Table of Contents

Three Mile Lake is a newly constructed regional water resource in southwest-central Iowa, Union and Adair counties. The 880-acre reservoir provides a drinking water source, through the Southern Iowa Rural Water Association, to a seven county area including 30 towns and more than 13,000 rural customers. Together with nearby Twelve Mile Lake, the water system will eventually provide more than three million gallons of potable water per day. In addition, Three Mile Lake is important to the local economy as a recreation area. There has been strong support for the development and protection of the lake in the local community.

Lake construction was completed in September, 1995, when the gate was closed on Three Mile Lake dam. Hydrologists projected the lake would take 18 months to fill, but heavy spring rains led to lake overflow by late May of 1996.

Landuse in the 22,730 acre watershed above Three Mile Lake is agricultural - about 52% cropland and 21% pasture. About eighty-six percent of the farms in the watershed have livestock. Like many other reservoirs in southern Iowa, the depth and quality of Three Mile is primarily threatened by agricultural nonpoint source pollution, including erosion, excess nutrients and pesticides, and bacteria from livestock operations.

Recognizing the potential for agricultural nonpoint source pollution risks to Three Mile Lake, local sponsors and natural resource agency staff initiated the Three Mile Watershed Project to assist watershed producers implement crop and livestock management practices that control agricultural nonpoint source pollution while protecting farm profitability. While earthen erosion control structures are the first line of defense in that effort, management practices related to soil and water conservation and integrated crop, livestock and manure management are of equal importance. The project has provided information, educational programs and financial and technical assistance.

The project is unique in its preemptive justification. Rather than waiting for costly water quality problems to develop, local sponsors planned to increase erosion control and improve crop chemical and manure management in the watershed even before the lake was completed. The major funding source for the project has been a USDA Hydrologic Unit Area (HUA) project. Three Mile was the first preemptive watershed protection project undertaken with USDA support.

The Union Soil and Water Conservation District (SWCD) and an advisory committee composed of watershed landowners, with assistance from the USDA Natural Resources Conservation Service (NRCS) in Iowa began organizing a watershed initiative for Three Mile Creek in 1988. Four priority problems were identified that could impair Three Mile Lake in the future: soil erosion on cropland, gully erosion on non-cropland, fertilizer and chemical runoff from cropland, and animal manure runoff.

Objectives for the initiative were to reduce potential agricultural nonpoint source pollution, and to develop strong local support for lake protection in the future. Ultimately, funding was obtained from numerous state and federal sources in order to support all the identified project objectives in a single, comprehensive watershed protection project plan.

The USDA HUA project proposed by the Union and Adair SWCDs in partnership with county Farm Service Agency Committees, Iowa State University Extension (ISUE) and NRCS was approved in 1991. Three Mile Creek Watershed was also approved in 1990 for an Iowa Water Protection Fund (WPF) project through the Iowa Department of Agriculture-Division of Soil Conservation. The WPF application was designed specifically to fill gaps in the watershed plan that the HUA project funding could not address. Both projects had an initial life span of five years and were subsequently renewed. USDA Water Quality Incentive Program funds were also received.

Information marketing, a major project objective, was not supported by either the USDA or WPF grants. Funding for a project information specialist, who provides brochures, newsletters and news releases, demonstration plot maps and other means of communicating project results, was received from a U.S. EPA Section 319 Nonpoint Source Pollution Prevention grant administered through the Iowa Department of Natural Resources. The Section 319 grant was approved for the watershed beginning in 1995.

The flexibility of the Iowa WPF has been critical to the overall success of the project. These funds were initially targeted to provide technical assistance and demonstrations of crop management practices to protect water quality. However, as the project developed, a need for cost sharing on pasture management and manure management practices was identified. Local project organizers were able to negotiate this priority for use of the fund directly with state program representatives.

The broad objectives and measurable goals set early in the watershed project planning stages have remained essentially unchanged since 1991. During the process of developing each year’s plan of work, an effort is made to build support and consensus among local groups, to encourage their participation in project activities.

Best management practices (BMPs) promoted by the project were selected to address the priority water quality impacts identified. Pasture and forage management were major components, because of the many beef cow/calf operations in the watershed. Conversion of pastureland to row crops is a recent trend, with increased potential for sediment delivery to the lake. Released CRP acres may also be converted to crop production. The project demonstrated and encouraged practices that improve profitability of grazing and forage production, in order to slow or prevent this landuse conversion on fragile areas of the watershed.

The overall project goal was to motivate landowners and provide them with the financial and technical resources to implement practices to protect water quality of the new lake. An NRCS project coordinator and an Iowa State University Extension project coordinator, both supported by the HUA, provide technical assistance with soil conservation measures, nutrient and pest management, manure management and forage and pasture management.

