skip to main content
Objects and Methods : Level Power Reservoir : User Methods : Additional Hydropower Release
Additional Hydropower Release
The Additional Hydropower Release category is used to calculate the additional release necessary to meet a hydropower demand.
The method is dependent on having the Phase Balancing or Operating Level Balancing flood control method selected. In addition, this category is dependent on having the Peak Power Equation with Off Peak Spill power calculation method selected. There are two methods: the default, no-action None method and the Meet Hydropower Load method.
See “Hydropower” in USACE‑SWD Modeling Techniques for details on using this method for USACE-SWD.
* None
This is the default method; there are no calculations or slots associated with this method.
* Meet Hydropower Load
The Meet Hydropower Load method is used by the COE- Southwestern Division to calculate the additional hydropower release necessary to meet a hydropower load. This method is executed from the HydropowerRelease() predefined rule function.
Slots Specific to This Method
 Additional Hydropower Release
Type: Series Slot
Units: FLOW
Description: The additional power release limited to prevent additional downstream flooding
Information: The value in this slot IS limited to prevent additional downstream flooding
I/O: output only
 Proposed Additional Hydropower Release
Type: Series Slot
Units: FLOW
Description: The additional power release to meet a load
Information: The value in this slot is not limited to prevent additional downstream flooding. It is temporary only, the values are only set at runtime but not saved in the model file.
I/O: output only
Method Details 
This method determines the additional outflow required to meet the load; or if the load cannot be met, to maximize the power production. The function determines the outflow to be the minimum of:
• The Outflow calculated to meet the given Load. The method uses the user selected methods on the reservoir; that is, it calls the Get Peak Power Equation with Off Peak Spill method and the selected tailwater method.
• The Outflow calculated such that the Pool Elevation would exactly equal the Minimum Power Pool Elevation.
• The Outflow calculated such that the Pool Elevation exactly equals the previous Pool Elevation minus the Maximum Power Pool Drawdown slot.
• The Outflow that generate the maximum possible Energy. This Energy is produced by running the turbines at max release (generator capacity) for the full timestep.
The method sets the Proposed Additional Hydropower Release slot and also returns the additional flow to the calling rule function. The rule function HydropowerRelease() then performs a check to ensure that no additional downstream flooding will occur. The rule then sets the Outflow and Additional Hydropower Release on the power reservoir.
See “HydropowerRelease” in RiverWare Policy Language (RPL) for more information on the HydropowerRelease function.
Revised: 11/11/2019