Water Quality Modeling Improvements for the Columbia and Cumberland River Basins
This project, completed in FY2016, created tools for improving the ability to predict environmental conditions in multi-reservoir systems to protect the environment and meet regulatory compliance and to optimize power generation without compromising the environment.
Two study sites were chosen for this project. The Mid-Columba River (Western U.S.) focused on modeling Total Dissolved Gas (TDG)) and the Cumberland River System (Eastern U.S.) focused on temperature and Dissolved Oxygen (DO). Both were addressing water quality within the context of hydro scheduling.
Hydropower operators must schedule and deliver water through systems constrained by these water quality specifications and other specific reservoir-related needs such as pool elevation requirements, for flood control. Balancing these constraints is challenging since generalized modeling capabilities do not exist or are too computationally expensive to directly couple high-resolution hydrodynamic and water quality estimates to real-time hydropower dispatch.
Water quality modeling improvements for the Mid-Columbia River System
Oak Ridge National Laboratory (ORNL) led a multi-year effort working with Iowa Institute of Hydraulic Research-Hdyroscience & Engineering on the development of a simplified TGD prediction expression. This was calibrated and validated for selected sites and the Center for Advanced Decision Support for Water and Environmental Systems (CADSWES) has incorporated TDG module into the real-time scheduling tool, Riverware, a commercially available, and commonly used, hydropower scheduling software that optimizes dam operations to maximize hydropower generation while meeting TDG water quality standards. The simplified techniques describing TGD exchange offer new pathways to predict future water quality conditions and examine tradeoffs under different operating policy scenarios. Additional information can be found below:
Water quality modeling on the Cumberland River System
ORNL, in collaboration with Vanderbilt University and Lipscomb University, developed a Decision Support System (DSS) for USACE Nashville District Water Management branch specific to two multi-functional reservoir systems, Cordell Hull and Old Hickory on the Cumberland River. Through the research, advances in hydrodynamic and water quality modeling techniques were achieved by the reduction of model complexity to allow real-time decision-making and forecasting application. This can also allow explicit operational optimization of complex hydropower systems that has previously not been possible. These advances can effectively accommodate constrained systems by increasing the efficiency of water use and the power system. They can also improve environmental outcomes by optimizing the most adequate water quantity and water quality releases at hydropower dams for aquatic life downstream.