Cost share funds to assist producers in implementing BMPs were provided by the HUA through the USDA Agricultural Conservation Program (ACP) and by the Iowa WPF. The WPF allowed the project to cost share on non-traditional practices that were not eligible for funding through USDA programs.

Another project goal was to increase recreational users’ and non-farm residents’ appreciation and support for the voluntary steps taken by watershed farms to control pollution sources. The Extension Information Specialist, supported by a Section 319 grant, has played a key role in achieving this goal - providing for "people oriented" contact and a working rapport with local media and various project constituents and audiences.

Results of this intensive technical and financial assistance are apparent in the watershed. Eighty percent of the watershed now has soil erosion rates at or below the tolerable soil loss level. Since 1991, eighty-two producers have put at least one soil and water conservation practice in place --reducing soil erosion on 12,702 watershed acres by more than 16,000 tons annually. They have built 83,436 feet of terraces and 85 ponds and sediment basins to reduce soil erosion and trap sediment. Crop residue cover on 11,700 acres of cropland has increased on average from 14% to over 27% on corn following soybeans, and from 22% to over 40% on soybeans following corn.

Twenty-seven producers have implemented nutrient and/or pest management programs on 6,418 acres. Average nitrogen use has been reduced eleven pounds per acre per year on 5,752 acres. Cooperators have also reduced phosphorus application an average of two pounds per acre per year on 6,177 acres. Results from the mid-project producer survey comparing activities in 1995 to 1991 showed that more watershed producers are giving credit for the nitrogen supplied by alfalfa to the succeeding corn crop.

Local producers have improved management of their permanent pastures to increase productivity. A project-sponsored pasture management demonstration has been very well received. More than 600 producers and other interested participants have viewed the demonstration since 1991. Applications for cost share of grazing management systems have averaged about two per year. In the mid-project producer survey completed in 1996, 38% of the respondents who had pasture indicated they made at least one change in their pasture management since 1991.

Local urban and rural non-farm residents have increased their understanding of farming activities used to protect water quality. An annual "Farm-City Tour" of lake development and conservation practices brings about 100 local town and rural non-farm residents out each year to learn about the voluntary activities watershed producers are implementing to protect water quality.

More than a dozen field demonstrations of BMPs, some multi-year, have been conducted in the watershed. Rural mailboxes at the sites contain brochures describing the demonstration and results, and the project also publishes an annual "self-guided tour" map to demonstration sites. Approximately 450 copies of the demonstration plot brochures have been distributed.

A bi-monthly project newsletter, The Water Link, is mailed to 550 people primarily in the Three Mile and Twelve Mile watershed areas. The newsletter was initiated in March, 1995, and circulation has steadily increased since then. Frequent news releases from the project information specialist have resulted in regular coverage by local newspapers, national farm magazines and agency publications.

WILL MOMENTUM CONTINUE WHEN THE PROJECT IS "DONE"

Staff and sponsors have asked, "How do we keep the fire going after the water is present?"

Information and education activities such as news releases, newsletters, field days, tours and workshops have helped the project reach a large audience. Townspeople and lake visitors as well as farmers now have a much greater awareness of the BMPs used by watershed producers to protect water quality. The project has recently installed road signs identifying the watershed boundary on major roadways through the area. These will remain as a constant reminder of the importance of watershed BMPs to those who drive through.

Field demonstrations have been effectively used in the watershed to allow local producers see BMPs in place under conditions similar to their own. Their design was as "user-friendly" as possible to encourage cooperators to continue gathering information. The pasture management demonstration has been an excellent example of this educational tool that may be continued.

The project provided a lot of one-on-one technical assistance to watershed producers, to ensure they had the information needed to implement BMPs on their own farms. These learning opportunities will help ensure that producers continue to critically evaluate crop production problems before making a decision that may impact water quality. One-on-one technical assistance will continue to be available through NRCS field staff and through programs such as ISU Extension’s Statewide Manure Management Initiative.

The project also stressed youth involvement as a way to continue water quality efforts into the future. The local SWCDs have sponsored teachers to attend environmental workshops in order to increase the amount of environmental education taking place in the classrooms. Project staff give presentations in local schools about water quality and the environment. A locally organized children’s water festival first held in the fall of 1998 is slated to become an annual event at Three Mile Lake.

Project staff are educated local FFA members on improved crop management practices. For example, FFA members have learned how to collect and evaluate the late spring soil nitrate test and fall cornstalk nitrate test procedures which are key to optimizing nitrogen fertilizer input decisions. Whatever their future choice of careers, experience like this will impact these young adults’ understanding of the link between environmental stewardship and profitability in crop and livestock management.

For further information about Three Mile Watershed Project, contact:

Paul Goldsmith, NRCS District Conservationist, Union County Soil and Water Conservation District

Susan Brown, Iowa State University Extension Water Quality Program Specialist

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