Linked Hydrodynamic-Sediment Transport-Water Quality Model for Support of the Upper Mississippi River – Lake Pepin TMDL
Nationally, nutrients and sediment/siltation rank among the top four impairments reported by states on their 303(d) lists. The State of Minnesota is developing a TMDL for the Upper Mississippi River and its watershed for both turbidity and nutrient enrichment (total phosphorus (TP) and chlorophyll a). In order to support this complex TMDL, the Minnesota Pollution Control Agency (MPCA), through a contract with LimnoTech, undertook the development and application of a linked hydrodynamic-sediment transport-water quality model (the UMR-Lake Pepin model). The model was successfully calibrated and confirmed using a 22-year database of water quality covering the model domain. The calibrated/confirmed model was then applied to develop a suite of solids and phosphorus load reduction scenarios to identify point and non-point source reductions necessary to meet turbidity and chlorophyll a TMDL targets. The results of the model application analysis confirmed that the critical conditions for meeting the turbidity targets was high spring flow while the critical conditions for meeting utrophication targets was low summer flow. Achieving the eutrophication targets in Lake Pepin will require significant phosphorus load reductions in major tributaries, especially the Minnesota River and the Upper Mississippi River at lock & dam no. 1. Phosphorus load reductions on the order of 20–50% for the Upper Mississippi River at lock & dam no. 1, 50–80% for the Minnesota River, and an effluent limit of 0.3–0.5 mg P/L will be required to assure summer average TP concentrations throughout Lake Pepin less than 0.075 mg P/L and chlorophyll a levels less than 30 μg/L during critical low flow conditions. Although the exact metric for the turbidity target has not been determined yet, model results indicate that total suspended solids load reductions should be on the order of 20% for the Upper Mississippi River at lock & dam no. 1 and 50–60% for the Minnesota River in order to meet the proposed total suspended solids target of 32 mg/l at lock & dam no. 3 during critical high flow years.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 2009-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites