 1991 to 2,500 in 1992. Lake monitoring also showed that atrazine and cyanazine levels dropped substantially (Fig. 7-1 and 7-2) in 1992. Average atrazine levels dropped below the maximum contaminant levels of 3 parts per billion (ppb), and average cyanazine levels were closer to the new health advisory level of 1 ppb.

The watershed management program has succeeded in reducing atrazine applications because a high percentage of farmers participated in the voluntary atrazine ban. According to participating farmers, voluntary compliance is quicker and more effective than waiting for mandatory regulatory compliance. The limited number of landowners and the relatively small size of the watershed helped ensure the program's success.

A major reason for the dramatic decrease in atrazine usage was the active BMPs information program. The program began in January 1991 with a kick-off, followed by classes for farmers on sprayer and planter calibration and general pesticide use. A watershed tour and news coverage added credibility to the project. In 1992, the SWCD held five classes on soils, residue management, herbicide strategies, and alternative cropping systems. This was followed by a no-till conference and more news coverage. A newsletter distributed countywide also informs and educates the general public. The project's ICM program provides recommendations for alternative solutions to atrazine use. The program helps producers make sound nutrient and pest management decisions for special fields. Services include soil tests, help in establishing realistic yield goals, and recommendations for managing pest outbreaks. In 1992, the ICM program provided improved nutrient management on 689 acres, resulting in less fertilizer applied and savings to producers. By reducing the application of phosphorous and potassium, one producer saved $18 per acre on 87 acres and another saved $15 per acre on 190 acres.

The project also resulted in a significant decrease in soil loss. In 1990, soil loss averaged 18.8 tons per acre; two years later, soil loss averaged 7.5 tons per acre. The Food Security Act of 1985 requirements and the Food Agricultural Conservation Trade Act of 1990 contributed to the reduction. However, significant reduction was also due to the widespread adoption of no-till, terraces and sediment control structures, field borders, waterways, buffer strips, and cross-slope farming--all promoted through the project.

Organizations involved in this project included:

  • Clarke County SWCD, which administers and manages the project;
  • the West Lake Watershed Committee, made up of watershed landowners, which promotes a voluntary ban of atrazine, periodically reviews and updates the project objectives, and sets examples of conservation practices;
  • Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, which provides a part-time technician to design the conservation practices, follow-up, and handle education;
  • Iowa Department of Natural Resources, which administers the section 319 program funding of $170,000;
  • SCS, which provides a part-time conservationist and a district conservationist to coordinate the project;
  • Iowa State University Extension Service, which has ICM responsibilities and coordinates information and education;
  • Local agricultural dealers and chemical companies, who assist in addressing proper herbicide use;
  • ASCS, which offers additional cost-share incentives for no-till, structural practices, forage/ pasture establishment, and renovation; and
  • Clarke Community FFA Chapter, which has initiated voluntary water monitoring of surface waters, with particular interest in pesticides such as atrazine.

Coldwater Stream Recovery Lets Trout and Cows Coexist

Stream restoration programs not only provide good fishing--they also help clean up northeast Iowa's coldwater streams. Each year, trout anglers purchase some 25,000 trout stamps in addition to the normal fishing license from Iowa Department of Natural Resources (DNR). But through the years, soil erosion from cropland and damage from livestock access and waste have degraded stream quality. To thrive, trout need shelter from predators, clean water, sufficient living space, favorable water temperature, and gravel stream beds for spawning. While livestock use streams to drink and cool themselves, they also deplete stream vegetation and trample streambanks, leaving the soil unprotected. Banks collapse and recede. Deep holes in the streams fill with sediment. Streams become shallow and wide, eliminating places for trout to hide. In addition, these streams absorb more heat than deep, narrow, fast-moving streams.

Trout need clean, well-aerated gravel beds found in swift-flowing coldwater streams. But slow-flowing waters deposit sand and silt on the stream beds, covering the gravel necessary for trout to spawn. In addition, cropland runoff may contain levels of pesticide, fertilizer, and animal waste that affect aquatic life. Nutrients entering the streams cause excessive growth -- or blooms--of algae. Decaying algae consume oxygen needed by fish. Livestock also add fecal matter and bacteria to the water and then ingest waterborne pathogens. This increases their risk of contracting such diseases as bovine leptospirosis, mastitis, and other ailments.

Iowa's coldwater stream restoration serves two purposes-- it promotes sport fishing and protects and enhances habitat and water quality. DNR funds to cost-share coldwater stream restoration and trout stream habitat improvement on state lands are limited. But some landowners are voluntarily undertaking streambank protection projects on private land with assistance from section 319.

Bigalk Creek in Howard County is a spring-fed tributary of the Upper Iowa River. DNR stocks the stream with rainbow trout from April through October. In 1991, habitat evaluations showed that Bigalk lacked pool habitat and in-stream cover for rainbow trout because of livestock over grazing, stream channelization, and sedimentation. In 1993, the landowner installed a number of restoration measures-- fencing a buffer strip along the streambank; planting trees to shade and cool the water; an electric fence powered by solar cells; and a gravel stream crossing with flood gates. An ingenious cow-powered drinking fountain eliminated the need for an electric pump. Much of the $5,000 cost of the project was funded by a section 319 grant. In another section 319 project, fencing and bank stabilization is being implemented on private property on Middle Bear Creek in Winneshiek County. Federal agencies and private organizations are working together to design corridor exclusion fences and providing funds for backslopes, riprap, and native prairie grasses. In addition, state, federal, and private conservation groups have formed partnerships to demonstrate and implement improved stream conservation practices on more than 13 coldwater stream watersheds in northeast Iowa.


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