Report highlights progress and long-term challenges of Iowa stream nutrient monitoring
A 2016 report of Iowa’s water monitoring efforts for nutrients highlights both the complexity and long-term value of evaluating nutrient levels in Iowa’s lakes, streams and rivers.
Developed jointly by the Iowa Department of Agriculture and Land Stewardship and Iowa Department of Natural Resources, with the support of Iowa State University and the University of Iowa IIHR—Hydroscience and Engineering Center, the report is the first of its kind in Iowa and includes a comprehensive list of surface water monitoring efforts specific to nutrients.
The report was developed in support of the Iowa Nutrient Reduction Strategy and is available at www.nutrientstrategy.iastate.edu/documents underneath the heading "Supplemental Documents."
“Iowa has a comprehensive water quality monitoring effort in place that is supported by a variety of partners. Monitoring results were central to identifying the practices highlighted in the Iowa Nutrient Reduction Strategy and have provided valuable information as we have established priority watersheds. It continues to be an important part of our efforts as we work to increase the pace and scale of practice adoption needed to improve water quality,” Iowa Secretary of Agriculture Bill Northey said.
Water monitoring can be used for a variety of purposes and look at a broad range of parameters. This report focused specifically on the numerous water monitoring projects for nutrients in place across Iowa to better understand the water quality status of streams and rivers. The report discusses the complexity of nutrient monitoring and practices; for example, when changes are made within a target watershed, water quality improvements will likely be visible sooner in smaller watersheds compared to a larger watershed. Therefore, current monitoring efforts target a variety of scales, including:
Large Watersheds: (approximately 950,000 acres, or about 2.5 counties in area). This includes Iowa DNR’s fixed-station network that monitors 60 sites across the state and the University of Iowa’s IIHR – Hydroscience and Engineering management of 45 real-time monitoring stations.
Small Watersheds: (approximately 22,500 acres, or about 16 per county). Several initiatives have been developed, including 18 projects with the Iowa Water Quality Initiative focused on targeted small-scale watershed areas. These focus on helping farmers implement proven conservation practices and monitoring to confirm their effectiveness.
Paired Watersheds: Two ongoing projects in Iowa look at similarly sized watersheds where one receives targeted conservation practices and the other does not. Water monitoring at the outlet of each watershed examines the collective impact of conservation practices.
Edge-of-Field Monitoring: The Iowa Soybean Association, Iowa State University and a number of other organizations conduct monitoring at the edge of farm fields through farmer collaboration and on research sites. This scale of monitoring is used to inform, target and prioritize implementation due to ability to implement practices that can have a measurable effect in a shorter time frame.
Even with the extensive network of water monitoring efforts in place, measuring changes in natural ecosystems presents several technical, scientific and policy challenges. The report outlines several of those complicating factors, including legacy nutrients, lag time, limitations of conservation practice data, extreme weather events, locations of monitoring sites, importance of long-term data collection and variable precipitation, and stream flow.
“While challenges exist, we believe continued nutrient monitoring is critical to understanding what Iowa can do to be successful,” said Chuck Gipp, DNR Director. “All partners involved in developing this report know the value of long-term evaluation and are committed to continuing with a science-based approach to nutrient reduction in Iowa waters.”
The Nutrient Reduction Strategy is a research- and technology-based approach to assess and reduce nutrients, specifically nitrogen and phosphorus, delivered to Iowa waterways and the Gulf of Mexico. Monitoring Iowa streams provides insight into measuring water quality progress and the reduction of surface water nutrient loss. The Nutrient Reduction Strategy aims to reduce the load, or amount of nutrients, lost annually from the landscape. According to Gipp, this report serves as a means to improve understanding of the extent of current nutrient monitoring networks in Iowa.