Search

After more than a century of intensive changes in the state's agricultural watersheds, repeated record floods motivated Iowa to innovate in its flood recovery and disaster mitigation efforts following the 2008 floods. The state created the Iowa Flood Center (IFC) and authorized the creation of Watershed Management Authorities. With enhanced funding from the federal government for disaster recovery, the groups collaborated in four watersheds as part of the Iowa Watersheds Project. The Watershed Management Authorities brought together governmental organizations and local stakeholders, developed watershed plans, defined potential flood and nutrient reduction projects, identified willing landowners for project locations in one subwatershed, and hired consultants to design and build the projects. The IFC coordinated efforts across the four watershed areas, provided hydrologic assessments for each, carried out monitoring and modelling to evaluate the performance of all the constructed projects, and developed water resources information systems to support ongoing activities. The Iowa Watersheds Project adopted a watershed systems approach, and the resulting synergy between engaged communities and technical professionals demonstrates avenues for implementing elements of an Integrated Water Resources Management framework in a highly decentralized setting. [ABSTRACT FROM AUTHOR]

Abstract: Various techniques exist to estimate stream nitrate loads when measured concentration data are sparse. The inherent uncertainty associated with load estimation, however, makes tracking progress toward water quality goals more difficult. We used high‐frequency, in situ nitrate sensors strategically deployed across the agricultural state of Iowa to evaluate 2016 stream concentrations at 60 sites and loads at 35 sites. The generated data, collected at an average of 225 days per site, show daily average nitrate‐N yields ranging from 12 to 198 g/ha, with annual yields as high as 53 kg/ha from the intensely drained Des Moines Lobe. Thirteen of the sites that capture water from 82.5% of Iowa's area show statewide nitrate‐N loading in 2016 totaled 477 million kg, or 41% of the load delivered to the Mississippi–Atchafalaya River Basin (MARB). Considering the substantial private and public investment being made to reduce nitrate loading in many states within the MARB, networks of continuous, in situ measurement devices as described here can inform efforts to track year‐to‐year changes in nitrate load related to weather and conservation implementation. Nitrate and other data from the sensor network described in this study are made publicly available in real time through the Iowa Water Quality Information System. [ABSTRACT FROM AUTHOR]