Eating the Elephant: Reaching Iowa's Water Quality Goals05/02/2017 | Water Quality
By Michelle Jones, environmental communications specialist
How do you eat an elephant? One bite at a time.
Eating an entire elephant is a daunting task for any one person — just as transforming water quality is to Iowans. The end goal is simple, but getting there is complex. However, when the goal is broken down into “bite size” pieces, it’s much more manageable.
The Iowa Nutrient Reduction Strategy set a statewide goal to reduce both nitrogen and phosphorus loads by 45 percent, which is distributed between point and nonpoint sources. Of that total, nonpoint sources — mainly agriculture — have the responsibility to reduce nitrogen loss by 41 percent and phosphorus loss by 29 percent.
Looking at this from a statewide view is like trying to eat an elephant in one bite. Yet, progress is possible when approached from a more feasible scale, such as the HUC-12 level — the smallest watershed scale, ranging in size from 10,000-40,000 acres.
Iowa has about 1,600 HUC-12 watersheds, which can be likened to neighborhoods. Each is small enough to identify the unique characteristics of the watershed, such as existing land and water quality conditions, and to monitor progress. At this scale, watershed leaders and farmers can work together to develop a plan of action — known as a watershed plan.
“A watershed plan provides a roadmap for water and soil improvements,” says Adam Kiel, Iowa Soybean Association (ISA) operations manager of water resources.
The ISA Environmental Programs and Services (EPS) team has worked in several watersheds across the state to develop these plans, including Rock Creek, Miller Creek, Benton-Tama, Lime Creek and Cedar Creek.
During the planning process, farmers, landowners, community members and other stakeholders provide input to identify and prioritize goals, such as water quality, production and habitat. Planning participants also work to develop targeted solutions to achieve these goals. Typically, solutions include adoption of nitrogen management and edge-of-field practices as well as land use changes.
Each of these options vary in the amount of nitrogen reduction possible, according to Chris Hay, ISA senior environmental scientist.
Nitrogen management practices offer minimal water quality gains, however they are the easiest and least expensive for farmers to implement. Most of these practices reduce nitrate losses by 4-10 percent on average. Other infield practices, such as cover crops and living mulches, reduce nitrate by 28-41 percent on average.
Edge-of-field practices deliver much greater nitrate reduction of 32-50 percent on average. These practices come with higher upfront costs, but are cheaper in the long-run.
Finally, land use changes provide the highest nutrient reduction rates — 42-85 percent on average — but current market opportunities make large scale land use changes economically challenging.
“It is important to understand the performance of these practices and how they fit in the larger picture of nutrient reduction across a watershed and the state,” Hay says. “Additionally, edge-of-field practices require a long-term commitment and don’t fit in all locations, so we need to work with farmers to implement these practices where they make sense and align with farmer goals.”
Recognizing this challenge, ISA evaluates practices during the planning process to ensure suggestions achieve desired goals. This is done through erosion and water quality modeling. Additionally, ISA uses computer models to determine the site suitability of each conservation practice identified in the watershed plan. The site suitability helps farmers and landowners understand the options on their farms and fields.
For example, it may not make financial sense to place a bioreactor in the drainage area of a wetland. A watershed plan can help fit the pieces together and determine the most cost effective location for the bioreactor.
“Through the planning process, we can identify where specific practices should be placed to have the greatest impact on water quality at the most efficient price,” Kiel says.
Once a plan is complete, the watershed group receives a conceptual plan outlining the appropriate practices and suggested locations to reach watershed goals along with a recommended implementation schedule. From this point, farmers and community leaders begin the implementation process.
In 2016, ISA completed watershed plans for six HUC-12 subwatersheds within the larger Middle Cedar River Watershed. While this is a small fraction of the subwatersheds in the Middle Cedar, it begins to paint the picture of efforts needed to achieve water quality goals at a regional scale.
Taking implementation to the regional scale requires adequate funding. Within the Middle Cedar, farmers and local leaders are using funds available through the state Water Quality Initiative program as well as USDA Natural Resources Conservation Service programs.
Similar watershed planning and funding efforts are underway across the state.
“By following the watershed approach — building from the local level to the regional scale and finally statewide — all Iowan’s will gain a better understanding of the task ahead and the path toward progress,” Kiel says.
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