Bank Storage

The Bank Storage methods are used to calculate the volume of water stored in the Reservoir banks. These methods also calculate the change in the volume of water stored in the Reservoir banks from one timestep to the next.

None

None should be chosen if the user does not want to calculate the amount of Bank Storage in the Reservoir. This is the default method for the Bank Storage category. Bank Storage and the Change in Bank Storage are set to zero but are not displayed. No calculations are performed in this method.

There are no slots specific to this method.

Input Bank Storage

The Input Bank Storage method allows users to directly input values into the Bank Storage slot or to set these values using a rule. Change in Bank Storage is calculated internally in RiverWare for use in the mass balance equations.

Slots Specific to This Method

Bank Storage

Type: Series Slot

Units: Volume

Description: Volume of water stored in the reservoir banks

Information:

I/O: Input only

Links: Usually not linked, but could be linked to Data Object.

Change in Bank Storage

Type: Series Slot

Units: Volume

Description: change in volume of water stored in the reservoir banks

Information:

I/O: Output only

Links: Not linkable

CRSS Bank Storage

The CRSS Bank Storage method replicates the U.S. Bureau of Reclamation’s CRSS bank storage calculation. The Bank Storage and the Change in Bank Storage are calculated using the Reservoir Storage and the Bank Storage Coefficients.

Slots Specific to This Method

Bank Storage

Type: Series Slot

Units: Volume

Description: Volume of water stored in the reservoir banks

Information:

I/O: Output only

Links: Not linkable

Bank Storage Coefficient

Type: Table Slot

Units: No Units vs No Units

Description: Gain or loss of storage vs change in bank storage

Information: The first coefficient (column zero) is for increasing storage and the second coefficient is for decreasing storage.

I/O: Required input

Links: Not linkable

Change in Bank Storage

Type: Series Slot

Units: Volume

Description: Change in volume of water stored in the reservoir banks

Information:

I/O: Output only

Links: Not linkable

Method Details

There are two ways Bank Storage can be calculated depending on the current Storage of the Reservoir. If the Reservoir’s current Storage is greater than the Reservoir’s Storage at the previous timestep, the Storage is increasing. Bank Storage is calculated using the following equation:

If the Reservoir’s current Storage is less than the Reservoir’s Storage at the previous timestep, the Storage is decreasing. Bank Storage is calculated using the following equation:

The Change in Bank Storage is calculated using the following equation regardless of which method was used to compute Bank Storage.

where:

– Bank Storage = the volume of water stored in the banks of the Reservoir at the current timestep

– Bank Storage(-1) = the volume of the water stored in the banks of the Reservoir at the previous timestep.

– Storage = the volume of water in the Reservoir at the current timestep

– Storage(-1) = the volume of water in the Reservoir at the previous timestep

Average Stage Change

The Average Stage Change method calculates the Bank Storage and Change in Bank Storage based on the flow from storage. The flow from storage is a function of the average stage change over a user defined number of timesteps.

Slots Specific to This Method

Ave Stage Change Coeffs

Type: Table Slot

Units: Area per Time and Flow

Description: Coefficient describing flow for a given change in pool elevation and a constant representing flow from bank storage

Information:

I/O: Required input

Links: Not linkable

Bank Storage

Type: Series Slot

Units: Volume

Description: Volume of water stored in the reservoir banks

Information:

I/O: Output only

Links: Not linkable

Change in Bank Storage

Type: Series Slot

Units: Volume

Description: Change in volume of water stored in the reservoir banks

Information:

I/O: Output only

Links: Not linkable

Timesteps to Average

Type: Table Slot

Units: No Units

Description: Number of timesteps used to calculate average pool elevation.

Information:

I/O: Required input

Links: Not linkable

Method Details

The average stage change is calculated using the following equation:

The change in flow to bank storage is calculated using the following equation:

The flow is converted to a volume by multiplying the value by the current timestep. The Change in Bank Storage is calculated using the following equation:

Revised: 08/02/2021