Potential for managing pool levels in a flood-control reservoir to increase nitrate-nitrogen load reductions

No Thumbnail Available
Schilling, Keith E.
Streeter, Matthew T.
Anderson, Elliot
Merryman, Jennifer
Theiling, Chuck
Major Professor
Committee Member
Journal Title
Journal ISSN
Volume Title
Wiley Periodicals LLC on behalf of American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
Arenas, Antonio
Assistant Professor
Research Projects
Organizational Units
Journal Issue
Is Version Of
Natural Resource Ecology and ManagementCivil, Construction and Environmental Engineering
Few strategies are available to reduce nitrate-nitrogen (NO3-N) loads at larger landscape scales, but flood control reservoirs are known to reduce riverine loads. In this study, we evaluated the potential to increase nitrogen (N) loss at Lake Red Rock, a large reservoir located in central Iowa, by evaluating the inundation of sediments deposited at the reservoir inflow. Sediment samples were collected at 51 locations in the lower delta region and analyzed for particle size and nutrient content. Nitrogen loss rates in delta sediments were determined from laboratory assays, and satellite imagery was used to develop a rating curve to quantify land area inundated within the delta. The daily mass of NO3-N reduced with delta inundation was estimated by applying the mean N 24-h loss rate (0.66 g N m2 day−1) by the area of inundation (m2). Results indicated that raising pool elevations to inundate more of the delta would result in greater N losses, ranging from 2 to 377 Mg per year. Potential N loss of 102 Mg achieved by increasing pool stage by 0.5 m would be equivalent to installing nearly 650 edge-of-field practices in the watershed. Although more work is needed to integrate with an existing environmental pool management plan, study results indicate that reservoir management could achieve N reductions at a novel landscape scale.
This article is published as Schilling, K. E., Streeter, M. T., Anderson, E., Merryman, J., Isenhart, T., Arenas-Amado, A., & Theiling, C. (2024). Potential for managing pool levels in a flood-control reservoir to increase nitrate-nitrogen load reductions. Journal of Environmental Quality, 1–11. https://doi.org/10.1002/jeq2.20539. © 2024 The Authors.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.